不同生物酶改性处理对麦秸秆纤维/高密度聚乙烯复合材料性能的影响

以麦秸秆纤维(WF)和高密度聚乙烯(HDPE)为原料,利用混炼和注塑成型的方法制备WF/HDPE复合材料。考察了木聚糖酶、漆酶、脂肪酶、木聚糖酶与脂肪酶复合处理对WF/HDPE复合材料力学性能、热稳定性、吸水率的影响,通过FTIR分析了酶处理前后的WF化学官能团变化,利用SEM观察了酶处理前后的WF表面形貌和WF/HDPE复合材料拉伸断裂面。结果表明:当WF/HDPE复合材料经木聚糖酶与脂肪酶复合处理后,吸水率最低且WF/HDPE复合材料的力学性能最好,其拉伸强度、弯曲强度、弯曲模量分别达到23.4 MPa、34.0 MPa、1 944.6 MPa;TG结果表明WF/HDPE的热分解过程分两个部分:WF的分解过程和HDPE的分解过程,酶能有效提高WF/HDPE的热稳定性;FTIR显示经酶处理后,WF的羟基振动峰微弱减小,在1 706~1 290 cm-1处光谱上出现部分小峰,SiO2的振动峰变得平缓;SEM显示经酶处理后,WF表面变粗糙,WF与HDPE结合紧密,其中经木聚糖酶和脂肪酶共同处理后两者界面结合性能最好。

Effect of different enzyme modification on properties of wheat straw fiber/high density polyethylene composites

WF/HDPE composites were prepared from wheat straw fiber(WF) and high density polyethylene(HDPE) by mixing and injection moulding. The effects of xylanase, laccase, lipase, xylanase and lipase on the mechanical properties, thermal stability and water absorption of WF/HDPE composites were investigated. The changes of chemical functional groups of WF before and after enzyme treatment were analyzed by FTIR. The surface morphologies of WF and the tensile fracture surface of WF/HDPE composites before and after enzymatic treatment were observed by SEM. The results show that WF/HDPE composites treated with xylanase and lipase have the lowest water absorption and the best mechanical properties. The tensile strength, flexural strength and flexural modulus of WF/HDPE composites reach 23.4 MPa, 34.0 MPa and 1 944.6 MPa, respectively. TG results show that the thermal decomposition process of WF/HDPE is divided into two parts: WF decomposition process and HDPE decomposition process, and the thermal stability of WF/HDPE composites can be effectively improved by enzyme.After treatment, the hydroxyl vibration peak of WF decreases, and some small peaks appeare in the spectrum at1 706-1 290 cm-1, and the vibration peak of SiO2 becomes gentle. SEM shows that the surface of WF becomes rough after enzyme treatment, and WF and HDPE are closely bound, among which the interface bonding performance of WF and HDPE treated by xylanase and lipase is the best.