| abstract |
A foamable polyester composition comprising a combination of blowing agent and mixed polymer composition comprising: a) a semi-crystalline polyester composition comprising a polycondensed branched polyester polymer, and b) an aromatic polycarbonate polymer. The foamable composition has a high extrusion melt strength, and can pulled across a die without ripping, to form a continuous thermoformable closed cell polyester sheet. The foamed sheets have a uniform, fine, and closed cell morphology; and simultaneously are less dense but have a higher impact strength than comparable closed cell polymers made in only with linear polyesters as the polyester component or without the aromatic polycarbonate. |