ANNUAL
G . A L L I G E R
REVIEW
F. C . W E I S S E R T
STATUS OF ELASTOMER TECHNOLOGY New synthetic rubbers, control of molecular structure, improved analytical methods, and increased understanding o f physical behavior-this review reports substantial progress ew commercial synthetic rubbers with unique structural features which demonstrated new and improved properties attracted the most attention in 1963. These elastomers owe their development to the revolutionary finding of the last decade that the molecular structure of polymers can be controlled with increasing specificity. Equally important, analytical tools are being devised to accurately characterize these polymers. At the same time an increased understanding of the relationships between such basic polymeric properties as glass temperature and the physical behavior of the elastomer is developing. Sparks (28A), in his 1963 Goodyear lecture, related the behavior of rubberlike materials to their chemical reactivity and molecular conformation. There is new emphasis on the consequences of polymer chain regularity, such as Rowzee’s recognition (23A) that the synthesis of a serviceable ethylene-propylene rubber requires the avoidance of long sequences of either monomer. The bibliography presented in this review follows that of Alliger ( 7 A ) and principally covers the period from March to December 1963. Extensive use was made of Rubber Abstracts in compiling this summary. I n place of an exhaustive evaluation of a limited number of references, this review includes tables of references to a large number of articles of interest. Specific mention is made of particular articles because of their importance or because they represent active areas of research in elastomers in 1963. Mark (734 74A) has reviewed the new developments in elastomer synthesis including high cis-l,4 polybutadiene and isoprene, EPR, and EPT, improved butyl, Hypalons,
N
36
INDUSTRIAL AND E N G I N E E R I N G CHEMISTRY
and neoprenes, fluoroelastomers, polyacetal and polyether elastomers. LeBras (72‘4) has summarized the recent advances in the chemistry and technology of rubber. Bateman (3A) has edited a book covering the extensive work of the Natural Rubber Producer’s Association on the chemistry and physics of rubber like materials. Elastomers
Diene H o m o - and Copolymers. Solution polymerized polyisoprenes and polybutadienes prepared w-ith stereospecific catalysts are finding increased usefulness where high abrasion resistance and low heat build-up are desired. The relatively narrow molecular weight distribution and linearity of these new elastomers are largely responsible for their superior performance. In uses of polybutadienes where high gum tensile strength is required a high purity of structure is desired (28B). The synthetic polyisoprenes are almost identical to natural rubber in structure and therefore have similar processing and vulcanization characteristics. Goodyear’s polyisoprene (Natsyn) (47B) handles like premasticated natural rubber. Shell I R 350 has been modified to produce increased green strength (35B). Poddubnyi (32%) reports that polyisoprenes made with lithium or Ziegler type catalysts are linear in structurd with little or no branching. The tensile strength and relaxation properties of polyisoprenes have been relatee to their structure by Hoffman (78B). Natta (28B) has set forth the structural characteristics of polybutadienes (e.g., a regular structure with a low melting point) which partially govern their elastomeric properties. He also states that the -1,4 structure is more flexible than the -1,2 structure. Blumel (5B) has compared the molecular structure with the polymer, compound, and vulcanizate properties of fourteen types Glen Alliger is Director of the Central Research Laboratories, T h e Firestone Tire @ Rubber Co., Akron, Ohio. F . C. Weissert i s Chemist in the polymer structure group of the same company.
AUTHOR
of polybutadienes, SBR, and natural rubber. Alfimov ( I B ) has measured the temperatures at which structural transformations occur for polyisoprene and polybutadiene. A new version of the alfin polybutadiene polymer was disclosed ( 7723) where excessively high molecular weight was regulated by the use of 1,4-dihydrobenzene, Cornel1 (44) sees a promising future as a general purpose rubber for cis-l,4-polybutadiene because of low raw material cost, the need for increasing supplies of rubber, and because it requires no major change in technology. The forecast for rubber consumption in the free world in 1975 in thousands of long tons is 2350 natural, 3350 SBR, 2800 stereorubbers, and 700 other synthetics. Burridge (8B) has compared polybutadiene, SBR, and natural rubber with respect to processing, tack, vulcanization, aging, resilience, wear. Solution polymerized polyisoprene and polybutadienes having achieved commercial success, it was not surprising that production of copolymers of butadiene with other olefins made in solution with anionic catalysts were announced. Firestone’s Diene 1000 (7623) and Duradene and Phillips’s Solprene X-40 and X-30 polymers were the first of such polymers available in semicommercia1 quantities. As in the case of the homopolymers, the structure of these new elastomers differs radically from that of emulsion polymerized SBR and hence will undoubtedly replace it in some uses. More thorough investigation of the production parameters of emulsion Svetlik SBR (7223) has led to improved properties. (24G) has shown that improved control is required to prevent the formation of a cross-linked fraction in high molecular weight SBR latex. Specification of a glass transition temperature, T,, greater than -35’ C. for the triad elastomer and a T , less than -355’ C. for the body stocks is said to produce an improved tire with good traction qualities (I3B). Mono-ene Elastomers, EPR,EPT,Butyl. In recent years, the modification of polyethylene by copolymerization with propylene to prevent a n undue degree of crystallization has resulted in a promising elastomer having good aging and weathering resistance.
TABLE 1.
GENERAL REFERENCES
7 A , 3 A , 6 A , 12A, 7 9 A , 2 8 A , 2 9 A 5A, I l A , 13A, 14A, 15A, 18A,25A 2A, 7 A , 9 A , 77A,27A 4A, l O A , 2 0 A , 2 2 A , 2 3 A , 2 4 A 8A, 16A,21A,26A
Reviews Synthesis Polymer science Applications Markets
TABLE I I .
