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Showing papers on "Styrene-butadiene published in 1976"



Patent
04 Mar 1976
TL;DR: In this paper, the epoxidized polymers having the structure S-D/S-S or D/S/S -S-D or S-S/D-S was presented, where S represents a polystyrene block and D represents a tapered block of styrene.
Abstract: Epoxidized polymers having the structure S-D/S-S or D/S-S-D/S-S in which S represents a polystyrene block and D/S represents a tapered block of styrene and butadiene and/or isoprene, with the further provision that 5-95% of the olefinic unsaturation of the polymer has been epoxidized, exhibit good oil and ozone resistance.

43 citations


Patent
17 May 1976
TL;DR: Foams of mixtures of polyolefins and styrene polymers are produced by mixing the polymers with low-boiling expanding agents in the presence of a hydrogenated styrene/butadiene block polymer or a graft polymer of styrene on a polyolefin at temperatures above the softening point of the polymer mixture and under a pressure which prevents foaming of the mixture, followed by extrusion of the foamable mixture into a zone of lower pressure.
Abstract: Foams of mixtures of polyolefins and styrene polymers are produced by mixing the polymers with low-boiling expanding agents in the presence of a hydrogenated styrene/butadiene block polymer or a graft polymer of styrene on a polyolefin at temperatures above the softening point of the polymer mixture and under a pressure which prevents foaming of the mixture, followed by extrusion of the foamable mixture into a zone of lower pressure The resulting foams are resistant to organic solvents

24 citations


Patent
19 Apr 1976
TL;DR: In this paper, a process for repairing concrete compositions using cement mortar compositions which are capable of being pneumatically sprayed and which provide unexpectedly enhanced bonding capabilities and resistance to slump is described, which are essentially a substantially non-air entraining portland cement, mineral aggregate, a styrene-butadiene copolymer latex present on a solids basis in an amount of from about 5 to about 25 percent by weight of cement, and water in an amounts sufficient to provide a total water to cement ratio of from 0.22 to 0.26.
Abstract: Process for repairing concrete compositions using cement mortar compositions which are capable of being pneumatically sprayed and which provide unexpectedly enhanced bonding capabilities and resistance to slump; said compositions comprising essentially a substantially non-air entraining portland cement, mineral aggregate, a styrene-butadiene copolymer latex present on a solids basis in an amount of from about 5 to about 25 percent by weight of cement, and water in an amount sufficient to provide a total water to cement ratio of from 0.22 to 0.26.

22 citations


Patent
Pollock Richard1
23 Feb 1976
TL;DR: In this paper, low density latex foams are improved in abrasion resistance, wear character and water resistance by spray coating the surface with a coating composition comprising a carboxylated styrene butadiene latex and from 5 to 100 parts per hundred parts latex solids of a hydrocarbon wax.
Abstract: Low density latex foams are improved in abrasion resistance, wear character and water resistance by spray coating the surface with a coating composition comprising a carboxylated styrene butadiene latex and from 5 to 100 parts per hundred parts latex solids of a hydrocarbon wax.

21 citations


Journal ArticleDOI
01 Jan 1976-Polymer
TL;DR: In this paper, structural and morphological characterization of a cruciform styrene-butadiene block copolymer of the (SB)4Si type is reported together with the stress-strain properties of films prepared by compression molding.

15 citations


Journal ArticleDOI
01 Mar 1976
TL;DR: In this paper, the dynamic mechanical properties of polystyrene and polybutadiene copolymers were studied in free oscillation experiments near 0.2 Hz and in forced oscillations over a frequency range from 0.1 to 1000 Hz at various temperatures between 1 and 96°C.
Abstract: The dynamic mechanical properties of a polystyrene‐1,2‐polybutadiene‐polystyrene (SBS) triblock copolymer were studied in free oscillation experiments near 0.2 Hz from −50 to 100°C and in forced oscillations over a frequency range from 0.1 to 1000 Hz at various temperatures between 1 and 96°C. For data which covered essentially the polybutadiene transition region, the temperature dependence of the mechanical properties could be described by a WLF equation whose parameters are in close agreement with those describing homopolybutadiene of similar microstructure. Data outside the polybutadiene transition region showed considerable lack of superposition when reduced by the WLF equation, as observed earlier in a triblock of similar molecular architecture but having a 1,4‐polybutadiene center segment. Contour plots of the loss compliance as a function of the temperature and the logarithmic frequency revealed significant differences in the temperature and frequency dependence of various viscoelastic mechanisms r...

15 citations


Journal ArticleDOI
TL;DR: This work pertains to the development of high strength elastomers potentially useful as nonthrombogenic cardiovascular prostheses subjected to surface hydroxylation which provide reactive sites at the surface for the subsequent coupling of heparin while retaining the unique mechanical properties of the SBS copolymers.
Abstract: Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1974.

