The reaction of tertiary hexadecyl mercaptan with a butadiene-styrene copolymer.

The amazing rise in importance of the synthetic rubber industry in the United States and Canada during the war years is now a well-known fact and requires no further description. To-day this industry has ceased to be merely an alternative source of rubber, and has achieved the status of a major industry with an annual capacity of one million tons. The maintenance of this position, in a peace time economy, depends on its ability to produce a low cost product with properties approaching or surpassing those of natural rubber. The properties of the present GR-S type synthetic rubber, are mainly controlled by the action of the chain transfer agents or modifiers used in its production. These modifiers act to control the physical properties of the polymer through the medium of regulating the chain length and the chain length distribution, i.e. the homogeneity of the polymer. In the absence of such control, a product would be produced containing much insoluble material of the cross-linked type, which is difficult to process and some low molecular weight polymer which lacks mechanical strength, along with the desirable medium-high molecular weight product. It is the purpose of this investigation to study some of the possible causes of this anomalous behaviour of tertiary hexadecyl mercaptan. Two possible effects will be considered, namely: (i) Polymer-Mercaptan Interaction. (ii) Oxidative Degradation of the Polymer