DIENE POLYMERS AND CO POLYMERS
Polyisoprene Structure Polymerization Applications Chemical modifications
1
3B. 4B. 9B. 78B., 21B., 32B.’ 39B 23B, 26B, 27B 7B, 35B, 41B ZOB, 22B, 29B, 31B, 43B
I-
Poly butadiene Structure Polymerization Applications
IB, 5B, 8B, 77B, 288, 36B 15B, 24B, 25B 79B, 37B, 40B, 42B
Cobolvmers ‘Bd7S copolymer Bd/S graft Other
TABLE 111.
I2B, 73B, 16B, 34B, 38B 2B, 77B 6B, 30B, 33B
MONO-ENE ELASTOMERS, EPR, EPT, BUTYL
Ethylene Propylene Go- and Te7holvmar.s - .c - 2 - Structure Vulcanization Fillers and extenders Applications
~
1
1
ZC, 4C, 18C, 24C, 37C IC, IOC, IlC, 12C, 74C, 17C, 22C 5C, 26C, 27C 3C, 8C, 2IC, 23C, 28C, 32C
1
Butyl Rubber Vulcanization Fillers Applications
7C, 13C, 7 5 2 , 16C, 25C 6C, QC, 19C, 20C 29C, 30C, 33C, 34C
TABLE IV.
URETHANE POLYMERS
Structure Studies
50, 6 0 , 7 0 , 750,260, 300, 410
Books and Reviews
30, 330
Production Composition Foam stabilizers Processing
2 0 0 , 2 7 0 , 3 2 0 , 340 700,140, 2 3 0 , 3 6 0 8 0 , 220, 240, 420
Applications Flexible and rigid foams Elastic fibers Reduced cost Special properties
ID, 4 0 , 9 0 , 190, 280, 370, 3 7 0 , 380. 3 9 0 . 4 0 0 170, 2 7 0 , 250 180, 2 9 0 2 0 , 110, 120, 730, 16D, 350
VOL. 5 6
NO.
a
AUGUST 1964
37
Methods used for problems in plastics can be applied to other elastomers
TABLE V. HALOGEN, OXYGEN, NITROGEN, SU L FU R CONTA I N I NG ELAST0 M ERS
-
Halogen Neoprene and Hypalon Fluorinated elastomers
2E, lOE, 72E, 15E, 20E 5E, 16E, 17E, 18E
Oxygen Polyalkene oxides Polyacrylate
6E, 8E, SE, l I E , 14E IE, 4E, 13E
Sulfur Polysulfides
1
7E, 1QE
Vinyl pyridine Rubber
I
3E
TABLE VI.
INORGANIC ELASTOMERS
1
General Silicone Polymers General properties Structure and uses Vulcanization
8F, SF, 73F, 14F, 78F 2F, 4F, 72F, 15F, 16F, 17F 5F, 6F, 7F, IOF
TABLE V I I. General Rheological properties Tack and adhesion Injection molding Fluid bed vulcanization Cure rate apparatus
IF, 3F, 77F
!
TABLE V I I I .
Ingredients, Book
PROCESSING
IG, 2G, 12G, 17G, 79G, 23G, 2GG 6G, QG, 78G, 22G. 24G 3G, 21G, 25G 7G, 13G, 14G, IGG, 20G 5G, 10G 4G, 11G, 15G
COMPOUNDING
40H
~
Compounding in Solution
7 H , 27H, 32H
Oil Extension
71H, ZZH, 29H, 34H
Fillers Carbon black Silicas
2H, 4H, 16H, 21H, 26H, 28H, 38H 6H, 13H, 24H
Vulcanization Sulfur accelerator Peroxide Other cure systems
8H, 23H, 30H, 33H 14H, 77H, 36H, 37H 5H, 35H, 39H
Aging Effect of structure Antioxidants Antiozonants
12H, 25H IOH, 15H, 19H, 20H, 31H l H , 3H, 9H, 78H
TABLE IX.
