Synthesis and Study of Melt Processing of Polyarylate-Polysulfone Cardo Block Copolymers

Cardo block copolymers containing phenolphthalein-based aromatic polyester blocks and 10–30 wt % of polysulfone blocks have been obtained via low-temperature single-phase polycondensation from commercially available precursors. The obtained block copolymers have been characterized by the methods of IR spectroscopy, GPC, DSC, TGA, and DMA. The processibility of the obtained block copolymers was studied measuring the stability of the melt flow index over time at different temperatures. It has been shown that, depending on the content of the polysulfone blocks, the prepared block copolymers may consist of a single phase with only one variable glass transition temperature or be separated into two macrophases enriched in polysulfone or polyarylate blocks. From the practical point of view, the block copolymers containing 30% of the polysulfone blocks have exhibited good thermomechanical parameters up to 200°C and can be processed through the melt due to its relatively low-viscosity and high temperature stability. Time-temperature parameters of stability of the block copolymer melts have been determined and possible regimes of their processing via injection molding and extrusion have been elucidated.