In this paper,tetraethyl orthosilicate(TEOS)and ammonia were used to prepare a solution gel to modify the surface of straw fibers(SF).The changes in chemical composition,surface morphology and hydrophobicity of SF before and after the modification were investigated.Long-SF-reinforced polypropylene(PP)composites were prepared through hot pressing,and the mechanical strength of PP/SF composites before and after the solution gel modification of long SF were compared.The PP/SF composites were designed and prepared with five different straw orientations of 0 °,15 °,30 °,45 ° and 90 °,and the effects of orientation angle on the mechanical strength of the composites were investigated.The experimental results indicated that the SiO2 particles deposited on the surface of the TEOS-treated SF could help to improve the hydrophobicity and roughness of the fiber surface,thus enhancing the infiltration and compatibility between SF and PP.Compared to PP composite with untreated SF,the tensile,flexural,and impact strengths of the composites with TEOS-treated SF were improved by 20.3%,11%,and 35.7%,respectively.The orientation angle of the fibers has a great influence on the mechanical strength of PP/SF composites.The smaller the angle between the orientation di-rection of SF and the direction of the applied stress,the more can the SF exert their reinforcing effect,and the higher are the tensile,flexural and impact strengths.
关键词
麦秸秆/聚丙烯/溶液凝胶改性/取向角度/力学强度
Key words
wheat straw/polypropylene/solution gel modification/orientation angle/mechanical strength
维普
万方数据