Review of
APPLIED
I
NATURAL AND SYNTHETIC RUBBERS Max Tryon and F. J . Linnig Ahtional Bureau of Standards, Washington 25, D. C.
INTRODUCTION
T
is the eighth of a series of review articles on test methods for natural and synthetic rubbers. It covers both the physical and chemical methods reported in the literature betn-een November 1956 and October 1958. As in the case of previous reviews (1-7), test methods applied to compounding ingredients have been omitted except for those involving their qualitative or quantitative determination in rubber. Similarly, test methods applied to the raIv materials used in the manufacturing of synthetic rubbers have also been omitted. Procedures cwncerned with fundamental problems have been included only when they involve unique apparatus or techniques t h a t promise to be useful in the testing of rubber. Old procedures have been included only if modified or improved. It has not been possible to make a n exhaustively complete review because of the volume of the publishrd work. The literature cited has been divided into subject classes for convenience. HIS
GENERAL INFORMATION
Of general intcrest are a number of books and handbooks t h a t have appeared since the last review, There are annual rrports on the progress of rubber tec4hnology edited by Drakeley (10A, l l d ) for 1956 and 195i. Each report includes a section dealing n i t h testing, equipment, and specifications for rubber materials other than latex. T h e book by K a k e (26.4) provides \Torking instructions for procedures covering, very generally, the chemical analysis of rubber and rubberlike polymers. The tenth edition of the Vanderbilt Rubbei Handbook, edited by Kinspear (27A), contains a variety of physical :tnd chemical test methods. Roff's handbook (20A) presents information 011 the identification of common polymers, including rubber. The book on latex by Cook (9A) for students and nen comers to the field covers such subjects as testing, vulcanization. and the testing of compounds of natural and synthetic latexes. The reference work by Lever and Rhys (I7A) is of general interest and contains sections on the identification and analysis of plastic inatrrials. It appeared as a
series of articles in Plastics, London, from March 1955 to June 1957. A handbook by Shcherbacheva (d3A) presents standard methods for the qualitative detection of mix ingredients and elastomers as well as a comprehensive survey of methods for the quantitative determination of these materials. Another Russian publication (%?6A)contains papers concerning methods of measurement of high elastic moduli of vulcanized rubber under stress compression, equilibrium and static moduli of vulcanized rubber, friction of rubber, and papers on the photocolorimetric determination of two accelerators. T h e manual published by Kovacs (16A) deals, among other things, with the testing of plastic materials, including elastomers. Olaszek (18A) outlines methods of testing rubber and rubber articles. Buist (6A), Scott (%'A), and Ecker and Brautigani (I3A) have reported the work of the 1957 meeting of the International Organization for Standardization. T h e American Society for Testing Materials has issued two editions, one in 1957 (ZA), and one in 1958 (&I), setting forth the standards and specifications developed by Committee D-11 for rubber products. T h e latest edition contains over 140 standards and specifications. This society has also issued a glossary of terms (4-4) including technical terms relating to the testing of rubber and rubberlike materials. The Federal Supply Service, U. S. General Services Administration (24A) has issued a federal standard on synthetic rubber including physical and chemical test methods for the principal synthetic rubbers and masterbatches originally marketed by the Reconstruction Finance Corp. Ratner, R e z n i k o d i i , and Zuev (19A) h a r e written a critical survey of present methods of testing rubber for static and dynamic deformability, mechanical interaction of rubber with other bodies in contact with it, low temperature resistance, and artificial aging. T h e subject of polymer testing and its contribution to developinents in industry n a s covered by Buist (7A). Fanica (14A) outlined some modern methods of analysis for plastic materials including flammability, elemental analysis, color reactions, and certain
types of chemical degradation. Rothermel (WIA), in a n article on natural and reclaimed rubber, summarized, among other things, methods of testing. Rubber and plastics-testing equipment ivas covered in a n article by Bennett (5A). Junker (26A) reviewed devices for testing hardness, elasticity, and permanent set. Drogin (12A) in a speech before the Xew York Rubber Group, considered the broad aspects of the significance of physical testing, I n a symposium held by t h e Akron Rubber Group ( I A ) , several papers dealt briefly with a variety of testing problems. Carpenter (8A) in the Charles Goodycar Medal Award Lecture for 1957, revien-ed in some detail the history of trsting methods for rubber and pointed out the ever-present need for standardization. T h e Research Association of British Rubber Manufacturers, Sham bury, Shrembury, Shropshire, England, publishes monthly, Rubber Abstracts, which covers the rubber literature generally, including test methods. CHEMICAL ANALYSIS
Numerous articles have appeared on the identification or analysis of polymer stiuctures. Hummel (%?@) described a satisfactory method for the identification of some chlorine-containing polymers. Hilton, Tolsma, and Newell (22B) presented a method for the determination of bond styrene in ran and cured polymers by nitration and oxidation. The p-nitrobenzoic acid formed is separated by liquid-liquid extraction and determined by ultraviolet absorption spectrometry. Drozdovski1 and T'ishnevskaya (12B) developed a method for determining the natural rubber hydrocarbon content of SKBnatural rubber vulcanizates. An ozonolytic method rt as described by Barnard (1B) for degrading the natural rubber trunk chains of interpolymers of natural rubber with meth! 1 methacrylate and styrene, leaving the remainder of the polymer intact for characterization purposes. Ubaldini (49B) described identification tests for plastics and high polymers including vulcanized rubber. chlorinated rubber, and neoprene. Sachse (@B) set forth a method for the determination of VOL. 31, NO. 4, APRIL 1959
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rubber hydrocarbon in soft and hard rubbei . Klitenik aiid Ginzburg (R9B) described a rapid method of identifying gritdes of butadiene nitrile unvulcanized rubbers. Davison (1 OB) reviewed the application of infrared spectroscopy to the study of structural problems in the rubber industry. Tanaka, Kaiio, aiid Hig'i4ii (48B) applied infrared spectroscopy to the quantitatil e deteriiiination of blend rutios of niivtures of iiaturnl rubber with either Butyl rubber or GR-S. A number of papers deal with various iiiethods for determining free, bound, and totitl sulfur. Bauniinger (SB) used disodiuni dihydrogw (ethylenedinitrilo) tetraacetate as the t i t r m t to determine total sulfur in synthetic elastomers containing chlorine and nitrogen. H e also (2B) described rapid semimicrovolumetric methods for thc determination of sulfur in natural and synthetic rubber vulcanizates with and n ithout certain niineral fillers, and also in vulcanizates containing chlorine and nitrogen. The methods involve, among other things. a modified combustion procedure and apparatus. Derinody ( I l B ) described a direct method for determining coinhined sulfur in rubber I ulcanizates employing methanol-benzene azeotrope to extract uncombined sulfur, accelerator residues, and other extraneous organic materials, prior to oxidation of the polymer. Superiority of direct determination over the indirect nietliod was clairned. Belitskaya and Zrereva (@) developed a polarographic method for the dcterniination of free sulfur in raw and vulcanized rubber. Tliiuram accelerators, Captax and dltax, did not affect the test. Bogina and Rlartyukhina (BB) reported a rapid open tube coInbustioii method for total sulfur, applicable to natural and synthetic rubber mixes and vulcanizates, including iiitr ile rubbers. Y amagu ch i (51B ) used a high frequency titration for the determination of free and total sulfui. Sikolinski and SlavoJr (37B) described a nen , rapid, inexpeneive method for free sulfur suitable for control purposes. dtafford and Sargent (@B) studied phases of the methods for combined sulfur described in British Standards 903 Part 3, 1950. The British Standards Institution (8B) published B.S. 903 Parts BG to B10, relating to the determination of sulfiii. I n the light of published work, Fiorenza and Lombardi (1 6 B ) have evaluated and reelaborated the methods for copper and manganese published in the XmeIicari Society for Testing Blaterials standaids foi 1955. They have applied the methods to some raw materials used in the rubber industry. Kiritescu, Ceamis, and Lazaiescu ( M B ) presented the results of tests for small amounts of copper in raw rubber latex,
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ANALYTICAL CHEMISTRY
vulcanized rubber, and fillers, using methods involving the measurement oi the intens t y of the yellow color of the copper diethyldithiocarbamate complex. Bogina and Martyukhina i7B) have described a simple rapid method for the determination of ferric oxide in raw rubber and vulcanizates. H a s l m and Hall (18B) have deve1opi.d a semimicroniethod for the determination of chlorine in polymers and copolymer3 of vinyl chloride, including those containing nitrogen, using a n automatic titrator. XcCoy aiid Bastin (34B) determined carbon and hydrogen in organic fluorine compounds, using a conibustion technique that ensures complete removal of fluoIine from the combustion products. Using spectroscopic andysis, Kh1ebriikov:t and Setkina (265') have determined barium, titanium, and sodium qualitatively, and magnesium, zinc, and calcium quantitatively (within 10%) in vulcanized rubber. A rapid determination of zinc, calcium, and niagnesiriin hits bcen dcscribed by Robertson ( $ l B ) in nhicli aliquots of extracts of the nshed vulcanized rubbcr are titrated with (ethylrnedinitrilo) tetraacetic acitl mider three different sets cf conditions. n'eher a i d Schulz (50B) proposed a modified nitiic acid method for the determination of carbon black in soft rubber valcanizates; alkiline washes and filtration difficulties were avoided. T h e authors also d i s c u w d the value of calculating the carbon black content from specific gravity, ash content, and per cent extract. Glander (16B) and Endter (14B) presented methods for the idcntification and analysis of filleis in rubber vulcanizatcs. Hagino and coworkers (I7B) h a r e used x-ray diffraction techniques to determine directly the mixing ratio of powders compounded in rubber. Kress ( S I B ) described a photonietIic determination for zinc oxide in rubber products, first precipitating the zinc as zinc diethyldithiocarbamate, and then measuring the absorbance of the complex. Berinan and Rachkulik (5B) used lumine-cent analysis for inspection of rubber mivcs in cable production, and found that adniivtures of 0.2 to 0.370 zinc ovid s and 0.1% phenyl-2-naphthylamine could be detected. Heinisch, Vervloet, and DOLIP( 19B) have investigated the dirt content of lower grade estate rubber. Pibarot (S9B) detcrmined residual acry onitrile in its polymers and copolymers by dissolving the polymer in toluene. dist!lliiig off the monomer, and measuring its absorption a t 2240 cni-l. Hilton (21B) describpd a direct ultraviolet spectrophotometric method for the determination of monomer styrene in SBR latex, which must be used in the absence of interfering substances, and s u g g s t e d an alternate distillation-ultraviolet
