氨基甲基吡啶改性氮化硼/线型低密度聚乙烯复合材料的热性能及力学性能

Thermal and Mechanical Properties of Boron Nitride Filled LLDPE Composites Modified with Aminomethylpyridine

利用4-氨基甲基吡啶与马来酸酐接枝线型低密度聚乙烯(LLDPE-g-MAH)成功制备了氨基甲基吡啶接枝线型低密度聚乙烯(LLDPE-g-Py),然后采用熔融共混法制备了改性的BN/LLDPE(mBN/LLDPE)复合材料。深入研究了mBN/LLDPE复合材料的热性能和力学性能等。结果表明,LLDPE-g-Py的加入,使mBN/LLDPE复合材料的导热性能得到很大提升,但LLDPE-g-Py过多会导致其耐热性降低。为了改善复合材料的耐热性,将LLDPE-g-Py质量分数固定为10%。当BN质量分数为40%时,mBN/LLDPE复合材料的导热系数达到了0.95 W/(m·K),为纯LLDPE导热系数(0.32 W/(m·K))的3倍。同时,mBN/LLDPE复合材料的拉伸强度在小幅度下降的情况下,其断裂伸长率得到明显的改善。

Aminomethylpyridine grafted linear low density polyethylene(LLDPE-g-Py)was successfully prepared with 4-aminomethylpyridine and maleic anhydride grafted linear low density polyethylene(LLDPE-g-MAH),and then the modified BN/LLDPE(mBN/LLDPE)composites were prepared by melt blending.In the composites,due to the non-covalent action of LLDPE-g-Py and BN,the interfacial thermal resistance between filler and matrix is reduced,and BN is evenly dispersed in LLDPE matrix,so as to enhance the thermal conductivity of the composite.The thermal and mechanical properties of mBN/LLDPE composites were deeply studied.The results show that the thermal conductivity of mBN/LLDPE composites is greatly improved by the addition of LLDPE-g-Py,but too much LLDPE-g-Py will reduce its heat resistance.In order to improve the heat resistance of the composite,the LLDPE-g-Py mass fraction is fixed at 10%.When the BN mass fraction is 40%,the thermal conductivity of mBN/LLDPE composite reaches 0.95 W/(m·K),which is about 3 times that of pure LLDPE(0.32 W/(m·K)).At the same time,the tensile strength of mBN/LLDPE composites decreases slightly,and its elongation at break is significantly improved.