Showing papers on "Polycarbonate published in 1972"

Deformation and annealing behavior. III. thin films of polycarbonate, isotactic polymethyl methacrylate, and isotactic polystyrene

Abstract: The morphology of thin films of polycarbonate (PC), isotactic polymethyl methacrylate (i-PMMA), and isotactic polystyrene (i-PS) were studied by bright field, diffraction, and dark field transmission, electron microscopy. The films were thermally annealed both before and after uniaxial deformation. The undrawn i-PMMA did not develop a crystalline texture upon annealing whereas the undrawn i-PS developed a random arrangement of lamellae. Thermal crystallization of undrawn PC has been shown to occur through the growth and merging of a nodular structure into fibrillar spherulites. Deformation of gold-decorated samples indicated a nonhomogeneous structure in the amorphous polymer on the 200-500 A scale. Thermal annealing of drawn samples resulted in fibrillar lamellae arranged perpendicular to the draw direction for all three polymers, indicating the straining has a marked influence on the crystalline morphology. This morphology is compared to similar morphologies reported in the literature for cryst...

Craze yielding and stress-strain characteristics of crazes in polystyrene

Abstract: The crazing behaviour of a grade of polystyrene which crazes profusely when tested in tension has been studied at 293°K using quantitative optical, electron and electron scanning microscopy. Tensile tests on this material showed that a high density of crazes was produced at room temperature. The crazes formed in a zone which spread progressively down the specimen. The plastic strain associated with crazing was sufficient to cause craze yielding and the phenomenon is compared with discontinuous yield in mild steel. Craze-yielded specimens were used to determine the stress—strain curve of craze material. Microstrain techniques were developed for this work and the total volume of craze was determined from the density, distribution and thickness of the crazes. It was found that the stress—strain characteristics of polystyrene crazes are similar to those observed by Kambour and Kopp (1969) for solvent-induced crazes in polycarbonate.

Gas transport in glassy polymers

Abstract: Sorption kinetics and equilibria for CO2 in polycarbonate were studied over a range of temperatures from 35° to 65°C and pressures from 3 to 22 atm. The dual mode sorption model of Vieth et al. was used to test the data, and a comparison was made with previous work on glassy polystyrene. Further evidence of the validity of generality of the model in providing a consistent picture of small-molecule diffusion in glassy polymers was thereby provided. The technical feasibility of membrane separation of H2 from a H2/CO2 mixture by selective permeation through polycarbonate was examined at 50°C.

Crazing of Polymers at Low Temperatures in He, Ar, N 2 and at Reduced Pressure

Abstract: IT is generally thought that having a polymer immersed in liquid nitrogen does not affect its stress-strain behaviour. We found that liquid and gaseous nitrogen and liquid argon affect the tensile stress-strain curve and the mode of fracture of amorphous polymers. Previous investigations at ∼78 K of the tensile behaviour of amorphous polymers have been conducted in liquid or gaseous nitrogen. Polymethyl methacrylate (PMMA), when stretched in liquid nitrogen, showed severe crazing1 with increased fracture toughness at 78 K. Beardmore and Johnston2 and Beardmore3 investigated PMMA tested in tension at 78° C; in the former paper no mention was made of test environment; in the latter paper, the specimen was surrounded with lead shot cooled with liquid nitrogen. Beardmore and Rabinowitz4 studied tensile crazing of PMMA, polycarbonate (PC) and polysulphone (PSF) at 78 K, but they did not specify the environment (S. Rabinowitz, private communication). Ekvall and Low5 studied PC from 78 to 300 K in nitrogen gas and found a ductile-to-brittle transition between 90 K and 143 K. Our work suggests that this transition was an environmental effect of the nitrogen gas.

Resinous composition comprising a blend of an abs resin and polycarbonate resin

Abstract: An impact-resistant composition comprising a blend of (1) an ABS resin prepared by the so-called bulk suspension polymerization, and (2) a polycarbonate resin, and a flame-resistant resin composition which is formed by incorporating into said impact-resistance resin composition a halogen compound and antimony trioxide as flame retardant.