method which is satisfactory even in the presence of most interfering substances. Kress (SOB) determined even very small amounts of polyisobutylene in rubber products. A number of papers have described methods for the determination of a variety of antioxidants and accelerators. Kubota and Kuroi (SBB)have developed a method for the identification of typical phenolic-type antioxidants using paper chromatography. ZiJp ( B f B )presented a n argentomptric method for the determination of Z-niercaptobenzimidazole. Nawakowski (SBB) has determined Polygard in synthetic rubber and latex by absorption spectrometry of the phenolic fragment made available by alkaline alcoholysis. Stepanova (46%) described a photocoloriiiietric method for the determination of diphenylguanidine in raw rubber mixes and vulcanizates, using the color reaction of this material n i t h cobalt oleate in benzene medium. The same author (47B)has developed a pliotocolorirnetric method for the determination of thiurani disulfides in raw rubber niives, aiid vulcanizates based on the color reaction of thiurani disulfide n itli cobalt chloride in a 7 to 3 alcohol-benzene medium. Prerii and con-orkers (40B) have determined simultaneously oil and stabilizer in oil-rubber masterbatches using ultraviolet spectrophotometry. Parker (3SB) briefly described semiquantitative methods of analysis for rubber additives, first using chromatography on silica gel, and then ultraviolet absorption spectrophotometry, or spectrofluorometry. I t is pointed out that additives may be transformed during vulcanization. Zijp (62B-B0B), in a series of articles, has described methods for the determination of a variety of antioxidants and accelerators including the use of paper chroniatography and color reactions. Hlavnicka and Tureckovi (2SB) described n e x methods for the identification of antioxidants in rubber, based on chromatographic separation on an alumina column and followed by paper chroinatography, with final identification depending on retention values and color reactions, Daottsoti ( I S B ) described a n accelerated method for the determination of aldol-1-naphthylamine. The Kurzschmitt method for the detection of o-tricresylphosphate in natural rubber and Buna vulcanizates was found satisfactory hy Heuer and Rachner ($OB). Detection tests are necessary because of the toxicity of the ortho compound. Lorenz and Echte ( S S B ) described methods for the deterniination of certain auviliary materials used in rubber. Scheele and Gensch (@B, 44B) presented methods for the quantitative determination of a number of accelerators. The qualitative aiid quantitative
analysis of organosilicon compounds, including rubbers, has been reviewed by Midland Silicones, Ltd. (35B). Khoroshaya and coworkers (27B) described accelerated methods for t h e chemical analysis of colored microporous rubber crumb. Isakova (Z5B) described methods of analysis used in production inspection of synthetic rubber, Burlakov (9B) presented a procedure and apparatus for investigating, over extended periods, the resistance of vulcanized rubber to chemically active media. A G I N G TESTS
Khile there have been several papers on the general oxidative aging of rubber or rubber articles in the past t u o years (5C, 8C, I Z C , 1 8 3 , the major literature has been in the field of ozone attack on elastomers. The ISO,Technical Committee 45 has reported the method proposed by the U.S.S.R. Committee for testing the ozone resistance of vulcanized rubber (6C). T h e Laboratoire de Recherches e t de Controle du Caoutchouc (7C) claimed a qualitatire if not quantitative correlation betneen accelerating aging tests in ozonized air and n eathering tests, nhile Vacca (IN7)indicated t h a t the carefully controlled laboratory test cannot be eypected to correlate completely with natural m a t h e r i n g in the presence of a nide variability in ozone concentration, sunlight, and rainfall. J’eith, on the other hand, attempted to improve t h e laboratory tests by overcoming certain deficiencies in the prescnt .UT11 D 1149 - 55T method of test for accelcrdted ozone cracking of vulcanized rubber (It7C). H e interpreted the results obtained from a n interlaboratory ozoiie test program of ASTM D-1 1 Subcommittee 15-1957 ( I Y C ) as cncouraging in that the agreement betn-een the participating laboratories ivas about the same as in other phases of interlaboratory testing of ru bbcr . T’acca and Lundbeig (I&‘) showed that a standard accelerated ozone test in conjunction with a 100” C. air-oven test gives a reliable criterion of expected service life of neoprene wire jackets, but questioned the value of a Weatheroineter for this purpose. Farbenfabriken Baycr A.-G. (SC, 4C) published the description and application of a method for testing surface cracking of 1-ulcanizates using cylindrical tubes as specimens. Carlson and Harenhill (ZC) described a new ozone fleu tester n hich combines dynamic and static conditions of test, Van Pul ( I C ) developed a n apparatus especially suited for exposure of rubber specimens to low ozone conceiitrationsbetween 5 slid 50 X lo-* parts by volume. T h e ozone content is kept constant automatically. Similarly, Zuev
( I 9 C ) described a n apparatus capable of combined light and ozone testing a t higher ozone concentrations. Phelan (9C) and Phelan and Dunkel (IOC) found that the rate of change of the apparent ozone resistance of a given polymer with changes in testing variables is a function of t h e polymer tested and, as a result, suggested a n ozone test which they claim can most accurately predict the weathering pcrformance of one polymer compound as compared to another. The paper of Regener and Olnier ( I I C ) described two methods for measuring ozone concentration, nhile the patent of Allison, Delman, and Simms ( I C ) described a method for evaluating antiozonant chemicals. LATEX
One entire issue of Vanderbilt S c w s (9D) m s devoted to the technology of natural and synthetic latexes, including testing, compounding, and processing. Smith (SD) briefly discussed various tests applied to latex and the meaning of the tests. A high-speed stirring test for the niechanical stability of natural preserved latex n-as recommended by the I S 0 ( 4 0 ) . Bruce and Luide (SD)reported the freezing characteristics of GR-S and natural rubber latexes n i t h a caution concerning the possible destruction of the stable emulsion caused by eucessively low temperatures. Sandomirskil and Vdovchenkova (7D) described a method of evaluating the stability of natural and synthetic latexes by controlled coagulation tests using Ca4jC12. T h e quantity of cnlcium combining with 1 gram of rubber on coagulation is denoted the calcium number and is claimed to be a measure of the latex stability to electrolytes. Bernal and Boucher (ID, 2D) used papei chromatography as a n analytical tool for the identification and quantitative determination of mineral elements in Hevea latcx. Roy ( 5 D ) used electrophoretic velocity measurements of latex systems ineluding fillers such as zinc oxide, China clay, and sulfur to determine the isoelectric point of the latex mixture. Rupar and Breitman (OD)claimed t o have prepared a latex n i t h a narrow particle size distribution suitable for use as a ealibiation standard for the electron microscope, and described the use of such a system for studying particle size distribution in latexes. VISCOSITY A N D PLASTICITY
Williams (8E) reviewed plasticity testing with considerations of the reproducibility and correlation of diffeient test methods. Edelmann and Horn (1E) used the Umstatter viscometer to determine the flow curve of solutions of
natural rubber in toluene. Weber (?E) described a n apparatus for the measurement of the plasticity and stress rclaxation of viscoelastic material; it relates a directly measured value to t h e complex elastic modulus. Nikolinski (SE) also described a n improved plastometer suitable for use with raw rubhcr and mixtures, while Gengrinovich and Slonimskil (ZE) studied the plastic flow pioperties of multicomponent unvulcanized mixtures. Kikolinski (4E) described a n elongation deformation method for the determination of the plasticity of unvulcanizcd mixes, expressing the results in terms of the Defo hardness. OrlovskiI, Lukomskaya, and Bogatova (5E) used a shearing plastonieter for the determination of shrinkage on a calender. T h e axial compression of cylindrical specimens at a constant rate combined n i t h the use of a n empirical relation between the instantaneous stress and the initial stress value was proposed by Weber (6E) for determining the relaxation of vulcanized rubbers. GRADING, STANDARDS, EVALUATION, A N D OTHER TESTS ON UNVULCANIZED RUBBER
The Rubber Research Institute of Malaya ( I I F ) published a resume of the current status of technically clnssified rubber in the industry and described the test procedures used for TC rubber. The Rubber Manufacturers’ Association, Inc. (IO$’), published the “Green Book” TI hich lists international standards and specifications for natural rubber. Titze (12F) reviened the work of the German Standardization Committee over the past years and covered 26 D I S specifications. T h e Sational Bureau of Standards issued three nciv standard rubber saniples for usc a s reference standards (I@‘) : natural rubbe1 and butadiene-styrene copolymer rubbers of Types 1000 and 1500, denoted as standard saniples 385. 3S6, and 367, respectively. A standar(l sample of mercaptobenzothiazol m s also issued under number 383. Karam ( 5 F ) suggcsted simplified testing procedures a i t h which lie claimed a complete evaluation could 1-e obtained fiom 40 grams of material. l l a r c l (68’) described a mechanical method for the determination of the vitrification temperature of rubberlike polymers. Fogel (4F) discussed analytical methods for calculating temperaturcs inside rubber articles during vulcanimtion. Okhiinienko and Feofanov ( S F ) determined decomposition tempemtures of rubber under conditions intended to duplicate the thermal cracking of massive rubber articles during rcpeated deformations. Debye (ZF) briefly described methods for determining the molecular m i g h t of VOL. 31, NO. 4, APRIL 1959
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high polymers in solution with emphasis on the light scattering method. Tobolsky, Mercurio, and Murakami (1SF) set forth a method for determining the molecular weight distribution of a polymer from stress relaxation measurements. Charlesby ( I F ) based his method for the determination of molecular weight distribution on the fact t h a t the rate of gel formation in a polymer by x-ray irradiation is a function of the initial molecular weight distribution of the polymer. Miller and Willis (78‘) found t h a t a quantitative analysis of synthetic polymers could be conducted by using thin pressings of the polymers and infrared spectrophotometry in the region of 1.5 to 2.7-micron wave length. Peter and Heidemann (9F) claimed to have developed a new method for determining the vulcanization characteristics of rubber compounds by measuring the dynamic shear modulus while the sample is held a t the vulcanization temperature. E r a t h and Spurr ( S F ) used x-ray scattering measurements to determine the extent to which a silicone resin is cured.
