高分子量聚乳酸立体复合结晶的研究进展

Stereocomplex Crystallization of High-Molecular-Weight Poly( Lactic Acid) : A Review

聚乳酸立体复合物(sc-PLA)具有高熔点、高耐热、高力学性能、耐溶剂和耐水解等优点,其研究备受关注。sc-PLA材料综合性能与工程塑料接近,作为高耐热生物可降解材料具有广阔的应用前景。但高分子量PLA不易立体复合结晶,所以高分子量sc-PLA材料较难制备。通过嵌段共聚、分子链化学拓扑结构以及结晶条件的改变,可促进PLA的立体复合结晶化,从而制备高分子量sc-PLA材料。文中根据促进高分子量PLA立体复合结晶方法的不同,详细综述了近年高分子量PLA立体复合结晶及其sc-PLA材料制备的研究进展,以及sc-PLA的高分子链结构、结晶条件、材料热性能之间的内在联系。

Poly( lactic acid) stereocomplex( sc-PLA) has drawn much attention due to its high melting point,enhanced heat resistance,high mechanical properties,and good resistances to solvent and hydrolysis. The physical performances of sc-PLA are similar to those of the engineering plastics and thus the sc-PLA has great potentials in the applications as highly heat-resistant biodegradable materials. However,the high-molecular-weight PLA does not tend to crystallize in the stereocomplex form,and therefore the preparation of high-molecular-weight sc-PLA material is quite difficult. It has been reported that the stereocomplex crystallization of PLA can be enhanced by the block copolymerization,control of polymer chain architecture and the change of crystallization conditions,which provide the feasible methods to prepare the high-molecular-weight sc-PLA material. According to the various methods to promote stereocomplex crystallization of the high-molecular-weight PLA,this paper reviewed the research progress in the PLA stereocomplex crystallization and preparation of high-molecular-weight sc-PLA materials in recent years. The correlations between the stereocomplex crystallization,chain architecture,crystallization conditions,and thermal properties of materials were also addressed.