Dienes and diamondoids: poly(2‐[1‐adamantyl]‐1,3‐butadiene) and random copolymers with isoprene via redox‐emulsion polymerization and their hydrogenation

Abstract

A novel route to adamantane substituted diene copolymers is demonstrated using emulsion polymerization, with an improved monomer synthesis. Heterogenous dehydration of 2-(1-adamantyl)-3-buten-2-ol using Amberlyst ® -15 cationic exchange resin at ambient temperature gave 2-(1-adamantyl)-1,3-butadiene (1) in excellent yield and presents an attractive alternative monomer synthesis route. Emulsion polymerization of 1 and mixtures of 1 and isoprene was carried out at room temperature using redox pair, hydroperoxide initiator. All poly(1) and poly(1-ran-isoprene) samples were soluble in common organic solvents and exhibited high 1,4-microstructure. A continuous increase in glass transition temperature from −63 to 172 C was observed by increasing the ratio of 1 in the comonomer feed of poly(1-ran-isoprene), and T g values were in good agreement with the Fox equation. After complete hydrogenation to poly(1-vinyladamantane-alt-ethylene-ran-propylene-alt-ethylene), a continuous increase in T g was observed from −55 to 152 C. The high solubility and improved access to 2-(1-adamantyl)-1,3-butadiene opens the door to exploration of diene polymers with enhanced high temperature properties.