an l ~ ] B l a t e r i a lofs Construction Review
by Raymond B. Seymour, Sul Ross State College, Alpine, Tex.
Plastics industry growth continues, despite business recession Functional uses a n d unique properties continue to be emphasized Sizable quantities of engineering plastics a r e being produced
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BUSINESS R E C E S S I O ~ which occurred during the past year affected the plastics industry in many ways. However, in spite of low prices and low profit margins, the growth of the plastics industry continued. While “engineering plastics” were emphasized, the growth of the billion pound plastics (olefin, vinyl chloride, and styrene polymers) continued. I t has been predicted that these three plastic types will account for about 607, of the 8 billion pounds of plastics produced in 1965. The total use of “engineering plastics” [acrylonitrile-butadiene-styrene (ABS), polyacetals, polycarbonates, polyoxetane, and nylon] should be about one half billion pounds in 1965. I t is significant that the growth of these tough materials is independent of the general purpose plastics The engineering plastics are replacing other accepted functional materials of construction. World-wide production of plastics paralleled growth in the U.S.A. This nation produced about 507, of the 15billion-pound total. West Germany, the United Kingdom, and Japan ranked second, third. and fourth. Significant advances were made in plastics education. technical publications, technical expositions, and large scale uses of plastics in structural applications. Los Angeles Trade Technical College and New York State University started two- and four-year courses in plastics technology. A traveling exhibit of plastics in building was sponsored by the Society of Plastics Engineers. New plastic journals were introduced in several countries. M a d e of Plastxr, a three-language publication (English, French, and German), was announced. Over 100,000 feet of plastic pipe and 10 acres of cellular plastic sheet were used in the construction of the United Kingdom’s largest office building. T h e pipe was in sizes u p to 6 inches in diameter and included poly(viny1 chloride), high and low density polyethylene, and nylon. This review includes significant developments in the plastics industry during the 12-month period ending June 1, 1961.
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Design and Engineering
Plastics, like all other materials of construction, creep when subjected to stress. Many past failures of plastic structures resulted from a lack of knoivledge of stress, strain, temperature, and time relationships for specific plastic materials. Fortunately, sufficient design data are now available to minimize the chance of underdesign and to reduce the need for overdesigned structures. I n addition to case history data covering periods as long as 20 years (22), the design engineer now can benefit from many new tests and standards which assure uniformity (29)and aid in predicting performance (66). I n addition to tests comparable to those used for other structural materials, a method based on the evolution of heat during swelling in solvents was proposed (39). I n the past, some engineers have criticized the industry because of lack of design data. ’Today, the industry questions why more engineers have not recognized the design possibilities inherent in plastics materials (87).Thus. the need for classical mortar joints and other accepted methods of construction are being scrutinized. I n contrast, helically wound fuel tanks holding 3100 gallons a t a pressure of 665 p.s.i. are now specified for rocket fuel tanks. Comparable modern functional design has created many other structures essential for the space age (52). Other new developments in design may result from a study of nature’s approach to reinforcements (53). Fortunately, new materials as well as structures may be designed. I t is now possible to graft new groups on natural polymers as well as synthetic plastics. For example, amine and carboxyi groups can be built on the polymer molecule. These can then be reacted further undei controlled conditions. Strucfural Application of Plesfics
New applications of plastics as structural materials range from standard molded plastic tanks to the aquarium a t the Brookfield Zoo: Chicago, Ill. Tanks range in size from polyolefin detergent
INDUSTRIAL AND ENGINEERING CHEMETRY
dispensers IO 100,000-gallon dracories The latter are forerunners of tanks at least 10 times this size. This type of tank has already been used for storage as well as transportation. A report on many phases of structural plastics has been published (64). Tanks u p to 12 feet in diameter have been constructed by filament winding. However. a stainless steel helical winding has been proposed as a n external reinforcemenr for all large plastic tanks. T h e use of vinyl liners for reinforced plastic structures has been proposed. The size of plastic stacks continues to make news. Yet, vinyl and reinforced plastic stacks u p to 40 inches in diameter and 200 feet in height have been in service for over 10 years. Reinforced plastic stacks 72 inches in diameter were installed in 25-foot sections last year. The tallest reported was 150 feet high. Regardlesq of originality these stacks are now commonplace and perform as expected. Plastic lined pipe which has been used successfully for over 25 yeari continues to be rediscovered. Newer linings of polyfluorocarbon and polyoxetane are more resistant than saran Large molded scrubbers arc commonplace. Plastic grids, molded oxetanc pumps, and metering devices are standard equipment. Acrylic structures have low absorption for T V beams and ara ideal for broadcasting. Sand has been stabilized by the addition of plastics (26). Modern iron casting technology has been improved by adding epoxy resin to surfactant-treated sand (64). A new roof design has been devised through the use of sectional cellular plastic paraboloids Reinforced Plastics
