立构复合聚乳酸/碳纳米管静电纺丝纤维膜的制备及其结晶性能

Preparation and Crystallization Properties of Stereocomplex Poly(lactic acid)/Carbon Nanotubes Electrospun Composite Fiber Membranes

利用羟基化的碳纳米管(CNT-OH)和辛酸亚锡分别作为引发剂和催化剂,右旋丙交酯在130℃下开环聚合反应,对碳纳米管(CNT)进行了改性处理。红外光谱和热失重分析结果表明,CNT被成功改性,聚右旋乳酸(PDLA)在CNT上的接枝率为34.8%。进一步通过静电纺丝法制备了聚乳酸/功能化碳纳米管(PLLA/CNT-f-PDLA)的复合纤维膜,纤维平均直径为890 nm。利用红外光谱和X射线衍射技术研究了复合纤维膜的结晶行为和晶体结构。结果表明,在120℃热处理0.5 h后的复合纤维膜中,只生成立构复合晶体(sc),无PLLA或PDLA的同质晶体(hc)产生,而且由于CNT-f-PDLA在PLLA基体中的良好分散性以及CNT的异相成核作用,相对于PLLA/PDLA复合纤维膜,PLLA/CNT-f-PDLA复合纤维膜的立构复合结晶度得到了提高。

In this work, carbon nanotubes （CNTs） were modified via ring-opening polymerization of D- lactide at 130 ℃ by using hydroxylated CNTs and stannous octoate as initiator and catalyst, respectively. The results of Fourier infrared spectrometer and thermogravimetry show that CNTs were modified successfully, and the grafting ratio of poly （D-lactic acid） （PDLA） was 34. 8 %. Poly （ lactic acid）/functional CNTs （ PLLA/ CNT-f-PDLA） composite fibers were prepared by eleetrospinning, and the average fiber diameter was 890 nm. The crystallization behavior and crystal structure of electrospun composite fibers were studied by FTIR, and X-ray diffraction analysis. The composite fibers formed stereocomplex crystals （sc） exclusively after heating treatmentat 120 ℃ for 30 min, without homocrystals （hc） of PLLA or PDLA. Compared with PLLA/PDLA nanofiber membrane, PLLA/CNT-f-PDLA composite fibers had an increased sc-crystallinity due to the good dispersity of CNT-f-PDLA in PLLA matrix and the heterogeneous nucleation effect of CNTs.