碱处理对加捻竹纤维/环氧复合材料润湿性与拉伸失效的影响
Effect of alkali treatment on the wettability and tensile failure of twisted bamboo fiber/epoxy composites
顾少华 1李昊远 1张文福 2王翠翠 1李明鹏 1程海涛 1王戈1
作者信息
- 1. 国际竹藤中心 竹藤科学与技术重点实验室,北京 100102
- 2. 国际竹藤中心 竹藤科学与技术重点实验室,北京 100102;浙江省林业科学研究院,杭州 310023
- 折叠
摘要
采用加捻竹纤维(TBF)为增强相、环氧树脂-酸酐体系为基体相,制备加捻竹纤维/环氧树脂(TBF/EP)复合材料,通过改变NaOH溶液浓度(1wt%～5wt%),研究碱处理对TBF/EP复合材料润湿性和拉伸失效的影响.采用SEM、表面张力测试、原位加载等纳米和微观试验手段,对纤维-树脂结合状态、润湿性能和拉伸力学特性进行了分析.结果表明:碱处理降低了纤维表面能和极性,使TBF与基体润湿力从0.45 mN降至 0.1 mN;3wt%NaOH溶液改性的TBF/EP复合材料含胶量降低至 62%,拉伸强度(TS)达到273.70 MPa,比未处理复合材料提高 178.64%;原位分析显示,TBF失效过程包括纤维断裂和纤维间滑移,而TBF/EP复合材料失效过程包括基体剪切屈服和纤维断裂,且随着浸润性提高,BF抑制屈服的效果增加.因此,TBF/EP复合材料的强度主要来源于纤维和界面的增强,受TBF与基体的浸润性、应力传递效果的影响.
Abstract
The twisted bamboo fiber(TBF)was used as the reinforcement phase and the epoxy resin-anhydride sys-tem as the matrix phase to prepare the twisted bamboo fiber/epoxy resin(TBF/EP)composite.The effects of alkali treatment on the wettability and tensile failure of TBF/EP composites were investigated by varying the concentra-tion of NaOH solution(1wt%-5wt%).Nano-scale and micro-scale experimental techniques,such as SEM,surface tension testing,and in-situ loading,were employed to analyze the fiber-resin interface,wetting properties,and tensile mechanical properties of the composites.The results show that alkali treatment reduces the surface energy and polarity of the fibers,resulting in a decrease in the wetting force between TBF and the matrix from 0.45 mN to 0.1 mN.The TBF/EP composite modified with 3wt%NaOH solution exhibits a tensile strength(TS)of 273.70 MPa,which is 178.64%higher than that of the untreated composite.In-situ analysis reveals that the failure process of TBF involves fiber fracture and fiber sliding,while the failure process of the TBF/EP composite includes matrix shear yielding and fiber fracture.Moreover,as the wetting properties improve,the inhibitory effect of the fibers on matrix yielding increase.Therefore,the strength of the TBF/EP composite is mainly derived from the reinforcement of the fibers and the interface,which is influenced by wetting properties and stress transfer effect between TBF and matrix.
关键词
竹纤维/加捻结构/复合材料/润湿性能/失效机制Key words
bamboo fiber/twisted structure/composite/wettability/failure mechanism引用本文复制引用
基金项目
国家自然科学基金(32371979)
国家重点研发计划(2022YFD2200903)
出版年
2024
NETL
NSTL
万方数据