Window of acrylonitrile content for miscibility in blends comprising poly(styrene-co-acrylonitrile)s and poly(benzyl methacrylate)

For the first time, miscibility between poly(styrene-co-acrylonitrile) (SAN ) and poly(benzyl methacrylate) (PBzMA) was proved. The miscibility window was found in SAN/PBzMA as the copolymer structure was varied systematically by altering weight percent of the acrylonitrile (AN) unit in the SAN copol ymers. The lower bound of AN content in SAN for miscibility of SAN/PBzMA bl end is 3.5 wt %, and the upper bound is 24.4 wt % AN in the copolymer. The trend of T-g broadening and LCST (cloud point) behavior for the SAN/PBzMA b lends in that these phase-related quantities were all affected by AN conten t in SAN copolymers. Within the window, the copolymer/polymer mixtures form ed a true miscible blend system. The effect of SAN structure (by controllin g AN weight percent) on the window miscibility of SAN/PBzMA. blends is inte rpreted and discussed in detail.