纳米SiO_2的均匀分散及其对MC尼龙6晶型结构及晶型转变的影响

Homogeneous dispersion of nano-silica and its effects on the crystalline structure and transition of MC nylon6

通过阴离子开环聚合法制备纳米二氧化硅(Si O2)/MC尼龙6原位复合材料,采用透射电子显微镜(TEM)对纳米粒子在基体中的分散行为进行表征,结果表明Si O2约以30～70nm左右的尺寸均匀分散在基体中。广角X射线衍射(WAXD)结果表明,纯MC尼龙6及其原位复合材料均呈现典型尼龙6的α晶型衍射峰,纳米Si O2的引入在MC尼龙6结晶过程中削弱了大分子链在c轴的取向。液氮淬冷样品经退火处理后的WAXD结果表明,纳米Si O2和MC尼龙6之间的相互作用阻碍了大分子链段的运动,从而使得γ晶型向α晶型的转变速率降低。

Nano-silica/MC nylon6 in-situ composites were prepared via anionic polymerization.And the subsequent dispersing behavior of nano-silica in MC nylon6 was also characterized by TEM.Results showed that silica dispersed rather well in MC nylon6 matrix and appeared to be ca.30～70nm in diameter.Based on the results of WAXD,the crystalline structure appeared merely in α form for both MC nylon6 and composites,however,the presence of nano-silica weakened the orientation of polymer chains in c-axis during crystallization.The quenched samples possessed α form and γ form after annealed at 200℃ for 10hr,however,the strong interaction between silica and MC nylon6 hindered the transition from γ form to α form.