ANNUAL REVIEW
Plasti Tech RAYMOND B. SEYMOUR N e w breakthroughs are anticipated
in almost every phase of the plastics technology because of t h e versatility and unique breadth of applications
of pIa st ics . PIa s t ics prod uc t io n has increased annually for 15 years and even greater annual increases
in growth are predicted over the next few years. Sheet of semipermeable membrane made of cellulose acetate, j i v e thousandths of an inch thick, is used in reverse osmosis f o r purifying brackish, sea, or waste waters
62
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
Exterior and interior automotive parts are being made from vinyls
his three-billion-dollar industry, which owes its
Tearly growth to empiricism, is continuing to grow
at a rate faster than any other industry as a result of its utilization of many new advances in polymer science and technology. Of the 25 billion pounds of synthetic polymers produced in the United States this year, over 60y0will be classified as plastics, most of which were not commercially available 30 years ago. I t has been suggested that the plastics industry adopt the practice used by the natural and synthetic rubber industry and report its production as tons rather than pounds. I t is anticipated that plastics will become the leading material of construction before the close of the century. Since this end use is associated with volume rather than weight, reports on a cubic foot or cubic meter basis would be more significant. Houwink ( 3 A ) has predicted that the volume of plastics produced in 1985 will exceed that of all metals. He has coined the expression “syntomer age” to describe the period when polymeric materials become the favored products for all applications. T h e broad spectrum of plastics applications is aptly demonstrated a t annual expositions (5A, 6A) and is recorded in annual reviews on this subject (4,9A, 70A). Progress depends on innovation, and plastics provide the tools that make such progress possible. Unique catalysts prepared by the interaction of chloroplatinic acid with nylon serve as examples of the versatility of polymeric materials ( 2 A ) . T h e flood damage to priceless art work at Florence was reduced by the application of temporary protective coatings of polybutyl methacrylate, and historical porous stone structures have been preserved through impregnation of epoxy resins (8A). Survival of modern civilization may depend on man’s ability to combat pollution of his present environment. I t has been demonstrated that the use of water soluble polymers as coagulation aids will increase the efficiency of treatment plants for industrial and sewage wastes ( 7 A ) . Polymers will also
play a leading role in smog abatement and the reduction of air and stream pollution. Modern man continues to depend on plastics applications for his transportation and recreation. Plastics are now being used for the construction of automobile bodies and grills, truck cabs, campers, and space craft ( 7 A ) . Spectators may now sit on reinforced plastic seats and watch baseball or football games being played on nylon-polyester surfaces. Since reinforced plastics are being used for vaulting poles, fishing poles, and golf clubs, it is not surprising to learn that the Tuscarora tribe on the Iroquois reservation in western New York has abandoned its use of hickory wood in favor of reinforced plastics for making lacrosse sticks. Native hat weavers are using polypropylene monofilaments in place of straw. Almost one half of the total output of cookingware is now coated with polyfluorocarbons, and glass milk bottles are being replaced by molded plastic containers. Disposable tooth brushes, which are being injection molded from polystyrene, include nylon bristles coated with a water soluble dentifrice. Nylon fabric is being tested for mail pouches, a n d acrylic fiber sand bags are being tested for flood control use. Larger presses and cold stamping plastic sheet techniques have reduced some of the size limitations which have limited some applications of plastics. For example, a 400-ounce injection molding press capable of producing 30 molded pieces per hour has been installed in a motorcycle manufacturing plant. Pla s t ic s Structures
As a result of increased emphasis on safety and performance by the automotive industry and on quality control and appropriate end use applications by the plastics industry (529, the previously quoted estimate of 100 pounds of plastics in each 1970 model automobile has been increased to 175 pounds (26B, 3223). If most of the anticipated breakthroughs occur, over 500 pounds of plastics could be used in each unit. VOL. 5 9
NO. 8
AUGUST 1967
63
Nylon-6,6 front fender extensions are being used on one 1967 model and polypropylene fender filler plates weighing over 6 pounds each are being tested. T h e anticipated breakthroughs would also include plastic bodies which would result in a sizable reduction in the use of metal and paint. A feasibility study of reinforced plastic minesweepers has been made (6B,33B). An all-reinforced plastic superstructure was used in the construction of the LrSS Asheville, a l63-foot Class 84 patrol boat. T h e weight of the M-16 rifle has been reduced by use of reinforced plastic components (9B). Included in the many potential space age applications is the use of quilted packets of polystyrene beads and polyvinyl acetate emulsion for the protection of space ships from micrometeorites. T h e use of plastics in buildings has been reviewed (7B, I I B , ?6B), and new books on this subject have been published (22B, 30B). Many unique plastic structures are being used as exhibition halls at Expo 67 a t Montreal. Habitat 67, an apartment building subsidized by the Canadian govcrnnient contains 282 factory assembled reinforced plastic bathrooms. This type of assembly has been reviewed (?4B),and costs of plastics construction have been analyzed (3B). Tlie Kew York City code now permits the use of plastics for windows and skylights and as piping for cold water, waste, drain, and venting. However, San Francisco has approved 23yc more plastic building projects than New York (23B). Fortunately, the code writers are now emphasizing end use performance rather than specific materials of construction. Over 60 thousand pounds of expandable polystyrene were bonded to aluminum sheet for the construction of a n 8-million-cubic-foot cold storage facility a t Houston. A 20-foot diameter reinforced plastic dome ~ 7 a sinstalled a t Melbourne (Australia) Boys High School. Liquid silicone roofing composition similar to that used for the General Electric Exposition Building at the New York World’s Fair as well as sulfochlorinated polyethylene and polyvinyl fluoride sheet a r e being used for roofs. Other major applications accounting for the 3 billion pounds used in construction include paints, plywood, floor coverings, wire coating, and pipe (27B). T h e previously reported uses of plastics in the Shell Center Office Building in London (25B)have served satisfactorily. KO failures occurred in 23 miles of plastic pipe except that used for soap dispensers. Some shrinkage was also noted with the polyvinyl chloride tile ( 7 B ) . A dispersion of polyester, stl-rene-water soluble redox catalyst, and portland cement has been proposed as a material of construction (2OB). Plastic grouts are being pressure injected for the support of heavy machinery (2?B,24B). T h e use of polyurethane (4B), epoxy (?OB, 28B), and polysulfide grouts (29B) has been reviewed, and tests for the performance of dynamic seals have been suggested (31B). Superior bearings have been injection molded froin oil impregnated polyacetal powder (77B). New information has been published on the bearing characteristics of polyfluorocarbon compositions (8B, 15B). 64
INDUSTRIAL A N D E N G I N E E R I N G CHEMISTRY
