Liu Jingwei, Tian Shenghui, Ren Jiaqi, Huang Jin, Luo Lin, Du Bing, Zhang Tianyong
Chongqing Key Laboratory of Nano-Micro Composites and Devices, College of Metallurgy and Materials Engineering, Chongqing University of Science and Technology, Chongqing 401331, China.
Department of Fine Chemicals and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
Materials (Basel). 2023 Oct 9;16(19):6611. doi: 10.3390/ma16196611.
Poor interlaminar fracture toughness has been a major issue in glass fiber-reinforced epoxy resin (GF/EP) laminate composites. In this paper, soft carboxy-terminated nitrile (CTBN) rubber particles and rigid nano-SiO are used to toughen the epoxy resin (EP) matrix to improve the interlayer properties of GF/EP laminate composites. The effects of adding two toughening agents on the mechanical and interlayer properties of GF/EP laminates were studied. The results showed that adding the two kinds of particles improved the mechanical properties of the epoxy matrix. When the additional amount of flexible CTBN rubber particles was 8 wt%, and the rigid nano-SiO was 0.5 wt%, the fracture toughness of the matrix resin was increased by 215.8%, and the tensile strength was only decreased by 2.3% compared with the pure epoxy resin. On this basis, the effects of two kinds of particles on the interlayer properties of GF/EP composites were studied. Compared with the unmodified GF/EP laminates, the interlayer shear strength and mode I interlayer fracture toughness is significantly improved by a toughening agent, and the energy release rate of interlayer shear strength and interlayer fracture toughness is increased by 109.2%, and 86.8%, respectively. The flexible CTBN rubber particles and rigid nano-SiO improve the interfacial adhesion between GF and EP. The cavitation of the two particles and the plastic deformation of the matrix is the toughening mechanism of the interlayer properties of the composite. Such excellent interlaminar mechanical properties make it possible for GF/EP laminates to be widely used as engineering materials in various industries (e.g., aerospace, hydrogen energy, marine).
层间断裂韧性较差一直是玻璃纤维增强环氧树脂（GF/EP）层合复合材料中的一个主要问题。本文采用软质羧基封端丁腈（CTBN）橡胶颗粒和刚性纳米SiO₂对环氧树脂（EP）基体进行增韧，以改善GF/EP层合复合材料的层间性能。研究了添加两种增韧剂对GF/EP层压板力学性能和层间性能的影响。结果表明，添加这两种颗粒提高了环氧树脂基体的力学性能。当柔性CTBN橡胶颗粒的添加量为8 wt%，刚性纳米SiO₂的添加量为0.5 wt%时，与纯环氧树脂相比，基体树脂的断裂韧性提高了215.8%，拉伸强度仅下降了2.3%。在此基础上，研究了两种颗粒对GF/EP复合材料层间性能的影响。与未改性的GF/EP层压板相比，增韧剂显著提高了层间剪切强度和I型层间断裂韧性，层间剪切强度和层间断裂韧性的能量释放率分别提高了109.2%和86.8%。柔性CTBN橡胶颗粒和刚性纳米SiO₂改善了GF与EP之间的界面粘结。两种颗粒的空化和基体的塑性变形是复合材料层间性能的增韧机制。如此优异的层间力学性能使得GF/EP层压板有可能在各种行业（如航空航天、氢能、海洋）中作为工程材料得到广泛应用。
