Study of miscibility of poly(styrene-co-methacrylic acid) with copolymers of isobutyl methacrylate containing a basic comonomer

The miscibility of poly(styrene-co-methacrylic acid)(SMA) with poly(isobutyl methacrylate) (PIBMA), or poly[isobutyl methacrylate-co-2-(N,N-dimethyl amino)ethyl methacrylate] (IBMDAEM), or poly(isobutyl methacrylate-co-4-vinylpyridine) (IBM4VP), has been studied. Poly(isobutyl methacrylate) is immiscible with SMA copolymers even at a relatively high content of methacrylic acid (45 mol%), as evidenced by differential scanning calorimetry (DSC), from the observation of two glass transition temperatures (T(g)s), and by viscometry. However, these SMA copolymers containing between 12 and 45 mol% of methacrylic acid are miscible with IBMDAEM containing 12 or 20 mol% of (N,N-dimethyl amino)ethyl methacrylate, or IBM4VP containing 10 mol% of 4-vinylpyridine as evidenced by DSC, viscometry and inverse gas chromatography (IGC). (C) 1998 Published by Elsevier Science Ltd. All rights reserved.