Thermoplastic polycarbonate/polybutadiene-methacrylate-styrene graft polymer/styrene-acrylonitrile copolymer blends

Abstract: A thermoplastic resinous composition (D) comprising A. a resin obtained by graft polymerizing 90 - 10 parts by weight of a monomeric mixture consisting of 90 - 10 percent by weight of a monomeric methacrylic acid ester and 10-90 percent by weight of an aromatic vinyl monomer, in the presence of 10 - 90 parts by weight of a polybutadiene or butadiene copolymer containing at least 50 percent by weight of butadiene unit; B. a thermoplastic resin obtained by copolymerizing an aromatic vinyl monomer with 15 - 70 percent by weight of said aromatic monomer of a vinyl cyanide monomer; and C. a polycarbonate resin derived from a (4,4'-dihydroxy diphenyl)alkane; WITH THE PROVISION THAT THE RATIO OF THE TOTAL AMOUNT CONTAINED OF THE RESIN (A) and the thermoplastic resin (B) to resin (C) is in the range of 70:30 - 10:90, and that polybutadiene or the butadiene copolymer component containing at least 50 percent by weight of butadiene unit is contained in an amount of 5 - 50 percent by weight of the total amount contained of the resin (A) and the thermoplastic resin (B).

Stabilized aromatic polycarbonates

Abstract: AROMATIC POLYCARBONATES HAVING ADDED A NEUTRAL ESTER OF PHOSPHOROUS ACID WITH AT LEAST ONE OXETANE GROUP, THE LATTER FUNCTIONS AS A STABILIZER FOR THE POLYCARBONATE TO LESSEN DISCOLORATION AFTER EXPOSURE TO HEAT. THUS, THE POLYCARBONATES OF THE INVENTION ARE PARTICULARLY USEFUL IN THE LIGHTING FIELD.

Thermally stable flame retardant polycarbonate composition comprising a polycarbonate and a stabilizer

Abstract: A THERMALLY STABLE POLYCARBONATE COMPOSITION CONSISTING OF IN ADMIXTURE AN AROMATIC POLYCARBONATE AND 0.05 TO ABOUT 2.0 WEIGHT PERCENT OF A PARTICULAR ADDITIVE. THE PARTICULAR ADDITIVE EMPLOYED HEREIN IS ONE THAT IS A MIXTURE OF (A) EITHER A BARIUM, CADIUM OR CERIUM OR OF ALIPHATIC ACID OF 2 TO 16 CARBON ATOMS OR A BARIUM OR CADIUM CARBONATE AND (B) A PHOSPHINITE OR A PHOSPHONITES.

Mechanical Properties of Very Thin Polymer Films

Abstract: The uniaxial and biaxial mechanical properties of five thin film polymers have been measured. Parylenes N, C, and M exhibit uniform properties to thicknesses as low as 0.12 μ; the 4.3 μ polyester (Mylar) and the 2.3 μ polycarbonate (Kimfol) show tensile and elongation properties inferior to those measured on thicker sections. Biaxial rupture strengths were found to vary directly with film thickness and inversely with the half‐power of the unsupported area. The measured rupture constant is shown to be a function of the tensile strength and ultimate elongation of the material.

Polyester molding compositions with triaryl phosphate and a polyphenylene oxide or a polycarbonate of bisphenol a

Abstract: TRICOMPONENT BLENDS OF COPOLY(BISPHENOL A TEREPHTHALATE/ISOPHTHALATE), TRIARYL PHOSPHATE AND EITHER POLY(2,6-DIMETHYL PHENYLENE OXIDE) OR BISPHENOL 9 POLYCARBONATE, OR MIXTURES THEREOF POSSESS REDUCED MELT VISCOSITY CHARACTERISTIC OF THE EFFECT OF ADDITION OF LOW-MOLECULARWEIGHT ADDITIVES WHILE MAINTAINING MECHANICAL PROPERTIES CHARACTERISTIC OF POLYMER ADDITION. THESE COMPOSITIONS CAN BE EXTRUDED AND INJECTION MOLDED AT TEMPERATURES UNEXPECTEDLY LOWER THAN IS CHARACTERISTIC OF EITHER TYPE OF BICOMPONENT SYSTEM TO GIVE EXTRUDED SHEET AND FILMS, PHOTOGRAPHIC BASE FILM, FOAMED ARTICLES, AND BLOW-MOLDED BOTTLES HAVING GOOD MECHANICAL PROPERTIES.

