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 caebonates to polycarbonate with molecular weight 110000 was pbtained by heating at 280℃ for 5min.in the present of catalyst.The polycarbonate has an initial modulus of 0.23GPa

tensile break strrngth 85MPa and an elongation 230%.The DMA measurement showed that the Tg of polycabonate presented at 157℃.