A 5-foot diameter insulator ring used as an alternating gradient synchroton was cast from epoxy resin a t the Brookhaven National Laboratories. A ‘/?-inch polyethylene profile, weighing 4 pounds per linear foot, is being used as an insulator in the San Francisco high speed transit system. Plastics applications in the hydroelectric industry have been reviewed (12B). Flexible heat exchangers consisting of braids of small diameter tubes of polyfluorocarbons continue to perform satisfactorily (18R). Plastic honeycomb trickling filters a r e being used for biological oxidation support in canning waste treatment. Polypropylene spheres are being used to reduce thc evaporation of liquids. Low density structures have been fabricated by bonding hollow epoxy spheres together. Over one million 6-inch polypropylene squares, each containing over 300 molded bristles, served as the gliding surface on a 7-acre ski slope in southern California. Lubrication consisted of a silicon emulsion applied to the skis. T h e rate of transport of water through semipermeable cellulose acetate membranes has been studied in desalination reverse osmosis processes (13B). The use of plastics in agriculture for mulching, greenhouse construction, irrigation, protection of crops, and for packaging is increasing (ZB, 19B). Containers and Vessels
Heavy duty polyethylene and polypropylene bags are being used as disposable garbage bags for low cost trash removal, as heavy duty shipping containers, and as sand bags in military combat. High density polyethylene folded sheet is being used for tote boxes and beverage containers (4C). This polymer has been blow molded and rotationally molded to produce fuel tanks for Jeeps and Broncos. The use of polyolefins for containers has been reviewed (S’C, 7C, 8‘2). I t is estimated that 3.5 billion plastic bottles will be blow molded this year. High density poll-ethylene is the preferred material for molding bottles, and it is anticipated that 1 billion pounds of this resin will be used for this purpose in 1970. Hollow objects made from polyvinyl chloride have been described (IC),and the potential for this type of bottle has been outlined ( 2 C ) . Limited clearance for the use of clear vinyl chloridepropylene copolymer bottles has been granted by the Food and Drug Administration. Bottles are also being produced from polycarbonates (3C) and nylon (6C). One-trip 50-gallon metal drums lined with a 20-mil fused coating of polyethylene are available. Flexible polyurethane liners have been proposed for use in the transportation of finely divided materials. Reinforced plastics are used for the construction of large containers and vessels. Composites
T h e annual production of reinforced plastics is slightly more than one-half billion pounds but over 7 billion pounds of composites of all types are consumed aniiually in the United States (350). Accordingly, the name of
one journal covering this field has been changed to Reinforced Plastics and Composite World. Almost 500 million pounds of phenolic resin are used annually for the production of plywood. Phenoxy, polyester, epoxy, nylon-epoxy, phenolic-epoxy, and acrylic resins are also used as structural adhesives ( 9 0 ) . A trace of water is used to initiate anionic polymerization of methyl 2-cyanoacrylate adhesives (320, 5 2 0 ) . New developments in the field of composites include instant helipads, carbon reinforced gas turbines ( 1 7 0 ) ) violin bows, supersonic aircraft, and new reinforced thermoplastic technology. Techniques have been developed for the continuous production of reinforced sheet and pipe ( 4 5 0 ) . The name cereplasts has been coined for mineral filled thermoplastics ( 7 0 0 ) . Filled ABS, polyacetals (250, 4 6 0 ) ) polycarbonates ( 4 2 0 ) )polyethylene ( 1 8 0 ) )nylon (20, 2 6 0 ) ) polypropylene, acrylates ( 4 7 0 ) ) and polyvinyl chloride are available. Concentrates with 80% filler may be purchased and blended with unfilled resin to yield the desired degree of reinforcement. The Society of the Plastics Industry has formed a group to study this phase of its industry. New books have been published on reinforced materials (190) and adhesion ( 3 3 0 ) . Several new reviews on reinforced plastics are available ( 1 0 , 290, 5 0 0 ) . Many new investigations have been undertaken in an attempt to develop more fundamental information on reinforced plastics (240, 4 4 0 ) . I t has been shown that high molecular weight polystyrene is adsorbed preferentially ( 3 0 ) and that physical properties are increased substantially by the use of appropriate coupling agents ( 4 1 0 ) . T h e decrease in entropy when polymers are reinforced has been attributed to a local ordering of polymer segments ( 2 3 0 ) . The reaction at the filler-matrix interface has been studied by DTA ( 2 2 0 ) , measurement of wetting angles ( 7 5 0 ) ) and joint tests ( 4 0 , 80). Shearing-type adhesive tests have shown the effectiveness of organic fillers to be in the following order: rayon, nylon4 polyester, and polypropylene (400). The effect of filler concentration on the properties of polyacrylates and phenolphthalein-formaldehyde resins has been investigated. The properties of asbestos composites and the effect of mineral fillers as reinforcements have been reviewed ( 7 4 0 , 5 1 0 ) . Superior ceramics parts have been obtained by the addition of 3% epoxy resin bender to the mixture before firing (5D). Over 300 million pounds of textile grade glass fiber
AUTHOR Raymond B. Seymour, a pioneer in polymer science and technology, has written the annual review on plastics for Industrial and Engineering Chemistry since 7950. He has been awarded over 40 patents in thisjeld and has authored over 200 technical articles and books including an undergraduate textbook in polymer chemistry. Dr. Seymour is now Associate Professor of Polymer Chemistry and Associate Director of Research at the University of Houston.
were produced last year, and it is anticipated that this volume will double by 1970. Specific bonding agents such as silanes are required for optimum adhesion of the matrix and the reinforcement. Other reports include production techniques (480))relationships of chemical structure and properties of composites ( 3 0 0 ) )and surface modifications of the glass filaments ( 1 6 0 ) . Low density troweling cements consisting of glass microspheres and fluorinated elastomers are available. Conductive plastics have been produced by using silver coated glass microbeads as fillers. The properties of glass composites have been investigated by use of microwaves (380, 4 9 0 ) . A new grade of fibrous yarn, which does not melt at 800' C., has been developed. Carbon fibers produced by the pyrolysis of organic fibers are being used to produce strong composites ( 3 9 0 ) . Comparable techniques have been used with oriented silicon carbide whiskers to obtain continuous reinforcing filaments ( 3 6 0 ) . The adhesion of resins to boron filaments has been improved by coating with inorganic fibers and by nitric acid etching ( 2 0 0 ) . The rigidity of boron fiber-epoxy resin composites surpasses that of most other materials of construction ( 3 4 0 ) . Whisker-type composites have been reviewed ( 4 3 0 ) ) and it is anticipated that this type construction will be used routinely in future aerospace construction. Tiny fibrils of crysotile are being used to control the flow of liquid resins. The effect of styrene monomer concentration on polyester (70) and epoxy-acrylic resins ( 2 7 0 ) and the use of chlorostyrene monomer in place of styrene ( 3 7 0 ) have been investigated. Other new developments include composites based on thermosetting vinyl ester resins ( 2 1 0 ) )ultraviolet sensitive preimpregnated polyester sheet, air inhibited adhesives which cure under anaerobic conditions, and ABS-chipboard laminates ( 2 8 0 ) . The effect of a large variety of reinforcements in phenolic resins has been studied (120). Negative phloroglucine tests have been used to show reactions between phenolic resins and wood flour (370). Methylmethacrylate and styrene monomers impregnated in wood are being polymerized in situ by peroxy and gamma ray initiation ( 7 3 0 ) . Sheet and Film
The production of sheet and film represents one of the fastest growing segments of the polymer industry. Low density polyethylene accounts for more than 30y0 of this 3-billion-pound market (75E). Much of this type film is used for packaging. A parchment-like sheet has been produced from high density polyethylene. Plastic films have been used successfully as membranes for biological and industrial separations ( 1 7E, 74E) such as the concentration of wines, vapor diffusion ( 5 E ) , and as heat exchangers in the desalination of sea water (723). A monograph for estimating the permeability of laminates has been constructed (6E). The effect of additives on semipermeable cellulose acetate films has been investigated (IOE). Other studies have shown that the transport of solute through these VOL. 5 9
