Macromers by Carbocationic Polymerization. X. Synthesis, Characterization, and Polymerizability of Cyanoacrylate-Capped Polyisobutylenes

The objectives of this research were the synthesis and characterization of the following linear and three-arm star cyanoacrylate polyi-sobutylenes: and an examination of their polymerizability. The syntheses involved the Diels-Alder protection of 2-cyanoisobutyl acrylate (IB-CA) with anthracene followed by hydrolysis and conversion to the 2-cyanoacryloyl chloride. The protected cyanoacryloyl chloride was then reacted with one- or two-ended linear or three-ended three-arm star -CH2OH terminated polyisobutylenes (PIB-OH, HO-PIB-OH, and Deprotection by excess maleic anhydride yielded the target macromers. 1H-NMR and FTIR spectroscopic analyses indicated quantitative CH2=C(CN)COO– end-capping. The solution polymerization of a PIB-CA macromer (M = 2380) with N,N-dimethyl-p-toluidine (DMT) at room temperature gave high molecular weight product (M 35,000). Solution polymerization of CA-PIB-CA and gave networks with low (9–12%) sol fractions. The bulk copolymerization of with IB-CA also occurred readily.