材料期刊网

通过溶液共混法制备了聚乳酸/碳纳米管（PLA/CNTs）复合材料,并利用差示扫描量热分析（DSC）研究了CNTs的种类、长度、直径和质量分数对不同升温速度下PLA非等温冷结晶性能的影响,结果表明,PLA/CNTs复合材料的玻璃化转变温度（Tg）和结晶峰温度（Tc）都随升温速度降低而逐渐降低,而结晶度和熔融温度（Tm）则升高。添加质量分数为0.1%的多壁碳纳米管（MWNTs）即可有效促进PLA的异相成核,提高其结晶速度和结晶度,以10℃/min升温冷结晶时,当CNTs用量达1%时会阻碍PLA的非等温结晶过程,并导致PLA复合材料的Tg、Tm和结晶度降低。MWNTs对PLA非等温结晶的促进作用比SWNTs或DWNTs明显,而较短的MWNTs比长MWNTs的作用略为明显。

carbon nanotubes（CNTs） were compounded with PLA via solution blending to improve the crystallization of poly-lactic acid（PLA）.Differential scanning calorimetry（DSC） was used to study the nonisothermal cold crystallization properties of PLA/CNTs composites.The influences of the CNTs’ types,tube diameter,tube length,mass fraction and also the heating rate on the crystallization properties of PLA composite were investigated.As the heating rate decreased,both the glass transition temperature（Tg） and crystallization peak temperature（Tc） decreased while the melting temperature（Tm） and crystallization degree increased.The 0.1% CNTs could act as heterogeneous nucleation agents and lift both the crystallization speed and crystallization degree of PLA,but when CNTs loading increased up to 1%,the crystallization was inhibited,and the Tg,Tm and crystallization degree of PLA all decreased under a heating rate of 10℃/min.Multi-walled carbon nanotubes（MWNTs） showed a more obvious accelerating action than single-walled carbon nanotubes（SWNTs） or double-walled carbon nanotubes（DWNTs） while shorter MWNTs showed a more obvious accelerating action than longer MWNTs for the nonisothermal cold crystallization of PLA.