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Showing papers on "Polystyrene published in 1969"


Journal ArticleDOI
TL;DR: In this paper, star-shaped polystyrene samples have been synthesized by anionic block-copolymerization of styrene and divinylbenzene (DVB), the proportion of the latter monomer being of the order of a few molecules per living end.
Abstract: Star-shaped polystyrene samples have been synthesized by anionic block-copolymerization of styrene and divinylbenzene (DVB), the proportion of the latter monomer being of the order of a few molecules per living end. Vacuum technique was used and benzene was chosen as solvent. The samples were found almost free of linear polystyrene, and of very low polydispersity. The number of branches was found to be a function of the overall concentration, of the amount of DVB, and of the molecular weight of the linear precursor. The results obtained with the meta and the para isomers did not differ significantly, as far as the products themselves are concerned. However, spectroscopic investigations carried out during reaction showed that the reactivity of the 2 double bonds of the para isomer differ significantly, whereas this is not the case with the meta isomer.

134 citations


Patent
17 Jul 1969
TL;DR: In this paper, the authors describe a set of 1,4-butanedIOL POLYESTERS, which can be divided into two classes: 1.4-BUTANEDIOL and TEREPHTHALIC.
Abstract: BLENDS OF 1,4-BUTANEDIOL POLYESTERS SUCH AS DERIVED FROM 1,4-BUTANEDIOL AND TEREPHTHALIC OR NAPTHALENEDICARBOXYLIC ACID, WITH VINYL AROMATIC POLYMERS SUCH AS POLYSTYRENE GIVE SHAPED ARTICLES HAVING AN EXCELLENT BALANCE OF PHYSICAL PROPERITIES.

127 citations



Journal ArticleDOI
TL;DR: The morphology of solution cast films of butadiene and styrene block polymers in both stretched and unstretched state has been studied by electron microscopy, and has been related to the mechanical behavior of these materials as mentioned in this paper.
Abstract: The morphology of solution cast films of butadiene and styrene block polymers in both stretched and unstretched state has been studied by electron microscopy, and has been related to the mechanical behavior of these materials. These micrographs confirm the indications from dynamic properties that this material consists of a two-phase system in which the relationship between the phases is sensitive to the solvent system used in casting. Although the basic morphological unit is a polystyrene sphere of 100 A diameter dispersed in a matrix of polybutadiene, the interaction between spheres is complex. These spheres are more deformable than would be predicted from their glass transition temperature. The dynamic mechanical properties, stress-strain properties, and stress relaxation properties of block polymers of styrene and dienes can be explained in terms of the morphology and changes of morphology on stretching in the electron microscope.

82 citations


Journal ArticleDOI
01 Sep 1969
TL;DR: Adsorption of sodium dodecylbenzene sulfonate emulsifier has been measured on polystyrene (PS) and poly(methyl methacrylate) (PMMA) latex particles as mentioned in this paper.
Abstract: Adsorption of sodium dodecylbenzene sulfonate emulsifier has been measured on polystyrene (PS) and poly(methyl methacrylate) (PMMA) latex particles. Surface tension titration curves permit calculation of adsorption at various concentrations of emulsifier. The data fit a Langmuir isotherm equation and indicate a limiting area A 0 of 35 A 2 for an emulsifier molecule. The A 0 does not depend on the nature of the polymer. But at the critical micelle concentration the area A m per adsorbed emulsifier molecule is 53 A 2 on PS and 131 A 2 on PMMA in .005 N salt. For salt-free PS latex A m is 62 A 2 . Thus A 0 appears to be a characteristic of the emulsifier. But A m depends markedly on the nature of the polymer surface. Hence measurements of A m may be used to characterize a latex particle surface. PMMA grown on a PS seed latex appears to cover the PS surface completely, from an adsorption standpoint, with a PMMA shell as thin as 25 A.

75 citations



Journal ArticleDOI
H. Y. Ku1, L. C. Scala
TL;DR: In this paper, the product of the minimum charge dose required and the weight average molecular weight is a constant and is a characteristic of the polymer, and the average molecular weights have only a very minor effect on their efficiency as positive resists.
Abstract: Crosslinking polymers may be used as negative acting resists. The product of the minimum charge dose required and the weight average molecular weight is a constant and is a characteristic of the polymer. At an electron beam voltage of 10 kV, this Q‐M product is found experimentally to be 6.3 coul‐g/cm2‐mole for polystyrene, 1 coul‐g/cm2‐mole for poly (vinyl chloride), and 14 coul‐g/cm2‐mole for polyacrylamide. Degrading polymers may be used as positive acting resists. Their average molecular weights have only a very minor effect on their efficiency as positive resists. Their glass transition temperatures are an important factor. It is recommended that these resists be prebaked at , stored and developed at , and postbaked at .