The design of a n all plastic rocket has been studied. Obviously, most of the material considered from the solid propellant to the phenolic nose cone is One classified as reinforced plastic. of the more important problems, adhesion of filler and resin, is still being studied, and progress is being made. The necessity of control of variables
a n m d Materials of Construction Review
has been recognized and is not being overlooked. T h e need for reinforcing fiber unaffected by moisture and high temperature has also been recognized. A new organic fiber (Pluton) which does not melt a t 18,000' F. has been announced. Tensile strength in excess of 120,000 p.s.i. has been observed with quartz fiber-reinforced plastics. A more critical look a t standard tests for reinforced plastics has been recommended (73). T h e state of the art in filament winding has been reported (96). Actually, the space age is the reinforced plastic age. This type of plastic is used for rotor blades, jet engine parts, compressor housing, radomes, radar reflectors, and nose cones. T h e total production of reinforced plastics in this country was less than 250 million pounds last year. Yet, conservative estimates predict that the use will double by 1965. Over 60% of the present production is used in construction of buildings, boats, and vehicles. Interest in polyester-methyl methacrylate reinforced plastics (5) and finishes for the glass reinforcement continues (78). However, recent developments with high-modulus glass fiber indicate that such reinforcements can be independent of finish. Hollow glass fibers have been proposed as fillers for light weight plastics. Levy (60) has championed reinforced plastic pipe and compared anticipated performance with nonreinforced pipe. Additional data on the effect of water on long term strength have been published (65). Heat Resistant Applications
T h e many successful space age accomplishments are monuments to advances in the technology of heat-resistant plastics. New developments have been reported in both resins and their reinforcements. T h e results of studies on the relationship of molecular structure to heat resistance were reported (86). Additional information on heat-resistant epoxy and phenolic resins has been published. Inorganic modifications of phenolic resins continue to be of interest (55). Marvel (63) has prepared heat-resistant resins by solid state polymerization of diaminobenzene and diphenyl isophthalate. These polyimidazoles are soluble in dimethyl sulfoxide, exhibit high strength a t 400' F., and lose hydrogen and cross link a t 800' F. A polycaprolactam film with ablative properties has been reported (36). Plastic Film and Sheet
T h e use of plastic film continues to increase. I t is estimated that almost one half billion pounds of transparent
plastic film will be consumed in 1965. Considerable water is being saved through the use of film as liners for irrigation ditches. Reservoirs and lagoons with capacities u p to 6 million gallons of water have been lined with film at Lancaster, Calif., Edmonton, Alberta, and in Australia (84. Vinyl-coated nylon fabric continues to be used for air-supported structures and inflatable dams. Air-supported structures 50 feet in diameter have been constructed. The capacity of a reservoir in Hawaii was increased by 500 million gallons through the use of an inflatable plastic dam. Polyethylene sheet can be adhered to copper plated steel (7). Microporous sheet has been produced by molding mixtures of low melting solids and phenolic resins (57). T h e use of vinyl-clad steel is now well established. Poly(viny1 fluoride) as well as poly(viny1 chloride) is being used in this application. Polyester film is now being laminated to plywood and other surfaces. A strong polyester film, poly( 1,4-cyclohexylenedimethylene terephthalate), is now available (93). Cellular Plastics
T h e use of cellular plastics has created a revolution in boat building. For example, the total weight of the nuclear powered submarine SS Skipjack was reduced by almost 10 tons. This was accomplished through the use of eight tons of polyurethane foam as insulation on the reactor core of the power plant. Extruded paperlike polystyrene foam is now available. A comparable technique has been applied to coated fabrics. Cellular polystyrene roof structures which require very little support are of considerable interest to architects. Steel sheet with a backing of polystyrene foam and sandwiches of foam glass and cellular polyurethane are available. Cellular products based on almost every available plastic have been described. Flame-proof properties have been incorporated by the addition of fillers (74) or by the reaction with halogens. Rubber latex foams have been improved by irradiation of the latex.