than either ASTllI or British Standards Institution methods. T h e British Standards Institution specified the apparatus and procedure for creep and stress relaxation tests in tension, Compression, and shear (5G). They also specified two methods for the determination of compression set
(7G)*
Berry (SG) and Lyubchanskaya, Shlyakhman, and Kuz’minskil (19G) described apparatus for the measurement of stress relaxation in rubber. Three papers describing apparatus for the high temperature testing of rubber under tension appeared (17G, BdG, Z7G). DYNAMIC TESTING
h survey by Abolafia ( I H ) and a summary of methods and equipment by Reznikovskii et a/. (Z7N) covered the general field of dynamic testing of rubber. Numerous papers described individual equipment for resilience measurements (6H, fiH,SOH, 31H ) ; flex life (IOH, 12H, I S H ) ; dynamic moduli (SH, I I H , I S H , 18H, 19H, 25H, 68H, SZH, S 4 H ) ; and for high speed testing of mechanical properties (14H, 17H, ZOH, 24H, 29H, SSH).
STATIC TENSION A N D COMPRESSION
A review of the widely used tensile testing methods for soft rubber was presented by Tangenberg (SfiG). The U.S.S.R. Komitet Standartov described a range of standard pendulum testers for the determination of the ultimate tensile strength of rubber (28G). T h e British Standards Institution (fiG)specified the test pieces, apparatus, and testing procedure for the determination of tension set. Eagles and Payne (PG, 10G) compared electronic and pendulum dynamometers and recommended the electronic device as being faster and capable of giving comparable results. A number of papers describing new or modified testeis for tension testing of rubber appeared (IG, 4G. 9G, I I G , IZG, 16G, 18G, 20G, B2G, Z5G, Z9G). The International Organization for Standardization recommended and detailed a particular dumbbell-test piece for the determination of tensile stressstrain properties of vulcanized natural and synthetic rubbers (14G). Bennett (2G) and Outa (2lG) described unsatisfactory features or deficiencies of testing machines and test specimens and recommrndrd modifications of cne or both. Scott and T’illars (2SG) reported the results of a n investigation of the sperd of testing on tension results. Gent presented the experimental iesults obtained on the load-deflection relations for flat rubber pads in compression ( 13 G ) . Kase (15G) gave a mathematical relationship purporting to give a better result for the value of tensile strength 770
ANALYTICAL CHEMISTRY
Bulgin (4H) reported on the Dunlop rotary power loss machine. ReznikovskiI, Vostroknutov, and Khromor (26H) described three methods of testing, one of which involved the rate of retraction of stretched and released samples. Payne, in a series of papers, discussed the application of the Ferry transformation to show the fundamental unity of diverse dynamic phenomena (ZdH). the use of dynamic test in choosing elastic mountings (ZSH), and a dynamic apparatus for the rapid evaluation of the optimum cure time ( B I H ) . Electronic apparatus for nieasuring the damping properties of rubber specimens was described ( Z H ) . Johnson (1fiH) proposed several model systems suitable for the mathematical analysis of dynamic test results. The Deutscher Kormenausschuss specified the conditions for bending fatigue tests of rubber, including appaiatus ( 9 H ) , flex cracking ( 8 H ) , and cut growth ( 7 H ) . HARDNESS
h paper on testing equipment for rubber by Bennett ( 1 J ) discussed the scale of International Rubber Hardness, agreed upon by the United States and United Kingdom, and also described the Wallace hardness tester. The British Standaids Institution specified a method for the determination of indentation and recovery number of ebonite ( S J ) and one for the determination of hardness of vulcanized rubber ( 4 4 . The Farbenfabriken Bayer -4.-G. presented a review paper on hardness testing over a range of temperatures
( 7 4 . Juve (11J) described changes in the Shore A Durometer scale to agree with the new I S 0 scale with low creep stocks. Maxwell ( I W ) studied the results of hardness testing from slom indentation tests to high speed rebound type tests. The results were interpreted in terms of the rheological properties of the materials under test. T h e U.S.S.R. Komitet Standartov specified ball indention and needle machines for hardness measurements of vulcanized rubber ( I d J ) . The Verein Schweizerischer hlaschinenindustrieller also specified a ball penetration teat with conversion of results to IRH degrees (15J). The IS0 recommended a hardness test using a ball penetration test in which the IRH degrees are calculated from the differences in penetration of the ball undei tn-o different loads (1OJ). Bird ( 2 4 described a new Shore hardness tester claimed to comply with ASTM D 767-4913 and D I X 53505. The same tester was described by the builder ( S J ) , Morris and Hollon a y ( I S J ) evaluated the IS0 microhardness tester. The Deutscher Nornienausschuss specified methods for determining hardness for foam latex articles ( 6 J ) . Frank ( 9 J ) described a hardness tester for foam latex designed to comply with the above specification. Eller ( f i J ) reported a n evaluation of the Pandux tester for hardness of foam latex materials in terms of the relationship betm-een Pandux hardness and compiession resistance. ABRASION A N D TEAR
Bttempts a t correlations betn een laboratory abrasion tests and actual use tests m r e reported by Burton and Herzog (2K) and Prat ( 1 7 K ) . The IS0 recommended a constant-load method of measuring abrasion resistance of vulcanized natural and synthetic rubber ( 1 I K ) . Apparatus for abrasion testing was described by Haines ( 8 K ) , Nelvton and Sears ( I f i K ) ,and Killiams ( 2 I K ) . Chim and Carideng ( 5 K ) gave a formulation for calculating the poner used during a n abrasion measurement. Vervloet (2OK) pointed out the necessity for correcting for the difference in temperature between labarntory \\ear tests and road \Tear tests. RubberStichting described its procedure for the road testing of tires (IC%). The I S 0 ( I b K ) , Vereiii Schn-eizerischer 1\Iaschinenindustriellri (19 K ) , and the Instituto Xacional de Racionalizaci6n del Trabajo (IOK) publiihed specification test procedures for determining tear propertirs of rubber vulcanizates. Greensinith ( 6 K ) reported on the various theoretical aspects of the tearing of rubber and discussed the idea of a characteristic tearing
energy concept. Chasset and Thirion ( 4 K ) presented a test method for measuring the longitudinal tearing of stretched vulcanizates. h e r , Doak, and Schaffner ( f K ) , Gurney and Cheetham (7K), Lukomskaya ( I @ ) , Hampe (9K), and Kainrad1 and Handler ( I S K ) presented methods of riieasuriilg cut growth and tear of rubber. Cardeiv (SK)and Nash and Thompson ( I 5 K ) described tests and equipment for testing the frictional properties of rubber samples and tires. ADHESION A N D TACK
ASTN Committw D-14 on adhesives detailed a wide range of tests for adhesion ( I L ) , a large part of which was dev0tr.d to rubber adhesives and rubber bonding. Buist, Xegrick, and Ptafford (2L) also published a n extensive evaluation of rubber-to-metal bonds. T h e Dayton Chemical Products Laboratories, Inc., described (&) three of their tests for testing rubber-to-metal bonds. Larsen (7L) suggested that ASTM D-429 method B for testing rubber-to-metal adhesion is preferred, because it is less sensitive to the thickness-diameter ratio and stock modulus t h a n the other proposed methods. Reznikovskii (I4L) and Shapovalova. Voyutskii, and Pisarenko (16L) described test methods designed to measure t h e bond strength between vulcanized rubbers. Levitin and coworkers (8L) and Novopol’skif (915)developed laboratory tests 10 determine t h e dgnaniic bond strength bet\\-een tire elements. T h e I S 0 (6L), Tsydzik. Lukoniskaya, and Slanimskii (IYL), and Uzina, Gromova, and T’asil’eva (ISL) were concerned with the measurements of the adhesion of textile cords or fabrics to vulcanized rubber. Kerren anti Eickner ( I 9 L ) described a climbing peel test for sandnich and bonded metal-to-metal construction. The measurement of the adhesion of pressure-sensitive tapes was discussed in papers by Wetzc.1 (2UL) the Pressure Sensitive Tape Council (12L, f S L ) , and Chang (3L). Forbes and 3lcLeod (5L) described a test mcthod for measuring tack strength a n d their conclusions from a study of the relation between tack strength and molrcular properties of the materials. Prentiss ( 1 I L ) and Pickup (1OL) reported iieiv apparatus for measuring the tack strength of materials. Roberts arid Pizer ( f 6 L ) devised a n electronic incasuring and integrating device for use n i t h the Interchemical adherometer which is claimed to yield better precision of test than the usual pendulum device. ELECTRICAL TESTS