NO. 8
AUGUST 1 9 6 7
65
membranes is a function of steric factors and hydrogen bonding capacity (SE, 76E). A cationic exchange membrane has been prepared by grafting polystyrene on ultraviolet irradiated polyethylene film or by hydrolysis of chlorosulfonated polyethylene film ( 2 E ) . Poromeric sheet is now being produced under the trade names Corfam, Azlran, Clarino, Ortex, Quox, and X) lee ( I Z E ) These coriaceous sheets, usually composites of polyurethanes with n) lon or polyesters, are now being used in many nonfootware applications. Another leather-like product is prepared by leaching out the starch from a starch-filled polyvinyl chloride sheet (9E). Polyacrylic sheet is being extruded directly from the monomer and cast continuously. The United States Pavilion at Expo 67 has blue tinted acrylic sheet which reduces glare but does not prevent grass growth. Equipment is now available for high frequency (7E) and ultrasonic welding (17E,78E) of thermoplastic film and sheet. IVew formulations of ABS sheet may be cold stamped ( 3 E ) . Seven-foot wide ABS sheet has been drawn 28 inches in the experimental forming of automobile bodies. This type sheet niay be etched with chromic acid and plated in an electroless nickel solution. New techniques have also been developed for the metal plating of polypropylene, polysulfone, and polyfluorocarbons (73E). The adhesion of epoxy resins to polyethylene or polyfluorocarbon surfaces has been improved by exposure to radiation activated inert gases. A system for bonding polyvinyl chloride sheet has been described ( 4 E ) . Sheets based on blends of acrylic resins and polyvinyl chloride h a \ e been used as linings for tanks containing chemical milling solutions a t a SYichita, Kan., plant. Over 60 tons of polyvinyl chloride sheet was used in the fabrication of ductwork at Sir George LYilliams Unilersity at Montreal. Other applications of plastic sheet include sound insulation barriers, subsurface membranes for agriculture, road patching, and sump liners. Protective Coatings
The difference between linings and coatings depends on thickness, effectiveness, methods of application, and definitions based on nonobjective preconceived opinions. Annual sales of protective coatings applied in the liquid state exceed 2 billion dollars. These products vary from the vinyl acetate-ethylene copolymer latex electrolytically deposited as a primer coat on automobile frames and bodies, to the thermosetting acrylic resins used for automobile enamels (75F). Other important applications include polyvinyldene fluoride coatings used to protect 3 million square feet of steel mill siding in East Chicago, Ind., and the polyurethane coatings used to coat fabric for 10,000-galloncapacity portable helicopter gasoline stations in Vietnam. Almost 10 million gallons of polyurethane coatings were used last year ( 2 F ) . Other new uses that have been reported (18F, 20F) include the protection ofjunctions of aluminum communication cable and sewer pipe gaskets (IF). New techniques are available for fusing polyvinyl 66
INDUSTRIAL AND ENGINEERING CHEMISTRY
chloride to steel wire (73F). Sheet coated with this resin may be deep drawn and spot welded without delamination. New reports have been issued on dispersion (22F) and on fluidized (70F), and marine coatings (77F) based on this polymer. The application of fluidized bed coatings ( T O ) , epoxy resins (76F),polyester resins (5F, 24F), nylon (@), and chlorinated polyethylene (6F)and extrusion coating with polyethylene (23F) and polypropylene (9F) have been reviewed. Coatings may be applied by the ionization of the monomer under vacuum ( 7 l F ) and cured by accelerated electrons or by previously irradiated inert gases. T h e properties of concentrated aqueous solutions of polyvinyl alcohol have been investigated (72F), and the characteristic properties of comparable solutions of polyethylene oxide have been widely publicized in nontechnical reports. The properties of coatings have been correlated with molecular structure ( 8 F ) , and methods for the analysis of coatings have been reviewed (27F). New information showing the effect of all intermolecular forces on solubility parameters is available (3F, 7F). These values have been related to classical Kauributanol numbers (79F). Plastic Pipe
Plastic coated and lined metal pipe continues to be used but the principal emphasis is on extruded thermoplastic pipe. A new voluntary standard TS-5673E has been issued for polyfluorocarbon lined pipe. T h e potentials for continuous extrusion have been discussed (SG)and the results of 8 years of experience with plastic pipes ha\ e been recorded (2G). Experience with plastic gas pipelines (77G)has been described and price data have been compared (78G). The use of epoxy ( 3 G ) , po1yeth)-lene, polypropylene (4G,5G),polybutene-I (75G), polyvinyl chloride (7G, 14G, 17G, 19G) has been discussed. High frequency equipment used previously to dry potato chips is being used to cure epoxy resin pipe. Llore than 25 thousand miles of rigid polyvinyl chloride water pipe is now in service. New information has been published on layjoining (6G, 13G), and testing plastic pipe under ing (gG), long time hydrostatic service conditions (76G). The relationship of chain branching to the physical properties of extruded pipe has been investigated ( I Z G ) , and the use of plastic pipe for waste lines has been reviewed (7G, 7OG). Practically every major plumbing code has approved ABS and PVC pipe for drain, waste, and vent services. The 250 million pounds of plastic extruded as pipe last year represented a 30y0 growth over 1965. Plastic pipe was installed in 15yGof all new stationary homes and in almost all of the 220,000 mobile homes constructed last year. Cellular Plastics
The cellular plastics segment of the plastics industry, like the pipe segment, has experienced rapid growth as a result of standards established by appropriate groups.
Over 400 million pounds of flexible plastic foam will be produced this year (28H). Polyurethane foam will account for over 50y0 of this volume but chemically blown vinyl foam may become the principal flexible cellular product before 1970 (24H). The heat resistance of this type product has been improved by the addition of maleic anhydride and isocyanates. New blowing agents have been described (26H),and the general properties of these products have been discussed ( 3 H ) . Vinyl foam is being used for insulated fabrics and shoe soles. A new book on insulating materials has been published (78H),and the potentials for cellular products in packaging have been evaluated (7ZH, IQH). Recent reviews have been published on formulations (SH, 14H), molding techniques (76H, 17H, 37H), and the use of cellular products in the construction of aircraft (29H), automobiles (4H, 6H,3OH), boats (25H),refrigerators (22H), and railroad cars (13H). The polymer foam industry has been reviewed (IOH), and the general use of these products for building construction has been discussed (2H, I I H ) . Over 100 million pounds of rigid polyurethane foam were produced last year, and it is anticipated that this volume will double by 1970. The use of phosphorus polylols increases the flame resistance of these products. The effect of polar solvents as cell opening agents in polyurethane products has been investigated (75H). New data on the thermal characteristics of rigid polyurethane foams have been published (27H). The results of other studies include the production of foams from latex systems (23H), diffusion of gases in polymer foams ( 7 H ) ,the determination of K factors ( Q H ) , and the properties of filled polyethylene (ZOH) and polyurethane foams ( Z I H ) . The production of rigid silicone foams at room temperature ( I H ) and use of epoxy resin foam for ceramic molds have been discussed (5H). Plastics vs. Corrosives
Since all polymers are subject to attack by their environment, information on the effects of these environments is useful to the materials engineer who specifies polymers for various end uses. Almost 1 million pounds of plastics are used annually as dentures, and their use in other biological applications is increasing (5J,