Potential creativity with plastic foams was demonstrated by the construction of a 15-foot cellular plastic statue for the American Bowling Congress. Polystyrene foam of controlled density is now being extruded (23). The use of foamed adhesives has reduced costs in plywood manufacture (34). The insulation of a 10,000-gallon wine tank with a 2-inch-thick sprayed polyurethane foam has been described (75). It has been estimated that 300 million pounds of this type of cellular product will be produced in 1965. Plastic Pipe
Because plastic pipe is now an accepted type of construction, large installations are no longer newsworthy A 53-mile length of reinforced submarine pipe with an inside diameter of 4.85 inches is conveying gas from Vancouver, British Columbia, to Vancouver Island; 300 tons of poly(viny1 chloride) was used for the inner liner. Polyethylene pipe was wrapped with strips of lead so that it rested on the bottom of a lakr at Milton, Vt. Twenty three miles of plastic pipe and 50 miles of nylon tubing was used in the construction of a new office building in London. Two miles of vinyl pipe u p to 4 inches in diameter was installed in a dairy in Illinois. Four miles of vinyl pipe has given satisfactory service for three years while conveying uranium concentrates in New Mexico. Four miles of ABS plastic pipe in 40foot lengths was installed in Orange County, Calif. Metal pipe is now being lined and clad with plastics. A pipe lined with polyethylene tubing measuring 42,000 feet was installed in Warren, Pa. The trend toward longer lengths of rigid pipe continues. A joining method which consists of shrink fitting by heating over a flexible ring insert has been described. Work on establishing pipe standards continues. There are now over 25 standards in the U.S.A. Some firms are giving a five year warranty with their pipe. Expansion and stretching during the extrusion process can increase strengths
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Clip and mail coupon on reverse side VOL. 53, NO. 10
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Materials of Construction Review
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by 100% (43, 74). Reinforced pipe can be made in continuous lengths (49,83). While water has a n effect on lubricants, stabilizers, emulsifying agents, and other components of pipe, moisture absorption should not be considered as a criterion of bursting strength (97). Van der Wal (92) believes that the heat distortion temperature is more important than water absorption. Plastics vs. Corrosion
T h e obvious functional use of plastics in corrosive atmospheres is now being accepted as engineers become acquainted with essential information now available. Recent graduates, of course, possess this knowledge, but too few engineers recognize the need of continued study. The knowledge of heat resistant plastics has been accumulated a t a rapid rate because of the space age emergency. A similar situation exists in industry, which is wasting a billion dollars annually in corrosion losses. Fortunately, more engineers are recognizing that the use of plastics can reduce this loss by many millions of dollars. Case histories of the use of reinforced plastics in corrosive environments have been reviewed ( 4 ) . Arndt has emphasized the need for evaluation under actual conditions of exposure. Bell (70) has recognized the obvious relationship of chemical resistance and molecular constitution. This relationship has been emphasized further by Feuer (37) in his studies of polyesters. H e compared three different polyesters and observed a wide variation in resistance to chemicals. A summary of the chemical resistance of plastics has been published (80). Those who recognized the relationship of chemical structure and corrosive resistance have already designed numerous hoods, ducts, and stacks which have stood the test of time in corrosive atmospherm Coatings and linings
I n spite of past mistakes caused by lack of knowledge and overemphasis on this
phase of plastics utilization, coatings and linings are now accepted as standard materials of construction. T h e advent of fluidized coatings has created considerable interest in even the most insoluble plastics. This technique and water suspensions have been used for the fabrication of unusually successful linings. The use of polyoxetane and polyfluorocarbon coatings and linings is now commonplace (70). Automatic coating installations are now in operation with almost every type of chemical resistant plastics (57, 82). The specific advantage of each type is discussed under subsequent headings.
