摘要
为研究竹材梯度结构对竹束纤维复合材料性能的影响,以竹束纤维(BF)为增强相,环氧树脂-甲基四氢邻苯二甲酸酐(EP-MeTHPA)体系为基体相,采用热压成型制备竹束纤维增强环氧树脂-甲基四氢邻苯二甲酸酐复合材料体系(BF/EP-MeTHPA)。通过改变BF单元−竹青侧束纤维(BF-GS)和竹黄侧束纤维(BF-YS),研究梯度结构对BF/EP-MeTHPA界面失效的影响。在分析复合材料力学性能的基础上,通过动态热机械分析(DMA)、原位加载、FTIR等纳、微观试验手段,对纤维-树脂结合状态、界面微区力学、热分析和宏观力学表征等进行研究。实验结果表明,由于BF-GS中纤维含量与强度较高,在EP-MeTHPA体系中的增强效果与分布均匀性优于BF-YS,弯曲呈现韧性阶梯状破坏;但其浸润性与界面性能却低于竹黄侧束纤维增强环氧树脂-甲基四氢邻苯二甲酸酐复合材料体系(BF-YS/EP-MeTHPA)。通过对竹材结构进行观察,发现BF-YS残留了更多的薄壁细胞,粗糙表面有利于EP的浸润与黏附,因此在接触角测试中,BF-YS的浸润力约为BFGS的60%。FTIR显示,MeTHPA可与BF羟基反应生成新的酯键,使得BF与EP-MeTHPA体系形成化学键,提高界面稳定性,而BF-YS中非结晶区的暴露使其极性更强(106.5 mN/m),各特征峰相对面积变化量也大于BF-GS,更容易形成化学键合,其稳定性也会提高。
In order to study the effect of bamboo gradient structure on the properties of bamboo bundle fiber composites,bamboo bundle fiber(BF)as the enhanced phase,epoxy resin(EP)-methyl tetrahydrophthalic anhydride(MeTHPA)system is the matrix phase,BF/EP-MeTHPA composite was prepared by thermopress molding.By changing the BF unit:yellow side(BF-YS)and green side bundle fiber(BF-GS),the effect of natural structure on the failure of interface of BF/EP composite was studied.Based on the mechanical properties of composites,through nano and micro test means such as dynamic thermomechanical analysis(DMA),in situ SEM and FTIR,the state of BF/EP-MeTHPA,interface microregion,thermal analysis and macromechanical characterization were studied.The experimental results show that due to the high fiber content and strength in BF-GS,the enhancement effect and distribution uniformity in epoxy system is better than BF-YS.But the permeability and interface performance are lower than bamboo bundle fiber of yellow side/epoxy resin-MeTHPA(BF-YS/EP-MeTHPA).Through the observation of the bamboo structure,it is found that BF-YS remains more parenchyma cells,and the rough surface favors the infiltration and adhesion of EP,so the infiltration force of BF-YS is about 60%in the contact angle test of BF-GS.FTIR shows that MeTHPA can react with BF hydroxyl groups to generate new ester bonds,making the chemical bond between BF and EP-MeTHPA system to improve the interface stability,while the exposure of the non-crystalline area of BF-YS makes its polarity stronger(106.5 mN/m),the relative area variation of the characteristic peaks is greater than BF-GS,easier to form,and the stability will also improve.
作者
顾少华
陈季荷
张文福
王翠翠
王戈
程海涛
GU Shaohua;CHEN Jihe;ZHANG Wenfu;WANG Cuicui;WANG Ge;CHENG Haitao(Key Laboratory of NFGA/Beijing for Bamboo&Rattan Science and Technology,International Center for Bamboo and Rattan,Beijing 100102,China;Zhejiang Forestry Academy,Hangzhou 310023,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2022年第8期4065-4073,共9页
Acta Materiae Compositae Sinica
基金
建筑用竹质复合覆面板及模块构件加工与性能研究(1632021002)。
关键词
竹纤维
梯度结构
天然结构
复合材料
界面
失效机制
bamboo fiber
gradient structure
natural structure
composite
interface
failure mechanism