Chain‐backbone motion in glassy polycarbonate studied by polarized infrared spectroscopy

Abstract: Chain-backbone motion in glassy polycarbonate has been investigated both under isothermal stress, and also under zero stress during isothermal annealing of freely contracting film specimens. In both types of experiment, backbone motion was detected by measuring the change in infrared dichroism. The dichroism of absorption bands at 1364 and 2971 cm−1, which have transition moment vectors directly related to the chain-backbone orientation, was studied. Under tensile stress in the homogeneous region of deformation, changes of up to 2.2° in the mean chain-backbone orientation angle were measured at 23°C. With the onset of cold drawing a total orientation change of some 8° was observed. For the isothermal annealing experiments, a film specimen holder employing conductive heating with radiative losses was employed. It enables infrared measurements to be made while the temperature of the contracting specimen is maintained constant to ± 0.5°C. Oriented specimens were prepared by isothermal stretching of polycarbonate films to strains of the order of 100%. Changes in the mean chain-backbone orientation angle were observed during annealing of these oriented films at temperatures between 80°C and the glass transition (149°C). Chain motion proceeded during annealing, and chain segments were observed to move cooperatively. The temperature at which the polymer is prestretched has a pronounced effect on its subsequent relaxation during annealing: when the sample was stretched at 23°C. motions were detected during annealing at temperatures as low as 81°C, while, if it was stretched at 154°C, no motion was detected at annealing temperatures below 127°C. The data are discussed in comparison with theories of the glassy state that predict the absence of chain-backbone motion at temperatures significantly below the glass transition. A shift in frequency of the νa (CH3) absorption peak in stretched polycarbonate was measured by using polarized radiation. The effect was interpreted in terms of changes in the intermolecular bonding structure of the oriented polymer.

Polycarbonate molding composition comprising an aromatic polycarbonate graft copolymer and a modifier

Abstract: AN IMPROVED POLYCARBONATE MOLDING COMPOSITION HAVING IN ADMIXTURE THEREWITH MINOR AMOUNTS OF A GRAFT COPOLYMER OF A POLYBUTADIENE AND A MIXTURE OF AN ALKENYL CYANIDE AND A VINYL AROMATIC HYDROCARBON.

Thermoplastic resin composition comprising polycarbonates and polyarylene esters

Abstract: A THERMOPLASTIC RESIN COMPOSITION OF POLYCARBONATE IMPROVED IN IMPACT STRENGTH AND HEAT DEFORMATION RESISTANCE WHICH COMPRISES 1 TO 99% BY WEIGHT OF POLYCARBONATE RESIN AND 99 TO 1% BY WEIGHT OF POLYARYLENE ESTER ON THE BASIS OF THE TOTAL WEIGHT OF THE COMPOSITION.

Tensile yield energy in glassy polymers

Abstract: An activation energy theory of yielding in glassy polymers has been proposed by Starita and Keaton. It predicts a linear relation between energy to yield and test temperature. This concept was tested and found valid for five amorphous polymers; poly(methyl methacrylate), polycarbonate, polyarylsulfone, polysulfone and poly(vinyl chloride), in uniaxial extension at temperatures from 25°C to the glass transition. For extenstion rates of 0.2 in/min, yield energy was found to go to zero at Tg, as commonly determined by thermodynamic methods like dilatometry or scanning calorimetry. The effect of other extension rates, plasticizer and molecular weight appears to affect only the intercept much as Tg is affected by the same changes. The slope, or the ratio of thermal to mechanical energy efficiency in overcoming the flow activation barrier, is largely unchanged.