WULCANIZATE TESTING
Methods Visco-elastic effects Hysteresis and failure effects Friction Applications
38
SI, 161, 241 41, GI, 701, 111, 771, 221 l I , 21, 31, SI, 12I, 141, 181, 231 ISI, 201 71, SI, 111, 131, 191, 211, 251, 261
INDUSTRIAL A N D E N G I N E E R I N G CHEMISTRY
Natta, in a n extensive review of polyolefin elastomers (78C), has described their synthesis and has related detailed molecular structure to the viscoelastic and other physical properties of the vulcanizates. The ethylene propylene copolymers are generally cured by means of peroxides. In the ethylene propylene terpolymers, such monomers as 2-alkylnorbornadiene (lOC), cyclo-octadiene ( 77C), and dicyclopentadiene (7SC) have been copolymerized into the elastomer in sufficient amounts to permit sulfur vulcanization. A new and unusual cross-linking system for EPR and EPT is the use of mono- and polyfunctional unsaturated monomers (in place of sulfur) in conjunction with peroxide (IZC, 14C). In compounding E P T rubbers for improved hot tear resistance, Adamek ( I C ) used a combined sulfur-peroxide cure plus an activated low structure black. Burgess (5C) obtained good reinforcement with heat promoted low structure black EPR masterbatches. EPR polymers respond well to oil extension (24C), an important factor in processing and cost considerations. The commercial EPR and EPT elastomers have outstanding resistance to ozone, heat, chemicals, and compression set, and have good abrasion resistance. Automotive design engineers find many promising applications for EPR and EPT in weather strip, wiring jackets, hose, floor mats, seals, engine mountings, and bumpers (8C, 27C, 33C). Zapp (34C) has written an excellent review on the viscoelastic properties of butyl rubber in relation to tire performance. The high skid resistant properties of butyl tires has been measured by Umland (29C). Resin cured butyl aircraft tires have been found (30C) to be promising for use up to 450” F. An active aspect of this development is the study of adhesive systems for butyl stocks and tire cords. Low structure carbon blacks, especially by solution masterbatch compounding, give better reinforcement of butyl rubber as well as with EPR and EPT (6C). At present, then, low structure blacks appear to be preferred for the mono-ene elastomers, while high structure blacks provide the desired properties with the diene rubbers. Heat treatment and heat treatment promoters of carbon black reinforcement of butyl rubber are continued fields of butyl compounding activity (79C, 20C). Several different halogenation reactions have been carried out on butyl rubber in order to step up the rate of sulfur vulcanization (7C, 13C). Urethane Polymers. Hicks ( 2 7 0 ) has given a resume of the development of polyurethane fibers by synthesizing structures with “a stable state of disorder’’ thus having a low modulus of elasticity and a high breaking elongation. Hick’s term “a stable state of disorder” closely specifies the structural characteristics
of any elastomer. (The other major feature concerns the crystallizability of the elastomer; cr ystalization may occur on stretching.) Whitman (470) has related urethane foam properties to polymeric structure as reflected in glass transition temperature, tensile strength, modulus and mechanical loss. Similar studies have interpreted modulus-test temperature relationships in terms of polymer structure ( 6 0 , 7 0 , 300). Such analytical techniques as x-ray diffraction (750) and infrared spectrometry ( 5 0 ) have been developed to characterize the structure of urethane polymers. The chemistry and technology of polyurethanes have been summarized in a book by Saunders and Frisch (330) and in review articles ( 3 0 , 4 0 , 380). Special isocyanate compositions have been developed so that one-shot formulations result in both foam expansion and cross-linking in one operation (270, 320). Silicone glycol copolymers have been developed for use as essential foam stabilizers and cell control additives for urethane foam (IOD, 740, 230, 3 6 0 ) . New low cost urethane elastomeric products have been developed which have good abrasion resistance and tear strength characteristics. They find use in solid tires, rollers, bearings, die pads, shock mounts, impellers, linings, and encapsulating compounds (780, 280). The major use of polyurethanes is the the commercial production of both flexible and rigid foams. The 1962 production of 171,000,000 lbs. have been projected to a 1965 volume of 310,000,000 lbs. (370). Patterson has compared rubber latex and urethane foam properties and production. Latex foam is still the most widely used material in commercial vehicles (280). Polyurethane foam has been "quilted" to textiles to produce materials for hard wear and industrial applications (400). Self erecting flexible polyether urethane foams have been found to be suitable for use in the space environment (390). Spandex, polyurethane elastic fiber, shows continued development and growth (770, 270, 250). Special modifications of polyurethanes have resulted in hydrolysis resistant ( 130), low temperature resistant ( 2 0 ), and flame resistant materials (ID).High specific impulse solid propellant compositions, with safe and controllable burning rates, have been based on polyurethanes (350). Polyether based urethane joint sealants have been developed with greater elongation, lower cost, and less susceptibility to attack by water than the corresponding polyester based urethanes (760). An interesting growth medium for plants has been disclosed in a polyurethane foam containing absorbed plant nutrients ( 9 0 ) . Elastomers Containing Halogen, Oxygen, Nitrogen, Sulfur. Oswald (75E) has shown that chlorinated polyethylenes can be considered as terpolymers of ethylene, vinyl chloride, and 1,2-dichloroethylene with the expected correlation between structure, glass transition temperature, and mechanical behavior. Conklin (3E) has outlined compounding principles for the development of neoprene and Hypalon compounds resistant to weather, heat, compression set, flame, fungus,