I S J , 26J). The use of plastics in biochemical, marine, and space environments has been reviewed (25J). The biological stability of polytetrafluoroethylene implants in rabbits has been investigated (1QJ). Nonthrombogenic polymer surfaces have been developed (24J)and improvements have been made in many paramedical applications (16J). The increased use of plastic bottles has resulted in additional investigations of the effect of solvents on polymers. Solubility parameter data have been used to predict the interaction of solvents and polymers ( 3 5 4 . Crazing has been attributed to the extraction of moisture from the polymer by solvents ( 7 1 4 . A chain transfer radical reaction has been proposed to explain the degradation of polypropylene by chlorinated alkanes at elevated temperatures ( 6 J ) . The service life of plastic pipe in corrosive environment has been estimated from the relative time for rupture with water and with the test solutions ( Z O J ) . Swelling and change in weight ( 3 7 4 , as well as changes in creep resistance ( I Z J ) , have been used to measure the chemical resistance of polyolefin pipe. The major factors influencing chemical attack on polymers are the reactivity of the functional groups and the accessibility of the reactive sites (73.4. The effects of corrosive liquids on polymers have been evaluated by the application of Fick’s law of diffusion and by determining coefficients of diffusion of the liquids (32, 4OJ). The effect of water on the mechanical and electrical properties of polymers has been reviewed (78J). Changes in electrical resistance have been used to measure the migration of water vapor in epoxy and polyester resins (232). The relative corrosive resistance of phenolic, polyvinyl acetate, acrylic, and polycarbonate resins has been reported ( Z Z J ) , and the compatibility of plastics with liquid propellants has been investigated (ZJ). The loss in strength of glass reinforced plastics in water has been attributed to a reduction in adhesion resulting from capillary action (30.4. Recent studies have shown that heat and moisture have a greater effect on glass reinforced nylon than on the unfilled polymer (27J). Changes in Brinnell hardness have been used to follow deterioration of glass reinforced resins in underground aging tests (38J). Test variables in the evaluation of the chemical reVOL. 5 9
NO. 8
AUGUST
1967
67
sistance of polyester resins have been outlined ( 3 6 J ) , and the successful use of reinforced plastics in the chemical industry has been reviewed (32J, 3 4 4 . The effect of nitric acid on mechanical and dielectric properties of phenolic and melamine molded parts ( 2 8 J ) and the effect of both oxidizing and nonoxidizing acids on reinforced polyester and phenolic resins ( 7 J , 8 J , 3 3 J ) have been investigated. A new book on the corrosion resistance of plastics has been published (IOJ). Recent reports include the use of plastics in chemical plant construction ( 7 7 4 , fertilizer plants ( 8 J ) , and the pulp and paper industry ( 9 J , 14J, 41J). Recent studies of the effect of fuming nitric acid on crystalline linear polyethylene suggest that the initial attack occurs preferentially a t the fold surfaces and is followed by a slower attack on the crystal core (ZQJ). These effects may be followed by measuring changes in weight, density, molecular weight, and heats of fusion ( 3 9 J ) . The high degree of swelling of polyethylene films in nitric acid has been attributed to a weakening of intermolecular forces resulting from diffusion of the acid ( 2 l J ) . New information has been published on the kinetics of polymer degradation ( 4 J ) and the hydrolysis of poly-macetimidostyrene (IJ). The reactions of polystyrene have been reviewed (31J). Plastics vs. Weather
Since almost 8 billion pounds of plastics are used outdoors, weatherability is an important consideration of the plastics industry. Inasmuch as the outdoor use of plastics should double by the early 1970's, the Manufacturing Chemists Association has sponsored a sizable project a t the National Bureau of Standards for a study of this type environmental attack. Accordingly, 20 papers were presented at a symposium related to this sponsored project ( 7 7 K ) . The aging of polyethylene and polyvinyl chloride has been attributed to heterogeneous volume relaxation ( 9 K ) . The many photooxidation studies of polypropylene include the effect of stabilizers ( 7 K ) , infrared spectroscopy and differential thermal analysis (ZK),and accelerated weathering tests ( 3 K ) . One investigation has shown this degradative reaction to be first order and the rates of thermal and photochemical decomposition to be about equal (GK). T h e effect of weathering on isotactic polypropylene has been attributed to photoionized oxidation chain degradation, secondary crystallization, and shrinkage (27K). New accelerated exposure tests have been debeloped ( 4 K ) , and intramolecular hydrogen bridge elongations of systems containing 2-hydroxybenzophenone-type stabilizers have been investigated (15K). The change in impact resistance has been used to measure the effect of weather on rigid plastics (72%). Photooxidation of polymer films has been followed by observing changes in the ratio of carbonyl and carbonhydrogen absorption using infrared spectroscopy (79K) or by using gel permeation chromatography to measure 68
INDUSTRIAL A N D E N G I N E E R I N G CHEMISTRY
changes in molecular weight (78K). Oxygen absorption measurements have shown polymethyl vinyl ether to be more resistant to oxidation in the presence of benzoyl peroxide than its isomer polypropylene oxide (13K). Accelerated exposure tests have been used to compare a large number of polyester formulations (5K). The change in glass transition temperature has been used to measure the ultraviolet degradation of polycarbonate filn1s (74K). New information has been provided on the photodegradation of polystyrene in solution (IOK, IO'K), of polymethyl methacrylate ( I K ) , of polymetallodirnethylsiloxanes (ZOIC), and of glass reinforced plastics (77K). The strength of epoxy resins joints increases on aging owing to hardening which results from surface oxidation ( 8 K )* Plastics vs. Temperature
The temperature resistance of polyhomocyclic compounds is superior to polymers containing heterocyclic rings (31L). Polyphenylenes, such as poly-p-xylylene (76L), may be produced by the condensation of benzene in the presence of aluminum and copper chloride (7215) or by the reaction of terphenyl and benzene sulfonyl chloride. T h e crystallinity of polyalkyl phenylenes improves as the number of methyl groups on the benzene ring increases. Those with less than four methyl groups are amorphous and the prepolymer may be cross-linked by heating (77L). Progress in ablative polymer evaluation (18L) and other heat resistant polymers has been reviewed (IOL, 75L, 27L, 24L). Techniques for screening heat resistant organic polymers have been discussed (GL, 27L). Over 50 million pounds of thermal stabilizers were consumed last year. Polyphenyl ethers are stable in inert atmospheres a t 800" F. but are degraded a t 600" F. in the presence of air ( 2 L ) . Thermally resistant sulfone polymers are produced by the condensation of bis-p-chlorosulfonyldiphenyl ether and diphenyl ether (4L). Aromatic dinitriles may be cyclized to yield triazine polymers which are stable at 1000" C. in an inert atmosphere (7L). Unsaturated polyesters with improved resistance to elevated temperature have been obtained from the beta naphthol maleic anh>-dride adduct ( 1 I L ) . Aromatic polyester imides are stable at 325" C. (74L). Polybenoxazoles obtained by the low temperature condensation of 3,3 '-dihydroxybenzidine with aromatic anhydrides were stable in vacuum at 500" C. (3L). Polybenzothiazoles obtained by the condensation of dimercaptobenzidine and phthaloyl chloride were stable a t temperatures below 570" C . (8L). Some commercial polyimides are moldable or may be used as solutions to form composites. Others are insoluble and supplied as film or fabricated part. Commercial polyimides are produced by the condensation of pyromellitic dianhydride and bis(4-aminopheny1)ether (26L) or benzene maleic acid adducts (2ZL).