Automotive body panel molded from polycarbonate foam

Abstract: A structural foam article prepared by injection foam molding a unique polycarbonate resin has the definitive characteristics prerequisite for and is eminently useful as an external automotive body panel. The structural foam is prepared by injection foam molding the resin, which is pre-dried, either with high or low pressure processes at a mold temperature of from about 90* to 250*F, in a period of about 0.5 to 6 minutes. The polycarbonate resin is essentially derived from the reaction of phosgene and/or a bischloroformate and Bisphenol A and has admixed therewith silicon dioxide.

Fibrous glass filled polycarbonate resins

Abstract: An aromatic carbonate polymer having uniformly dispersed therein finely divided fibrous glass filaments. The glass filaments employed herein are those that have been treated or coated with a particular binding agent, namely a styrene-ethyl acrylate copolymer.

Thermally stable flame retardant polycarbonate composition containing in admixture a polycarbonate and a phosphinic or a phosphoric acid additive

Abstract: A THERMALLY STABLE FLAME RETARDANT POLYCARBONATE COMPOSITION HAVING IN ADMIXTURE A FLAME RETARDANT POLYCARBONATE AND AN ADDITIVE WHICH MAY BE EITHER THE BARIUM OR CADMIUM SALTS OF EITHER PHENYL PHOSPHINIC ACIDS OR MONO-OR DIPHENYL PHOSPHERIC ACIDS.

Blends of polycarbonate grafts on vinyl polymers with polycarbonates and/or vinyl polymers

Abstract: This invention relates to thermoplastic graft copolymers of a polymer backbone having aromatic hydroxy groups and an aromatic polycarbonate grafted onto said backbone via the aromatic hydroxy groups, and more especially to blends of said graft copolymer with aromatic polycarbonates and/or polymers of olefinically unsaturated monomers.

Transport and Mechanical Properties of Polycarbonate

Abstract: Sorption kinetics and equilibria for C02, A, and CO in polycarbonate were studied over a range of temperatures from 25°C to 120°C (Tg ≈ 150°C) and pressures from 3 to 23 atm. abs. The dual mode sorption model of Vieth and Sladek (1) was used to test the data. The microvoid free volume fraction was found to be the same as that for glassy polystyrene (2).

Polycarbonate-vinylidene fluoride hexafluoropropylene copolymer blend

Abstract: Blends of polycarbonate resin with vinylidene fluoridehexafluoropropylene copolymer are characterized by improved impact strengths, and especially by reduced notch width sensitivity.

Scratch proof coating for plastics - based on highly cross-linked polysiloxane from methyltrialkoxysilane

Abstract: Plastics surface is given a scratch-proof coating by applying a mixt. of a methyltrialkoxysilane with is not >4C in the alkoxy gps. in an organic solvent, contg. 0.5-1 mole water/mole silane and 0.15 wt.% of a strong inorganic acid (w.r.t. the silane), evaporating the solvent, and curing the silane in 10-15 min. at 80-85 degrees C, forming a highly cross-linked polysiloxane. A very hard coating can be produced on plastics such as polymethyl methacrylate, polycarbonate, polystyrene, polyacetal, polyethylene, polypropylene, PVC and cellulose ester. The coating is not scratched by paper or dry cigarette ash and has a lead pencil hardness >10 H. It is also resistant to water and org. solvents and is esp., useful for protecting such plastics as acrylic glasses which are prone to stress cracking.

Thermoplastic molding compositions and molded articles

Abstract: THERMOPLASTIC MOLDING COMPOSITIONS AND MOLDED ARTICLES WHICH HAVE A HIGH STIFFNESS ARE PROVIDED WHEREIN THE THERMOPLASTIC IS A POLYCARBONATE CONTAINING ASBESTOS FLOUR. THERMOPLASTIC MOLDING COMPOSITIONS AND MOLDED ARTICLES HAVING HIGH STIFFNESS AND FIRE RESISTANCE ARE PROVIDED WITH THE ASBESTOS FLOUR CONTAINING POLYCARBONATE ALSO CONTAINS FROM ABOUY 3% TO ABOUT 7% BY WEIGHT BASED ON THE TOTAL WEIGHT OF THE ABSESTOS FLOUR CONTAINING POLYCARBONATE OF GLASS FIBERS.

