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 net works were quaternized by reaction with methyl iodide. Quaternization of th e tertiary amine groups in the poly(2-(dimethylamino)ethyl methacrylate) (D MEAMA) segments was close to quantitative as determined by gravimetry and n itrogen 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-qua ternized parent amphiphilic networks exhibited a strong pH dependence. Swel ling in n-heptane was greatly diminished in quaternized networks relative t o the non-quaternized parent materials, even at high polyisobutylene conten ts.