70 citations


Journal ArticleDOI
TL;DR: In this article, the effects of temperature and penetrant activity on the sorption kinetics and equilibria of a series of alkanes in glassy, biaxially oriented polystyrene were studied.
Abstract: The effects of temperature and penetrant activity on the sorption kinetics and equilibria of a series of alkanes in glassy, biaxially oriented polystyrene were studied. Normal isomers of pentane, hexane, and heptane cause crazing of polystyrene film samples at high penetrant activities (> 0.85). Crazing kinetics are identical to the kinetics of Case II transport. Transport of these normal hydrocarbons in glassy polystyrene in the temperature range 25 to 50°C is markedly non-Fickian; limiting Case II transport is observed at activities in exces of 0.6. Sorption appears to be controlled by highly activated relaxation processes including primary bond breakage at these high penetrant activities. Fickian diffusion behavior is approached, however, as penetrant activity is reduced. Sorption of the branched isomers of these compounds does not result in polymer microfailure. The sorption kinetics of the branched isomers, although time dependent, appear to be controlled primarily by thermally activated diffusion rather than large scale polymer relaxations which control Case II transport.

66 citations


Journal ArticleDOI
TL;DR: In this paper, the surface charge density of the particles was reduced by lowering pH, and increased by adding anionic surfactant, and the effect of these changes on the flocculation behavior has been investigated.
Abstract: Monodisperse polystyrene particles, with surface carboxyl groups, have been prepared by emulsion polymerization. These have been used in flocculation studies with two commercially available cationic polyelectrolytes, one of low and the other of high molecular weight. Surface charge density of the particles was reduced by lowering pH, and increased by adding anionic surfactant. The effect of these changes on the flocculation behaviour has been investigated. The results, together with electrophoretic data, indicate that polymer bridging is a significant mechanism for the high-molecular weight flocculant, but that the low-molecular-weight polymer is effective mainly as a result of charge neutralization.

58 citations


Patent
18 Mar 1969
TL;DR: In this article, a linear block copolymer consisting of at least one organosiloxane block (A) containing at least 20 units of the formula R2SiO- was defined.
Abstract: A composition comprising (1) an organic polymeric material selected from the group consisting of polyolefins, polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, polystyrene, polymethyl methacrylate, natural rubber, polyisoprene, butadiene-styrene copolymer, chloroprene polymers, isobutylene polymers, acrylic resins, epoxy resins, polyamides, butadiene-acrylonitrile copolymers, melamine-formaldehyde resins, phenol-formaldehyde resins, and urea-formaldehyde resins; and (2) from 0.001 to 10 percent by weight based on the weight of said organic polymeric material of a linear block copolymer comprising at least one organosiloxane block (A) containing at least 20 units of the formula R2SiO- wherein each R is selected from the group consisting of hydrogen atoms, monovalent hydrocarbon radicals, monovalent halogen-substituted hydrocarbon radicals and amino alkyl radicals and at least some of the R groups in said organosiloxane block are not hydrogen; and an organic block (B) selected from the group consisting of polymers formed by the polymerization of at least one compound selected from the group consisting of methyl methacrylate, styrene, chlorostyrene, alpha methyl styrene, vinyl chloride, vinyl pyridine, acrylonitrile, butadiene, isoprene, epsilon-caprolactum, and olefins, said organic block being at least partially compatible with said organic polymeric material; and said linear block copolymer being of the type BAB or of the type AB wherein B represents said organic block and A represents said organosiloxane block.

56 citations


Patent
01 Jul 1969
TL;DR: In this paper, a method for making at least one chemically combined IMIDO-SUBSTITUTED ORGANIC RADICAL is provided and a methodology for making SUCH MATERIALS is presented.
Abstract: POLYARYLENEOXIDE HAVING AT LEAST ONE CHEMICALLY COMBINED ALIPHATICALLY UNSATURATED IMIDO RADICAL IS PROVIDED AND A METHOD FOR MAKING SUCH MATERIALS. BLENDS OF THE IMIDO-SUBSTITUTED POLYARYLENEOXIDE AND A VARIETY OF ALIPHATICALLY UNSATURATED ORGANIC MONOMERS, SUCH AS STYRENE, DIALLYLPHTHALATE, N-PHENYLMALEIMIDE, OR ORGANIC POLYMERS SUCH AS POLYSTYRENE, POLYSULFONE, POLYCARBONATE, POLYPHENYLENEOXIDES, ETC., ALSO ARE PROVIDED. THE IMIDO-SUBSTITUTED COMPOSITIONS OF THE PRESENT INVENTION CAN BE EMPLOYED AS COATINGS, VARNISHES, INJECTION MOLDING COMPOUNDS, LAMINATING COMPOUNDS, ETC.

