LABORATORY STUDY OF LOW RATIO BUTADIENE–STYRENE COPOLYMERS

1949 ◽  
Vol 27f (2) ◽  
pp. 35-46 ◽  
Author(s):  
J. M. Mitchell ◽  
H. Leverne Williams
Keyword(s):  
Induction Period ◽  
Chain Transfer ◽  
Viscosity Data ◽  
Reactivity Ratios ◽  
Styrene Copolymers ◽  
Rate Of Reaction ◽  
Styrene Content ◽  
Mass Basis ◽  
Dodecyl Mercaptan ◽  
Butadiene Styrene

The copolymerization of styrene and butadiene in ratios in which the styrene equals or predominates over the butadiene on a mass basis is essentially similar to copolymerization in the presence of a predominance of butadiene. However, the rate of reaction and the length of the induction period is increased. Increasing the amount of the dodecyl mercaptan regulator results in a slight increase in rate and diminution of the induction period. The dodecyl mercaptan reacts at a lower rate than during the production of GR–S. The regulating index as defined by the ratio of the logarithm of the residual mercaptan over the conversion is 1.53. The bound styrene and increment styrene curves seem to be normal and indicate reactivity ratios r1 (butadiene) equal to 1.4 to 2.2, r2 equal to 0.5 to 0.7. If these reactivity ratios are corrected for the bifunctional nature of butadiene then the constants for butadiene monomer are Q equal to 0.9 and e equal to − 1. Likewise the gel–viscosity data are similar to those observed with GR–S except that the pre-gel rise in viscosity, the formation of gel, and the slope of the viscosity conversion curves diminish with increasing styrene in the charge. The chain transfer action of styrene is increasingly evident with increasing styrene content in the charge but in all cases the regulating effect of dodecyl mercaptan is still apparent.

THE COMPOSITIONAL HETEROGENEITY OF BUTADIENE-STYRENE COPOLYMERS SYNTHESIZED AT −18°C. IN EMULSION

1951 ◽  
Vol 29 (3) ◽  
pp. 270-283 ◽  
Author(s):  
R. J. Orr ◽  
H. Leverne Williams
Keyword(s):  
Transfer Reaction ◽  
Chain Transfer ◽  
Polymerization Temperature ◽  
Viscosity Data ◽  
Compositional Heterogeneity ◽  
Molecular Weights ◽  
Styrene Copolymers ◽  
Chain Transfer Reaction ◽  
Molecular Weight Heterogeneity ◽  
Butadiene Styrene

A study has been made of butadiene-styrene copolymers formed at −18°C. From analyses for bound styrene in the product for various conversions and initial butadiene-styrene ratios the reactivity ratios were calculated to be r1 = 1.37 and r2 = 0.38 compared with 1.8 and 0.6 at 45°C. Q and e for butadiene were 1.38 and 0.008 relative to styrene at 1 and −0.8. Increment bound styrene curves calculated for each stage of the reaction indicated that the polymers were remarkably homogeneous at low conversions. The chain transfer reaction using mixed tertiary mercaptans as the modifier was studied. Regulating indices were found to have decreased with polymerization temperature. Number average [Formula: see text] and viscosity average [Formula: see text] molecular weights were calculated from mercaptan disappearance and vistex intrinsic viscosity data respectively. The molecular weight heterogeneity increased with increasing conversion and initial mercaptan content. The increment number average molecular weights were found to diminish with conversions, whereas the increment viscosity average increased at higher conversions as conversion increased.