and abrasion. The mechanical properties of Neoprene Type W have been measured over the temperature range of -7O to 70" C. (20E). Maynard (72E)has also demmonstrated how the properties of elastomeric chlorosulfonated polyethylenes may be controlled by changes in the base polyethylene, chlorine content, chlorine distribution, and the choice of curing chemistry for the sulfonyl chloride cross-linking sites. Copolymers of vinylidene fluoride and hexafluoropropylene, exhibiting good heat and compression set resistance a t 400' to 600' F. are finding special uses in seals, gaskets, O-rings, valves, and tank linings (78E). Sharkey (76E) has polymerized thiocarbonylfluoride at - 80' C. to form an elastomer having good gum tensile strength and tear resistance. New alkylene oxide polymers polymerized to a high molecular weight and copolymerized with glycidyl ether (8E) may be vulcanized either by sulfur or peroxides (6E) to give commercially competitive elastomers. Polyacrylate elastomers are attracting new interest especially in response to the growing demand for heat resistant seals in transmission gears, because of the ability of the polyacrylates to resist sulfur-modified oils at temperatures over 350' F. (7E). Polyacrylates can serve as low cost replacements for fluorocarbons in many applications. Epoxy resins have been prepared by direct epoxidation of unsaturated polymers by peracetic acid in the presence of cation exchange resins to give epoxy rubber which forms films showing excellent adhesion to metal with good strength and elasticity (74E). The good abrasion resistance of vinyl pyridine modified rubber treads has been attributed to chemical rubber-to-filler bonds which are temperature dependent and can be erased a t 100' C. Effective elastomeric polysulfide sealants for the building industry and aircraft construction have been evaluated in terms of their chemical structure and crosslinking reaction (7E). Tobolsky (7923) has related cross-link variation with the viscoelastic properties of polyethylene tetrasulfide polymers. Inorganic Polymers. High temperature resistance is the major property that has stirred the present interest in inorganic polymers from P, N, Si, B, and Se containing monomers ( I F ) . Gimblett (77F) has demonstrated that the well established principles of organic polymer structure apply equally well to the field of inorganic polymer chemistry. Silicone elastomers, linear polymeric siloxanes containing hydrocarbon side chains, may be vulcanized in the presence of peroxy compounds. This vulcanization reaction has been studied with reference to the type and number of reactive side chains and the type and amount of peroxide catalyst (76F). Borisov (2F)has shown that ethyl phenyl siloxanes have better cold resistance and heat stability than diethyl siloxane vulcanizates. Greenfield (12F) reported on engineering research aimed at obtaining thermally stable silicone compounds for use on advanced aerospace vehicles. Tsou (75F) has pointed out the suitability for trimethylsilyl and triphenylsilyl VOL. 5 6
NO. 0 A U G U S T 1 9 6 4
39
modified silicas in the development of reinforced high temperature elastomers. Transparent silicon rubber containing dicyclopentadiene dioxide ( 78F) has been found to show improved stability toward atmospheric sulfur in windshield interlayers. R T V (room temperature vulcanizable) silicone elastomers are available in one or two part systems (6F). Some of these R T V systems are prepared from hydroxy endblocked diorganopolysiloxanes, acyloxy silanes, and magnesium oxide. A new class of R T V silicones has been produced which is free from the disadvantage of liberation of acetic acid during cure (77F). Preparation and Evaluation of Products
Processing. Kennaway (72G) has proposed that the classical methods of rheology, heat transfer, thermodynamics, and mathematics, which have formed the basis of an integrated attack on the processing of plastics, can be generalized to cover the processing of elastomers. The processability of elastomers has been related to chemical constitution, molecular weight, molecular weight distribution, and degree of branching. The results of such studies have been set forth by Spitsbergen (22G) and Devine (6G) for Neoprene, Einhorn (9G) for SBR, and Nichols (76G) for a series of raw polymers. The technical literature of 1963 contains numerous references to the measurement and interpretation of rheological studies made on polyethylene and polypropylene melts (9G, 77G, 23G, 26G). These papers suggest the experimental approach that can be (and is being) undertaken for similar rheological studies of rubbers. A great deal of interest was expressed in the possibilities for injection molding of rubber compounds (74G, 76G) with advantages in high speed production of lower cost and high quality products. This technique is of special importance for non-tire mechanical goods made from rubbers in competition with plastics. Sharpe and Schonhorn (21G) have stated that the criteria for thermodynamic spreading and for strong adhesion are the same. The polymer with the lowest possible surface tension would be the nearly universal adhesive. A new instrument for measuring tack has been developed by Bussemaker (3G). Compounding. One of the potentially important changes in mixing techniques is the direct addition of fillers to the rubber cements that arise from solution polymerization systems (27H, 32H). The degree of predispersion in the case of carbon black masterbatches derived from filler-polymer-hydrocarbon suspensions is greater than that obtained from latex carbon black masterbatches. Highly oil extended polybutadiene-SBR stocks have good tread wear, groove cracking, and heat degradation resistance (29H). Polybutadienes are now being marketed as oil extended polymers ( 7 7H). Naphthenic oils offer the best balance of properties in polybutadiene and natural rubber blends. Natural rubber treads having a high oil content have been developed (22"). The theory of rubber reinforcement by fillers continues 40
INDUSTRIAL A N D ENGINEERING CHEMISTRY