Several reviews of the field of clec-
trical tests appeared as services to workers in this field, T h e extensive digest edited b y Hoffman and H a r t ( 5 M ) and the serial work of Norman on conductive rubber ( 9 M , I U ~ l f ) , which has also appeared in book form (&If), n-ere the most comprehensive. Heron and Dubois ($V) briefly summarized electrical tests applicable to insulating materials. T h e British Standards Institution ( 1 M )’ the Deutschei Normenausschuss ( 2 U ) , and the International Electrotechnical Commission (6M) specified or recommended test methods for electrical resistance of rubher materials. Zernial ( I 4 J i ) described a method for the measurement of t h e electrical conductivity of rubber specimens. KallFveit (711) studied t h e measurement of the electrical resistance of polymers under the conditions of various electric fields. temperature, time, and polarity. Thevenou (13~11) developed a device for the specific testing of electric insulation on cables. The British Insulated Callenders’ Cables. Ltd. (33f) patented a device invented by Gooding to detect voids or imperfections in cable insulation b y measuring the transient electrical oscillation produced as the cable and t h e imperfection pass through a tubular electrode while a high voltage is applied. Rothert (IZM) described the properties and electrical testing of silicone rubbers and lubricants. Ratner and Lavrent’ev (IfM) discussed the relations between the graphite, carbon black, or alumina content of SKS-30 rubber and the friction, electrical conductivity, and strength. LOW TEMPERATURE TESTS
Some low temperature test methods with particular reference to recent I S 0 recommendations were presented by Edlvards ( 2 s ) . Kebber (YS) reviewed existing methods for determining brittleness of elastomers at lon- temperatures. H e concluded that ASTJI Method D 746 is the only suitable method a t present for routine testing purposes. Craig ( I S ) as a result of a study of high speed impact tests at low temperatures, concluded t h a t the ,4ST;\I Method D 746 is the only consistently reproducible test of those investigated even though it did not agree with failure temperatures in field performances. The C.S.S.R. Komitet StaiidartoT(6.Y) proposed a brittleness test based on the highest temperature a t n.hich t h e specimen breaks or cracks under specified impact conditions. Ofner (5-47)studied the effect of impact speed on t h e brittle temperature of elastomers. H e recommended that the prese n t impact speed of 6.5 be raised to 12 feet per second. Hanok, Chatten, and Lichtman coni-
pared a number of instruments for measuring hardness of elastomers at low temperatures (3s) and stress decay ( 4 S ) . Several instruments proved suitable for hardness measurernents; a tensile stress decay instrument was superior to t h e several compression types studied. TIRE TESTING
Thornley (22P) has given a general account of test methods used in evaluating tire compounds including both laboratory and service tests. Fromandi, Clamroth, and Oettner (IOP) reported on t h e statistical assessment of tire tests on the Siirburgring. These studies indicated t h a t results could be predicted more reliably when the tests were made using tires with divided treads rather than tires n ith uniform treads. Riehl (ISP)discussed the increased severity of tread n e a r in tires and the need, not only for improved tire construction, b u t also for more severe testing conditions and described facilities for the latter. Beharrell ($E‘), anticipating new speed records, described a machine for testing tires a t speeds u p to 650 miles per hour. Stiehler and Gregg ( 2 f P )have patented a device for testing tires under simulated service conditions of load, pressure, road surface, speed, and cornering. Roniani (dUP) described a trailer used for studying tires while running on t h e road. Carr and Daw (4P)invented a device for testing tubeless tires and Benjamin (3P) one for determining the optimum degree of inflation for a tire under load to ensure maximum safety and w a r . I n a study of the wear of passenger car tires Geesink and P r a t ( I I P ) described a test severity factor expressed in terms of the absolute n e a r of a reference tire during the same test run. I n another article, P r a t ( 1 7 P ) discussed correlation b e h e e n laborator) abrasion and road testing in terms of this factor. T h e follo\T,ingthree articles discussed the general subject of research in automobile stability and control and in tire performance: Milliken and K h i t comb (16P)discussed a program of dynamic research; Close and Xuzzey ( 5 P ) described a device to measure the six force-and-moment components in a tire and nheel rolling along a road surface, nhile the slip angle. camber angle, load, and breaking effort are varied; Fonda (SP)discussed tire tests and the interpretation of experimental data. Roberts and Cough ( f 9 P ) described a precision test machine for measuring cornering force and aligning torque over a range of camber and slip angles. Zakharov and Novopol’skil (23’) proposed a new method for measuring the forces in the contact area of tire and VOL. 31, NO. 4, APRIL 1959
771
road b y a tensometric device which fits on the IPS-1 drum tester. Gokhale ( 1 P ) also described a simple method of determining stress intensities a t diflerent points on the contact patch between the tire and road. Constantakis (6P) has patented a device for testing the traction properties of a tire tread on s n o x or ice. Metzeler Gummiwerke A. G. (16P) described a n oscillographic apparatus for measuring the effects of local deformation on tires under varying conditions of inflation pressure, velocity, temperature, road surface, and type of vehicle. Frenzel and Kittelman (9P) critically reviexved the static and dynamic stresses t h a t tires undergo and the test methods used to determine the response of the textile components of tires to these stresses. Several patents ( I P , 7 P , I S P , 14P) have been issued for devices used in measuring tire thump and related matters. MISCELLANEOUS
General papers on t h e application of statistical methods to rubber testing were presented by Buist (7Q, SQ), Freeman ( I @ ) , Gol’berg ( I Y Q ) , Ratner and Burov (COQ), Thornley (5WQ), and Williams (56Q). qtiehler and Mandel (@&) discussed the use of the sensitivity criterion in the evaluation of analytical methods. Baker (39) described a systematic method for analyzing t h e results of factorial experiments. Microscopic techniques lvere applied by Andrens ( I & ) t o study microscopic stress distortions in rubber a t the tip of a tear. Lagoni and hIerten i27Q) used a microscope to distinguish microscopic irregularities of rubber surfaces by replicas on silver or copper surfaces. Andren s and Kalsh (WQ) used gelatin first stage replicas of rubber surfaces in the electron microscopy of vulcanized rubber. Chappius and Robblee (9Q) developed a freezing technique for rubber specimens, allon ing ultra thin sectioning for electron microscopy. Pohle (SQQ) discussed a variety of methods used for the in\ estigation of vulcanized rubber surfaces. Microscopic techniques for evaluating the dispersion of carbon blacks in rubber mixes n.ere the subjects of papers by Drogin ( I I Q ) and Slveitzer, Hess, and Callan (60&, 5IQ). Methods for the determination of the sivelling of rubber vulcanizates in various media m-ere proposed by t h e Deutscher Normenausschuss (IOQ), Fujiwara and Spain ( I C Q ) . and Shcherbacheva and Gusexa (44Q). Kraus (25Q) used sn elling measurements to determine the degree of cure in filler reinforced wlcanizates. Wilson, Griffin, and llontermoso (66Q) suggested a niethod for determining the losses in physical properties of rubber samples
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ANALYTICAL CHEMISTRY
