Synthesis and Characterization of Microcellular Plastics

微孔热塑性塑料是一种新型材料，含有大量的闭孔，通常为106/cm3或更多，直径约为10微米。这样的微观结构可以在不影响基本机械性能的情况下显著降低密度。近年来，以聚碳酸酯和聚对苯二甲酸乙二醇酯（PET）为原料，以二氧化碳为成核气体，生产出了令人瞩目的新材料。在PET中，高浓度的二氧化碳被发现可以使PET结晶，从而创造出具有完整结晶皮肤的细胞复合材料。在聚碳酸酯中，气泡密度达到50亿个/cm3或更高，从而可以制造具有多种性能的微孔泡沫。在本研究中，将对CO-2聚碳酸酯和co - pet材料体系进行详细表征。研究了co2诱导PET结晶、细胞壁分子取向和细胞形态。将实验表征PET和聚碳酸酯中的气泡成核现象。此外，微孔复合材料的力学行为将被测量并通过理论模型与微观结构相关联。

Microcellular thermoplastics are novel materials containing a large number of closed cells, typically 106/cm3 or more, of order 10 microns in diameter. Such a microstructure allows a significant reduction in density without compromising the essential mechanical properties. Recently remarkable new materials have been produced from polycarbonate and from polyethylene terephthalate (PET), using carbon dioxide as the nucleating gas. In PET, high concentrations of carbon dioxide have been found to crystallize PET, enabling creation of cellular composites with an integral, crystalline skin. In polycarbonate, bubble densities of 5 billion/cm3 or more have been achieved, allowing for creation of microcellular foams with a wide range of properties. In this research a detailed characterization of the CO-2 polycarbonate and CO2-PET material systems will be carried out. The CO2-induced crystallization in PET, molecular orientation in cell walls, and the cell morphology will be studies. Bubble nucleation phenomena in both PET and polycarbonate will be experimentally characterized. Also the mechanical behavior of microcellular composites will be measured and related to the microstructure via a theoretical model.