Sung Kyung-Soo, Kim Namil
Research & Development Center, Protavic Korea, Daejeon 34326, Republic of Korea.
Department of Chemical Engineering, Hannam University, Daejeon 34054, Republic of Korea.
Polymers (Basel). 2023 May 25;15(11):2452. doi: 10.3390/polym15112452.
Epoxy resin was mixed with benzoxazine resin and an aluminum trihydrate (ATH) additive to provide flame retardancy and good mechanical properties. The ATH was modified using three different silane coupling agents and then incorporated into a 60/40 epoxy/benzoxazine mixture. The effect of blending compositions and surface modification on the flame-retardant and mechanical properties of the composites was investigated by performing UL94, tensile, and single-lap shear tests. Additional measurements were conducted including thermal stability, storage modulus, and coefficient of thermal expansion (CTE) assessments. The mixtures containing more than 40 wt% benzoxazine revealed a UL94 V-1 rating with high thermal stability and low CTE. Mechanical properties including storage modulus, and tensile and shear strength, also increased in proportion to the benzoxazine content. Upon the addition of ATH to the 60/40 epoxy/benzoxazine mixture, a V-0 rating was achieved at 20 wt% ATH. The pure epoxy passed a V-0 rating by the addition of 50 wt% ATH. The lower mechanical properties at high ATH loading could have been improved by introducing a silane coupling agent to the ATH surface. The composites containing surface-modified ATH with epoxy silane revealed about three times higher tensile strength and one and a half times higher shear strength compared to the untreated ATH. The enhanced compatibility between the surface-modified ATH and the resin was confirmed by observing the fracture surface of the composites.
将环氧树脂与苯并恶嗪树脂以及三水合铝（ATH）添加剂混合，以提供阻燃性和良好的机械性能。使用三种不同的硅烷偶联剂对ATH进行改性，然后将其加入到60/40的环氧/苯并恶嗪混合物中。通过进行UL94、拉伸和单搭接剪切试验，研究了共混物组成和表面改性对复合材料阻燃性能和机械性能的影响。还进行了额外的测量，包括热稳定性、储能模量和热膨胀系数（CTE）评估。含有超过40 wt%苯并恶嗪的混合物显示出UL94 V-1等级，具有高的热稳定性和低的CTE。包括储能模量、拉伸强度和剪切强度在内的机械性能也与苯并恶嗪含量成比例增加。在60/40的环氧/苯并恶嗪混合物中加入ATH后，在ATH含量为20 wt%时达到了V-0等级。通过加入50 wt%的ATH，纯环氧树脂通过了V-0等级。在高ATH负载下较低的机械性能可以通过在ATH表面引入硅烷偶联剂来改善。与未处理的ATH相比，含有用环氧硅烷表面改性的ATH的复合材料的拉伸强度提高了约三倍，剪切强度提高了一倍半。通过观察复合材料的断裂表面证实了表面改性的ATH与树脂之间增强的相容性。
