Preparation and characterization of biodegradable foams from calcium carbonate reinforced poly(propylene carbonate) composites

Biodegradable foams were successfully prepared from calcium carbonate reinforced poly(propylene carbonate) (PPC/CaCO(3)) composites using chemical foaming agents. The incorporation of inexpensive CaCO(3) into PPC provided a practical way to produce completely biodegradable and cost-competitive composite foams with densities ranging from 0.05 to 0.93 g/cm(3). The effects of foaming temperature, foaming time and CaCO(3) content on the fraction void, cell structure and compression property of the composite foams were investigated. We found that the fraction void was strongly dependent on the foaming conditions. Morphological examination of PPC/CaCO(3) composite foams revealed that the average cell size increased with increasing both the foaming temperature and the foaming time, whereas the cell density decreased with these increases. Nevertheless, the CaCO(3) content showed opposite changing tendency for the average cell size and the cell density because of the heterogeneous nucleation. Finally the introduction of CaCO(3) enhanced the compressive strength of the composite foams dramatically, which was associated with well-developed cell morphology. (c) 2006 Wiley Periodicals, Inc.