Styrene-Diene Resins in Rubber Compounding

1947 ◽  
Vol 20 (1) ◽  
pp. 241-248
Author(s):  
A. M. Borders ◽  
R. D. Juve ◽  
L. D. Hess
Keyword(s):  
Tensile Elongation ◽  
Chemical Properties ◽  
Aryl Hydrocarbon ◽  
Styrene Copolymers ◽  
Synthetic Rubber ◽  
Brittle Point ◽  
Styrene Content ◽  
Physical And Chemical ◽  
Preparation And Evaluation ◽  
Butadiene Styrene

Abstract Early in the investigation of butadiene-styrene copolymers as synthetic rubbers, this laboratory became interested in copolymers containing much more styrene than any of the American or German synthetics. This interest was soon directed to the resinous copolymers obtained when the styrene content is increased beyond the range in which rubberlike properties are observed at room temperature. The exploratory work, therefore, involved preparation and evaluation of butadiene-styrene copolymers containing from 65 to 98 per cent styrene. No description of similar polymers has been found. Konrad and Ludwig claimed the improvement of rubberlike properties of butadiene-styrene copolymers by increasing the styrene content from the normal range to “between about 47.5 and about 70 per cent”. The claims and examples of this patent emphasize the improvement of rubberlike properties, such as tensile, elongation, and rebound, at high temperatures. It is well known in this country, however, that increase in styrene content beyond a certain point, perhaps 50–55 per cent, is accompanied by a loss of overall balance of rubber characteristics. Therefore, the copolymers at the upper end of the range described by Konrad and Ludwig have definite limitations for rubber uses—for example, low rebound, high brittle point, shortness, etc. In the writers' laboratory useful resins have been prepared from dienes and vinyl aryl hydrocarbons in the range 5 to 20 per cent diene and 80 to 95 per cent vinyl aryl hydrocarbon. This paper describes the properties and certain uses of one of these copolymers containing approximately 15 parts of butadiene and 85 parts of styrene. This material possesses a combination of physical and chemical properties which permit its use in several applications where cyclized natural or synthetic rubbers are commonly employed. Cyclized natural rubber has been described by Bruson, Endres, and Thies and Clifford. Cyclized synthetic rubbers were described recently by Endres. One product of this type is made from a special synthetic rubber. The new 15 butadiene—85 styrene copolymer is now identified as Pliolite S-3, since it may be used in many Pliolite applications, often with distinct advantages over either the natural or synthetic rubber derivatives.

Crystallization in Butadiene-Styrene Copolymers

1955 ◽  
Vol 28 (1) ◽  
pp. 51-56
Author(s):  
Lawrence A. Wood
Keyword(s):  
Experimental Observation ◽  
Polymerization Temperature ◽  
Styrene Copolymers ◽  
Styrene Content ◽  
Butadiene Styrene

Abstract From Figure 3 one draws the following significant conclusions: (1) Crystallization is not observed if the polymerization temperature is above 60° C. (2) For polymerization at 50° C, a small amount (2 to 6 per cent) of bound styrene inhibits crystallization completely. (3) For polymerizations at 5° C, the limit is at about 15 to 18 per cent bound styrene content. (4) At the lowest polymerization temperatures normally utilized, this limit is at about 30 per cent bound styrene. Direct experimental observation is in general accord with these conclusions.

scholarly journals Synthesis of Environmentally Friendly Acrylonitrile Butadiene Styrene Resin with Low VOC

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1663
Author(s):  
Licheng Fan ◽  
Lijuan Wei ◽  
Yongfei Zhu ◽  
Yibo Wang ◽  
Jianmin Fei ◽  
...  
Keyword(s):  
Residence Time ◽  
Chain Transfer ◽  
Acrylonitrile Butadiene Styrene ◽  
Extraction Process ◽  
Supercritical Extraction ◽  
Vacuum Degree ◽  
Abs Resin ◽  
Methyl Styrene ◽  
Dodecyl Mercaptan ◽  
Butadiene Styrene

Most acrylonitrile butadiene styrene (ABS) resin is plagued by an unpleasant odor attributed to the high residual volatile organic compound (VOC) content. This paper primarily aimed to solve the odor issue of ABS resin by effectively reducing the VOC content. To that end, a synthesis of ABS resins was optimized through a supercritical extraction process while evaluating multiple novel chain transfer agents (linear dimer of α-methyl-styrene, methyl 3-mercaptopropionate, and dodecyl mercaptan). ABS resin obtained through a α-methyl-styrene chain transfer agent demonstrated the lowest odor. Moreover, it had the least amount of VOC content which was three times lower than when dodecyl mercaptan was employed. To improve the supercritical extraction process, an orthogonal test was designed to optimize four main process parameters: extrusion temperature, residence time, vacuum degree and extractant dosage. The most optimal conditions were found to be 250 °C extrusion temperature, one minute residence time, vacuum degree of minus 99 KPa, and 1.5% CO2 extractant dosage.