Patent
01 Jul 1969
TL;DR: In this paper, the authors provide a comparison of the IMIDO-SUBSTITUTED POLYCARBONATE with VARIOUS ALIPHATICALLY UNSATURATED MONOMERS, SUCH as StylENE, CHLOROSTYRENE, N-PHENYL MALEIMIDE, DIALLYLPHTHALATE, TRIALLYLCYANURATE, ETC.
Abstract: POLYCARBONATE COMPOSITIONS ARE PROVIDED COMPRISING POLYCARBONATES SUBSTITUTED WITH AT LEAST ONE CHEMICALLYCOMBINED ALIPHATICALLY UNSATURATED IMIDO RADICAL, SUCH AS A MALEIMIDO RADICAL. THE IMIDO-SUBSTITUTED POLYCARBONATES CAN BE BLENDED WITH VARIOUS ALIPHATICALLY UNSATURATED MONOMERS, SUCH AS STYRENE, CHLOROSTYRENE, N-PHENYL MALEIMIDE, DIALLYLPHTHALATE, TRIALLYLCYANURATE, ETC. AND VARIOUS ORGANIC POLYMERS, SUCH AS POLYSTYRENE, POLYCARBONATE, POLYSULFONE, POLYPHENYLENEOXIDE, POLYURETHANE, ETC. THE POLYCARBONATE, COMPOSITIONS OF THE PRESENT INVENTIONS CAN BE EMPLOYED AS MOLDING COMPOUNDS, FOR MAKING FILMS, LAMINATES, ETC.


Journal ArticleDOI
TL;DR: In this article, the authors present a model which invokes a coupling mechanism between two distinct modes of side group motions for dielectric measurements of polystyrene and poly(2,3,4 or 3,4-chlorostyrene) at audio frequencies ranging from 0.1 to 20 kHz.
Abstract: Dielectric measurements of carefully purified specimens of polystyrene and poly(2,3,4 or 3,4-chlorostyrene) have been obtained at audio frequencies ranging from 0.1 to 20 kHz and at temperatures between 4 and 300°K. Each of the samples exhibits a dielectric loss maximum in the range 15–50°K. The temperature of the maximum loss decreases with the addition of a substituent which lowers the symmetry of the pendant phenyl group. The results are explained by a model which invokes a coupling mechanism between two distinct modes of side group motions. This same model also explains some results of previously reported measurements of mechanical losses in similar polymers.

Journal ArticleDOI
01 Jan 1969-Polymer
TL;DR: In this paper, an anionic polymerization procedure for preparing styrene and methyl methacrylate block copolymers is described, and the products are characterized by combustion analysis, osmometry, light scattering measurement, and gel permeation chromatography.

Journal ArticleDOI
TL;DR: In this paper, a hydrogen-bonded intermediate complex with reaction mechanisms was proposed for formic acid dehydration in a flow reactor at atmospheric pressure and temperatures between 110 and 157 °C.

Journal ArticleDOI
TL;DR: In this article, a volume generated by electron bombardment was determined, and flight times of predominantly mobile carriers to the bombarded surface determined, using a single activation energy, and the temperature dependence of mobility was analyzed.


Patent
21 Jan 1969
TL;DR: In this article, expanded polystyrene pearls are made in sandwiches of which the layers differ in their constitution, the size of the pearls, their densities and the like.
Abstract: Objects of expanded polystyrene pearls are made in sandwiches of which the layers differ in their constitution, the size of the pearls, their densities and the like. Such objects are stronger, more flexible, and provide better sound and heat insulation than objects of like thickness made from a single type of material. Sandwiches of cellular polystyrene and cellular polysulfone, and sandwiches of different kinds of cellular polystyrene, or different polysulfones exemplify the invention. Novel machinery is provided for making the new materials.

