Poly(N-vinylimidazole)-l-Poly(tetrahydrofuran) Amphiphilic Conetworks and Gels: Synthesis, Characterization, Thermal and Swelling Behavior

A novel class of amphiphilic conetworks (APCNs), poly( N -vinylimidazole)- l -poly(tetrahydrofuran) (PVIm- l -PTHF) (“ l ” stands for “ linked by ”), was prepared by free radical copolymerization of telechelic PTHF dimethacrylate macromonomer and N -vinylimidazole in ethanol as a suitable cosolvent for all the components. Low amounts of extractables were obtained indicating successful conetwork formation. A series of transparent, macroscopically homogeneous PVIm- l -PTHF conetworks with a wide composition range of 25–89 wt % PTHF were prepared. Investigations by DSC revealed the existence of two distinct glass transition temperatures ( T g ) in the vicinity of the T g of homopolymers proving microphase separation of PVIm and PTHF in these conetworks. Surprisingly, the crystallization of PTHF is strongly suppressed and prevented at lower than 38 wt % PTHF in the presence of the glassy, amorphous PVIm in these APCNs. The amphiphilic nature of the PVIm- l -PTHF conetworks was proved by their uniform swelling in both nonpolar (tetrahydrofuran, carbon tetrachloride) and polar solvents (water, methanol) in a broad composition range, indicating bicontinuous (cocontinuous) phase separation in these novel, unique bicomponent polymeric materials.