to receive considerable attention. Andrew ( 2 H ) has postulated that the high rupture resistance of reinforced rubber is the result of the reduction of stress a t the tip of the propagating crack due to mechanical hysteresis, The degree of filler dispersion (4H, 28H) and the structure of the carbon black (26H) have both been modified by an amine and chlorine treatment (27H) or by neutron radiation (76H) with improved abrasion resistance and hysteresis loss in reinforced vulcanizates. Clambroth (6H)has improved fine particle silica reinforced SBR compounds by high temperature mixing procedures. I t is claimed that Manomet 10, a zinc and aluminum complex linked to unsaturated fatty acids, improves the dynamic properties of silica filled SBR and natural rubber compounds. The delayed action sulfenamide accelerated curing system has been generally reviewed by Morita (23H) and has been evaluated in polybutadiene-SBR blends by Davis (EN). Studebaker (33H) has shown that a larger proportion of monosulfidic cross-links result from the vulcanization of cis-l,4 polybutadiene in comparison to natural rubber. Dicumyl peroxide exhibits different degrees of cross-linking efficienciesin natural and synthetic rubbers (74H, 77H, 36H, 37H). Tt'ith polyisoprene, one mole of cross-link is formed per mole of peroxide. With polybutadiene, the polymeric free radical attacks the double bond of another growing polymer chain, so that the ratio of cross-link density to initial peroxide concentration is much greater than unity. The cross-linking reactions of carboxylic elastomers have been summarized by Brown ( 5 H ) and resin curing systems for rubber have been reviewed by Thelamon (35H). Maleimide curing systems are claimed to produce rubbers with good high temperature resistance (39H). The protection of rubber against aging has been included in reviews by Kempermann (75H)and Lundberg (79H). Shelton (31H) has elucidated the mechanism for antioxidant activity in cis-l,4 polybutadiene. Parks and Lorenz (25H) have shown how the chemical nature of the network affects the rate of oxidation of vulcanizates. Andrews and Braden (ZH) have proposed that the rubber surface exposed to ozone is protected by a n ozonized layer 100 A. thick which is inert to further ozone attack. Certain antiozonants protect only against crack initiation and others retard the rate of crack growth. A heptyl-p-phenylenediamine has been said to be effective in all types of rubber, and to have low volatility and a low order of toxicity (QH). Vulcanizate Testing. The evaluation of such important vulcanizate properties as static and dynamic modulus, flow characteristics, resistance to rupture and abrasion, friction properties, and heat build-up are to an increasing extent being carried out as functions of the speed and temperature of the test (61). Watson (241)has reviewed the present status on the testing of rubbers. Parks (761)has presented a systematic classified review of the chemical and physical testing literature for 1960-62. Payne, Andrew, Waters, and Greensmith (71, 81,781, 231) have shown, in an important way, how the me-
chanical and failure properties of rubber may be related to the development of hysteresis. Good strength properties are generally achieved in compounds with high heat build-up characteristics, within the limits of polymer degradation. Livingston (721) has described a compact test instrument for determining indentation failure of a vulcanizate. Bueche (31) has developed a molecular theory of tensile strength which relates the ultimate properties of both unfilled and filled elastomers to the viscoelastic properties of the elastomer. The thermophysical profile of elastomers have been outlined by a variety of test methods in order to locate the transition temperatures which define the temperature range of viscoelastic properties (41,51, 701). Elastomeric compounds were sought for use in such special conditions as high temperatures (261), cryogenic (76’ to 300” K.) temperatures (791), space environment ( 7 7 1 ) , and in solid rocket propellants (71, 781). Recent laboratory findings indicate that rubber and asphalt blends are superior to asphalt alone in road surfaces (271). More extensive testing and evaluation of elastomers over wide ranges of test speeds and temperatures are providing data which can be used in choosing the appropriate elastomer for a given use. New understanding is coming forth as to the polymeric structures which produce a given set of mechanical properties. The polymerization chemists are developing the tools for the production of polymers of unique structure. The development of new and better elastomers continues. REFER EN C ES General (1A) Alliger, G., IND.ENC.CHEM.5 5 , No. 11, 52 (1963). (2A) Bamford, C. H., J.Appl. Chem. 13, 525 (1963). (3A) Bateman, L., ed., “Chem. & Phys. Rubberlike Substances,” Maclaren and Sons, Ltd., 1963. (4A) Cornell, P. W., Rubber Age 93, 606 (1963). (5A) Ibdd., p, 766. (6A) Glazer, J., Repts. Prog. Appl. Chem. 47, 859 (1962). (7A) Gordon, M., “High Polymers Structure and Physical Prop.,” IliffeBook Ltd., 1963. (8A) Hibbert, F. W., Trop. Sci. 5 , No. 2, 99 (1963). (9A) Inst. of Rubber Ind., Rubber Plastics Age 44, 691 (1963). (10A) Jago, D. G., Plastics Rubber J. 18, No. 217, 23 (1763). (11A) Kline, G. M., S . P . E . J . 19, No. 3, 278 (1963). (12A) LeBras, J., Rev. Gen. Caout. 40, 1501 (1963). (13A) Mark, H. F., Rev. Gen. Caout. 40, 1529 (1963). (14A) Mark, H. F., Rubber Age 93, 99 (1963). (15A) Messenger, T. H . , Proc. Fourth Rubber Tech. Conf. (1962). (16A) Mobius, K., Gummi, Asbest. Kunst. 16, 104 (1963). (17A) Nat. Research Council (U.S.A.) Publn. 995, Washington, D. C., 1962. (18A) Natta, G., Chim. Ind. (Paris) 89, 545 (1963). (19A) Natta, G., Mater. Plast. 29, 3 (1963). (20A) Ott, E. K., Rev. Gen. Caout. 40, abs. 601 (1963). (21A) Phillips, C. F., Rubber World 148, No. 5, 109 (1963). (22A) Rotgans, G . E., Plastics 28, No. 303, 100 (1963). (23A) Rowzee, E. R., Rubber Chem. Technol. 36, 26 (1963). (24A) Rowzee, E. R., Rubber Plastics Age 44, No. 7, 803 (1963). (25A) Rubber Research Inst. Malaya, Bulletin No. 66, 49 (1963). (26A) Ruebensaal, C. F., Rubber Plastics Age 44, 1172 (1963). (27A) SOC.Chem. Ind. Monograph 17, London (1963). (28A) Sparks, W. J., Rubber World 148, No. 1, 74 (1963). (29A) Watson, W. F., Catalyst 10, 28 (1963). Diene H o m o - a n d Co-Polymers (1B) (2B) (3B) (4B) (5B) (6B) (7B) (8B)
Alfimov, M. V., Nikol’skii, V. G . , Rubber Abstracts 41, abs. 6214 (1963). Allen, I., c t al., U. S. Patent 3,062,777 (Nov. 6, 1962). Beattie, W. H., Booth, C., J.Appl. PolyrnerSci. 7, 507 (1963). Binder, J. L., J . PolymerSci. A l , 37 (1963). Bliimel, H . , Kautschuk Gummi 16, 571 (1963). Boguslavskii, D. B., et ai., Soviet Rubber Tcchnol. 21, No. 12, 15 (1962). Bruns, V. R., Rubber World 149, No. 2, 98 (1963). Burridge, K . G., Rubberplastics WkIy. 144, No. 22,720 (1962).