Journal ArticleDOI
TL;DR: In this article, it was shown that for high concentrations of solute, less than 25% of the solute triplet states are derived from ion neutralization inside the spur and no evidence of intersystem crossing from solute excited singlet states was observed.
Abstract: Polystyrene and poly(methylmethacrylate) (PMMA) containing diphenyl and naphthalene as solutes have been studied by nanosecond pulse radiolysis. Solute negative ions were detected in PMMA but not in polystyrene. Solute triplet states were formed in times short compared with the lifetimes of the solute excited singlet states, whose presence was observed via their fluorescence. G (triplet) values of 0.2M samples of naphthalene and diphenyl in polystyrene were estimated to be 1.7 and 1.3, respectively. It is also shown that for high concentrations of solute less than 25% of the solute triplet states is derived from ion neutralization inside the spur. No evidence of intersystem crossing from solute excited singlet states was observed. Triplet yields in PMMA were smaller than those in polystyrene by a factor of 2 or more and were strongly affected by other transient species accumulated in previous irradiations. This latter quenching mechanism appears to involve the precursor, rather than the solute triplet states themselves. Possible modes of solute triplet‐state formation are discussed, and it is concluded that triplet energy transfer from the solvent is the most probable mechanism.

Patent
13 Jan 1969
TL;DR: In this paper, heat-insulating compositions are made by mixing porous plastic particles with an inorganic binder consisting of a suspension of water-containing particles of alkali metal silicate and inorganic fillers in an aqueous solution of an alkali-metal silicate, and solidifying at a temperature above > 0 DEG C. but below that at which the plastic sinters can be assisted by extracting water down to a content of 20%.
Abstract: Heat-insulating compositions are made by mixing porous plastic particles with an inorganic binder consisting of a suspension of water-containing particles of alkali metal silicate and inorganic fillers in an aqueous solution of an alkali metal silicate, and solidifying at a temperature above >0 DEG C. but below that at which the plastic sinters. Solidification can be assisted by extracting water down to a content of 20%, by treatment with carbon dioxide, or by the application of pressure. The porous plastic may be polyurethane, polystyrene, copolymers of styrene and acrylonitrile, acrylic acid, or butadiene, vinyl chloride, or copolymers of vinyl chloride and vinylidene chloride. Flame retardants such as inorganic halogen compounds or mixtures of chloroparaffins and antimony trioxide may be included. The alkali metal silicate powder is preferably sodium silicate containing 16-20% water and having an Na2O/SiO2 ratio of 1:2.0 to 1:4.0. The solution is of 15-60 DEG Be1 concentration, and the total water content varies between 25 and 75% of the weight of the silicate. Magnesia, talc, calcium carbonate, powdered asbestos, glass, quartz, zinc carbonate, sodium silicofluoride, or silica gel can be used as fillers in the ratio of 1:1 to 4:1 relative to the anhydrous silicate.

Journal ArticleDOI
TL;DR: In this article, the formation of radicals detected by ESR spectroscopy is greatly reduced in the presence of pyrene, while crosslinking and hydrogen production are almost unchanged.
Abstract: In γ-radiolysis of polystyrene at room temperature, the formation of radicals detected by ESR spectroscopy is greatly reduced in the presence of pyrene, while crosslinking and hydrogen production are almost unchanged. The formation of these radicals was shown to start from the first excited singlet state of polystyrene competing with radiationless energy transfer to pyrene. Crosslinking and hydrogen production, on the other hand, are independent of the formation of these radicals and attributable to hot hydrogen or ion-molecule reactions. Besides energy transfer from polystyrene to pyrene by dipole–dipole interaction the results indicate that intramolecular energy transfer within polystyrene is present.


Journal ArticleDOI
TL;DR: In this article, the effect of microstructure on the glass temperature T(g) of poly(alpha-methyl styrene) has been investigated, and it has been observed that T increases as the syndiotacticity of the molecule increases.
Abstract: : The effect of microstructure on the glass temperature T(g) of poly(alpha-methyl styrene) has been investigated. It has been observed that T(g) increases as the syndiotacticity of the molecule increases-thus T(g) = 446K for polymer with 67% syndiotactic placements, while a value of T(g) = 453K is found for a sample with 95% syndiotactic placements. Coefficients of expansion for the liquid and glassy states have been calculated and from these a chain stiffness parameter has been estimated using the Gibbs-DiMarzio theory. The result indicates that the flex energy of the alpha-methyl styrene chain is about 20% larger than for the polystyrene chain. (Author)

Patent
03 Sep 1969
TL;DR: A mixture of buoyant small pieces, flakes, grains and powdery adsorption agents contain polystyrene foam and also foam materials of polyurethane and/or hardened polycondensation resins as mentioned in this paper.
Abstract: A mixture of buoyant small pieces, flakes, grains and powdery adsorption agents contain polystyrene foam and also foam materials of polyurethane and/or hardened polycondensation resins, pref. a mixture of 10-90 wt.% polystyrene and 90-10% polyurethane, the amounts dependent on the oil to be adsorbed. Heavy oils require an excess of polystyrene and light oils an excess of the polyurethane. Used to remove oil emulsions from industrial waste water.