COMPOSITIONAL HETEROGENEITY OF BUTADIENE–ACRYLONITRILE COPOLYMERS PREPARED IN EMULSION AT 5°C

1951 ◽  
Vol 29 (3) ◽  
pp. 253-269 ◽  
Author(s):  
W. H. Embree ◽  
J. M. Mitchell ◽  
H. Leverne Williams
Keyword(s):  
Molecular Weight ◽  
Weight Distribution ◽  
Viscosity Data ◽  
Reactivity Ratios ◽  
Compositional Heterogeneity ◽  
Dilute Solution ◽  
Molecular Weights ◽  
Conventional Solution ◽  
Acrylonitrile Copolymers ◽  
Butadiene Styrene

The copolymerization of butadiene and acrylonitrile is very similar to the copolymerization of butadiene and styrene. Polymers predominantly butadiene may be studied by conventional solution techniques but the study of polymers rich in acrylonitrile requires improved solvents for these materials. Polymerization rates are greatest for monomer ratios approximating equal proportions. The mercaptan modifier disappears much more slowly than in the butadiene–styrene system, the regulating index approximating unity. The number average molecular weights calculated from the mercaptan disappearance curves indicate uniform polymer molecular weights to relatively high conversions after which there is a decrease. The viscosity data indicate a rise in viscosity with conversion, which effect is overcome for charges rich in acrylonitrile by the lessening of branching, the more rapid disappearance of mercaptan at high conversion, and the tendency of polymers containing over 50% acrylonitrile to show very low dilute solution viscosities in the solvents tested. Viscosity molecular weights have been calculated and estimates of the molecular weight distribution made. These distributions appear to be quite narrow and the usual broadening at higher conversions is prevented by the increased modifier consumption and increased vinyl content of the polymer prepared with 50 parts acrylonitrile in the charge. The bound acrylonitrile has been determined at various conversions and the reactivity ratios have been found to be r1 = 0.28 and r2 = 0.02 for emulsions and r1 = 0.18 and r2 = 0.03 for oil phase portion only. Q is 0.74 and e is 1.47 as calculated by the Alfrey–Price equations.

Spectrophotometric Determination of the Styrene Content of Butadiene-Styrene Copolymers

1946 ◽  
Vol 19 (4) ◽  
pp. 1077-1084 ◽  
Author(s):  
E. J. Meehan
Keyword(s):  
Molecular Weight ◽  
Spectrophotometric Determination ◽  
Extinction Coefficient ◽  
Ultraviolet Spectrophotometry ◽  
Relative Precision ◽  
Specific Extinction Coefficient ◽  
Styrene Copolymers ◽  
Styrene Content ◽  
Butadiene Styrene

Abstract The ultraviolet absorption of polystyrene, with maximum absorption at 262 mµ, is due to the presence of phenyl residues in the polymer. The specific extinction coefficient is constant, i.e., independent of the molecular weight of the polymer. This shows that the extinction of the phenyl residues is additive. On the basis of this fact, it is shown that the styrene content of a butadiene-styrene copolymer (such as GR-S rubber) can be determined by ultraviolet spectrophotometry. The relative precision of the determination is about 1 per cent, the probable relative accuracy is about 3 per cent.

