Amphiphilic networks XII:: synthesis and characterization of quaternized amphiphilic networks derived from polyisobutylene-l-poly(2-(dimethylamino)ethyl methacrylate)

Polyisobutylene-l-poly(2-(dimethylamino)ethyl methacrylate) amphiphilic networks were quaternized by reaction with methyl iodide. Quaternization of the tertiary amine groups in the poly(2-(dimethylamino)ethyl methacrylate) (DMEAMA) segments was close to quantitative as determined by gravimetry and nitrogen and iodine analysis. The glass transition temperature of the DMEAMA phase strongly increased upon quaternization. The swelling behavior of the quaternized networks did not much vary with changing pH, while the non-quaternized parent amphiphilic networks exhibited a strong pH dependence. Swelling in n-heptane was greatly diminished in quaternized networks relative to the non-quaternized parent materials, even at high polyisobutylene contents.