碳酸钙协同海藻酸(盐)改性PLA复合材料的制备及性能

以聚乳酸(PLA)为基体,通过添加海藻酸(或海藻酸盐)、纳米碳酸钙与PLA熔融挤出制备PLA/海藻酸(盐)/纳米CaCO3复合材料.并利用傅里叶变换红外光谱(FTIR)、热重(TG)分析、流变和力学性能测试等对复合材料的化学结构、热性能、流变行为和力学性能等进行了表征和测试.结果表明,添加纳米碳酸钙、海藻酸盐及其复配组分对PLA的化学结构基本没有影响;复合材料表现出更低的复数黏度;热稳定性较纯PLA有所下降;复合材料的拉伸强度有所下降,而缺口冲击强度有所增加,尤其是用海藻酸盐直接改性PLA复合材料的缺口冲击强度有了较大提高.

Preparation and Properties of Calcium Carbonate Combined with Alginic Acid(salt) Modified PLA Composite

Polylactic acid (PLA) by addition of the alginic acid and alginates combined with nano-calcium carbonate was modified by reactive extrusion method. The chemical structure,thermal properties and mechanical properties of the composites were evaluated by Fourier transform infrared spectroscopy (FTIR),thermogravimetric analysis (TG),rheological behavior and mechanical properties measurement. The results show that the chemical structure of PLA is nearly unaffected by the addition of nano-calcium carbonate,alginate alone or by the addition of alginate and nano-calcium carbonate compounds. Rheological behavior measurement show that the composites have a lower complex viscosity and the improvement in impact strength of the resultant composites,while the tensile strength and thermal stability decrease. The impact strength of the composite material is significantly improved,especially when the PLA is directly modified with alginate alone.