Plastic Materials
Polyolefins. Because of the utility of the end products, the availability of the starting materials, and the ability to regulate molecular structure during polymerization, polyolefins have attracted world-wide attention. T h e production of linear polyolefins increased by over 100% during the past year. This rate will continue; yet, it will not detract from the growth of the general purpose olefin polymers. It has been predicted that linear polymers will account for 2570 of the 3 billion pounds of polyolefins produced in the U.S.A. in 1965. Comparable advances have been made with diolefins. I t is now possible to produce either elastic &-polymers or hard trans-polymers by appropriate selection of catalyst (68). Copolymers of ethylene with ethyl acrylate, vinyl acetate, and styrene are available. T h e stability of polypropylene fiber has been increased by the addition of appropriate inhibitors. All polyolefins can be cross linked if compounded with organic peroxides (79). Chlorinated polyethylene is more stable than chlorinated rubber. Blends with poly(viny1 chloride) have improved heat distortion points. Copolymers of ethylene and propylene exhibit elastic properties (2). Leather can be improved by impregnation with a hot melt of polybutene ( 6 ) . T h e ad-
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verse effect of ultraviolet light on polyolefins has been minimized (41). T h e permeability of polyethylene has been decreased by surface fluorination (72). T h e effects of irradiation on polyolefins has been reviewed (94). Vinyl ChIoride Polymers. I n spite of low prices and low profit margins, the growth of vinyl plastics continues. Over 1 billion pounds were produced in 1960. I t has been predicted that almost 2 billion pounds will be produced in 1966. Rigid poly(viny1 chloride) (PVC) should account for over 5Y0 of this volume. At least 25% of the total production will be used as materials of construction. Over 250 million pounds of vinyl plastics were used in construction in 1960. The thermoplastic structure division of the Society of the Plastics Industry has published a manual on the use of PVC in construction. New information has been supplied on fabrication and 48,54,97). welding (44, Large structures fabricated from rigid poly(viny1 chloride) are now commonplace. Blends of poly(viny1 chloride) with chlorinated polyethylene, halogenated butyl rubber, polymethyl acrylate, and a blend of copolymers of styrene-acrylonitrile and butadienemethyl isopropenyl ketone have been investigated. These products, like the so-called poly(viny1 dichloride) (78), have superior heat resistance and ease of fabrication. Since it serves both as a heat stabilizer and a light stabilizer, di(isodecy1)-4,5epoxytetrahydrophthalate has been proposed as the ultimate plasticizer for poly(viny1 chloride). Studies on the relationship of solvating power and structure of plasticizers have been made (33). Users have been cautioned about the acute toxicity of triaryl phosphate plasticizers (73). However, conclusions should be based on end use rather than composition of the ingredients (20). Polyfluorocarbons. Because of their characteristic resistance to chemicals and heat, polyfluorocarbons continue to be selected for unique and critical applications. Polytetrafluorocarbon reinforced by ceramic fibers served as the beacon antennae on Diszoverer XI[. Glass fiber-reinforced polyfluorocarbons have proved superior when used as piston rings in jet engines. Self-lubricating retainer rings are fabricated from similar compositions compounded with MoS2. Asbestos saturated with polyfluorocarbons continues to be used for high temperature gaskets. Thin films of poly(viny1 fluoride) pass 95% of the sun’s energy yet reflect heat. Thus 2-mil films have been proposed as a cladding for roofs. Monofilament polyfluorocarbon fibers are also available. Improved flexible hose is
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now produced continuously by simultaneously winding polyfluorocarbon impregnated tape and stainless steel tape around a mandrel. Copolymers of trifluoronitrosomethane and tetrafluoroethylene are flexible a t low temperatures and possess the characteristic chemical resistance of this type product (67). A change in volume in excess of 1% has been noted when polytetrafluoroethylene is heated a t 394.2’ F. (59). Case history data have been provided showing excellent performance of fluorocarbon-lined pipe (88). Additional information on old and new fluorinated polymers has been published (8, 77, 76). Less than 15 million pounds of polyfluorocarbons was produced by three different firms last year. However, it has been predicted that more than 40 million pounds will be consumed in
