单向竹原纤维表面改性对其增强不饱和聚酯树脂复合材料性能的影响

采用碱处理、碱-偶联剂联合处理对竹原纤维进行表面改性,通过缝合-模压工艺制备了单向连续竹原纤维/不饱和聚酯树脂(BF/UP)复合材料。研究了不同表面改性方法对BF/UP复合材料静态、动态力学性能、吸水性能等的影响,并用SEM、红外光谱等技术研究了改性处理后纤维的表面及复合材料界面结合情况。结果表明:经过不同表面处理后BF/UP复合材料的性能均有所改善。当采用5wt%碱-3wt%偶联剂联合处理时,BF/UP复合材料综合性能最优,其拉伸强度、弯曲强度、弯曲模量、剪切强度较未处理的分别提高了34.29%、15.95%、11.26%、29.39%;复合材料存储模量(33℃)较未处理的提高了63.80%,损耗因子有所降低;BF/UP复合材料24h、720h吸水率较未处理的分别减小了55.35%、27.32%。SEM和红外光谱结果表明,改性处理后竹原纤维表面杂质减少,附着了一层偶联剂膜,BF/UP复合材料中纤维与树脂之间的界面结合更好。

Effect of surface modification of unidirectional bamboo fiber on the properties of its reinforced unsaturated polyester resin composites

The surface of bamboo fibers was modified by using two sorts of methods including alkali treatment, alkali-silane treatment.Then unidirectional continuous bamboo fibers reinforced unsaturated polyester resin (BF/UP)composite was prepared by means of stitching-compression molding technology.The effects of different surface modification methods on the static and dynamic mechanical properties,water absorption were studied.SEM and FITR were used to describe the surface of treated fibers and the interface bonding condition in the BF/UP composite.The results show that the properties of the BF/UP composite after treating bamboo fiber using different modification methods all are improved.The performances of BF/UP composite are optimal with the treatment of 5wt% alkali-3wt% silane coupling agent.The BF/UP composite has the best comprehensive properties with the treatment of 5wt% alkali-3wt% silane coupling agent,whose tensile strength,flexural strength,flexural modulus and shear strength increase by 34.29%,15.95%,11.26% and 29.39% respectively.Compared with the untreated sample,the storage modulus of the BF/UP composite increases by 63.80%,the loss factor of BF/UP composite decreases,and the 24 h and 720 h water absorption of the BF/UP composite decrease by 55.35% and 27.32%.The results of SEM and FITR show that the impurity decrease and a layer of coupling agent film is attached on the surface of bamboo fiber,and there is a better interface adhesion occurs between the fiber and matrix after surface modification.