on snelling in liquids. Shvarts (47Q) published a series of nomograms for determining t h e compatibility of vulcanizates of a given rubber n i t h a series of solvents. Votlokhin (5SQ) described a n apparatus designed to measure t h e changes in dimensions of a rubber test piece in hot petroleum under pressure. T h e use of radioactive isotopes in the rubber industry was reviewed by Kaplunov and Tarasova (WSQ), while Boguslavskii, Tikhomirov , and Bokharev (6Q)used radioactive irradiation techniques to assess the uniformity of rubber mixes. Blokh and coworkers (6Q) and Novikov and Koloskova (S5Q) used radioactive sulfur to determine the diffusion and dispersion of sulfur in rubber. Michael, Gilbert, and Kalinsky ( S l Q ) used synthetic radioactive seaivater to measure seawater sorption b y synthetic rubbers. Rolls-Royce, Ltd., and the U. K. Atomic Energy Authority nere granted a patent for a method of inspection and apparatus for detection of cracks or flaws in rubber-reinforced hose, using radioactive substances in the pressurizing liquid (32Q). Richardson’s book (42Q) on acoustic relaxation described t h e behavior of rubber under sonic and ultrasonic ribrations. Gorlick (18&), No\-itskii and Fridman (SSQ), Sandler 14SQ), and Shinyanskil and Solonko (46Q, 46Q) described methods and apparatus for relating the ultrasonic behavior of rubber to its elastic and dynamic properties. Wilke and Altenburg (54Q) revien ed the experimental n-ork done on the mechanical degradation of high polymers b y ultrasonic vibrations. Palen (SSQ) presented examples shoiving how x-ray analysis techniques can be of value in practical tests for uniformity and contamination of rubber mixes. Yokoyama et al. (57Q) used x-ray diffraction measurements in their studies on rubber and filler compounds. Kroplin (26Q) described a thicknesb gage particularly suited to measuring the thickness of elastic foams. Remington and Pariser (,$I&) developed a method for determining the cell structure of both rigid and flexible foams. Permeability measurements and methods n ere reported by Koide, Kubota, and Shimoda (Z4Q) for air, by Finkel ( I 4 Q ) for water, and by Zoebelein (5SQ) for water vapor. Berman and Rachkulik (4Ql tlescribed a visual inspection method for rubber mixes using ultraviolet light. Hill and Leonard (20Q) applied reflectance spectrometry to the measurenierit of discoloration of rubber films. Soltham (34Q) reviewed the terms and concepts of color description to explain the important considerations in matching colors in elastomers. The
Society of Motor Manufacturers and Traders in London described two tests to evaluate the staining of organic finishes and plastics materials b y rubber (48Q). Hagman, lIueller, and Thompson (19Q) studied the effect of compounding ingredients on the flame resistance of neoprene. Merz (300) compared t n o methods for the determination of the volatility and migration of high molecular Jveight plasticizers. Lanzavecchia (28Q) suiveyed various applications of nuclear magnetic resonance methods to problems in the field of high polymers, including rubber. llikhlin (SSQ) described a gasometric method for the determination of the water content of vulcanized rubber. OrlovskiI, Lukomskaya, and Bogatova (37Q) deleloped a method for the evaluation of calendaring and estrusion properties of carbon blackrubber niixes based on a recoyery test. Eagles and Payne (I2Q) proposed the use of proof rings IT-ith induction transducers for the measurement of the forces developed during rubber testing in tensile machines. Ito ( Z I Q ) , Jobling and Roberts (22Q), and Lesavre (29Q) described aids for the measurements of the mechanical properties of rubber vulcanizates. These included measurement of temperature dependence of mechanical behavior, methods for triasial stressing of rubber test specimens, and a description of the Brhsilien test, respectively. Eccher (130) dereloped a method for assessing the suitability of rubber miles to form moldings free of air inclusion. LITERATURE CITED
Introduction (1) Bekkedahl, Sorman, ASAL. Cmm. 22,
253 (1950). (2) Ihid., 23, 243 (1951). (3) Ibid., 24, 279 (1952). (4) Ihid., 25, 54 (1953). Bekkedahl, Sorman. Sorman, Stiehler, R. D., ((5) 5 ) Bekkedahl. Zbid., 21, 266 (1949). (6) Belikedahl. Korman., Tryon. Max. ’ Ihid., 27, 589 (1955). (7) Tryon, Mas, Ihid., 29, 714 (1957). “
I
General Information (1A) Akron Rubber Group, Rubber TVorld 135, 903 (1957); 136, 80 (1957); R7thhe? Age, (*V. Y.) 80, 1019 (1957); 81, 83 (1957). (2.4) -km. SOC. Testing Materials, Pliilsdelphia, Pa., Committee D-11 on Rubber and Rubber-Like llaterik la, “ASTAI Standards on Rubber Products (xith Related Information),” 10.5T. (3.k) Ibid., 1958. (4A) -km, Soc. Testing IIateriaia, Philadelphia, Pa., Committee D-11 on Rubber and Rubber-Like hlaterials, “Glossary of Terms Relating to Rubber fjnd RubberLike Materials,” ASTlI m e r . Tech. Publ. 184, 1956. -1-.
(5,1) Bennett, F. K. B., Rubber J. 133, 300, 346, 380 (1957). (6.1) Buist, J. RI., Rubber J . Intern. Plast. 133, 930, 932, 944, 984 (1957); I S o / TC/45 (Rubber) Zurich, Sept. 30-Oct. 5, 1957. (7.4) Buist, J. AT., Trans. Inst. Rubber I n d . 33, 102 (1957). (8.1)Carpenter, A. W., Rubber TVorld 137, 241 (1957). (9.1)Cook, ,p. G., “Latex: Tatural & Synthetic, Reinhold Pilot Book 8, Reinhold, S e w Tork, 1956. ( l o a ) Drakeley, T. J., A n n . Rept. Prcgr. Rubber l’echnol. Vol. XX, 1956, Inst. Rubber Ind., London, TV. Heffer & Pons,, Cambridge, 1957. (11A) Ibid., XXI, 1957. (121) Drogin, I., Rubber J . Intern. Plast. 134, 374 (1958’). (18.1) Ecker, It., Brautigam, C., liautschuk 21. G u m m i 10, 302 (1957). (14.1) Fariica, Id., Chinz. anal. 38, 353 (1956); Rei’. gBn. caoutchouc 33, 1305 I 19.56). ---,( I 5.1) Junkcr, E., Tertii-Rundschau 11, \
S o . 10. 587 (19561. (I(i.1)Iiovacs, I,., “LIlinyag Zsebkonyv” i “Plasticls l l a n u a l ” ) , lliszaki, Buda-
peat, 1956. (17.1) I,ever, .I E., Rhjs. J., “Properties
and Testing of Plastics hIaterials,” Temple Press, London, 1957. (18.1) Olaszck, -1.“Zarys hIetod Badan Gumv i T1-j robo\v Guniovvych” (“Outline of Jlethods of Testing Rubber and Rubber 1rticles”). Panstxion e Wvd. ~ e c ~ iKarsaw, ., 16d. (19.4) Ratner, S. B., Reznikovskil, 11. II.,Zuev, 1-11. P., Zai~odskaya Lab. 20, s o . 7, 849 (1954). (20A1)Rofi‘, I\-. %J., “Fibres, Plastics and Rubbers: A Handbook of Common l’olynicrs,” Butterworths Scientific Publications, London, 1956. 121 .A\ Rotliermel, E. )I,, Rubber World 135, 892 (1957). (22-1) Scott, J. R., Proc. Inst. Rubber I n d . 5, 54 (1958); (ISO/TC 45, Zurich, ~~~~
Feptcmber-October
,.
1 ~ 7 )
*I
123.\’1 Slicherbacheva, RI. h., “Khimirlieskie RIetodv Analiza Rezinv” (“Chemical RIeihods of Analysis “of J-ulcanized Ritbbers”), Goskhimizdat, l l o s c o n , 1957. (24.1) U. S.Generd Services .idministi-ation, Federal Suppli- Service, Federal Standard 90, “RubbtLr, Synthetic: SpecifieaLion Limits, Sampling, and Testing, Government Printing Office, Iyasliington 25, D. C., 1956. (251) 1T.S.S.R. Saiichno Issledovatel’skii Institiit Rezinovoi Proniyshlennosti “Trudy Sauchno-Issledovatel’BkogoInstituta Rezinovoi Promyshlennosti Sbornick 2” (“Transactions of the Research Inetitiite of the Ruhher Indiistrv No. 2”), Cjoskhimizdatt, Rloscon-, 1955.(26.1) \I ake, IT. C., “Anal! sis of Rubber and Rubber-Like Polvmrrs,” Maclaren & Pone, Tandon, 195%. (2i.1) Myinspear, G. G;, “The T’anderbilt Rubber Handbook, R. T. Vanderbilt Co., S e w Tork, 1938. Chemical Analysis (1B) BRrnard, D., J . Polymer Sci. 22, 213 (2956). Rubber Chem and Technol. 31, 82 (1958).
(2B) Bauniinger, B. B , Kautschuk u. Gumrnz 8, TTT 31 (1955), Rubber Chem. and Technol. 30, 354 (1957). (dB) Bauminger, B. B., Trans. Inst. Rubber I n d . 32, 218 (1956). (4B)Belitskaya, R. AI., Zvereva, R. AI., T r u d y A-auch-IssledoLatel’ Inst. Rezinot01 Promyshlennostz, Sbornzk 4, p. 89, U.S S R. Sauchno. RIoscoir , 1957.
(5B) Berman, RI. L., Rachkulik, V. I., Inform. Tekhn. St. M m i s t . Elektrotekhn. Prom. S.S.S.R., S o . 10, 31 (1956). (6”r Bozina. I,. L.. Martvukhina. I. P.. k a u c h h i R e z i n a 16, KO.12, 27 ‘(1957): (7B) Bogina, L. L., Martyukhina, I. P., Leqkaua Prom., No. 6 , 31 (1957). ( 8 2 ) ”British Standards Institution, lfethods of Testing Vulcanized Rubber. Parts B6 to B10. Determination of Sulfur.” BS 903. Parts B6 to B10, London, 1958. (9B) Burlakov, V. S.,K h i m . Prom., KO. 6, 363 (1956). (10s) Davison, \I7.H. T., Chem. & I n d . p. 131, 194 (1957). (11Bi Dermody, TV. J., Rubber Age 83, 103 (1958); Rubber World 138, 96 (1WIR)
(l2B)~DrozdovskiI,T’. F., VishnevEkaya, I,. RI., Legkaya Prom., KO. 2, 34 (1956). (13B) Dzottsoti, S.Kh., Cchenue Zapiski Azeibaidzhan Cnza., Xo. 6 , 29 (1955). (14B) Endter, F., Kautschuk u. G u m m i 8 . TVT 402 (10551: Rubber Chem. and ~-~ Fechnoi. 30, 180 (f957). (15B) Fiorcnza, A., Lonibardi, E., “Detcrniinazione di Piccolissime Quantith di Ranie e Manganese nelle Gomme greggie e in alcuni Ingredienti” (“Evaluation of Very Small iimounts of Copper and Manganese in Raw Rubbers and Some Ingredients”), Pirelli S.p. .1.,Ricerca e Sviliippo 10: LIilan, 1958. (16B) Glander, Fr., Rubber Chein. and Techno/. 30, 191 (1957).
