Preparation of the PLA/CaCO3 Composites and the Retardation Effect of the CaCO3 on the Hydrolytic Degradation of the PLA in the Composites
Abstract: The poly (lactic acid) (PLA)/CaCO3 composites were prepared via melt blending in an intensive mixer of the torque rheometer. Hydrolytic degradation of the composites obtained was investigated comparatively with the pure PLA matrix. The hydrolytic degradation was carried out by immersing the film samples in phosphate buffer saline (pH = 7.4) at 37˚C, and the viscosity of the PLA in the degraded films was measured. The results indicated that the hydrolytic degradation of the PLA matrix in the composites was retarded as a result of the incorporation of the basic CaCO3 which would react with the partial end-carboxyl groups of the PLA matrix. It was showed that the tensile strength, elastic modulus, elongation at break and maximum load of the composites were enhanced significantly. Also it was found that the water absorption of the PLA/CaCO3 composites at low CaCO3 loading (2% and 5%) slightly increased compared with the pure PLA upon immersion for 4 weeks, while the PLA/CaCO3-7 composite had a much higher water absorption (5.5% - 6.0%) than the pure PLA in two immersion mediums. All composites exhibited slightly higher water resistance in the distilled water than in the phosphate buffer solution at pH = 7.4.
文章引用: 关怀民 , 黄世俊 , 童跃进 (2012) 聚乳酸与碳酸钙复合物的制备及碳酸钙的降解抑制作用。 材料科学， 2， 89-95. doi: 10.12677/ms.2012.22016
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