环状碳酸酯低聚物的合成及其开环聚合的研究

环状碳酸酯低聚物的合成及其开环聚合的研究陈雨萍魏玮李革（中国科学院化学研究所工程塑料国家重点实验室北京１０００８０）关键词环状碳酸酯低聚物，聚碳酸酯，开环聚合环状单体的开环聚合在合成高聚物方面具有突出的优点，即在聚合过程中没有副产物、热效应低、聚合...

SYNTHESIS AND RING OPENING POLYMERIZATION OF THE CYCLIC OLIGOMERIC AROMATIC CARBONATES

The synthesis of cyclic oligomeric carbonates of 2,2 bis (4 hydroxylphenyl) propane (BPA) were carried out in an interfacial hydrolysis/condensation of BPA bischloroformates.The cyclic oligomeric carbonates are an important intermediate (cyclic monomer) in the preparation of the polycarbonates (BPAPC) vis a ring opening polymerization.The ability of ring opening polymerization of cyclic monomer is influenced by its ring size and ring strain.In this paper,the different ring size of cyclic dimer,trimer and teramer carbonates have been chosen to investigate the effect of the ring strain on their structure and properties.The structure of cyclic dimer,trimer and teramer carbonates were characterized by FTIR,NMR,and DSC.The ring strain in the cyclic dimer carbonate is evident from FTIR, 1H NMR and DSC results.The DSC results demonstrate that either cyclic dimer or trimer or tetramer carbonates,the ring opening polymerization take place immediately after melting.Polymerization of the cyclic oligomeric carbonates to polycarbonate with molecular weight 110000 was obtained by heating at 280℃ for 5min. in the present of catalyst.The polycarbonate has an initial modulus of 0 23GPa,tensile break strength 85MPa and an elongation 230%.The DMA measurement showed that the T g of polycarbonate presented at 157℃