(17Bj Hagino, Y., Hirata, Y., Yokoyama, T., Hashizume, G., A-ippon Gomu K?jdkaishi 29, 1033 (1956). (18B) Hnslem, J., Hall, J. I., Analyst 83, 196 (1958). (19B) Heinisch, IC. F., Vervloet, C., Doup, D., Arch. Rubber Cultivation ( B o y o r ) 33, 241 (1956). (20B) Heuer, D., Rachner, lI.,Pharmazie 8, 1028 (1953). (21B) Hiltoii, C. I,., Rubber Chem. and Technol. 30, 1183 (1957). (22B) Hilton, C. L., Tolsma, J., Sewell, J. E.. Rubber Aoe 81. 634 (1957). (23B) Hlavnicka, J..T&ecko 85 (1958). 125B) , , Ilakova. S . A , , Zauodskazia Lab. 20, S o . 7, y98 (1954). (26B) Iihlebnikova, L. Ya., Setkina,
0 . K . , Sbornik 12-auch. Trudov Kafedr. Illatem. Mekhan. K h i m . Leningr. Inst. Tochizoi IlIekhan. i Optiki S o . 24, 110
(1957). (27B) Khoroshaya, E. S., Lykova, A. S . , Rubina, S. I., Sidiropulo, K. K., Sekrasova, L. il., Zalonchkovskil, A. D., Sauch.-Isseledocatel T r u d y lseiatr. .Y.-I. Inst. Zanien. Kozki SI). 8, 146 (1956% (28B) Iiiritescu, A . , Ceamis, M., Lazarescu, I., I n d . Usodra (Bucharest) 3, 500 (1956). (29B) Klitenik, G. S., Ginzburg, S. B., Byull. P O dbnienu Opytom v Prom. Rezim-Telt-h. Izdelil, KO.3, 30 (1955). (30B) Iiress, It,F. N . B., Rubber J . Intern. Plast. 134, i24, 130 (‘1958). (3G) Berry, J. P., Tram. Inst. Rubber Ind. 32. 224-30 11956). (4G) Bouche; R R., Tate, D. R., ASTM Bull., SO 228, 33-42 (1958). (5G) Biitish Standards Institution Specn. B. S. 903, Part Al5, London, 1938. (6G) Ibid., Part A5. (7G) Ibzd., Part A6. (8G) Eagles, .4.E., Payne, A. R., Research Assoc. Brit. Rubber Jl.frs., Shawburv, research memorandum R.405 ’
(IS;?).
(9G) Eagles, A. E., Payne, A. R., Rubber 6 Plastics Age 38, 811-3 (1957); Rubber Chem. and Technol. 31, 673-9 ( 1958).
Viscosity and Plasticity (1E) Edelmann, K., Horn, E., Gunzmi u. Asbest. 10, 456-60 (1957). (2E) Gengrinovich, B. I., Slonimskif, G. L., Kolloid. Zhzir. 20, SO. 2, 143-8 (1958). (3E) Sikolhski, P. D., Izrest. Khim. Inst. B’lgar. Akad. .Vauk. 3, 223-36 i19.55I. \ - - - - >
(4E) Ibid., pp. 237-54. (5E) OrlovskiK, P. K., Lukomskaya, A . I., Bogatova, S. K., Khim. Prom., S o . 4, 217-24 (1956). (6E) Weber, K., Kolloid. Zhur. 20, S o . 2, 135-42 (1958). (7E) Keber, K., Plaste u. Kautschuk 4, S O .1, 22-8 (1957). (8E) Williams, G. E., Kautschztk u. G u ~ m 11, i K T 8-14 (1958). Grading, Standards, Evaluation, and Other Tests on Unvulcanized Rubber ( I F ) Charlesby, A., Ricerca sei., Supple 25, 400 (1955); (“Simposio Intern. Chim. Macromolecolare”3. (International Organization of Pure and Applied Chemistry) Turin (1954). (2F) Debve, P. J. IT., Sei. American 197, IYG. 3, 90-7 (1957). (3F) Erath, E. H., Spurr, R. A., J . Polvmer Sci. 28. 233-4 11958). (4F) Fogel, V: O.‘, Trudy‘ Moskov. Inst. Tonkoi Kham. Tekhnol. im. M. V . Lomonosova, S o . 5 (1955); Rubber Chem. and Technol. 30, 757-70 (1957). (5F) Karam, H. J., Rubber World 137, 570 (1958). (6F) RlareK, A. I., Rubber Chem. and Technol. 29, 1174-80 (1956). (7F) Miller, R. G. J., Willis, H. A., J . Appl. Chem. 6, 385-91 (1956). (8F) Okhrimenko, I. S., Feofanov, A. P., Zacodskaya Lab. 23, 333-5 (1957). (9F) Peter, J., Heidemann, W., Kazctschuk u. Gummi 10, Xo. 7 , WT 168-172 (1957): Rubber Chem. and Technol. 31, 105 (1958). (10F) Rubber Manufacturers’ ASSOC.,
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ANALYTICAL CHEMISTRY
(IOG) Eagles, A. E., Payne, A. R., Smith, J. F., Ibid., R.403, (1955) (released 1957). (11G) Farlie, E. D., Hawkes, J. F., IT-aters, S.E., Rubber J . 132, 648-50, 652 (1957). (12G) FoldesL_G., Schweiz. Arch. 23, 188-93 (193i ). (13G) Gent, A. S., Rubber Chern. and Technol. 31, 395 (1958). (14G) International Organization for Standardization, I S 0 Recommendation ISO/R37 (Geneva, 1957); Rubber Chena. and Technol. 31, S o . 1,xxiii (1958). (15G) Kase, S., ATippon Gomu RzJGkaishi 30, 852-6 (1957). (16G) Kurshinskif, E. V., Sidorovich, E. A,, Zhur. Tekh. Fiz. 26,878-86 (1955). (17G) Lavery, T. F., Grover, F. S., Smith, S., Kitchen, L. J., Rubber Age (1%‘. Y . ) 80, 843-9 (1957). (18G) Lezhnev, S. N., Zuev, Yu. S., Trudy iYauch-Issledocatel Inst. Rezin. Prom. SO.2, 35-47 (1955). (19G) Lyubchanskaya, L. I.,Shlgakhman, A. A , , Kuz’minskii, A . S.,Kauchuk z Rezina 16, Yo. 2, 3.1-3 (1957). (20G) Xovozhilov, h. I., Byull. p o Obmenu Opytom v. Prom. RezinoTekh. Irdelii No. 2, 23-4 (1956); Kauchuk i Rerina 16, Yo. 2, 40 (1957). (21G) Outa, M.,Proc. Insf. Rubber Ind.
4, 143-6 (1957). (22G) Research Assoc. Brit. Rubber Mfrs., Rubber J . 132, 607 (1957). (23G) Scott, D. C., Jr., Villars, D. S., “Symposium on Speed of Testing of Son-Metallic hlaterials,” Am. SOC. Testing Materials, ASThl Spec. Tech. Pub. 185, 62-71 (1956). (24G) Smith, F. &I., Rubber Age 83, 100 (1958); Rubber World 138, 93
(1958).
(25G) Strella, S., ASTM Bull., No. 219, 29-33 (1957). (26G) Tangenherg, H., “Symposium on Tension Testing of Son-hletallic hlaterials,” ASThl Spec. Tech. Publ. 194, 30-48 (1957). (27G) Tsetlin, B. L., Gavrilov, V. I., Velikovskaya, N. A,, Kochkin, 1’. V.,
Lab. 22, KO. 3 , 352-5 (19561. (28G) L.S.S.R. Koiiiitet Standai tov, Xer i. Izmerztel-nykh Przborev Prz Sovete Mznistrov Soyzrta S S.R. GOST, 7762-55 (1955). (29G) T’ishnitskaya, L. A., Xovikov, V. I., Zauodskaya
Trudy Sauch-Issledotatel Insf. Rezzn. Prom., S o . 2, 27-34 (1955).
Dynamic Testing (1H) Abolafia, 0. R., C . 5‘.Goat. Research Reds. 27. 111 (1957): PB121767. (2H)’Anon,’ Rubder 6 Plastics Aye 38, 253, 255 (1957). (3H) BorovitskiK, S . M.,Doklady Akad. S a u l S.S.S.R. 109, S o . 5, 923 (19561 14H) Bulein. D Rubber J . Intern. Plast. 134, 967 ’(1958). (5H) Bulgin, D., Hubbard, G. D., Rubber Age (‘4-. Y . ) 81, 95 (1957); Rubber TVorld 136, 75 (1957). (6H) Bulgin, D., Hubbard, G. D , Rubber J . Intern. Plast. 133, 622 (1957). (7H) Deutscher Sormenausschuss, Kautschuk u . G Z L ~ V11, I I 37-8 (19583 (8H) Ibid., pp. 34, 36-7. (9H) Ibid., p. 34. (10H) Ecker, R., Brchiv tech. Nessen ( 4 T h I ) 244, 99-102 (1956). (11H) Fitzgerald, E. R. (to \Tiwon sin Alumni Research Foundation). U. S. Patent 2,774,239 (1956). (12H) Gehman, S. D., Wilkinson, C. S., Jr., Deut. Kautschzik-Ges. Conference, Cologne, hlay 7-10, p. 26 (1958). (13H) Gent, A. K.,Rubber J . Intern. Plast. 134, 830 (1958). (14H) Hasui, A,, b y 6 Bicts~iz25, 244-8 (1956). (15H) Instituto Sational de Racionalisaci6n del Trabajo, Bol. insf. espa6. caucho 3, 97-8 (1957). (16H) Johnson, K. L , Rubber J . Intern. Plast. 134, 719-20 (1958). (17H) Jung, P., Kautschuk u . Gummz 11, K T 38 (1958); Kmststofe 48, 114 I
~
~
i 1 Q5R)
(ISH) Kline, D. E , J . Poluiner SCL.22, 449-54 (1956). 119H) Kouuelmann, J , Gutnniz u. Asbest. 9, 702 -(1956). (20H) Kuvbhinskii, E. V., Sidorovich, E. A , , Zhur. Tekh. F i t . 26, 878 (1956); Soviet Phys.-Tech. Phys. 1, 863-72 (1957); Kauchuk z Rezana 16, S o . 2, \ - - - -
40 (1957).
