化学发泡剂含量对秸秆纤维/聚丙烯复合材料性能的影响机理  

Effects of Chemical Blowing Agent Content on Properties of Straw Fiber/Polypropylene Composites

作　　者：李伟 郝加杰[1] 李文鹏 袁泉[2,3] 郭巍 孟正华[2,3] LI Wei;HAO Jia-jie;LI Wen-peng;YUAN Quan;GUO Wei;MENG Zheng-hua(SAIC GM Wuling Automobile Co.,Ltd.,Guangxi Liuzhou 545007,China;Hubei Key Laboratory of Advanced Technology for Automotive Components,Wuhan University of Technology,Wuhan 430070,China;School of Automotive Engineering,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]上汽通用五菱汽车股份有限公司,广西柳州545007 [2]武汉理工大学现代汽车零部件技术湖北省重点实验室,武汉430070 [3]武汉理工大学汽车工程学院,武汉430070

出　　处：《精密成形工程》2023年第9期57-64,共8页Journal of Netshape Forming Engineering

摘　　要：目的揭示发泡剂含量对微发泡注塑成型秸秆纤维/聚丙烯复合材料(SF/PP)密度及力学性能的影响规律,提供制备低密度高性能SF/PP材料的发泡剂用量工艺参考。方法以偶氮二甲酰胺(AC)为化学发泡剂,制备了注塑发泡SF/PP,利用扫描电子显微镜、电子万能实验机和红外光谱测试等手段,分析了不同发泡剂含量下SF/PP的拉伸、弯曲、冲击性能、泡孔微观形貌和分布以及复合材料红外光谱图,通过实验对比分析了不同发泡剂含量下材料性能的变化规律。结果当AC含量增加时,微发泡SF/PP的密度先降低后升高,冲击强度则先升高后降低,拉伸和弯曲强度为逐渐降低。当AC的质量分数为4%时,微发泡SF/PP的综合性能最佳,泡孔结构最好;微发泡(SF/PP)红外光谱图结果显示,在3420 cm^(-1)处的—OH伸缩振动峰强度高于未发泡复合材料的,这表明秸秆纤维表面极性增大,秸秆纤维与树脂之间的结合性变差,导致微发泡SF/PP的拉伸强度低于未发泡材料的。结论适当增加AC含量可使复合材料获得微小、致密的泡孔微观结构,降低材料密度,提升产品的力学性能;但当AC含量过多时,泡孔坍塌会使泡孔直径增大、泡孔结构变差,从而影响复合材料的力学性能。The work aims to investigate the effects of foaming agent content on the density and mechanical properties of straw fiber/polypropylene composites(SF/PP)under micro-foaming injection and provide a process reference for dosage of foaming agent for preparing low density high performance SF/PP materials.Foamed SF/PP was prepared with azodicarbona-mide(AC)as chemical foaming agent.The tensile,bending and impact properties,cell morphology and distribution,infrared spectra tests were performed with a scanning electron microscope,an electronic universal testing machine and infrared spectroscopy to analyze the changing rules of SF/PP with different foaming agent contents.The experimental results showed that,with the increase of AC content,the density of micro-foamed SF/PP decreased first and then increased,the impact strength in-creased first and then decreased,and the tensile and bending strength gradually decreased.When the AC content(wt.%)was 4%,the comprehensive performance of the micro-foamed SF/PP was optimal along with the suitable foam size and distribution.The infrared spectroscopy of SF/PP showed that the strength of the-OH stretching vibration peak of the micro-foamed composite at 3420 cm^(-1) was higher than that of the un-foamed composite,which resulted in the increase of the cellular of the straw fiber surface and the poor bonding between the straw fiber and PP resin,leading to the lower tensile strength of the micro-foamed SF/PP than that of the un-foamed material.Suitable AC additions makes the cell tiny and dense during the injection,reduces the material density and improves the mechanical property of product,while overdose AC additions causes cell collapses,which in-creases the cell diameter and worsens the foam structure,and thus affects the chemical property of composites.

关 键 词：微发泡注塑 植物纤维复合材料 泡孔结构 力学性能 

分 类 号：TB332[一般工业技术—材料科学与工程]