竹纤维和海藻酸钠提升聚乳酸的降解性能  

Study on bamboo fiber and sodium alginate enhancing the degradability of polylactic acid

作　　者：柴喜存 周凌蕾 何春霞[1] CHAI Xicun;ZHOU Linglei;HE Chunxia(College of Engineering,Nanjing Agricultural University,Nanjing 210031,China)

机构地区：[1]南京农业大学工学院,南京210031

出　　处：《复合材料学报》2023年第6期3553-3561,共9页Acta Materiae Compositae Sinica

基　　金：自治区区域协同创新专项(2019 E0241);江苏省研究生科研与实践创新计划项目(KYCX21_0574)。

摘　　要：为提高聚乳酸(PLA)的降解性,将竹纤维(BF)和海藻酸钠(SA)与PLA共混制备复合材料,并进行土壤降解试验以探究其降解性能,检测降解后复合材料的质量损失率、表面微观结构、官能团变化、热性能和结晶度等指标。结果表明:SA和BF均可提升PLA复合材料降解的质量损失率。降解21天后,BF/PLA和SA-BF/PLA复合材料的质量损失率分别为0.83%和2.54%,相较于纯PLA的0.11%分别提高了7.55和23.09倍。降解后,SA-BF/PLA复合材料的表面出现大量的裂痕与凹陷,这增大了复合材料与土壤中的接触面积,进而加速了复合材料的降解。纯PLA在降解过程中质量损失率很低,但降解后其羰基含量明显上升,表明土壤降解会导致部分PLA长链高分子断裂为小分子。相比于纯PLA,BF/PLA和SA-BF/PLA复合材料的结晶度大幅度降低,表明SA和BF可降低PLA复合材料的结晶度,提高其降解性。由此可见,SA和BF可提升PLA复合材料的降解性能。此研究结果将为高降解性PLA复合材料的制备提供理论参考。In order to improve the degradability of polylactic acid(PLA),bamboo fiber(BF)and sodium alginate(SA)were blended with PLA to prepare composite materials.And then the PLA composites were buried in soil for degradation test.The mass loss,morphological properties,FTIR,thermal properties and crystallinity of the PLA composites were measured after degradation.The results shown that both SA and BF can improve the mass loss of PLA composites during degradation.After 21 days of degradation,the mass loss rates of BF/PLA and SA-BF/PLA composites were 0.83%and 2.54%,which were 7.55 and 23.09 times higher than that of pure PLA(0.11%),respectively.A large number of cracks and depressions appeared on the surface of SA-BF/PLA composites after degradation,which increased the contact area between the PLA composites and the soil,and thus accelerated the degradation of the PLA composites.The mass loss rate of PLA materials was very low after degradation,but the carbanyl group of PLA materials increased significantly,this indicated that soil degradation could lead to the fracture of some PLA long-chain polymers into small molecules.Compared with pure PLA,the crystallinity of BF/PLA and SABF/PLA composites was significantly reduced,this meant that SA and BF could reduce the crystallinity of the PLA composites and enhance their degradability.The results indicated that SA and BF can improve the degradability of PLA composites.The results would provide theoretical reference for the preparation of highly degradable PLA composites.

关 键 词：聚乳酸 竹纤维 海藻酸钠 土壤降解 降解性能 

分 类 号：TB332[一般工业技术—材料科学与工程]