Properties of Polymers as Functions of Conversion. II. Intrinsic Viscosities<sup>1</sup>

Wall, Frederick T.; Powers, R. W.; Sands, Gillian; Stent, Gunther S.

doi:10.1021/ja01196a050

Cited by 13 publications

(2 citation statements)

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“…If carried far enough in conversion, virtually all the sol polymer can be converted to gel, the conversion and rate at which this takes place being dependent on the amount of modifier charged and temperature of polymerization. The process is described especially well by Wall and co-workers (9). Tire rubbers are generally produced nearly free of gel, but many specialty rubbers are deliberately made to a high gel content.…”

Section: Effect Of Rubber Powder On Propertiesmentioning

confidence: 99%

Effect of Synthetic Elastomers on Properties of Petroleum Asphalts

Endres¹,

Coleman²,

Pierson³

et al. 1951

Ind. Eng. Chem.

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Section: Effect Of Rubber Powder On Propertiesmentioning

confidence: 99%

Effect of Synthetic Elastomers on Properties of Petroleum Asphalts

Endres¹,

Coleman²,

Pierson³

et al. 1951

Ind. Eng. Chem.

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“…; acrylonitlile polymers and copolynlers have been studied but the data published on the emulsion copolymerization of butadiene and acrylonitrile are scarce. The [nost directly useful results are those of Wall (23,24) and of Semon (19,20). Some data obtained during the copolymerization of other monomers with acrylonitrile (4, 5, 6, 9, 15) ma)-be used to calculate the approximate behavior of the butadiene-acrylonitrile system.…”

Section: Introductionmentioning

confidence: 99%

Compositional Heterogeneity of Butadiene–acrylonitrile Copolymers Prepared in Emulsion at 5°c

Embree¹,

Mitchell²,

Williams³

1951

Can. J. Chem.

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The copolymerization of b~rtadiene 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 modilier disappears much more slowly than in the b~~tadiene-styrene system, the regulating index approximating unity. The n~unber average molecular weights calculated from the mercaptan disappearance curves indicate uniform polymer molecular weights to relatively high conversions after which there is a decrease. T h e viscosity data indicate a rise in viscosity \vith conversion, which elfect is overcome for charges rich in acrylonitrile by the lessening of branching, the more rapid disappearance of mcrcaptan a t high conversion, and the tendency of polymers containing over 50% acrylonitrile to show very low dilute s o l~~t i o n viscosities in the solvents tested. Viscosity molecular weights have been calculated and estimates of the molecular weight tlistributjon made. These distributions appear to be quite narrow and the ~~s u a l broaden~ng a t higher conversions is prevented by tlre increased nrodiher consun~ption and increased vinyl content of the poly~ner prepared with 50 parts acrylonitrile in the charge. The bountl acrylonitrile has been determined a t various conversions and the reactivity ratios have been found to be r, = 0 . 2 s and r2 = 0.02 for emulsions and rl = 0. 18 and r? = 0.03 for oil phase portion only. Q is 0.74 and e is 1.17 as calculated by the Alfrey-Price equations.

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