Journal ArticleDOI
TL;DR: In this paper, a new synthetic route involving the Wittig reaction was used to obtain poly-2,6-dimethoxystyrene (P26) backbone by polymerizing styrene with stannic chloride as catalyst in the presence of various concentrations of preformed P26.
Abstract: Poly-2,6-dimethoxystyrene (P26) was used as the polymeric backbone and was obtained by a new synthetic route involving the Wittig reaction. The grafting reaction was studied by polymerizing styrene with stannic chloride as catalyst in the presence of various concentrations of preformed P26 in solution with carbon tetrachloride and nitrobenzene at 60, 45, 30, and 0°C. The product was fractionated with cyclohexane and the fractions were analyzed by ultraviolet absorption spectroscopy and density-gradient ultracentrifugation. The molecular termination constant of P26 at 30°C was 0.106 much larger than the value of 0.016 which had been obtained for poly-p-methoxystyrene at 0°C. The amount of grafting and grafting efficiency generally increased with increasing temperature, contrary to results using the cationic initiation reaction. Anomalous results were obtained at 0°C as the product was no longer completely soluble. The ratio of grafted to ungrafted polystyrene chains was proportional to the concentration of P26 and generally increased with temperature. The grafting reaction was competitive with the normal termination reaction, and the energy of activation of the grafting reaction was estimated to be larger by ca. 7 kcal/mole.

Patent
21 Mar 1969
TL;DR: In this article, the block car drivers of the ABA type are described in terms of a platoon of block cars, in which one unit is a patrol car and the other is a dynamite dynamite.
Abstract: BLOCK COPOLYMERS OF THE ABA TYPE ARE DESCRIBED IN WHICH BOTH A UNITS ARE POLYPIVALOLACTONE, OR OPTIONALLY ONE A UNIT IS POLYSTYRENE, AND THE B UNIT IS A POLYDIENE (ISOPRENE OR BUTADIENE). THE BLOCK COPOLYMERS ARE USEFUL ELASTOMERS WHICH REQUIRE NO VULCANIZATION. WHEN THE TWO A UNITS ARE THE SAME, THE POLYDIENE UNIT IS FIRST FORMED WITH TWO "LIVING" ANIONIC GROUPS, E.G., FROM SODIUM OR LITHIUM, AND POLYPIVALOLACTONE FORMED FROM THE ENDS. WHEN POLYSTYRENE IS PRESENT, IT IS FIST FORMED WITH N-BUTYLLITHIUM, THE DIENE POLYMERIZED ON THE "LIVING END" OF THE POLYSTYRENE, AND THE POLYPIVALOLACTONE PRODUCED ON THE "LIVING END" OF THE DIENE.

Journal ArticleDOI
TL;DR: In this paper, T 1 measurements were made for each species of proton as a function of solution composition for the solvent, non-solvent pairs benzene + cyclohexane, benzene+ heptane, and dioxane + polystyrene.
Abstract: T 1 measurements were made for each species of proton as a function of solution composition for the solvent, non-solvent pairs benzene + cyclohexane, benzene + heptane, and dioxane + heptane. When polystyrene is dissolved in these mixtures, the relaxation times of the solvent protons are reduced. Calculations of preferential adsorption of good solvent by polymer can be fitted to the data obtained from light-scattering results for the systems benzene + cyclohexane + polystyrene, and for benzene + heptane + polystyrene but not for dioxane + heptane + polystyrene.

Journal ArticleDOI
TL;DR: In this article, a graft copolymer was formed by forming a derivative with trimethylchlorosilane and examining by NMR, it was possible to establish the proportion of lithium scavenged by impurities, the amount of polymeric lithium which reacted with styrene, and the amount which did not.
Abstract: Styrene has been grafted onto poly(2,6-dimethyl-1,4-phenylene ether) (I) with the use of lithiated I as an initiator. In benzene solution, solvent metalation resulted in some polystyrene homopolymer. In tetrahydrofuran, however, only graft copolymer was formed. By forming a derivative with trimethylchlorosilane and examining by NMR, it was possible to establish the proportion of lithium scavenged by impurities, the amount of polymeric lithium which reacted with styrene, and the amount which did not. The chain length of the grafted polystyrene was also calculated. No crosslinking was found, except where a high ratio of lithium to styrene resulted in some unreacted ring-metalated polymer. In this case only, reaction with trimethylchlorosilane causes some crosslinking.

Journal ArticleDOI
A Lambert1
01 Jan 1969-Polymer
TL;DR: In this article, a method of measuring the glass transition temperature of a polystyrene sample using a Perkin-Elmer differential scanning calorimeter DSC-1 was developed.