Simultaneous construction of polymer backbone and side chains by terpolymerization. Synthesis of polyethers with the allyl side chains from dialdehydes, alkylene bis(trimethylsilyl) ethers, and allyltrimethylsilane

Abstract

Polyethers with allyl side chains were synthesized by the simultaneous acid-catalyzed reaction of dialdehydes ( 1), alkylene bis(trimethylsilyl) ethers ( 2), and allyltrimethylsilane ( 3). The reactions of 1, 2 and 3 were carried out in the presence of 10 mol% of triphenylmethyl (trityl) perchlorate at −55°C to yield polyethers having allyl groups in the side chains. When the dialdehyde having the ester moieties as 1, ethylene bis(trimethylsilyl) ether and 1,4-bis(trimethylsiloxy)cyclohexane as 2 were used, high molecular weight polymers were obtained. In the polymerizations at ambient temperature, the polymer was precipitated during the reaction because of crosslinking between the aromatic rings via a trityl perchlorate assisted Friedel-Crafts reaction. The soluble polyether with the allyl side chains reacted with 1,2-ethanedithiol in the presence of a radical initiator in benzene at 60°C to yield a crosslinked polymer quantitatively within 1 h. This polymer synthesis is unusual in that it concurrently constructs both the polymer backbone and the functional side chains from three monomers.