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 (R)-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 degrees 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 degrees 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.

Automated summary

A novel route to synthesize adamantane substituted diene copolymers using emulsion polymerization was demonstrated, with an improved monomer synthesis method. The high solubility and improved access to 2-(1-adamantyl)-1,3-butadiene provide potential for exploring diene polymers with enhanced high temperature properties.