甜高粱渣/高密度聚乙烯复合材料的热稳定性与力学性能研究

Study on thermal stabilities and mechanical properties of sweet sorghum slag/high density polyethylene composites

甜高粱发酵生产燃料乙醇时产生的甜高粱渣中含有丰富的纤维素及半纤维素,可用来进一步构筑功能复合材料。为了研究甜高粱渣对复合材料热稳定性及力学性能的影响规律,文章选取高密度聚乙烯与甜高粱渣为主要原料,采用注塑成型法制备复合材料,并借助傅里叶变换红外光谱及化学成分分析仪研究甜高粱渣的表面官能团及组分含量,采用扫描电子显微镜分析复合材料的微观形貌,通过热重分析评价复合材料的热稳定性,利用万能力学试验机和动态热机械分析仪分析复合材料的力学性能。研究结果表明;作为生物大分子,甜高粱渣会降低复合材料的热稳定性及冲击强度,但对复合材料的抗蠕变能力、抗应力松弛能力及弯曲强度均有不同程度的增强作用;当甜高粱渣的含量为40%时,复合材料的界面结合情况良好,弯曲强度可达40 MPa,较高密度聚乙烯纯料提高了46%,展现出较高的力学性能。

The sweet sorghum slag produced by the production of fuel ethanol by fermentation of sweet sorghum is rich in cellulose and hemicellulose,which can be used to further prepare functional composites.In order to study the effects of sweet sorghum slag on the thermal stabilities and mechanical properties of the composites,high density polyethylene(HDPE)and sweet sorghum slag(SSS)were used as the main raw material by using injection molding to prepare materials in this research.The surface functional groups and component contents of SSS were studied by Fourier transform infrared spectroscopy and chemical composition analysis,the microstructure of the obtained composites was analyzed by scanning electron microscope,the thermal stabilities of composites were evaluated by thermal gravimetric analysis,and the mechanical properties of composites were tested by using universal testing machine and dynamic thermomechanical analyzer.The results show that as a biological macromolecule,SSS can reduce the thermal stabilities and impact strength of the prepared composites,while enhance the creep resistance,anti-stress relaxation abilities and bending strength of composites to different degrees.When the content of SSS was 40%,the composite exhibited well interfacial bonding,and its bending strength reached 40 MPa,which was 46%higher than that of HDPE,showing excellent mechanical properties.