不同表面处理麦秸秆对木塑复合材料性能的影响

Effects of different surface treatment for wheat straw on performances of wood-plastic composites

为提高麦秸秆纤维与聚丙烯(polypropylene,PP)基体的界面结合力,采用复合处理法对麦秸秆纤维进行表面处理:先分别用NaOH、乙酸溶液浸泡、水热处理、蒸汽爆破和微波等方法对麦秸秆纤维进行预处理,再复合偶联剂法处理麦秸秆纤维;用熔融共混、模压成型方法制备麦秸秆/废弃PP木塑复合材料,探讨了麦秸秆不同表面处理方法制备PP木塑复合材料力学性能和吸湿吸水性能;用体视显微镜对不同处理的麦秸秆及木塑复合材料拉伸断面进行观察。结果表明:经复合处理的麦秸秆与PP木塑复合材料力学性能和吸湿吸水性能均优于单纯使用偶联剂处理的麦秸秆与PP木塑复合材料;NaOH和乙酸复合处理的复合材料力学性能和抗吸湿吸水性能较好,水热和蒸汽爆破复合处理的复合材料次之。麦秸秆经复合处理后,表面变粗糙,秸秆纤维和PP基体的界面黏合性得到改善。该文研究结果对通过麦秸秆纤维表面处理提高麦秸秆/废弃PP木塑复合材料的性能有重要的实际意义。

In order to improve the interracial bonding strength of wheat straw fibers and polypropylene （PP）, the wheat straw fibers were treated by combined treatment. The surfaces of fibers were pretreated by 5 methods, such as NaOH, acetic acid, hot water, steam explosion and microwave, and then compounded by coupling agent treatment. The wheat straw/PP wood-plastic composites were prepared by blending with PP and wheat straw through melt blending and molding. The mechanical, properties, water absorption and moisture absorption performance of the PP wood-plastic composites filled with different surface treated wheat straw fibers were investigated. The tensile sections of the composites were observed by the stereo microscope. The results showed that the mechanical properties, water absorption and moisture absorption performance of PP composites filled with combined treated fibers were excellent that the composites filled with coupling agent treated fibers. It was found that the composites with wheat straw treated by NaOH and acetic acid had good mechanical properties and anti-water absorption and anti-moisture absorption performance, followed by the composites with wheat straw fibers treated by hydrothermal and steam explosion. After combined treatment, the surface of wheat straw became rough, so that the interracial adhesion of straw fibers and PP matrix was improved. The results of this paper had great practical significance on improving the properties of wheat straw/waste PP wood-plastic composite by straw fiber surface treatment.