Poly(Alkylene Ether)s With Nitrile Pendent Groups

ABSTRACT There is significant interest in elastomers with high thermal and oil resistance. Elastomers such as nitrile butadiene rubber (NBR) are available but have insufficient thermal stability in certain applications due to unsaturation in the polymer backbone. Hydrogenation produces hydrogenated NBR (HNBR), providing improved heat resistance, but the added manufacturing step and expensive catalysts make HNBR prohibitively expensive for many applications. Additionally, the structure of HNBR imparts lower limits to its glass transition temperature ( T g ). Poly(alkylene ether) elastomers are potential alternatives to HNBR, requiring only one manufacturing step and avoiding expensive catalysts, but past attempts to investigate these polymers met limited success. Here we describe the preparation of β‐cyanoethyl glycidyl ether and its homopolymerization using the Vanderberg chelate initiator. Careful monomer purification was essential to obtain soluble elastomers, but the polymer still exhibited poor thermal stability due to facile decyanoethylation. We also prepared other poly(alkylene ether) nitrile polymers with improved thermal stability, including one with a T g of −51°C. When the side chain was 7‐cyano‐1‐heptylene, the polymer was semi‐crystalline, resulting in a thermoplastic elastomer. These elastomers could present alternatives to NBR and HNBR and could be investigated in areas such as solid polymer electrolytes in renewable energy applications.