The properties of reinforced polyimides have been described (5L). Novel polyimides (23L) and aromatic copolyamides have been synthesized (2OL). Several polymers with decomposition temperatures above 400" C. have been prepared by the interfacial or solution condensation of aromatic diacid chlorides and symmetrical diamines ( 79L). Benzophenone tetracarboxylic dianhydride is commercially available and may be condensed with polyaromatic amines. Properties and applications of polybenzimidazoles have been reviewed (7L). Thermally stable polyquinoxalines have been produced by the condensation of tetraamines and bisglyoxals (28L)or dihydroxybenzophenones (29L). Polybenzimidazo-benzophenanthrolenes have been obtained by the condensation of naphthalene tetracarboxylic acid and aromatic polyamines (30L). Recent investigations have shown that the crystallinity of zinc and cobalt alkyl or aryl phosphinates is a function of molecular symmetry (Z5L). Chelates of heavy metals and pyromellitimide are stable a t 300" C. ( Q L ) . A bibliography on ferrocene polymers has been published (73L). Plastics vs. Flame
The continued increase in growth of plastics as materials of construction is dependent on their superiority over other materials. Classical materials of construction such as wood and paper will continue to be acceptable, but their replacements must be flame resistant. A comprehensive review on self-extinguishing polyesters actually supplies considerable information on the general problem of flame resistance and includes a summary of the principal six methods used for the evaluation of flame resistance ( 7 M ) . Products such as polyvinyl chloride or polyacrylonitrile are inherently flame resistant but polyesters must be modified by the addition of chlorinated polyethylene and antimony pentoxide to meet flame resistant specifications (5M, IOM). T h e flammability requirements for plastics have been summarized ( 3 M ) , and the use of chlorinated paraffins as additives has been discussed ( I M ) . Approximately 100 million pounds of flame retardants will be consumed by the plastics industry this year. The flammability of flame resistant polyvinyl chloride and polyethylene systems has been compared using oxygen index values obtained from candletype tests ( 4 M ) . Tests for glow resistance, flash temperature, and flame resistance have been reviewed (9M). The thermal degradation and flammability of urethane polymers have been investigated ( I I M ) , and the use of open cell polyurethane foam as a flame resistant baffle in gasoline tanks has been discussed (8M). The effect of the addition of dibromostyrene and antimony oxide to alkyd resins has also been reported ( Z M ) . Polyvinyl alcohol fibers have been made flame resistant by reacting with dimethyl01 urea and tetramethylolphosphonium chloride (6M). A new book on flameproofing of plastics has been published (72M).
Synthetic Fibers
Even in the absence of flameproofing additives, it is anticipated that a blend of polyvinyl alcohol and polyvinyl chloride will be used as a replacement for wool in France and Italy. Surligomer wool surface modifiers consisting of copolymers of methacrylyl chloride are being used to reduce shrinkage and to aid the felting process. Approximately 4 billion pounds of synthetic fibers will be produced this year, and it is anticipated that this volume will exceed 6 billion pounds before 1970 ( 3 N ) . Viscose and acetate rayon accounts for almost 50y0 of the present volume, but the growth of the true synthetic fibers is expected to be much greater than the cellulosics in the future. Recent developments in fiber technology have been reviewed ( 4 N ) . The flexibility of viscose rayon fibers has been increased by grafting alkyl acrylates to the cellulose backbone. Stainless steel fibers have been blended with synthetic fibers to eliminate static. Fibrils of polymethyl methacrylate encased in a plastic skin are being used as light conducting cable. Polyesters are now being produced directly from terephthalic acid instead of the dimethyl esters. Considerable growth is anticipated for polypropylene fibers in the U.S.A. The use of split nylon bristles for paint brushes has been described ( I N ) . Structural modifications of nylons including a heat resistant fiber produced by the condensation of arylene diamines and arylene diacids have been discussed ( Z N ) . Progress in Polymer Science
Progress in anionic polymerization has been reviewed (32P), and techniques for radical type addition polymerization have been described ( ? P , 4P, QP, 27P, 35P). Triphenyl phosphine has been suggested as an initiator for photopolymerization (78P), and the reactivity of telogens has been predicted by the application of the concept of equality of product probabilities (73P). A new book on polymer structure has been published (2OP). T h e advantages of upgrading injection molding operations through automation have been outlined (22P). Techniques have been discussed for obtaining optimum performance of large scale injection molding on the basis of small scale experiments ( I Q P ) . Gel permeation chromatography may be used to separate different molecular weight fractions from solution (ZP, ?7P, 25P, 30P, 33P). Improved high speed membrane osmometers for determining number average molecular weights of polymers are available (34P). Gas chromatography has been used to identify plasticizers (IOP) and to characterize oxygen degraded polyethylene oxide (26P). Pyrolytic gas chromatography has been used to analyze asphalt (76P), synthetic polymers (72P, 75P), and brake lining constituents (7P). Thermal degradation products of phenolic resins have been analyzed by mass spectrometry (28P). Chemical and physical techniques for characterization of polymers have been discussed (5P). VOL. 5 9
NO. 8
AUGUST
1967
69
Differential thermal analysis has been used to differentiate polymers prepared by different techniques ( I 7 P ) and as an analytical tool in polymer chemistry (3P, 6P, 8P, 23P, 29P). Ultraviolet spectroscopy has been used to characterize pyrolytic products from elastomers (24P). The use of infrared spectroscopy (I@) and nuclear magnetic resonance spectroscopy (ZIP) for the analysis of polymers has been reviewed. The Society of Plastics Engineers has compiled a list of specifications and standards for plastics ( 3 I R ) . Thermosetting Plastics
T h e total annual production of phenolic resins is now in excess of 1 billion pounds (8Q). Approximately 400 million pounds of reinforced phenolic resins and 250 million pounds of phenolic molding compounds were produced last year. The physical characteristics of phenolic molding compounds have been reviewed (24). Phenolic molding compounds may be molded by compression, jet, and injection molding techniques (9Q). These resins have been blended with other thermosetting resins ( I Q ) , and phenolformaldehyde condensates have been grafted on nylon ( I IQ). Sulfur modified phenolic resins have been described (44). A reduction in selling price and an increase in use of melamine resins may be anticipated as a result of a iiew commercial synthesis based on the ammoniation of urea. Over 100 million pounds of epoxy resins are produced annually, and it is anticipated that this volume will double by 1970 (34). A new mechanism has been proposed for curing epoxy resins with amine complexes of Lewis acids (SQ). Kew infrared spectrograms of epoxy resins (724) and iiew information on catalyst selection are available (6Q). A comprehensive review of epoxy resin technology has been published (74). The relationship of crack resistance to monomer content (134) and the fracture toughness of epoxy resins have been investigated (704). Plastics with excellent flame and temperature resistance have been obtained by blending phosphonitrilic and epoxy resins. Polyolefins
T h e almost 5 billion pounds of polyolefins produced this year will include almost 3 billion pounds of low density and over 1 billion pounds of high density polyethylene. T h e production of polyethylene has been re70
INDUSTRIAL A N D ENGINEERING CHEMISTRY
viewed (IR,IOR,19R). T h e kinetics of polymerization by emulsion (2OR) and radiation techniques ( I 3 R ) have been discussed. New information published on ethylene propylene terpolymers (9R)includes effects of catalyst and solvent (4R) and concentration of dicyclopeiitadiene (6R). Ethylidene bicycloheptene called ethylidene norbornene is also being used as the cross-linking agent in these systems. Peroxide and radiation continue to be used for cross-linking low density polyethylene (76R). A relationship has been shown between chain transfer constants and tlie rates of abstraction of hydrogen atoms by methyl radicals (75R). Copolymers of ethylene and maleic anhydride have been produced by y-ray and chemical initiation (I4R). Heat resistant plastics have been produced by the copolymerization of ethylene and S-vinyl carbazole (3R). Guidelines for testing polyolefins have been published ( 7 IR),as well as applications for chlorinated polyethylene (7R). Over 50 different components in new model automobiles are fabricated from polypropylene (7ZR). This polymer is being produced at an annual rate of over 500 million pounds by nine different producers. New information on the kinetics of pyrolysis of polypropylene has been provided (18R). T h e kinetics of the titanium trichloride catalyzed polymerization of propylene have been investigated (ZR). The properties of poly-1-butene and poly-4metliylpentene-1 have been reviewed (SR,8R,17R). Vinyl Halide Polymers
T h e oxychlorination process which utilizes the classical Deacon process for the oxidation of hydrogen chloride is replacing the acetylene and conventional ethylene processes for the production of vinyl chloride monomer (IS,2s). Techniques for the polymerization of vinyl chloride near its boiling point have been described (7s). New information has been provided on formulations (5S), processing parameters (9S),and molding techniques (8s)for pol) vinyl chloride. Kew information on plasticizers has been published (3S, 4S, 70s:7 I S ) , The annual production of plasticizers is now in excess of 1 billion pounds. T h e rheological and gelation properties of plastisols have been investigated (6s). New methods for the application of polytetrafluoroethylene have been described (12s).
