关键词: 原位聚合法, MC尼龙, 纳米ZnO, 动态高温XRD, 膨胀系数

Abstract: MC nylon 6/ZnO nanocomposite was prepared by in situ polymerization method. Dynamic high temperature XRD patterns indicate that with the temperature increasing the α1 (200 lattice plane) of MC nylon 6 was shrunk, but the α2 (002+202 lattice plane) was expanded, the thermal expansion coefficients of the lattice planes of pure MC nylon 6 were aTα1=-8.8×10-5 ℃-1, and aTα2=1.6×10-4 ℃-1, the thermal expansion coefficients of MC nylon 6/ZnO nanocomposites were aTα1=-1.7×10-4 ℃-1, and aTα2=3.4×10-4 ℃-1 respectively. With the temperature increasing, the relative crystallinity of MC nylon 6/ZnO nanocomposite decreased, the crystal structure was almost destroyed at the temperature close to the melting temperature, and with the temperature decreasing from the tiptop, it recrystallized, the variation of crystalline morphology and relative crystallinity was almost reversible in the tested temperature range from 20 to 210℃. Along with the increase of the content of nanometer particles, the thermal stability of the composites showed a rising trend. The more evenly the particles distributed, the better the thermal stability was. Nano-ZnO addition made starting degradation temperature of MC nylon 6 increased by 1~9℃ and the maximal weight-losing rate temperature also increased.

Key words: in situ polymerization, MC nylon, nano-ZnO, dynamic high temperature XRD, expansion coefficient