中文摘要：

采用熔融共混法制备了不同凹凸棒（Attapulgite,AT）含量的聚乳酸（PLA）/AT纳米复合材料.通过DSC研究了AT对PLA结晶行为的影响.结果显示,少量AT（≤3%）的加入使得PLA的冷结晶温度升高、高温熔融峰焓值下降,表明少量AT对PLA的结晶有抑制作用.当AT含量增加时（≥8%）,PLA的冷结晶温度逐渐降低、高温熔融峰焓值逐渐增加,表明AT具有促进PLA结晶的能力.材料中,AT含量对PLA结晶能力有极大的影响.在379K进行等温结晶时,PLA的半结晶时间（t（1/2））为4.47min;添加1%AT时,t（1/2）增至5.63 min;而当添加8%AT时,t（1/2）降低至3.98 min.同时,AT的加入使得PLA的结晶活化能E明显降低.在368~398K范围内,对PLA/AT纳米复合材料的熔体等温结晶动力学过程进行了分析.计算得到Avrami指数n为2.34~2.42,表明PLA主要以球晶形式生长.

英文摘要：

Polylactic acid （PLA） /attapulgite （AT） nanocomposites with various AT contents were prepared via melt blending processing. The crystallization behavior of the blends was investigated by differential scanning calorimetry （DSC）. Compared with pure PLA, the cold crystallization temperature increases and the enthalpy of high temperature melting peak decreases with the AT content ≤ 3wt%, indicating an inhibition effect on crystallization of PLA chain. In contrast, the cold crystallization temperature decreases and the enthalpy of high temperature melting peak increases with the AT content 8 wt%, suggesting AT can promote crystallization of PLA chain. Isothermal crystallization at 379 K, the value of half-time of crystallization （t1/2） for PLA/AT nanoeomposites increases and then decreases with increasing AT content. Meanwhile, with increasing the AT content, the crystallization activation energy of PLA/AT nanocomposites decreases. The melt isothermal crystallization kinetics of PLA/AT nanocomposites was analyzed by Avrami theory at various temperatures and the Avrami exponent n ranges from 2.34 to 2.42, which means that spherulites morphology of PLA crystals formed.