The Effect of Comonomer on the Microstructure of Butadiene Copolymers

1953 ◽  
Vol 26 (4) ◽  
pp. 832-839
Author(s):  
Frederick C. Foster ◽  
John L. Binder
Keyword(s):  
Infrared Absorption ◽  
Theoretical Explanation ◽  
Experimental Results ◽  
Vinyl Monomers ◽  
Styrene Copolymers ◽  
Wide Range ◽  
Styrene Content ◽  
Comonomer Content ◽  
Butadiene Styrene

Abstract The microstructure of butadiene-styrene copolymers having a wide range of styrene contents has been determined by infrared absorption. The results demonstrate that the percentage of trans-1,4-addition increases, the 1,2-addition decreases, and the cis-1,4-addition decreases as the styrene content is increased. Similar measurements of five other butadiene copolymer systems indicate that all these vinyl monomers, acrylonitrile, methacrylonitrile, methylvinyl ketone, vinylpyridine, and α-methylstyrene, change the microstructure in the same direction as styrene, differing only in the magnitude of their effect. A theoretical explanation, consistent with the experimental results obtained, is given for the change in microstructure with comonomer content.

Plastic Yield of Butadiene-Styrene and Isoprene-Styrene Ebonites

1951 ◽  
Vol 24 (2) ◽  
pp. 381-383 ◽  
Author(s):  
J. R. Scott
Keyword(s):  
Plastic Deformation ◽  
Natural Rubber ◽  
Elevated Temperatures ◽  
Styrene Copolymer ◽  
Heat Resistant ◽  
Plastic Yield ◽  
Styrene Copolymers ◽  
Styrene Content ◽  
Butadiene Styrene

Abstract In unloaded ebonites made from butadiene-styrene copolymers, the resistance to plastic deformation at elevated temperatures is better the higher the styrene content of the copolymer, at least up to 46 per cent. An isoprene-styrene copolymer ebonite has poorer plastic-yield resistance than a corresponding butadiene-styrene ebonite. All the styrene-containing copolymers, however give ebonites more heat-resistant than natural rubber ebonite, the best giving yield temperatures 30° C above the latter. To attain the best plastic-yield resistance in butadiene-styrene ebonites, the amount of sulfur added should correspond to more than 1 atom (e.g., 1.2 or even 1.4 atoms) per butadiene molecule.

Evaluation of Sodium-Catalyzed Copolymers of 1,3-Butadiene and Styrene

1948 ◽  
Vol 21 (2) ◽  
pp. 452-460
Author(s):  
A. E. Juve ◽  
M. M. Goff ◽  
C. H. Schroeder ◽  
A. W. Meyer ◽  
M. C. Brooks
Keyword(s):  
High Temperature ◽  
Free Radical ◽  
Low Temperature ◽  
Crack Growth ◽  
Monomer Composition ◽  
Styrene Copolymers ◽  
Identical Monomer ◽  
Emulsion Polymers ◽  
Styrene Content ◽  
Butadiene Styrene

Abstract Sodium-catalyzed butadiene-styrene copolymers (S-BS), of composition 75 weight-per cent butadiene: 25 weight-per cent styrene, have been compounded in tread type recipes. Evaluation tests showed properties significantly different from those of GR-S, the emulsion-phase free radical—catalyzed copolymers of identical monomer composition. 1. The processing characteristics of S-BS are considerably superior to those of GR-S, although one experience with a high temperature internal mix may indicate some limitation. Objective laboratory processing tests show that S-BS resembles high-styrene emulsion copolymers in that it can be satisfactorily fabricated from stocks containing less filler than is required in GR-S stocks for similar uses. 2. Stress-strain properties based on limited compounding studies are similar to those of GR-S. 3. The flex crack growth—hysteresis balance for S-BS vulcanizates is much superior to that of GR-S vulcanizates. Vulcanizates of emulsion polymers of high styrene content also had a flex crack growth—hysteresis balance superior to that of GR-S vulcanizates. 4. The low temperature properties of S-BS vulcanizates are inferior to those of GR-S vulcanizates. Brittle points and low temperature Young's modulus of S-BS vulcanizates are much higher than those of GR-S vulcanizates.

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