Investigation of the Plasticizer Content Effects on the Operability of the Epichlorohydrin Rubber Based Elastomeric Material during Full-Scale Test under Cold Climate Conditions and Hydrocarbon Medium Influence

Sealing rubbers used in the climatic conditions of the Far North and the Arctic, based on butadiene-nitrile rubbers contain significant amounts of plasticizers, which increase their frost resistance. They lose low-temperature and operational properties when they contact with the hydrocarbon medium due to intensive plasticizer washing out. Zeon Hydrin T6000 epichlorohydrin rubber, has a low glass transition temperature (Tg = -60 °C) and resistance to aggressive media. The model rubber was developed that minimally meets the requirements for sealing rubbers. Samples were exposed in oil, for 2 years, in climate of Yakutsk, the Republic of Sakha (Yakutia), Russia. The climate is characterized by significant average daily temperature fluctuations with a transition through the 0 °C and low temperatures below-60 °C. For comparison, simultaneously rubbers based on butadiene-nitrile rubbers was investigated. Every two months, the main parameters were measured: swelling degree, tensile strength, elongation, frost resistance coefficient for elastic recovery after compression at-50 °C and-30 °C, compression set and plasticizer content by means of IR spectroscopy. Model rubber showed excellent frost resistance while retaining the other properties, regardless of the plasticizer content, while rubber based on butadiene-nitrile rubber irreversibly lost low-temperature properties in the first months. Similar results were obtained earlier in the study propylene oxide rubber produced in Russia (Tg = -74°C). During full-scale exposure, a small dependence of its low-temperature characteristics on the amount of plasticizer in the elastomeric material was also revealed. Thus, epichlorohydrin rubber Hydrin T6000 can be used as a sealing rubber.