(9B) Cooper, W., Smith, R. K., J . PolymerSci. Al, 159 (1963). (10B) Crespi, G., Flisi, U.,Mokromol. Chcm. 60, 191 (1963). (11B) Crompton, T. R., Reid, V. W., Ibid., p. 347. (12B) Duck, E. W., Chem. Ind. London 33, 1393 (1963). (13B) Dunlop Rubber Co., Brit. Patent 929,302 (June 19, 1963). (14B) East, G. C., others, PoIymcr4, 139 (1963). (15B) Fetters, L. J., Diss. Abstr. 23, 230 (1963). (16B) Firestone Tire and Rubber Co., Chem. Eng. News 40,19, 42 (1962). (17B) Hansley, V., Greenbcrg, H., Rubber Abstracts41, abs. 6849 (1963). (18B) Hoffman, M., Unbehend, M., Rubber Chem. Technol. 36,815 (1963). (19B) Klingender, R . C., Polymer Corp. Sarnia, Ont. Tech. Report 63:38 (1963) (20B) Koessler, I., others, Inter. Symp. Macromol. Chem., Paris, No. 36 (1963). (21B) Koessler, I., Vodehnal, J., J . Polymer Sci. B1, No. 8, 415 (1963). (22B) Loan, L. D., RubberDevelop. 16, No. 2, 45 (1963). (23B) Mayor, R . H., others, U. S. Patent 3,047,559 (July 31, 1962). (24B) Mazzei, A,, others, J. Polymer Sci. B1, 79 (1963). (25B) McCall, A., others, Rubber World 148, No. 2, 31 (1963). (26B) Minoux, J., Makromol. Chcm. 61, 22 (1963). (27B) Morton, M., Bostick, E. E., Clarke, R. G., J . Polymer Sci. A l , 475 (1963). (28B) Natta, G., Rev. Gen. Caout. 40, 785 (1963). (29B) Natural Rubber Prod. Assoc., Brit. Patent 939,350 (Oct. 16, 1963). (30B) Nikitin, V. I., others, Soviet Rubber Technol. 2 1 , No. 8, 2 (1962). (31B) Pinazzi, C., others, Reu. Gcn. Caout. 40, 1341 (1963). (32B) Poddubnyi, I . J., Erenburg, E., Rubber Chcm. Technol. 36, 807 (1963). (33B) Porri, L., others, Makromol. Chcm. 61, 90 (1963). (34B) Ross, E., Phillips Chem. Co. Report 640-P-63 (1963). (35B) Schue, F., Dole-Robbe, J. P., Rubber Abstracts 42, abs. 762 (1964). (36B) Shell Chcm. Co., Tech. Bull. SCR 62-101 (1962). (37B) Short, J. N., others, Rev. Gin. Caout. 40,253 (1963). (38B) Short, J. N., U. S. Patent 3,094,512 (June 18, 1963). (39B) Teitelbaum, B. Y . , others, Souiet Rubber Technol. 21, 4 (1962). (40B) Thorsrud, A,, Kautschuk Gummi 16, 560 (1963). (41B) Todd, R. V., Rubber Age 94, 302 (1963). (42B) Wallace, E. H., SAE No. SP-244 (1963). (43B) Wallenberger, F. T., Special Publn. Rubber Chem. Technol. 36, 558 (1963). Mono-ene Elastomers, EPR, EPT,Butyl (1C) Adamek, S., Dingle, A. R., Woodhams, R. T., Rubber Age 93, 100 (1963). (2C) Baccaredda, M., Butta, E., Frosini, V., Makromol. Chem. 6 1 , 14 (1962). (3C) Bliimel, H., Paul, H., Schleich, G., &utschuk Gummi. 16,369 (1963). (4C) Bombaugh, K. J., Cook, C. E., Clampitt, B. H., Anal. Chem. 35,1834 (1963) (5C) Burgess, K. A., Thune, S., Palmesi, E., Rubber Age 93, 595 (1963). (6C) Columbia Carbon Co., Rubber Age 94, 463 (1963). (7C) Dudley, R. H . , Enjay Chem. Co., Tech. Inform. B-74 (1963). (8C) Gardner, A. R., Product Eng. 34, No. 9, 46 (1963). (9C) Gessler, A. M., Payne, A. R., J . Appl. PolymerSd. 7, 1815 (1963). (1OC) Gladding, E. K., Nyce, J. L., U. S. Patent 3,063,973 (Nov. 13, 1962). (11C) Haxo, H. E., others, Rubber Age 94, 255 (1963). (12C) Howarth, J. T., Cornell, J., Rubber Age 93, 99 (1963). (13C) Kuntz, I., U. S. Patent 3,091,603 (May 2 8 , 1963). (14C) Lenas, L. P., Rubber World 148, No. 1, 75 (1963). (15C) Mincker, L. S., Jr., Cottle, D. L., Lemiska, T., U.S. Patent3,080,337 (March 5, 1963). (16C) Mitchell, J.M.,others, Rubber World148,No.1,72 (1963): (17C) Natta, G., others, Rubber Age 93, 96 (1963). (18C) Natta, G., others, Rubber Chem. Technol. 