Styrene Plastics
Over 2.5 billion pounds of styrene plastics will be produced this year. Chain transfer in the anionic polymerization of styrene has been studied ( Z T ) ,and the synthesis of block copolymers of polystyrene and acrylonitrile has been described (523. The thermodynamic properties of atactic polystyrene have been reported (477. Monodisperse polystyrene (6T ) and thermoplastic copolymers of styrene and butadiene ( 3 T ) are available. Copolymers of styrene and n-carbamoylmaleimide have been investigated ( 7 T ) . ABS copolymer continues to be one of the fastest growing of all plastic materials. I t is now being accepted for large structural uses. For example, over 300 pounds of this product are being used in a new thermoformed camper. New formulations (7OT) and processing techniques ( 9T ) have been discussed. The cold flow of blends of ABS with rubber, polyvinyl chloride ( 8 T ) , and polycarbonates ( 7 T ) has been investigated. Polyamides
Over 100 million pounds or about 10% of the total production of nylon is being used for plastics. The base materials for the production of nylon-6,6 are now being produced by the electrohydrodimerization of acrylonitrile ( 6 U ) . Polyamide films have been stabilized by the addition of metallic bromides (5U) or traces of aniline-phenolic resins ( 7 U ) . Nylon-6,10 may be produced in situ in wool by reacting hexamethylene diamine and sebacoyl chloride. The thermodynamic properties of this polymer have been determined ( 4 U ) . Nylon4 may be produced continuously by the aqueous catalyzation of caprolactam and removal of the low molecular weight products by vacuum distillation. T h e synthesis of @-vinylnylon-6,6 has been described ( 7 U ) , and transparent polymers have been produced by the condensation of terephthalic acid and alkyl substituted alkylene diamines ( 3 U ) . Poly-l,4-cyclohexylene-trans-methylene suberamide is available ( 2 U ) . Acrylates
T h e properties of acrylic resins have been reviewed (7V, 3 V ) . The polymerization of methyl methacrylate in the presence of chain transfer agents has been in-
vestigated ( 5 V ) . Blends of the copolymer of methyl methacrylate and acrylonitrile with polybutadiene have been approved for blow molding peanut butter jars. The stereo regularity of polyisopropyl acrylate ( 4 V ) and the dielectric relaxation of poly-n-butyl methacrylate (8V) have been studied. Acrylic acid is being produced by the direct oxidation of propylene. Both acrylonitrile and methacrylonitrile are being produced by the oxyammoniation of olefins. Colorless transparent polymers of acrylonitrile have been produced by bulk polymerization (7V). a-Chloroacrylonitrile is available commercially ( 2 V ). Fluoroajkylacrylates and methacrylates have been synthesized ( 6 V ) . Polyurethanes
The optimum conditions have been suggested for the preparation of elastomers from o-tolyl diisocyanate (5W). New polyurethanes have been synthesized from polyols (7W) and starch derived polyethers ( 2 W ) . New information has been published on the synthesis of polyurethanes or polyureas with long methylene chains (6W) and on the properties of oil resistant polyetherurethane-urea elastomers (4W). The synthesis of polyurethanes has been reviewed (3W). Miscellaneous Polymers
The processing and properties of polyphenylene oxide have been discussed ( 3 X , 5X). Polysulfonates have been produced by the condensation of diphenols and disulfonyl chlorides. Mechanisms have been proposed for the synthesis of polyxylenols ( 7 0 X ) . Vinyl acetate is being produced by the catalytic oxidation of ethylene and acetic acid. The latter may be synthesized directly from carbon monoxide and methanol. Copolymers of vinyl acetate and maleic anhydride have been prepared at low p H values in aqueous solution ( 4 7 ) . The preparation and properties of polyacrolein acetals have been discussed ( 1 4 X ) . New sources of acetal and polycarbonate resins are available ( 6 X ) . The properties of polyalkylene oxides have been reported ( 7 X ) . Propylene oxide may be produced by the direct oxidation of propylene. New information has been published on polyvinyl ethers ( 1 7 X ) , conductive plastics ( 7 X ) , and esters of cellulose and high molecular weight organic acids ( 8 X ) . VOL. 5 9
NO. 8
AUGUST 1 9 6 7
71
Several different water soluble cationic polymers of ethylene imine are commercially available ( 7 3 X ) . A new crystalline polyethylene terephthalate has been reported (QX), and progress in inorganic polymer chemistry has been reviewed (2X, 722’). REF ER ENC ES G e n e r a l Information (1A) Freeman, R . F., Boundy, R . A . , Harrington, R., Rubber Plastics Age 47 ( 7 ) , 777 (1966). (2A) Harrison, D. P., Rose, H. F., IND.EX. CHEM. FUXDAYENTALS 6 ( 2 ) , 161 (1967). (3A) Houwink, R., Modern Plastics 43 (121, 98 (1966); Plastica 19 (8), 320 (1966). (4A) Kline, G. M.,Modern Plaiticr 44 (6), 129 (1967). (5A) McCann, H., S P E J . 22 (71, 30 (1966). (GA) Parducci, M., Materie Plastiche Elastomere 32 (51, 450; (6), 594; (lo), 996 (1966). (7A) Sakaguchi, K., Nogese, K., Chem. SOC.J@nn J . 69 (6), 1199 (1966). (8A) Schroeter, J., Hugenschmidt, F., Kunrtrt~fee-Plastics13 (5), 209 (1966). (9A) Seymour, R . B., Plastics (Bus.) 18 ( Z ) , 1 3 (1967). (10A) Spencer, F . J., Hydrocarbon Process. Petrol. R e j n e r 4 5 ( 7 ) ,83 (1966). Plastics Structures (1B) Appl. Plastics 9 (101, 30 (1966). (2B) Bry, A , , Connaissance Plastiques 7 (66): 78 (1966). (3B) Cocks, T. C., PlarticsZnst. Proc., June 14-16, 1965, paper 3, p. 13. (4B) Colovos, G . C., McClellan, T. R., Rausch, K. W., Adhesives AEP 9 (11), 23 (1966). (5B) DeBell, R. S., SPE J . 