纳米SiO2改性环氧-聚三唑胶黏剂体系研究

Study on the nano silica modified epoxy-polytriazole adhesive system

为改善改性聚三唑胶黏剂(E PTA)高温粘接性能和耐湿热老化性能,将纳米SiO 2引入E PTA中制备E PTA SiO 2胶黏剂。研究纳米SiO 2含量对E PTA SiO 2粘接性能、高温性能和耐湿热老化性能的影响。利用傅里叶变换红外光谱仪(FT IR)、激光粒度分析、电子扫描显微镜(SEM)、差示扫描量热法(DSC)、动态力学热分析(DMA)和热质量分析仪(TGA)对纳米SiO 2改性情况、在胶黏剂中的分散情况以及E PTA SiO 2的固化行为和热性能进行研究,同时研究了E PTA SiO 2对7075铝合金试样的粘接性能和耐湿热老化性能。结果表明:玻璃化转变温度T g随着纳米SiO 2质量分数的提高先升高后降低;E PTA SiO 2胶黏剂与7075铝合金试样有较好的黏结性,纳米SiO 2的引入对常温剪切强度影响不大,对高温剪切强度有显著影响,随纳米SiO 2质量分数的增加,200℃剪切强度先升高后降低,当纳米SiO 2质量分数为2%时,200℃剪切强度最高,为(20.5±0.4)MPa,强度保留率95.35%,另外,E PTA SiO 2胶黏剂耐湿热老化性也较E PTA有所提高。

In order to improve the high temperature bonding property and the heat and humidity aging resistance of modified polytriazole adhesive(E-PTA),nano-SiO 2 was introduced into E-PTA to prepare E-PTA-SiO 2 adhesive.The effect of nano-silica content on the high temperature bonding property and wet heat aging property of modified polytriazole adhesives was investigated.Fourier transform infrared spectrometer(FT-IR),laser particle size analysis,scanning electron microscopy(SEM),differential scanning calorimetry(DSC),dynamic mechanical thermal analysis(DMA),and thermogravimetric analysis(TGA)were used to study nano silica modification,dispersion in adhesive,curing behavior and thermal property,and the bonding property and damp heat aging performance of E-PTA-SiO 2 adhesive on 7075 aluminum alloy samples were examined.Results showed that the glass transition temperature T g increased first and then decreased as the proportion of nano-silica increased;E-PTA-SiO 2 adhesive had good adhesion to 7075 aluminum alloy samples.The introduction of nano-SiO 2 had little effect on normal temperature shear strength but had a significant effect on high temperature shear strength.With the increase of nano-SiO 2 content,the shear strength of 200℃increased first and then decreased.When the nano-SiO 2 mass ratio was 2%,the shear strength at 200℃was the highest of(20.5±0.4)MPa,and the strength retention rate was 95.35%.In addition,the damp heat aging performance of E-PTA-SiO 2 adhesive was also improved compared with E-PTA.