接枝改性木纤维/聚己内酯复合材料的制备与性能

Preparation and Properties of Graft-Modified Wood Fiber/Polycaprolactone Composites

将木纤维(WF)经马来酸酐酯化改性后,再以过氧化二苯甲酰(BPO)为引发剂,苯乙烯(St)与丙烯酸正丁酯(BA)为单体,在甲苯溶剂中对其进行接枝改性,然后使用密炼机将改性木纤维(MWF)与聚己内酯(PCL)复合制备复合材料。通过红外光谱、力学测试、广角X射线衍射、差示扫描量热-热重同步热分析和扫描电子显微镜研究了MWF和复合材料的结构与性能。结果表明,MWF成功地接枝上了疏水单体,当单体St与BA的摩尔比1.5∶1时,接枝率达到最大值,同时表现出较好的疏水性能;与未改性WF/PCL(20/80)复合材料相比,MWF/PCL(20/80)复合材料的拉伸强度最大增加了22%,断裂延伸率提高了718%;WF经接枝改性后,其复合材料中PCL相的晶粒尺寸、结晶度和热稳定性皆有提高;SEM分析表明MWF和聚合物基体之间的界面粘合明显改善。

Wood fiber( WF) was esterified with maleic anhydride,then was modified by grafting copolymerization using benzoyl peroxide( BPO) as initiator,styrene( St) and n-butylacrylate( BA) as monomers. The modified wood fiber( MWF) and polycaprolactone( PCL) were compounded to prepare composites using a mixing chamber. The structure and properties of MWF and MWF /PCL composites were analyzed by FT-IR,mechanical testing,WAXD,TG-DSC and SEM. The results show that hydrophobic monomers were grafted on MWFs successfully. The graft degree of hydrophobic monomers reaches the maximum when the mole ratio of St to BA is 1. 5∶ 1,and MWFs show better hydrophobic properties. Compared with WF /PCL( 20 /80) composite,the tensile strength and the elongation at break of the MWF /PCL( 20/80) composite increase 22% and 718% respectively,and the PCL phase in MWF/PCL composites also exhibits increase in the crystalline size,crystallinity and thermo-stability. SEM analysis reveals improved interfacial adhesion between MWF and the polymer matrix.