22 (12), 17 (1966). (6B) Dellarocca, R. J., Spaulding, K . B., Plnrtica 19 (lo), 446; (11 j 505 (1966). (7B) Domininghaus, H., Kunststofe-Plastics 13 (j),194 (1966). (8B) Hawker, R . H., Rubber Plnrtics Age 4 7 ( 9 ) , 940 (1966). (9B) Hutchins, W. J., SPI Z7rt Tech. Conf. Proc., Feb. 1966, paper 20-E. (10B) Johnston, 4.H., Drewett, G. I. H., iVew Zeaiond E n g . 21 ( 3 ) , 126 (1966). (11B) Johur. A . S., Instr. Engr. 46 (71, 266 (1966). (12B) Kellam, B., SPE J.22 (121, 41 (1966). (13B) Kesting, R . E., Eberlin, J. E., J . Appl. PoiymerSci. 10 ( 7 ) , 961 (1966). (14B) Kirby, D . C., MacLeod, N. D., Plasticr Insf.P70c., June 14-16, 1965, paper 9, p. 51. (15B) Lewis, R . B., A S M E Paper 66, W A l R P , 1, Nov. 27-Dec. 1, 1966. (16B) Lien, A . P., Battelle Tech. Rev. 15 (4), 9 (1966). (17B) Lomax, .I. G., O’Rourke, J . T., Machine Design 38 (15), 158 (1966). (18B) Minor, Mr. R., Petro/Chem. Engr. 38 (2). 34 (1966). (19B) Nisen, A , , Rev. Belge des Matieres Plostiques 7 (11, 23 (1966). (20B) Nutt, M‘.O., Plastics Znst. Proc., June 14-16 (1965). (21B) Overbeck, C. F., Chem. E n g . 7 3 (19), 220 (1967). (22B) “Plastics in Building,” McGraw Hill (23B) Platzker, J., Mod. Plastics 44 (3), 105 (24B) Rowan, R . L., Overbeck, C. F., Hydrocarbon Process. Petrol. &finer 45 ( l ) , 128 (1966). (2jB) Seymour, R . B., IND.ENO.CHEII.35 ( l o ) , 848 (1961). (26B) Ibid., 58 (81,61 (1966). (27B) Sheer, A. E,, S P E J . 22 (6), 32 (1966). (28B) Sheridan, M . B., Appl. Plastics 9 ( 9 ) , 28 (1966). (29B) Sittig, M . , Plont Eng. 20 (8), 116 (1966). (30B) Skeist, I., “Plastics in Building,” Reinhold, New York, 1966. (31B) V a n Deven, D . A . , Rubber W o r l d 154 ( I ) , 87 (1966). (32B) Wendover, W . R., SPE J . 22 ( 6 ) , 44 (1966). (33B) Wimmers, H. J., Plastica 20 (I?, 20 (1967). Containers a n d Vessels (IC) Bursian, W,, Plastverarbeiter 17 (5), 261 (1966). (2C) Cheely, J. F., Plastics World 24 ( l ) , 24 (1966). (3C) Hoffman, D., Muller, T., Pelzecker, A . , Plartigues M o d . Elastomeres 18 ( l ) , 99 (1966). (4C) Lodi, F. E,, Shister, E . D., M o d . Plustics 44 (E), 123 (1967). ( 5 C ) Molijn, J. C., Plartica 19 (lo), 466 (1966). (6C) Pelka, A , , Plastiques Mod. Elastomers 18 (lo), 102 (1966). (7C) Schwelde, F., Peters, H., Plastusrarbeiter 17 (4), 189 (1966). (8C) Wilson, G. .4.R., Plartica 19 ( l o ) , 420 (1966). Composites ( I D ) Barret, F. R . , Prosen, S . P., McLean, 14’.L., Mech. Ens. 88 ( 2 ) , 38 (1966). (2D) Barton, G . M’. L., Rubber Plastics Age 47, 847 (1966). (3D) Bogacheva, E. F., Kiselev, A . V., Eltekov, Y. A , , Colloid J . U S S R 27 (6), 679 (1965). (4D) Brourman, L. J., Polymer Eng. Sci. 6 ( 3 ) ,263 (1966). (5D) Cowan, R . E., Ehart, E . P., A m . Ceram. Soc. Bull. 45 (5), 535 (1966). (6D) Cryor, E., Mater. Design Eng. 63 (4), 92 (1966). (7D) Demmler, K . , Kunststoffe 5 6 , 606 (1966). (8D) Donovan, C . F., Adhesiver Age 9 (3), 24 (1966). (9D) Dunn, P. A . , Rubber Plastics Age 4 7 (O), 953 (1966). (lOD) Fallich, G.: Bixler, A,, Marsella, R.. et n l . , Plastics Technol. 13 ( Z ) , 33 (1967). (11D) Fishlock, D., M e t . Work. Produc. 110 (33), 58 1966). (12D) Gardziella, A , . Kunstsloffe-Plasltcr 9 (5), 161 (1966). (13D) Gibson, E . J . , Laidlaw, R . A , , S m i t h , G . A , , J . Appl. Cheni. 16 (Z), 58 (1966). (14D) Gibson, P . R . S., Plastics (London) 31 (3481,1295 (1966).
72
INDUSTRIAL A N D ENGINEERING CHEMISTRY
Gilman, T. P., Zatsepin, K . S., el al., Int. Chem. Eng. 6 (Z), 247 (1966). Gorbatkina, Y. A., Plnste Kautschuk 13 ( 3 ) , 145 (1966). Hardesty, E. E., West. Plastics 14 (4), 47 (1967). Hoflman, K. A,,Fiala, E. R., SPE J. 22 (lo), 60 (1966). (19D) Holister, G. S., Thomas, C., “Fiber Reinforced Materials,” Elsevier, Kew York, 1967. (20D) Jafle, E. A., SPI Z7st Ann. Tech. Conf. PTGC., Paper 8c (1966). (21D) Jernigan, J. W., Plastics Technol. 1 3 (Z), 34 (1967). (22D) Kercha, Y. Y . , Voitsekhovskir, R . V., Vysokomolekul. Soedin. 8 (3), 415 (1966). (23D) Kwei, T. K., J.Polymer Sci. Pt. A 3 (91, 3229 (1965). (24D) Lipatov, Y. S., Plastic5Inst.-Trans. 34 (110), 83 (1966). (25D) Lindegren, C . R., Roth, C. F., SPE J.22 (7), 38 (1966). (26D) Maxwell, J., Plastics 31 (340), 149 (1966). (27D) May, C . A., Newey, H. S., Rea. Plait. Mod. 17 (117), 181 (1966). (28D) McDougle, S. M., SPE J.22 (12), 31 (1966). (29D) Menges, G., Kunststofe 5 6 , 818 (1966). (30D) Messing, hf., Ibid., 55, 948 (1965). (31D) Meyer, B., Plarte Kautschuk 13 ( 3 ) , 150 (1966). (32D) Page, R . C., Adhesioe Age 9 (12), 27 (1966). (33D) Parker, R . S . R., Taylor, P., “Adhesion and Adhesives,” Pergamon, New York, 1966. (34D) Preiswerk, E., Kunrtstoffe-Plasticr 1 3 (6), 262 (1966). (35D) Rosato, D . V.,S P E J . 22 (6), 36 (1966). (36D) Rubber Plastics Age 4 7 (2). 163 (1966). (37D) Rubens, L. C., Thompson, C. F., Nowak, R . W., Kunstsfoff~Rundschau13 ( 7 ) , 455 (1966). (38D) Schaper, H., Schitlko, H., Kunststofe 56, 824 (1966). (39D) Schmidt, D. L., Hawkins, H. T., RubberPlnsticr Age 4 7 (6), 642 (1966). (40D) Shiryaeva, G. V., Kurilenko, A . I., Karpov, V. I,., So& Plnsttcs 3, 6 2 (March 1966). (41D) Sterman S . Marsden, J. G., Pol)rner Eng. Sci. 6 (Z), 97 (1966); M o d . Plastics 44 ( G ) , 91 (1I., Purr iipp!. Chem. 12 (1-4), 127 (1966). (33P) Tung, L. H., J . Appl. Polymer Scz. 10, 375 (19661. (34P) \Valdman, M.H., Coupe, D . , Chem. Ind. 1967 (2), p. 69. (35P) b’ohl, bf. Chrrn. En!. 73 (16), 60 (1966).