Effect of Interlayer on Impact Resistance of Acrylic/Polycarbonate Laminates

Abstract: : This paper describes an investigation of the relationships be-tween microstructure of transparent segmented polyurethane (PU) ADHESIVES, THEIR OPTICAL PROPERTIES AND LAMINATE BALLISTIC PER-FORMANCE THAT HAS LED TO A FORTY- FIVE PERCENT ADVANCE IN THE STATE-OF-THE-ART OF BALLISTIC RESISTANCE OF TRANSPARENT PLASTICS.

Mechanical degradation of organosilicon polymers

Abstract: Many studies have been made in recent years, in which the EPR method was used to elucidate the mechanism of mechanical degradation of polymers It was shown that degradation of organic synthetic and natural polymers takes place by the radical mechanism An analysis of EPR spectra of primary “mechanical” free radicals formed during polymer decomposition suggests that homolytic breakdown of chemical bonds in chains of main macromolecular valences in the initial mechano-chemical stage [1–3] To stabilize active free radicals formed during the decomposition of polymers, experiments should be carried out at low temperature Drilling or milling of polymers in liquid nitrogen is a simple method of decomposing polymers at low temperature, which ensures intensive cooling of the products of decomposition During the decomposition of polymers under these conditions EPR signals are always observed which indicate the formation of free radicals “Mechanical” free radicals were obtained from many organic polymers decomposed in liquid nitrogen EPR spectra have been reported in separate papers [1,2, 4–7] of free radicals stabilized at liquid nitrogen temperature in pieces of polyethylene, polyvinylchloride, polytetrafluorethylene, polyisobutylene, polymethyl methacrylate, polyvinylacetate, polystyrene, polyisoprene, polyethylene sulphide, polypropylene sulphide, thiokols, ebonite, polycarbonate, polyepoxide, polycaprolactam, polyurethane and keratin proteins We also observed EPR spectra of free radicals in polypropylene and polyethylene terephthalate

Fiber glass-reinforced resin compositions and their preparation

Abstract: 1,268,834. Compositions containing glass fibre. DART INDUSTRIES Inc. 16 June, 1969 [19 June, 1968], No. 30340/69. Headings C3P and C3R. A resin containing 40-90% by weight of glass fibre dispersed therein is blended with a dissimilar resin so that the final composition contains 15-40% by weight of glass and the resins and the glass fibre are intimately dispersed. Resin blends exemplified are styreneacrylonitrile copolymer with ABS resin, polyphenylene oxide, nylon, polycarbonate, polysulphone, polypropylene, and polyacetal; polystyrene with polyethylene, ABS, nylon, polycarbonate, polysulphone, polypropylene and polyacetal; polyethylene and nylon, polyacetal and a blend of polyphenylene oxide and polystyrene.

Polypropylene film - contg finely dispersed micro-particles of a thermoplastic

Abstract: Polypropylene film contains 0.01 to 1 wt %, based on polypropylene, of a synthetic thermoplastic resin having a pt. of higher than that of polypropylene and substantially little compatibility with polypropylene upon being melted is dispersed in the form of finely divided particle. The object is to provide a transparent polypropylene film improved in blocking resistance and smoothness. The thermoplastic synthetic resin is e.g. polyamides such as nylon 6, nylon 66 and the like, polyesters such as copolymer consisting mainly of polyethylene terephthalate and ethylene terephthalate, and polycarbonate. A uniform dispersion of the thermoplastic synthetic resin in microparticle (0.1-10 mu) into polypropylene is easily effected by extruding the molten blend through a die of an extruder.