1965. Styrene Polymers. As a result of over 10 years of successful performance as a structural plastic, the blend of copolymers of styrene, acrylonitrile, and butadiene (ABS) has been classified as an “engineering plastic.” This type of product is now being produced by four firms, and production capacity is being increased. I t has been predicted that this product will be produced a t a rate of 100 million pounds in 1965. New copolymers of styrene with butadiene and methyl methacrylate are also available. I n spite of its shortcomings, polystyrene continues to be produced a t annual rates in excess of a billion pounds. Among the many new uses of styrene plastics (72), probably the most significant is a simple polystyrene clip for holding six beer cans. The ability of polystyrene to react with a wide variety of reagents has attracted considerable attention (75). The sulfonated product is used in water softening. Pdystyrene has been cross linked with formaldehyde and chlorosulfuric acid (69). A polymer containing lithium has been described (5G). Polyacetals. A commercial polymer of formaldehyde introduced less than 2 years ago is already being accepted widely as an “engineering plastic.” Approximately 10 million pounds will be used in 1961. Production is expected to exceed 100 million pounds annually by 1964. A new copolymer acetal (90) has been announced, and a third firm is considering the production of these interesting tough products. The strength properties of acetals approach those of nonferrous metals. Properties of acetal resins have been described ( 9 ) , and crystalline polymers have been obtained from other aldehydes including chloral (35, 37). Lee (58)
has discussed a more efficient gear pump molded from acetal polymer. Polycarbonates. Polycarbonates can be made by the condensation of phosgene with polyhydric compounds such as bisphenol A (27). Because of its excellent impact resistance, this type of product is also classed as a n “engineering plastic.” Approximately 1 million pounds were produced by two firms in the U.S.A. last year. Another firm has announced interest in the production of “phenoxy materials.” Predictions for the sale of 50 million pounds in 1965 and 100 million pounds in 1970 appear to be conservative. This type of plastic is resistant to aliphatic hydrocarbons, salt solutions, and dilute acids. I t is soluble in chlorinated hydrocarbons and slightly soluble in aromatic hydrocarbons (47). Gruenwald (45) has described cold stamping of this type plastic. Polyesters. Polyesters have been produced by the reaction of epoxides and anhydrides in the presence of tertiary amines (32). Phosphorous-containing polyesters have superior resistance to flame and heat (38). The significance of acid number in evaluation of long-term wet strength of glass reinforced polyesters has been discussed (67). Scheimer has emphasized the importance of variables including curing time (79). Hazards associated with the use of isopolyesters as maintenance coatings have been discussed (85). Epoxy Resins. Progress in epoxy resin applications continued during the past year. Over 60 million pounds of base resin was produced by five different firms. Since, in its final application, most of the product was reinforced or filled, the end point weighed about 200 million pounds. T h e base epoxy resin used in 1966 should approach the present volume of filled resin. In addition to satellite and missile applications, epoxy resins were used widely for repair of equipment and as jointing materials. A special valveequipped wrapping for pipe repair is now available. Economies have been claimed when thin metal pipe has been joined with epoxy resins. High impact sheet has been produced by reinforcing combinations of epoxy resins and thermoplastic materials (30). Epoxy resins have also been used as sprayed coatings (95), trowelling cements (27), adhesives, and foams. Flexible products have been obtained by using tin(I1) octoate as the hardener. Self-extinguishing formulations are available. Several new base resins have been introduced commercially (46, 50). Crystallinity of epoxy resins is reduced by atomic irradiation (7). Ehlers (28) has investigated the relationship of
Materials of Construction Revlew