36, 1583 (1963). (19C) Naylor, R. A,, U. S. Patent 3,070,571 (Dec: 25, 1962); (2OC) Payne, A. R., J . Agpl. Polymer Sd. 7 , 873 (1963). (21C) Peffer, P. A., Rubber Abstracts 41, abs. 4368 (1963). (22C) Roche, I. D., Rubber Age 93, 921 (1963). (23C) Schoenbeck, M . A,, Rubber Agc 94, 292 (1963): (24C) Scott, C. E., Rubber World 149, No. 3, 64 (1963). (25C) Serniuk, D. L., others, U. S. Patent 3,081,284 (March 12, 1963): (26C) Sieron, J. K., Rubber World 149, No. 1, 58 (1963). (27C) Sierra Talc Co., Publn. Rubber 48 (1962). (28C) Sutton, M. S., Rubber Age 94, 293 (1963). (29C) Umland, C. W., others, Mon. Summ. Automob. Eng. Lit. 9, abs. 13 (1963). (30C) Van der Burg, S., Manchette, J. G., Rubber Age 93, 594 (1963). (31C) Van Schooten, J., Mostert, S., Polymer 4, 135 (1963): (32C) Waddell, H. H., Auda, R . S.,Fusco, J. V., Rubber Agc 94,427 (1963): (33C) Yoran, C. S., Rubber Abstracts41, abs. 4364 (1963). (34C) Zapp, R . L., Reu. Gen. Cooui. 40, 265 (1963): U r e t h a n e Polymers (ID) Anderson, J. J., IND. ENQ.CHEM.Prod. Res. Deuel. 2, No. 4, 260 (1963). (2D) Axelrood, S. L., Lajiness, W. J., U . S. Gov’t. Res. Rept. 38, No. 9, 45 AD295909 (1963). (3D) Boor, M., Chem. Can. 12, No. 10, 35 (1960): (4D) Buist, J. M., Rubber Plastics Wkly. 145, No. 12, 382 (1963). (5D) Burns, E. A,, Anal. Chem. 35, 1270 (1963). (GD) Cusano, G. M., others, Inter. Symp. Macromol. Chem., Preprint 66, Paris (1963). (7D) Darr, W. C., others, IND.ENC.CHEM.Prod. Res. Deuel. 2, No. 3, 194 (1963). (8D) DiPinto, J. G., others, E. I. du Pont de Nemours & Co., Inc., Adiprene Rubber Bull. 3 (1963). (9D) Dow Chemical Co.;Dow Diamond 26, No. 2, 1 (1963). (10D) Dow Corning Corp., Rubber Agc 93, 627 (1963); (11D) Elmer, 0. C., Schmucker, A. E., Rubber World 148, No. 1 , 7 4 (1963). (12D) Farbenfabriken Bayer A. G., Brit. Patent 926,766 (May 22,1963). (13D) Ibid., Brit. Patent 933,683 (Aug. 8, 1963).
VOL. 5 6
NO. 0
AUGUST 1964
41
(14D) Ibid., German Patent 1,144,475 (Feb. 28, 1963). (15D) Flocke, H . A., Koll. Zeits. 188, S o . 2, 114 (1963). (16D) Fosgate, C. M., Jr., Building Res. Inst. Publn. No, 1006, 115 (1963). (17D) Frazer,A. H., Shivers, J. G., Jr., U. S. Patent 3,071,557 (Jan. 1, 1963). (18D) Goldschmidt, T., German Patent 1,148,740 (May 16, 1963). (19D) Hallinar, M. R., others, S P E Tech. Papers 8, Paper 4 (1962). (20D) Hannoosh, M. M., Rubber Plastics Age 44, No. 6, 683 (1963). (21D) Hicks, E. hl., Fares, B. F., Amer. Dyestufl Reptr. 52, No. 1, 18 (1963). (22D) Klotz, M. A,, others, Rubber Age 93, 595 (1963). (23D) Mobay Chem. Co., Brit. Patent 923,403 (April 10, 1963). (24D) Ibid., “Processing Manual-Multrathane F-66,” Pittsburgh, Pa., (1962). (2iD) Moncriefl, R. W., Text. Mfr. 88,404 (1962). (26D) Oberbach, K., Kunstufe53,358 (1963). (27D) O h , J. H., IND.END.CHEM. 55, h-0. 9, 48 (1963). (28D) Patterson, P. D., Rubber Abstracts 41, abs. 5080 (1963). (29D) Phoenix Gummiwerke A. G., German Patent 1,146,249 (March 28, 1963). (30D) Polyakov, Y. N., Tarakanov, 0. G., Rubber Abstrncts41, abs. 5729 (1963). (31D) Reeves, J. F., Rubberplastics Age 44, No. 6, 683 (1963). (32D) Sandridge, R. L., others, SPE Trans. No. 2 , 117 (1963). (33D) Saunders, J. H., Frisch, K. C., “High Polymers Vol. XVI,” Interscience, New York, 1962. (34D) Smith, H . A,, J. Appl. Polymer Sri. 7, 85 (1963). (35D) Thiokol Chem. Corp., Brit. Patent 927,612 (May 29, 1963). (36D) Union Carbide Corp., Silicone Divn., Bull. 45-6 (1962). (37D) Urethane Institute, Rubber Age 93, 294 (1963). (38D) Valthier, E,, Rev. Gen. Caout. 40, 595 (1963). (39D) Vaughan, V. L., Jr., Hoffman, E. L., Rubber Abstracts 41, abs. 7069 (1963). (40D) Weinstock, L., Man-Made Textiles 38, No. 444, 46 (1961). (41D) Whitman, R . D., others, Rubber Plastics Age 44, No, 6, 683 (1963). (42D) Witco Chem. Co., Tech. Service Bull. F-8, Iiew York, (1962). Elastomers Containing Halogen, Oxygen, Nitrogen, Sulfur Brucksch, W. F., Jr., Rubber World 148, No. 1, 75 (1963). Chem. Eng. News 41, No. 46, 27 (1963). Conklin, R . N., Rubber News 11, No. 6, 21 (1963). d’Adolf, S. V., Rubber World 148, No. 6, 43 (1963). (5E) Doede, C. M., Rubber Age 93, 411 (1963). (GE) General Tire and Rubber Co., Brit. Patent 941,959 (Nov. 20, 1963). (7E) George, D. A., others, Adhesives Age 6 , No. 2, 32 (1963). (8E) Gurgiolo, A. E., others, Rubber Age 93, 101 (1963). (9E) Hendrickson, J. G., others, IND.ENC. CHEM.Prod. Res. Develop. 