Abstract: In this study, poly(propylene carbonate) (PPC) was chain extended with 4,4-diphenylmethylene diisocyanate（MDI）via melt reaction. On the FTIR spectra, the absorption bands observed at 1600 and 1535 cm-1 were attributed to the vibration of benzene ring and -N-H (amide Ⅱgroups), respectively, suggesting the occurrence of chain extend reaction. The dynamic rheological tests showed that MDI-modified PPC had higher storage and loss moduli and complex viscosity than unmodified PPC. Moreover, modified Cole-Cole plots revealed that the MDI-modified PPC samples possessed higher elasticity, broader molecular weight distribution, longer stress relaxation time than neat PPC.

Key words: poly(propylene carbonate), diphenylmethylene diisocyanate, rheological behavior, chain extension