structure and heat resistance. Michaels (64) has suggested use of highly filled products as low cost materials of construction. Recommended procedures for safe use of formulated epoxy compounds have been compiled by SPI’s Epoxy Resin Formulators Division. Silicones. New developments in silicone technology included polyphenylsilsesquioxanes with a double chain formula, transparent potting compounds (76), filled silicone moldings, cyanoethylsubstituted dimethyl siloxanes, organosilicon esters of acrylic acid (25), and fluorosilicone rubbers (77). All possessed excellent high temperature properties. The cyanoethyl derivative has unusual electrical properties. Miscellaneous. Polyspiroacetals made by the condensation of pentaerythritol and glutaraldehyde are being investigated. Polyoxetane is produced by chlorination of pentaerythritol (87). This product which is being used for pipe, linings, and molded products is classified as an engineering plastic. High melting polyspiroxetanes are also being investigated. Building codes have been modified to permit the use of transparent sheets of poly(methy1 methacrylate). Reactive esters such as diaminoethyl and hydroxyethyl methacrylate are available. Transparent copolymers have been obtained from tin derivatives of methacrylic acid. Plastics with better resistance to temperature were obtained by adding bentonite derivatives before polymerization. Several reports have been presented on thermosetting methacrylate compositions (40). New water-soluble oxazolidinones are available. Several new copolymers of maleic anhydride have also been announced. Crystalline polymers of propylene oxide have been described. Condensation anhydride polymers have been produced from dibasic aromatic acids (62). Nylon-7 has been obtained by heating esters of aminoheptanoic acid in water. Colorless resins have also been obtained when e-caprolactam was heated with ammonium thiocyanate (3). Over 30 million pounds of nylon was molded last year. I t is anticipated that the use of these engineering plastics will double during the next five years. Filled nylon is used for floor tile and piston rings. I n addition to their use as cellular plastics, polyurethanes are finding application as adhesives, coatings, castings, and moldings. Liquid polysulfide manufacture has been discussed by Bertozzi ( 7 7 ) . This type of polymer is being used as a binder for NH&lOd in solid propellants; a butadiene-acrylic acid copolymer has also been investigated. Flexible phenolic resins have been VOL. 53, NO. 10
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a n m d Materials of Construction Review prepared by chlorination or alkylation of the phenolic grouping. Furfuryl alcohol has been cross linked with polyamines. Furfural has been condensed with epichlorohydrin to produce a thermosetting plastic. Flame resistant products have been obtained from chloromethyl derivations of diphenyl ether (24). Polytetracyanoethylene has been described. Copolymers of acrylonitrile and nitroethylene have been reduced to yield amine-containing polymers. Uranek (89) has cross linked blends of butadiene copolymers of acrylic acid and vinylpyridine. Interest in conductive polymers continues (77). Additional information on chelate polymers and polyphosphonitrilo chloride (42) has been published. Three dozen different plastics are being consumed with satisfaction at the rate of almost 7billion pounds a year in the U.S.A. Obviously, the newer polymers must possess unique and desirable properties to justify future commercialization. Acknowledgment The assistance of N. J. O'Kelley in the preparatian of this report is appreciated. Literature Cited (1) Aitken, I. D., Ralph: K . ; At. Encrgy Research Establ. (Gt. Brit.) R30, p. 85. 1960. (2) Amberg, I,. O., Robinson, A. E.? IND. ENG.CHEM.53, 368 (1961). (3) Antykov, A. P., Zhur. Priklad. Khini. 33, 2371 (1960). (4) Arndt! F. W., Corrosion 16, No. 11, 14 (1961). (5) Xvrasin, Y . D., Prigoreva, A. 1.; Plasticheskie Massy 1960, N o . 1, p. 13. (6) Bailey, M. (to U. S. Government), U. S. Patent 2,967,165 (Jan. 3,1961). (7) Baker, R. G., Spencer, A. T., IND. ENG.CHEM.52, 1015 (1960). (8) Barnhart, M'. S., Fetten, R. A , , Isotson, H., 17th Ann. Mtg., SOC.Plastics Engrs., Washington D. C., January 1961. (9) Barrett, G. F. C., Plasticc. (London) 25, No. 4, 136 (1960). (10) Bell, E. G., Bobolek, E. G., Proc. Paint Research Inst. Oficial Digest, p. 878 (July 1959). i l l ) Bertozzi, E. R., Helmer, W. D., 53rd Ann. Mtg., Am. Inst. Chem. Engrs.. Washington, D. C., December 1960. (12) Bird, A. I)., Modern P h i & 38, N o . 2. 93 (1960). (13) Bondy, H. F., Field, E. V.. others, J . 2nd. Brit. Mtd. 17, 190 (1960). (14) Bramstang, T. E., Erlandsson, E. L., Brit. Patent 839,862 (June 29, 1960). (15) Braun, D., Kunststofe 50, 375 (1960). (16) Brennan, P. J., Chem. Eng. 67, No. 17, 156 (1960). (17) Bringer, R. P., Sovia, C. C., Chern. Eng. P r q r . 5 6 , No. 10, 37 (1960). (18) Brookfield, K. J., Pickthall, D., Plastics 26, No. 280, 135 (1961). (19) Carlson, B. C.: SPE Journal 17, 265 (1961). (20) Chancellor, S. F.. Nature 185. 841 (1960). (21) Chopey, N. P., Chem. 6 n g . 67, No. 23, 174 (1960). (22) Cleneay, W. A., 9th Natl. Plastics Conf., SOC. Plastics Ind.. New York, .June 1961.
