The effect of the plasticizer injection method on the physical -mechanical and low-temperature properties of rubbers based on mixtures of polar and nonpolar rubbers

Abstract

The effect of various methods of introducing a plasticizer into blended compositions based on a combination of polar (NBR and CR) and non-polar (BR and SSBR) rubbers with low glass transition temperatures is studied. Methods of adding a plasticizer both directly during the mixing process (method 1) and through preliminary production of a masterbatch of rubbers with a plasticizer (method 2) were considered. It was shown that adding a plasticizer through the masterbatch leads to a decrease in the degree of crosslinking of rubber macromolecules and a decrease in its vulcanization rate by 22%–37%. Vulcanizates obtained through the masterbatch, compared to samples obtained by method 1, are characterized by lower strength characteristics and wear resistance. Abrasion resistance of NBR/CR/BR and NBR/CR/SSBR vulcanizates decreases by 2.5 and 4.8 times, respectively. It has been established that the introduction of a plasticizer through the masterbatch helps to obtain more frost-resistant vulcanizates, which are characterized by less loss of plasticizer during thermal exposure in an aggressive hydrocarbon environment.