【作者】 李志超；

【导师】 于开锋； 高蔚；

【作者基本信息】 吉林大学 ， 材料工程（专业学位）， 2021， 硕士

【摘要】 伴随着我国汽车轻量化技术和科学发展的进步,复合材料越来越多地出现在汽车的关键零部件中。纤维复合材料（FRTP）具有一体化成型,理化性能良好等优点,是我国汽车制造工业中具有开拓性的潜在材料。玄武岩纤维（BF）作为天然环保的增强材料,是由破碎处理的细粉状玄武岩石混合物在1500-1700℃下进行熔融,生成玻璃状熔融液体,然后经过均质化处理和纤维提取制成,在生产过程中不会释放任何有害化学元素,具有优异的机械与化学性能且回收率较高。用作增强纤维时,其表面光滑且惰性较大,与基体材料之间的粘合性能较差,限制玄武岩纤维复合材料发展。硅碳黑（Si CB）是通过稻壳的选择性热解和定向破碎技术获得的微米级黑色粉末。可通过研磨和偶联剂改性有效地降低其表面能,避免颗粒之间的团聚,改性后的硅炭黑（KSi CB）与树脂基体的粘附性较强,可以改善复合材料的综合性能。本文以尼龙6（PA6）为基体,以BF和Si CB为增强材料,聚烯烃弹性体接枝马来酸酐（POE-g-MAH）为增韧材料,制备多元复合材料,对其综合性能进行研究。1.以不同含量的玄武岩纤维为增强体制备二元复合材料PA6/BF,采用煅烧、酸碱活化、偶联剂处理等方法对纤维进行表面改性,提高玄武岩纤维与PA6的界面结合能力,对改性前后的BF和复合材料进行表征。BF对PA6增强效果明显,相较于纯PA6,PA6/BF-30%体系的拉伸强度,弯曲强度和冲击强度分别提升了53.69%,48.66%和174.23%。其中BF起到异相成核作用,提高材料结晶度,此时材料的表观剪切粘度与热稳定性均有大幅度的提高。相较于未经过改性且BF质量分数为30%的复合材料,H₂SO₄加以偶联剂（KH-550）协同处理的PA6/BF复合材料的力学性能最佳,其拉伸强度,弯曲强度和冲击强度分别提升了24.36%,28.26%和37.41%,此时材料的表观剪切粘度与热变形温度有所增加。2.对最佳BF改性的二元复合材料PA6/BF进行填充改性,表征改性前后的硅炭黑粒子与复合材料。当复合体系中添加POE-g-MAH时,材料力学性能上整体表现出高韧性,低强度现象,此时体系的热稳定性与结晶度下降,但是粘度有所增大。将无机颗粒KSi CB单独添加到PA6/BF中,KSi CB/PA6/BF体系在力学上表现出高强度,低韧性现象,与此同时,材料的热稳定性、结晶度与粘度有所提高。但是,当同时添加POE-g-MAH和KSi CB时,KSi CB和POE-g-MAH具有更好的协同作用,当KSi CB含量为2.5phr时,复合材料的力学性能最佳,其拉伸强度,拉伸模量,弯曲强度和冲击韧性分别提高了4.46%,171.79%,15.14%和27.77%。更多还原

【Abstract】 With the progress of our country’s automobile lightweight technology and scientific development,more and more composite materials appear in the key parts of automobiles.Fiber composite material（FRTP）has the advantages of integrated molding,good physical and chemical properties,etc.,and is a pioneering potential material in our country’s automobile manufacturing industry.Basalt fiber（BF）,as a natural and environmentally friendly reinforcing material,is made by crushing a finely powdered basalt mixture at 1500-1700℃ and melting it to produce a glassy molten liquid,which is then homogenized and fiber extracted.It will not release any harmful chemical elements during the production process,has excellent mechanical and chemical properties,and a high recovery rate.When used as a reinforcing fiber,its surface is smooth and inert,and its adhesion to the matrix material is poor,which limits the development of basalt fiber composite materials.Silicon carbon black（Si CB）is a micron-sized black powder obtained by selective pyrolysis and directional crushing of rice husks.Grinding and coupling agent modification can effectively reduce the surface energy to avoid agglomeration between particles.The modified silicon carbon black（KSi CB）has strong adhesion to the resin matrix,which can improve the overall performance of the composite material.In this paper,nylon 6（PA6）was used as the matrix,BF and Si CB were used as reinforcing materials,and polyolefin elastomer grafted with maleic anhydride（POE-g-MAH）was used as toughening materials to prepare a multi-element composite material and study its comprehensive properties.1.Different content of basalt fiber was used as reinforcement to prepare binary composite PA6/BF.The surface modification of the fiber was carried out by calcination,acid-base activation,and coupling agent treatment methods to improve the interfacial bonding ability of basalt fiber and PA6.The BF and composite materials were characterized before and after use.BF had an obvious enhancement effect on PA6.Compared with pure PA6,the tensile strength,the bending strength,and impact strength of the PA6/BF-30%system were increased by53.69%,48.66%,and 174.23%,respectively.Among them,BF played a role in heterogeneous nucleation and improved the crystallinity of the material.At this time,the apparent shear viscosity and thermal stability of the material were greatly improved.Compared with the unmodified composite material with a BF mass fraction of 30%,the mechanical properties of the PA6/BF composite material treated with H₂SO₄ and the coupling agent（KH-550）were the best,and its tensile strength,flexural strength,and impact strength were increased by 24.36%,28.26%,and 37.41%respectively,at this time the apparent shear viscosity and heat distortion temperature of the material increased.2.The best BF modified binary composite PA6/BF was filled and modified,and the silicon carbon black particles and composite materials before and after the modification were characterized.When POE-g-MAH was added to the composite system,the overall mechanical properties of the material showed high toughness and low strength.At this time,the thermal stability and crystallinity of the system decreased,but the viscosity increased.When inorganic particles KSi CB were added to PA6/BF alone,the KSi CB/PA6/BF system exhibited high strength and low toughness mechanically.At the same time,the thermal stability,crystallinity and viscosity of the material were improved.However,when POE-g-MAH and KSi CB were added at the same time,KSi CB and POE-g-MAH had a better synergistic effect.When the content of KSi CB was 2.5 phr,the mechanical properties of the composite material were the best,and its tensile strength,tensile modulus,bending strength,and impact toughness increased by 4.46%,171.79%,15.14%,and 27.77%,respectively.更多还原