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(23) Collins, F. H., SPB Journal 16, 705
(1960). (24) Doedens, J. D., Cordts, H. P., IND. ENG.CHEM.53, 59 (1961). ('5) Dolgov, B. N., Kukhaiskaia, E. V., N , Vysokomolekulyarnye Andreev, D. I Soedineniya 2, 1463 (1960). (26) Dorian, G. H., Burkhard, H., Llihite, M. L., A S T M Bull. No. 250, 34 (1960). (17) Dunn, P. A,, Rubber t 3 Plastics Age 42, 200 (1961). (28) Ehlers; G. F. L., Poiymer 1, 304 (1960). (29) Eichhorn, R. M., IND. ENG. CHEM. 53, 67 (1961). (30) Evdokimov, F. K., Dadeka, V. 0.. Russ. Patent 131,427 (Sept. 10, 1960). (31) Feuer, S. S., Plastics World 18, No. 9, 7n (ioc,n\ -" \-'-"/' '32) Fischer, R. F., J . Polymer Scz. 44, 155 (1960). '33) Fissell, W.J., Modern Plastics 38, No. 9, 232 (1961). 134'1 Freeman, H. 6..Sorsa, B.. Valtzon T e k ?utkeniusZait& 1, No. 16 (1960). (35) Fujii, H.. Makromol. Chem. 40, 226 (1960). (36'1 Fullerton, A, Ann. Mtg., Western Div.. Sac. Plastics Ind., San Diego, April 1961. (37) Furukawa, J., others, Makromol. Chem. 37, 149 (1960). (38) Gefter, E. L.: Rubtsova, I. K., Russ. Patent 132,404 (Oct. 5, 1960). (39) Geller, B. E., ~~"l'sokornol~kulyarnye Soedineniya 2, 1466 (1960). (40) Gerhart, H,L.. IND.F,NG.CHEW53, 458 (1961). (41) Gibson: R. E.. Wester~i Plastics 8, Xo. 4, 37 (1961). (42) Gimblett, F. G. R., Plastics Inst. (London) Trans. and J . 28, 65 (1960). (43) Gloor, W. E.. Modern Plastics 38, N o . 3: 111 (1960). (44) Grishin. N. h.. Voyutskii, S. S.. Vysokomolekulyarnye Soedineniya 1, 1778
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(45) Cruenwald, G., Modern Plastics 38, No. 1, 137 (1960). 146) Guccione, E., Chem. Eng. 67, No. 17. 78 (1960). (47) Haas, H. C., Schuler. 9.W., J . Polymer Scz. 91, 237 (1960). 148) Haim, G.. Rubber €3 Plastics Age 41, 1507 (1960). (49) Henis, D.. Modern Plastics 38, No. 1, 119 (1960). 150) Johnston, C. W., Greenspan, F. P., Ibid., 38, No. 8, 135 (1961). (51) Kawasaki, A., U. S. Patcnt 2,946,094 (July 26. 1960). (52) Kendall, J. N., Sussman, S. E., 17th Ann. Mtg., SOC.Plastics Engrs., Washington. D. C.. Januarv 1961. (53)"Knoppel, C. A., Ibid. (54) Kohler, R., Kunstof-Rundschau 5, No. 9. 385 11958). (55) Landry, 'R. J , , Bartel, E. H., 17th Ann. Conf., Soc. Plastics Engrs.. Washi-ngton D. C., January 1961. (56) Leavitt, F. C., Mattervas. L. V., J . Poljrner Soc. 31, 249 (1960). (57) Lee, M. M.: Electro Tech. 6 6 , No. 10, 149 (1960). (58) Lee, P. A,, Materiais in Design Eng. 53, No. 5, 138 (1961). (59) Leksina, I. E., Xovikova, S. I., Soviet P/zjs.-Solidstate 1, 453 (1959). (60) Levy, R. M.. Corrosion 16, No. 11, 33 (1960). (61) Loetel. C. E., Fordyce, H. E., SPE Journal 16,1137 (1960). (62) McIntyre, J. E., Pugh, S. C., Brit. Patent 838,986 (June 22, 1960). (63) Marvel, C. S., 139th Meeting, ACS, St. Louis, Mo., March 1961.