e.,
Thermosetting- Plastics (1Q) Ashion, A. L., H a p . a r d , J. E . H., Plastics Znnst. (London) 7’ran.r. J . 34 (lo), 251 (1966). ( 2 Q ) Bainbridge, R . TV., SPE J . 22 (12), 37 (1966). ( 3 4 ) Brushwell, JY,, Auitrulion Paint J . 12 ( 7 ) , 23 (1966). (4Q) Cherubin, M . , Kunstrloff-Rundschau 13 (5), 235 (1966). (5Q) Harris, J. J., Temin, S. C., J . Bflpl. f o i j m e r Sct. 10, 523 (1966). (60) Hersch, P., Plasfrci Tecbnol. 12 (11), 37 (1966). ( 7 4 ) Lee, H., Neville, K., “Handbook of Epoxy Resins,” McGraw-Hill, New York, 1967. ( S Q ) Martino, C. F., SPE J . 23 (33, 961 (1967). (9Q) Morita, Y . , 22 (E), 57 (1966). (1OQj Montavoy, E. S., Ripling, E. J . , J . Afipl, Polymcr Sei.10 (O), 1351 (1966). (1lQ) Ravve, A , , Fitko; C. W., J . Poljrner Sei. Pt. A-7, 2533 (1966). ( I Z Q ) Serboli, G , , Kunrtstof8-Plastzcr 13 (4), 150 (1966). (13Q) Weatherhead. R . G., A m l j s t 91 ( 7 ) , 445 (1966). Polyolefins (1R) Albright,L.F.. Chem. Eng. 73 (26), 113 (1966); 74 ( Z ) , 169; (4), 159 (1967). (2R) Ambroz, J., Osecky, P., Mejzlik, J., et nl., .I. Polymer Sci. Pf. C 16, 423 (1966). (3R) Cornish, E. H.,Bush, E. L.: Kumar. M., Plarfics31 (340), 157 (1966). (4R) Cunningham, R. E., Rubber Chem. Technol. 40 ( Z ) , 556 (1967). (5R) Deanin, R . D., S P E J . 23 (l), 43 (2), 39 (1967). (6R) DeKock, R . J., Veermans, A , , Rubber Chem. Terhnol. 40 (Z), 563 (1967). (7R) Del Gatto, J., Rubber W o r l d 155 (61,5 3 (1967). (8R) Ehrig, R.J.. Godfrey, J. J., Krishnarnuihy, G . S., Advan. Ckem. Soc. 52, 105 (1966). (9R) German, G., H a n k , R., Vaughan, G., Riibter Chem. Technoi. 40 (21, 569 (1966). (1OR) Hansen, R. H., SPC J . 22 (6), 50 (1966).
74
INDUSTRIAL A N D E N G I N E E R I N G CHEMISTRY
Vinyl Halide Polymers (1s) Albright, L. F., Chem. Eng. 74 (7), 123; ( 8 ) , 219 (19673, (2s) Buckley, J. A., Ibid., 73 (24), 102 (1966). (3s) Deanin, R.D., SPE J . 22 (4), 18 (1966). (4s) Gould, R. F., “Plasticization and Plasticizer Processes,” Am. Cllem. Soc., Publ., M’ashington, D. C., 1965. (5s) Hyndman, J. R., Polymer Eng. Sm. 6 (2), 169 (1766). (6s) Johnson, C. W.,Brower, C. B., S P E J . 22 ( l l ) , 45 (1966). (7s) Juhasz, K., Plaste K a ~ t s c h u k14 (1). 2 (1967). (85) Kochis, S. N., Plastics W ~ i 25 d (2): 60 (1967). (9s)Parodis, R . A., Cham. En!. Progr. 62 (12): 68 (1966). (10s) Penn, W. S., Rubber J . 148 (4), 312 (1966). (11s) Rosato, D. V., Plastics I“/or!d 24 ( 8 ) : 38 (1966). (12s) Visser, P. J.: Plastica 19 (lo), 414 (1966). Styrene Plastics U T ) Arends, C. B., J. Appl. Polymr Sci. 10, 1099’(1966). (2T) Brooks, B. W., Chem. Cornmun. 1967 ( 2 ) . p. 68. (3T) Deanin, R . D., SPE J . 23 (l), 45 (1967). (4T) Griskey, R. G., Din, Lf.W., Gellner, C. A . , M o d . Plmfics44 11); 165 (1966). (5T) Kolesnikov, G. S.,Yaralor, L. K., V p k o m o EJhl. S o t d ~ n 8. ( l l ) , 2018 (1966). (6T) McIntyre, D., J . Res. N a i l . Bur. Sfd. 71 (l), 43 (1967). 17T) Noma, K.; Kiwa, M . , Kawade, A.?Kobunshi Kagaku 23 (258): 754 (1966). ’81) Polthoff, H., Kmststofe 56, 703 (1966). 9 T ) Rogcrs, T. H., Roennau, R . B., Chcm. Eng. Progr. 62 ( l l ) , 94 (1966). 10T) Wentworth, V. H., Rubber Plastics Age 47 (G), 655 (19663. Polyamides (1U) Baron, A. L., hlarshall, R. A., Mnkromol. Chem. 99, 243 (1966). (2U) Credali, L., .Mn!erie Plastiche Elortornerze 32 ( 7 ) ,758 (1966). (3U) Doffin, H., Pungs. W., Gabler, R., German Plostics 56 (8),1 (1966). (4C) Griskey, R . G., Din: M. W., Gellner, C. A . , AV.iod.Plarticr 44 13), 129 (1966). (5U) Kochetkov, N . A’., Rogov, V. hl., hlorzova, h-.V., e! el., Swiet Plastics 1966, p. 16 (March). (6U) Prescott, J. H.. Cihm. Eng. 72 (23), 238 (1966). (7U) Siderov, V. .4., Prosman, G . M . , Rogov, V.M., Soliet Plasfics 1966, June. p. 68. Acrylates (1V) Deanin, R. D . , S P E J . 23 (31, 90 (1967). (2V) Grarsie, N., Grant, E. 41., J . Polqmer Sei. Pt. A-7 4, 1821 (19663. (37.’) Hadley, D. J.: Hall, R.W., PlasficsInrf.(London) T m n s . J . 33 (121, 237 (1965). (4V) Mark, J. E., riesling, R. .A, Hughes, R. E., J.P l y Cheni. 70, 1895 (1966). (5V)0Miira, B. C . , Chadka. S. C., Ghosh, P., et ai., J . Poljmer Sci. PI. A-7 4, 901 (?266). (6V) Pirtman, A. G.; Sharp, D. L., Lundin, R . E., e t al.,fbid., p. 2637. (7V) Shavir, N.,Konigsbuch, AI., Ibzd., Pt. C 16, 43 (1966). (8V) Williams, G., Xdwards, D . A , , Trans. Faraday Soc. 62, 1329 (1966). Polyurethanes (1W) Kuryla, W.C., Critchfield, F.E., Platt. L. W., e t a!.. J . Celluiar Plaificr 2 (Z), 84 (1966). ( 2 W ) Leitheisen, R . H., Impala, C. N., Reid, I