(21H) Payne, A . R., Rubber J . Intern. Plast. 134. 915 (1Y58). (22H) Ibid.,‘pp. 950, 964. 123H) Ibid.. D. 984. (24H) P a y n < -1. R., Smith, J. F., J . Sci. Instr. 33, 432-5 (1956). (25H) Reznikovskii, 11, 11..Vostroknutov. E. G., U.S.S.R. Patent 102,635; Byull. IzoGTeteni‘i, S o . 2, 31 (1956); Kaztchuk i Rezina 16, S o . 2, 40 (1957). (26H) Reznikovskif, 11. >I., Vostroknutov, E. G.,Khromov,31.K., “Starenie i Utomlenie,” pp, 68-75, 1953. (27H) Reznikovskii, AI. 11.)Vostroknutov, E. G., Pries, L. S., “Starenie i Ctomlenie,” pp. 76-88, 1953. (28H) Strella, S., Rei,. current Lit. Paint, Colour. Vamish and .4llied
j i 8 (1957).
Ind. 30,
S.,Sigler, H.. Chmura. hl., Holman, B., A S T J l ‘Bull., No: 228, 50-2 (1958). (30H) Tichava, 1I,, Chem. prdmysl 8, 268-72 (19%). 131H) Tobiishi, T., Natsui, S.,Fujimoto, K.. iYiv.non Gomu Ku6kaashi 30,87-1 03 (1957): (32H) Volodin, 1‘. P., Kushinskii, E. V., Prtbory i Tekh. Eksp., KO.2,94-8 (1957). (33H) Vostroknutov, E. G., Reznikovskif, M. hI., Zaz’odskaya Lab. 885-6 (1954). (34H) Ibid., pp. 361-4. (29H) Strella,
~
Hardness (1J) Bennett, F. K. B., Rubber J. 132, 280, 348 (1957). (25) Bird, V., Plastics (London) 22, 106 11957). (35) British Standards Institution, London, Spec. BS 903, Part D6, 1958. (45) Zbid., Part A7, 1957. (55) Deutscher Kormenausschuss D I N 7790, Berlin, 1956. (6J) Eller, S. A , , Rubber Age (IT. Y.)81, 460-4 11957). (75) Farbenfabriken Bayer A.-G., Tech. Notes Rubber Ind., S o . 23, 7-14, (1956); KO. 24, 7-12 (1957). (85) Frank, G. m. b. H., K., Brzt. Plastics 29, 350 (1956). (9J) Frank, G. m. b. H., K., Kautschuk u. Gurnmz 9, WT 236 (1956). (1OJ) International Organization for Standardization, Rubber Chem. and Technol. 31, KO. 1, xxv-xxix (1958). (llJ) Juve, A. E., Rubber Chem and Technol. 30, 367-79 (1957). (125) Maxwell. B.. U . S. Goet. Research Repts. 29, 319 (1958); PB 126745. (135) Morris, R. E., and Holloway, J. >I., A S T M Bull., S O .222, 45-50 i(1957). lQ.5i) (l4J) U.S.S.R. Komitet Standartov, X e r Izmerztel’nukh Przborov W T Z Sovete Mznzstrov SO&YE S.S.R. GOS‘T 7761-55
z
(1956). (l5J) Verein Schweizerischer Rlaschinenindustrieller, Zurich, VSM 77052,1956.
Abrasion and Tear (IK) h e r , E. E., Doak, K. IT., Schaffner, 0. J., Rubber Chem. and Technol. 31, 185 (1958); Rubber World 135, S o . 6, 876-885 (1957). (2K) Burton, R. €I., Herzog, R., Schwezz. Arch. 24, 63 (1958). (3K) Cardeiv, K. H. F Mon. Summ. Automot. Eng Lit. abs. ;7/10/16 (1957). (4K) Chasset, R., Thirion, P.. Reu. a h . caoutchouc 35, 165-i1, 451-6 (1958j. (5K) Chini, Sc., Carideng, S. A4., Ibid., 33. 881 119.56). (6K)’ Greensmith, H. W.,British Soc. of Rheology Conference, “Rheology of Elastomers,” 1lay 30-31, 1957. (7K) Gurney, W. A., Cheetham, I. C., Rubber Age 83, 126 (1958); Rubber World 138, 275 (1958). (8K) Haines, R. C., Coleman, C. R., Proc. Inst. Rubber Znd. 5 , 38-40 (1958). (9K) Hampe, E. A . , Kautschuk u.Gummi 10, TVT 141-5 (1957). (IOK) Instituto Kacional de Racionalizaci6n del Trabajo, Bol. znst. espaA caucho 2, 174, 176 (1956). (11K) International Organization for Standardization, I S 0 Recommendation ISO/R33 (1957) Geneva; Rubber Chem. and Technol. 31, No. 1, xiv (1958). (12K) Zbzd., ISO/R 34; xviii. (13K) Kainradl, P , Handler, F., Deut. Kautschuk-Ges Conference, Cologne, 11av 7-10, 1958 (14Kf Lukomskava, -4. I., ZCauchuk i Rezzna 16, Xo. 11, 4-9 (1957). (15K) Nash and Thompson, Ltd., Rubber Age (S. Y . ) 80, 140 (1956). (16K) Newton, E. B., Sears, D . S. (to B. F. Goodrich Co.), U. S. Patent 2,799,155 (1957). (17K) Prat, C., Rev. gdn. caoutchouc 34, 1122-6 (1957). (18K) Rubber-Stich. (Delft), Englebert iWagazzne 38, No. 250, 85-8 (1957). (19K) Verein Schweizerischer RIaschinenindustrieller, Zurich, V S K I 77051, 1956. (20K) Vervloet, C., Deut KaulschukGes. Conference, Cologne, May 7-10, 14552
(21K) Williams, I., Rubber Age (S. Y . ) 81, 95-6 (1957); Rubber World 136, 75 (1957).
Adhesion and Tack (1L) Am. Soc. Testing Materials, Philadelphia, Pa., Committee D-14 on Adhesives, “ASTM Standards on Adhesives (with Related Information),” 1957. (21,) Buist. J. 21.. Mevrick. T. J.. Staf‘ ford, R.’ L., Tians. ?nst.’ Rubbir Znd. 32, 149-67 (1956). (3L) Chang, F, S. C,, Abstracts of Papers, 3T, Division of Rubber Chemistry, 130th ;\leetine: ~ C S ,Atlantic Citvs “, X. J., SeptemLer 1966. (4L) Dayton Chemical Products Laboratories, Inc., Thixon ITews Letter, No. 1. 1-3
(19.5.5)
\ - - - - / .
(SLj Forbes, w. G., McLeod, L. A., Rubber Age (IT.Y . ) 81, 97 (1957); Rubber World 136, 77 (1957). (6L) International Organization for Standardization. I S 0 Recommendation ISO/R36 ’(1957); Rubber Chem. and Technol. 31, S o . 1, xxi (1958). (7L) Larsen, P. J., Rubber Age 82, 485-6 ilQ.57) ,---.
(8L) L e h i n , I. A., Korablev, Yu. G., Kornev, A. E., BobitskiI, B. L., “Prochnost’ Svyazi,” 173-83, 1954. (9L) Novopol’skif, V. I., Ibid., 196-200, 1954. (1OL) Pickup, B., Trans. Znst. Rubber Znd. 33, 58-70 (1957). (11L) Prentiss, S. S. (to Phillips Petroleum ‘20.).U. S.Patent2.762.219 (1956). ( 1 2 ~ PressLre ) Sensitive ‘T& ~ b i i i i ’ l , Publ. PSTC-9, Glenview, Ill., 1957. (13L) Zbid., Publ. PSTC-10. (14L) Reznikovskii, RI. AI., “Prochnost’ Svyazi,” 166-77, 1954. (l5L) Roberts, -4. G., Pizer, R . S., A S T N B u l l . . S O .221. 53-8 11957’1. (16L) Shapovalova, A . I., Voyutskii, S. S.,Pisarenko, A. p., Kollozd. Zhur. 18, 475-482, 455-93 (1956); Rubber Chem. and Technol. 31, 89 (1958). (17L) Tsydzik, 11..4.>Lukomskaya, -1.I., Slanimskii, G. L., “Prochnost’ Svyazi,” 201-11. 1954. (18L) U & - R . V., Gromova, L. S., Vasil’eva, S. A , , Zbzd., 184-95, 1954. (19L) Werren, F., Eickner, H. IT., JIodern Plastics 34, Yo. 4, 187-8, 190; 264 (1956). (20L) Wetzel. F. H., A S T M Bull., KO. 221, 64-8 (1957).
