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

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 Tg 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 Tg 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. [ABSTRACT FROM AUTHOR]