12 citations


Journal ArticleDOI
TL;DR: The results clearly indicate that in the range of styrene contents of 30-40 mol %, the modulus behavior is greatly affected as the solubility parameter of the casting solvent, delta, is varied.
Abstract: Using a well characterized series of styrene butadiene triblock copolymers a systematic study was carried out to determine the influence of casting solvent, used for film preparation, on the final mechanical properties. The results clearly indicate that in the range of styrene contents of 30-40 mol %, the modulus behavior is greatly affected as the solubility parameter of the casting solvent, delta, is varied. Specifically, the modulus increases as delta increases to the value of polystyrene. At lower or higher styrene content, the properties are influenced but to a much lesser degree. Other mechanical properties measured were yield stress and breaking stress. The ramifications of these data are discussed in light of preparing prosthetic material via solvent casting.

11 citations


Journal ArticleDOI
01 Jan 1976
TL;DR: In this paper, the amount and composition of various styrene/butadiene polymers adsorbed on the flocculated and stabilized fractions of silica dispersed in perchloroethylene (26°C) have been determined spectroscopically.
Abstract: The amount and composition of various styrene/butadiene polymers adsorbed on the flocculated and stabilized fractions of silica dispersed in perchloroethylene (26°C) have been determined spectroscopically. Centrifugation for 15 min at 11,900 × g separated the dispersed silica into flocculated and stabilized fractions. It was found that silica dispersed in C 2 Cl 4 will not resist removal from suspension by the centrifugation routine until polymer adsorbances exceed 140 to 160 mg/g silica. Above this threshold adsorbance, the fraction of silica stabilized increases in an essentially linear manner as polymer adsorbance on flocculated silica increases. Silica stabilizing capability of the various polymers examined depends solely on adsorbance. Block copolymers are superior to styrene/butadiene homopolymers or random copolymers as silica stabilizing agents in C 2 Cl 4 only when their adsorbances are higher. The fraction of silica stabilized is a function of agitation time, but polymer adsorbances associated with flocculated or stabilized silica appear independent of length of agitation. The effect of agitation on silica stabilization is interpreted in terms of the redispersion reaction whereby large flocs formed during initial silica/polymer solution mixing are slowly broken up. Compositional fractionation of the copolymers occurred when they adsorbed on the dispersed silica. Copolymer adsorbed on flocculated silica is richer in styrene than the original sample; copolymer adsorbed on stabilized silica contains less styrene; unadsorbed copolymer has the lowest styrene content. These results underscore the importance of minimizing copolymer compositional heterogeneity in order to achieve optimum stabilizing performance.

10 citations


Journal ArticleDOI
TL;DR: In this article, the authors described the application of the unit work concept to some of these areas: emulsion styrene-butadiene polymers, extenders, and fillers.
Abstract: Work reported recently described a “unit work” concept, according to which the flow behavior of a rubber-carbon black mixture was shown to be a function of the mixing work input. These results were shown to be independent of the size of the mixer, the speed of the mixer, and mixing time so long as the temperature-time profiles were similar, the same loading procedure was employed, and the same loading volume percentages were used. This concept provides a means to characterize not only the effect of various polymers, extenders, fillers, and minor additives, but also the uniformity of a given major constituent, which, in the case of an elastomer, may be a processability index. The work described in this paper is the application of the unit work concept to some of these areas : emulsion styrene-butadiene polymers, extenders, and fillers. By means of this concept of mixing, laboratory investigation can be translated, not only qualitatively, but much more important, quantitatively, into factory operat...

Journal ArticleDOI
TL;DR: In this paper, a simple rapid method has been developed for the quantitative analysis of styrene monomer in butadiene/styrene latexes using Raman spectroscopy, where latex samples were sealed in capillary tubes and scanned under high resolution conditions using a Spex Ramalog 1401 with a Spectra Physics 2 W argon ion laser.
Abstract: A simple rapid method has been developed for the quantitative analysis of styrene monomer in butadiene/styrene latexes using Raman spectroscopy. The latex samples were sealed in capillary tubes and scanned under high resolution conditions using a Spex Ramalog 1401 with a Spectra Physics 2 W argon ion laser. The Raman method involves ratioing the olefinic C=C (1632 cm−1) band of styrene monomer to the trans 1:4 C=C (1668 cm−1) band of butadiene in the butadiene/styrene polymer. Typical samples were found to have as low an unreacted styrene concentration as 0.7 wt. %. Reproducibility between samples was found to be within 0.1%. The values of residual styrene obtained by the Raman technique agreed within 0.25% with those obtained by liquid chromatography.

Patent
01 Jul 1976
TL;DR: An improved method for the separation of the individual components contained in a process stream consisting essentially of 1,3-butadiene, styrene and cyclohexane is provided in this article.
Abstract: An improved method for the separation of the individual components contained in a process stream consisting essentially of 1,3-butadiene, styrene and cyclohexane is provided which comprises passing a sample of the stream through a silica-filled column in a liquid chromatographic apparatus. The carrier is passed through a drying chamber prior to introducing the carrier onto the column.



Journal ArticleDOI
TL;DR: Some pyrimidine thiol derivatives were synthesized and tested in rubber formulations and they were incorporated in natural rubber, styrene butadiene rubber and polychloroprene mixes.

Journal ArticleDOI
TL;DR: In this paper, different combinations of various multifunctional monomers and halogen co-agents were used to sensitize the radiation vulcanization of styrene-butadiene rubber (SBR).