Electrical (111) British Standards Institution, London, Spec. B.S. 2050 1958, (1958). 1211) Deutscher Sormenausschuss, Kautschuk u. Gummi 11. 9-10, ~12. 14-15 ~- _ _ (1958); Spec. D I K 53596, il957). (3R4) Gooding, F. H. (to British Insulated Callenders’ Cables, Ltd.), British Patent 782,290 (1955). (4M) Heron, R., Dubois, P., Znd. plastaques mod. (Parzs) 9, S o . 9, 38-43 (1957); KO. 10, 60-1. (5M) Hoffman, J. D., Hart, J., Kat. Acad. Scz A-at. Research Councal 562,
vol 20, Publ. (1957). (611) Inter. Electrotechizzcal Commzsszon, Publ 93, Geneva (1958). (7R4) Kallweit, J. H., Kunststoge 47, 651-5 (1957). (8M) Sorman, R. H., “Conductive Rubber: Its Production, Application, and Test Methods,” RIaclaren & Sons, London, 1957. (911) Sorman, R. H., Rubber J . 131, 822, 824-7, 834, 871-2, 874-6 (1956). (1011) Zbid., 132, 274, 276-7, 284-5, 304-6, 308-9, 336-8, 340, 373-4, 376 119571. (11x1) Ratner, S. B., Lavrent’ev, V. V., Zhur. Tekh. Fiz. 26, 853-6 (1956). (1211) Rothert, H., Elektrotech. u. Maschinenbau 74, 326-35 (1957). (13Rl) Thevenou, H., Can. Patent 545,916 (1957).
(1411) Zernial, D., Kautschuk u. Gummi 10, WT 1-5 (1957). Low Temperature (1s)Craig, C. L., “Symposium on Minimum Prooertv Values of Electrical Insulating -~Ia~erials,” pp. 33-7 (1956); Rubber Abs. 35, KO. 6, 2741 (1957). (2S) Ed’vards, F. Engzneerzng lS5, 113 (1958). (3x1 Hanok, 11.9 Chatten, C. K., Lichtman. J. Z.. Rubber Aoe ( N . Y.)81. (4N) Hanok, AI., Lichtman, J. Z., Chatten, C. K., Adler G., Rubber Age 82,
275-85 (1957). (51) Ofner, R. E., C . S . Gout. Research Repts. 27, 30 (1957), PB 121502; Rubber World 136. 130 11957). ( 6 s ) U.S.S.R. Komitet Standardtov, Mer z Zzmerztel’ nykh Priborov Prz Sovete Jfznzstrov Soyuza S.S.R. Specn. GOST 7912-56. ( 7 5 ) Webher, A . C., A S T N B u l l , KO. 227, 40-4 (1958). Tire Testing (1P) Apps, D . C. (to General Motors Corp.), U. S. Patent 2,820,361 (1958). (2P) Beharrell, G. E., Rubber Deuelopments 1.1, 56 (1958). (3P) Benjamin, B. R., U. S. Patent 2,792,633 (1957). 14P) Carr. F. R.. Darr. R. F. (to DunloD . Rubber’ Co., ’ Ltd.j, British Paten’t 787,955 (1955). (5p) Close, IT., hIuzzey, C. L., hfon. Summ. Automot. Eng. Lit. 1956 ab8 56/12/45; Inst. Mech. Engrs., Automobile Diu.. advance CODV. November 1956. 47-68. (6P) constantakis, (2. V. (to United States Rubber c o ), c.S.Patent 2,798376 (1957). (7P) Enabnit, R. S. (to Goodyear Tire & Rubber Co.. Inc.). V. S. Patent 2,764,018 (1956). (8P) Fonda, A. G , Mon. Summ. Automot. Eng. Lzt. 1956 abs. 56/12/3 Inst. Mech. Engrs. Automobile Dzu., advance copy, Sovember 1956, 64-82. (9P) Frenzel, IT.> Kittelman, IT., Faserforach u. Teztzitech. 8, 222 (1957). (1OP) Froinandi, G., Clamroth, R., Oettner, K., Kautschuk u. Gummz 11, K T 83 (1958). (11P) Geesink, H. -1.0 . W.,Prat, C1. P.,Re&.gBn. caoutchouc 33, 973 (1956); Rubber Chem. and Technol. 31, 166 11958). (l2P) Gokhale, Y.C., Mon. Summ. Automot. Eng. Lzt. 1957 abs. 57/9/48 D.S.I.R. Road Research lab. note No. RN/2940/YCG Feb. 1957. 113P) Goodvear Tire & Rubber Co.. A “ I
mzberei’ung 33, S o . 10, 21 (1957). 116P) Milliken. W. F.. Whitcomb. D. K.,5Ion. Summ. Automot. Eng. Lzt. 1956 abs. 56/12/1 Znst. Xech. Engrs. Automobale Dz~t., advance copy, S o -
vember 1956, 3-25.
(17P) Prat, C., ReL. gCn. caoutchouc 34, 1122 (1957); Rubber Chem. and Technol. 31, 387 (1958). (18P) Riehl, T A Mon. Summ. Automot. Eng. Lzt. 1958 abs. 58/3/20, S.A.E.
Preprint, Kational Passenger Car, Body and Materials Meeting, March 4-6, 19.58
(liPT-Roberts, G. B., Gough, V. E., Rubber J . 131, 878 (1956). (LOP) Romani, L., Rev. ydn. caoutchouc 34, 1107 (1957). (21P) Stiehler, R. D., Gregg, A. P. (to U. S. Deoartment of Commerce). U. S. Patent 2,-766,618 (1956). VOL. 31,
NO. 4,
APRIL 1959
775
(22P) Thornley, E. R., Trans. Inst. Rubber Ind. 33,211 (1957). (23P) Zakharov, S. P., Sovopol’skir, \-. I., Trudy Sauch.-Zssledozatel’ Inst. Shznnoi Promyshlennosti Sbornak 3 Metody Rascheta i Ispytanzya A atonaobzl’nykh Shzn; U.S.S.R. Xauchno, plloscow, 1957, p. 139. Miscellaneous Andrew, E. H., J . Sci. Znstr. 34, 115-7 (1957). (2Q! Andrews, E. H., Kalsh, A,, ,Vature 179, 729 (1957). (3Q2) Baker, A . G., A p p l . Statist. 6, 45-55 (1Qi
i19.57) ~ ~ -,_ - .
(4Qj Berman, 11. L., Rachkulik, V. I., hauchuk i Rezina 16, S o . 12, 33-6
(1957).
(50)Blokh, G. il., Korniltseva, Z. P., Olshanskaya, L. Ll,> Kolobenin, V. N.,
T’estnik Elecktroprom. 27, S o . 6, 66-69 (1956); Rubber Cheni. a n d Technol. 31, 356 (1958). (6Q) Boguslrvskii, D. B., Tikhomirov, B. P., Bokharev, 4. I., Kauchuk i Rerina 16, S o . 12, 24-7 (1957). (7Q) Buist, J. LI., Rubber J . 132, 714-6 11 0.5? /-“I.,.
(8Q) Buist, J. N.,Rubber J . Intern. Plast. 134, 949-80, 982-3; 135, 5-7 (1958). (9Q) Chapqius. 11. AI.] Robblee, L. S., Rubber 11 orid 136,391-2. 436 (1957). (lOQ) Deutscher Sormenausschuss, Gummi u . Ashest 10, 122, 124, 126 (1957). Specn. D I S 53521, Draft of Februarv 1937. ( l l Q ) Drb;gin,I., Ruhher Age 83, 463-71 (1958). (12Q) Eagles, A . E., Payne, A. R., Rubber h Plasfics Age 38, 127 (1957). (13Q) Eccher, S., Deut. Kautschuk-Ges. Conference, Cologne, M a y 7-10, 1958. (I4Q) Finkel, E. E., Zhitr. Fir. Khim. 31, KO. 7, 1650-3 11957). (15Q) Frreman, L. N., Rubber W o r l d 138, 107-10 (1958). (16Q) Fujiwara, E. J.: Spain, R. G., Ibid., 136, 233 (1957).
Kecieu! of APPLIED ANALYSIS
(1957).
(24Q) Koide, T., Ilubota, T., Shimoda, T., ‘Yippan Goniu k‘!j&kaishi 29, 389-04
(19561. (25Q) Kraus, G., Rubber TT70ild 135, 67-73, 254-60 (1956). (26Q) Ilroplin, €I. C.. G. 111. h. H., Kaitlschuk ZL. Gummi 11, IVT 100 (1958). (27Q) Lagoni, H., lIerten, D., Salicrwissenschaflen 44, 10. 6: 177 (1957). (28Q) Lanzavecchia, 6.)X a f e r i ‘ e plastiche 23, 561-70 (1957). (29Q) Lesavre, J., Inr!. plastipices niod. (Paris) 8, S o . 10. 48, 51-2 (1956). (30Q) Mere, A,, Kunststofe 47, 69-73 (1957). Gilbert. B. I,.. Kal131Q) Michael. 1.. iniky, J. Id.)’Ind. Eng. Cheni. 49, 918 (19.57). (32Q) lliddleton, AI., Strvmson, W.d , Smith, D. B. (to Rolls-Royce, arid United Kingdom Aitomic Energy Authoritri. British Patent 782.752 11955). (33Q) A’Iikhlinj E. D., Zauodskai~a Lab. 23, S o . 12, 1466-71 (1957); Rejeiat. Zhzir. Khini. abs. 45264 (1958). (340) Sortham, A. J., Rubber Aiie .. (-T . Yr)80, 77-80 (1956). (35Q) Kovikov, A. S., Iloloskova, 11. V.) Kolloid. Zhur. 18, 321-5 (1956); Co!!oid J . (U.S.S.R.) (Eng. Trans.) 18, 311-5 11956). (36Q) Sovitskii, B. G., Fridmau, V. RI., Akust. Zhur. 3, S o . 1, 92-4 (1957). (37Q) Orlovskii, P; S . , Lukomskaya, A. I., Bogatova, S.I
