1

6-Bis(hydroxyisopropyl urethane)hexane(BPU) was prepared by non-ioscyanide route from propylene carbonate and 1

6-hexanediamine

whose molecular weight was 320. Blends of biodegradable poly(propylene carbonate)(PPC) and BPU were prepared by melt blending.BPU as modifier to PPC was found to be miscible with PPC

and the thermal properties of the PPC/BPU blends were evaluated by differential scanning calorimetry(DSC) and thermogravimetry analysis(TGA).The thermal stability of the blends was significantly improved compared with pure PPC

a 24~33℃ increase in Td

5%was observed.Toughening PPC was also realized

when the BPU loading was 15 wt%

the maximum of elongation at break of the blends could reach 53.4%

increased to four times of that of pure PPC

accompanied by the relatively high mechanical strength and modulus.When the content of the plasticizer was less than 10 wt%

reinforcing and toughening of PPC were achieved simultaneously.Shear deformation as well as crazing observed in the scanning electron microscopy(SEM) images of the blends provided good evidence for the toughening mechanism of PPC.