复合方式对木纤维-聚乳酸生物质复合材料结构与性能的影响  

Effects of compounding modes on structure and properties of wood fiber-poly(lactic acid) bio-composites

作　　者：郭文静[1] 鲍甫成[1] 王正[1] 

机构地区：[1]中国林业科学研究院木材工业研究所

出　　处：《北京林业大学学报》2009年第4期106-111,共6页Journal of Beijing Forestry University

基　　金：中央级公益性科研院所基本科研业务费专项资金项目(CAFINT2007C02);"十一五"国家科技支撑计划项目(2008BADA9B01)

摘　　要：为研究不同受热与剪切作用程度的复合方式对木纤维-聚乳酸(WF-PLA)生物质复合材料结构与性能的影响,分别采用常规混合、高速混合、熔融挤出法制备了WF-PLA生物质复合材料,并用DSC、TGA、GPC等方法进行了分析。结果表明:①不同复合方式对WF-PLA生物质复合材料结构与性能有显著影响。②受热与剪切作用时间最长的熔融挤出法制备的WF-PLA生物质复合材料,弯曲强度最低(25.39 MPa),密度最大(1.34 g/cm3),耐水性最好,熔点和热分解温度明显降低,聚乳酸相-Mw和-Mn分别只有聚乳酸原料的13.5%和14.6%。③受热与剪切作用时间最短的常规混合法制备的WF-PLA生物质复合材料密度最小(1.25 g/cm3),弯曲强度最高(50.98 MPa),但耐水性差,聚乳酸相-Mw和-Mn分别是聚乳酸原料的69.9%和67.3%。④受热与剪切作用适中的高速混合法制备的WF-PLA生物质复合材料弯曲强度、密度、耐水性均居中,弯曲模量最高(5.13 GPa),综合性能最好,聚乳酸相-Mw和-Mn分别为聚乳酸原料的51.0%和51.9%。⑤不同复合方式引起聚乳酸分子降解是影响复合材料性能的关键。Wood fiber-poly （lactic acid） （WF-PLA） bid-composites were prepared by three compounding modes, i.e. normal mixing, high-speed mixing and melt extrusion. The influences of different heat and shear procedures on physical, mechanical, and thermal properties of the composites, and molecular weight of PLA in the composites were investigated using DSC, TGA and GPC techniques. The results indicated that the effects of compounding modes on properties of the WF-PLA bid-composites were significant. The WF-PLA composites produced by melt extrusion, which experienced a long heat and shearing procedure, had the lowest flexural strength （25.39 MPa）, the highest density （1.34 g/cm3） and the best water resistance. Both melt temperature and thermal degradation temperature were lowered. Mw and M, of PLA in the composites were just 13.5% and 14.6% of raw PLA. The composites produced by normal mixing, which experienced a short heat and shearing procedure, had the lowest density （1.25 g/cm3）, the highest flexural strength （50.98 MPa）, and the poorest water resistance. Mw and M, of PLA in the composites were 69.9 % and 67.3 % of the respective raw PLA values. For the composites from high-speed mixing and experiencing a moderate heat and shearing procedure, flexural strength, density and water resistance were all moderate. Flexural modulus of the composites was the highest （5.13 GPa）. Mw and M, of PLA were 51.0% and 51.9% of the raw PLA values. It is, thus, concluded that the degree of degradation of the PLA molecules caused by different compounding modes is the key factor influencing the properties of WF-PLA bid-composites.

关 键 词：常规混合 高速混合 熔融挤出 木纤维 聚乳酸 木纤维-聚乳酸生物质复合材料 

分 类 号：TS653[轻工技术与工程]