ENHANCING PLASTIC YIELDING IN POLYESTERCARBONATE GLASSES BY 1,4-CYCLOHEXYLENE LINKAGE ADDITION

Two series of polyestercarbonates containing 1,4-cyclohexylene linkage s were designed and synthesized to allow investigation of the relation ship between local molecular motion and mechanical properties in these materials. Incorporation of increasing amounts of 1,4-cyclohexylene d icarboxylate linkages enhanced the segmental mobility in tetramethyl B isphenol A polyestercarbonates and in Bisphenol A polyester carbonates . This effect is thought to be due to the cooperative conformational t ransition of neighboring cyclohexylene rings. The cooperative conforma tional transition is thought to be able to activate motions of the lin ked carbonate segments and further facilitate the molecular motions of neighboring segments. This motion is thought to favor shear yielding. The results are found to be consistent with this notion.