INDUSTRIAL AND ENOINEERING CHEMISTRY
(64) Michaels, A. S., IND. ENG. &EM. 52, 785 (1960). (65) Millane, J. J.; Brit. Plastics 33, No. 5, 194 (1960). (66) Molt, R. P., 17th Ann. Mtg., SOC. Plastics Engrs.: Washington, D. C January 1961. (67) Montermoso, J., Division of Rubber Chemistry. ACS, New York, September i 9150.
(68) Gatta, G., Crespi, G., Rubber G" Plastics Age 42, No. 1, 53 (1961). (69) Patterson, J. A., Abrams, I. M., U. S . Patent 2,953,547 (Sept. 20, 1960). (70) Pavne, C. R., Central Regional Conf., Satl. ' ~ s s o c . .Corrosion Xngrs.. St. Louis, Mo., October 1961. (71) Pierce, 0. R., Holbrook, G. W., others, IND.ENG. CHEM.52, 753 (1960). (72) Pinsky, J., Adakonis, A,, Nielsen, A. R., Modern Packaging 33, 130 (1960). (73) Raech, H., Materials in Design En,?. 53, No. 5, 121 (1961). (74) Reed, G. H.; S P E Journal 16, 1101 (1960). (75) Riley, N. W., Materials in Desi,yn Eng. 53, No. 3, 119 (1961). (76) Robb, L. E., Western Plastics 7, No. 12, 23 (19601. (77) Roubhe, K. L., Wasserman, A,, Proc. Chem. SOC.(London) 1960, p. 248. (78) Rubber C8 Plastzcs Age 42, No. 5, 53 (19611 (7j) Scfieimer. H., Kunststofle 50, 388 (1961). (80) Seymour, R. B., "Modern Plastics Encyclopedia," Vol. 9, No. IA, p. 29, Breskin Publications, Inc., New York, 1961. (81) Seymour, R. B., 17th Ann. Conf., Natl. Assoc. Corrosion Engrs., Buffalo, N. Y . , March 1961. (82) Sherwood, P. W., Plastics 25, 495 (1960). (83) Smoluk, G. R., Modern Plasticz 38, No. 1, 119 (1960). (84) Soice, H. R., Plastics 25, 386 (1961). (85) Skphenson, R. W., Fosdick, L. D., Am. Ind. Hjg. Assoc. J . 6 , 522 (1960). (86) Streble, E., 17th Ann. Conf., Soc.. Plastics Engrs., Washington, D. C.: January 1961. (87) 'Taylor, G. M., Wenger, E. C., IND. ENG. CHEM.53, No. 3, 48A, No. 4: 5214 (1961). (88) Thierry, T. R., Corrosion 16, No. 11, 9 (1960). (89) Uranek, C. A, Sonnenfeld, R. F., IND.EKG.CHEM.52, 790 (1960). (90) VBn Boskirk, R. L.; Modern Plastics 38, h o . 8, 41 (1961). (91) Van der Vegt, .4.K., KunstJtofe 50, 537 (1960). (92) Van der Wal. A. A , , Plastics 25, 361 (1961). (93) Watson, M. T., 17th Ann. Conf., Soc. Plastics Engrs., Washington. D. C., .January 1961. (94) Weiss, J., J . Polyniet .Sei. 29, 425 (1 05R\
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(95) LVittcoff, H., Floyd, D. E., others,
17th Ann. Mtg., Natl. Assoc. Corrosion Engrs., Buffalo, N. Y., March 1961. (96) Young, R. E., SOC.Aerospace Material & Process Engrs., Filament Winding Symposium, Pasadena. Calif., March 1961. (97) Zade, H. P., ''Heat Sealing of Plastics," Temple Press Books, London, 1960. After October 1962 the complete bibliography can be obtained from the AD1 Auxiliary Publications Project, Library of Congress, Washington 25, D. C . , as Document No. 6835, at $1.75 for microfilm and $2.50 for photostat copies,