2, No. 3, 199 (1963). (10E) Karmitz, P., Rev. Gen. Caout. 40, 605 (1963). (11E) Lal, J., McGrath, J. E., Rubber World 148, No, 1, 75 (1963). (12E) Maynard, J. T., Johnson, P. R., Rubber World 148, No. 1, 75 (1963). (13E) Mendelsohn, M . , Rubber Age 93, 594 (1963). (14E) O’mel’chenko, S. I., others, Rubber Abstracts 41, abs. 5454 (1963). (l5E) Oswald, H . J., Kubu, E. T., S P E Tech. Papers 9, Paper 1 (1963). (16E) Sharkey, W. H., Chem. Enj. News 41, No. 38, 46 (1963). (17E) Sieron, J. K., Rubber World 148, No. 1, 77 (1963). (18E) Stivers, D. A , , Lanin, P. D., Rubber Age 93, 592 (1963). (19E) Tobolsky, A. A,, others, J . ColloidSci. 18, No. 4, 353 (1963). (20E) Yin, T . P., Pariser, R., J. Appl. Polymer Sci. 7, 667 (1963). (1E) (2E) (3E) (4E)
Inorganic Elastomers (1F) Appl. Plastics 6 , No. 7, 14 (1963). (2F) Borisov, S . N., others, Soviet Rubber Technoi. 21, No. 6, 3 (1962). (3F) Breed, L. W., Elliot, R. L., U. S.Gob’t. Res. Rept. 38, No. 8, 46 AD-294196 (1962). (4F) Burdick, D. F., Pollmanteer, K. E., U. S. Patent 3,094,446 (June 18, 1963). (5F) Dow Corning Corp., Rubber Age 93, 109 (1963). (6F) Ibid., Bull. 08-034 (1963). (7F) Ibid., Brit. Patent 933,417 (Aug. 8, 1963). (8F) Ibid., Bull. 09-004 (1963). (9F) General Electric Co., Silicone Prod. Tech. Data S-1A (1963). (10F) Ibid., Rubber Age 93, 134 (1963). (11F) Gimblett, F. G. R., “Inorganic Polymer Chem.,” Butterworth & Co., London (1963). (12F) Greenfield, G. L., U.S.Gout. Res. Rept. 38, No. 4, 66, AD-28794 (1963). (13F) Roesler, H., Piaste. u. Kaut. 10, No. 7, 394 (1963). (14F) Swain, J. W., Mathis, J. R., U.S. Gout. Res. Rept. 38, S o . 4, 65, AD-287969 (1963). (l5F) TEOU, K. C., Goldey, R. N., U. S. Gout. Res. Rept. 38, No. 8, 48, AD-294770 (1963). (1GF) Union Carbide Corp., Silicones Divn. Bull. 90-15 (1963). (17F) Warrick, E. L., U. S. Patent 3,090,738 (May 21, 1963). (18F) Youngs, D. C., Konkle, G. M., Rubber Age 93, 592 (1963). Processing (IG) Baccaredda, M., others, IUPAC Inter. Sym. Macrmol. Chem. Preprint 58, Paris (1963). (2G) Baur, C., Rev. Gin. Caout. 39, 361 (1962). (3G) Bussemaker, 0. K. F., Rubber Age 93, 589 (1963). (4G) Claxton, W. E., Liska, J. W., Rubber Age 93, 590 (1963). (5G) d’Adolf, S., Rubber World 149, No. 1, 45 (1963). (6G) Devine, F. E., Ross, J. A., Trans. I.R.I. 39, No. 6, T314 (1963). (7G) Dorko, Z . J., others, Rubber World 148, No. 1, 77 (1963). (8G) Einhorn, S.C., Rubber World 148, No. 5, 40 (1963). (9G) Einhorn, S. C . , Turetzky, S. B., Rubber Age 93, 590 (1963). (10G) Humpridge, R. T., Rubber and Plastics Age 44, h‘o. 3, 287 (1967). (11G) Juve, A. E., others, Rubber World 148, No. 4, 86 (1963). (12G) Kennaway, A,, RubberAge 93, 588 (1963).
42
INDUSTRIAL AND E N G I N E E R I N G CHEMISTRY
Lane, R . G., Rubber Age 93, 915 (1963). Mason, P.Y., Rev. Gen. Caout. 40, 748 (1963). Monsanto Chem. Co., Chem. Eng. News 41, No. 19, 59 (1963). Morisson, B., Rev. Gen., Caout. 40, 1292 (1963). h-ichols, P. iM., Kienle, R . N., Clifton, M. C., Rubber Age 93, 591 (1963). Pearson, J. R . A , , Devine, F. E., Rubber Age 93, 588 (1963). Peticolas, W. L., J . Chem. Phys. 39, 3392 (1963). Prat, C., Rev. Gcn. Caout. 40, 737 (1963). Sharpe, L. H., Schonhorn, H., Chem. E n g . A‘ews 41, No. 15, 67 (1963). Spitsbergen, J. C., Rubber Bge 93, 591 (1963). Stevens, E. T., “Rheology of Polymers,” Reinhold, New York, 1963. Svetlik, J. F., others, Rubber M’orld 148, KO. 4, 85 (1963). Voyutskii, S. S., Vakula, V. L., J . Appl. Polymer Sci. 7, 475 (1963). Westerman, L., J . Polymer Sci. A l , No, 1, 41 1 (1963). Compounding (1H) Andrews, E. H . , Rubber Chem. Technol. 36, 325 (1963). (2H) .4ndrews, E. H., Braden, M., J. Appl. Polymer Sci. 7, 1003 (1963). (3H) Bergstrom, E. 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