硅改性BPA-PA酚醛环氧树脂导电胶的合成及性能

以双酚A多聚甲醛酚醛树脂（BPA-PA酚醛树脂）、二甲基二甲氧基硅烷和环氧氯丙烷为原料，通过酯交换反应和亲核取代反应得到硅改性BPA-PA酚醛环氧树脂。采用傅里叶变换红外光谱（FTIR）、X射线光电子能谱（XPS）分析进行结构确证。结合非等温DSC、T-β外推直线和FTIR分析研究了最佳固化工艺条件。探讨了不同硅烷添加量对硅改性BPA-PA酚醛环氧树脂性能的影响。最后以硅改性BPA-PA酚醛环氧树脂为基体树脂，加以导电填料和助剂，制备出中温型导电胶。对导电胶进行拉伸剪切强度、体积电阻率和热重测试分析，结果显示：自制硅改性BPA-PA酚醛环氧树脂导电胶拉伸剪切强度达到20.18MPa、体积电阻率达到7.44×10^-4Ω·cm，残炭量达到68.89%。相对市售E-51环氧树脂所制导电胶，自制硅改性BPA-PA酚醛环氧树脂导电胶拉伸剪切强度提高5.73MPa，体积电阻率降低3.86×10^-4Ω·cm，残炭量提高7.49%。

Synthesis and performance of silicon modified BPA-PA phenolic epoxy resin conductive adhesive

Using bisphenol A paraformaldehyde phenolic resin (BPA-PA phenolic resin), dimethyldimethoxysilane and epichlorohydrin as raw materials, silicon-modified BPA-PA phenolic epoxy resin was obtained through transesterification and nucleophilic substitution reactions. FTIR and XPS were used for structural confirmation. Combining non-isothermal DSC, T-β extrapolation line and FTIR analysis, the optimal curing process conditions were studied. The effects of different silane addition levels on the properties of silicon-modified BPA-PA phenolic epoxy resin were discussed. Finally, silicon-modified BPA-PA phenolic epoxy resin was used as the matrix resin, and conductive fillers and additives were added to prepare a medium-temperature conductive adhesive. Conduct tensile shear strength, volume resistivity and thermogravimetric test analysis of its conductive adhesive were tested and analyzed. The results showed that the self-made silicon modified BPA-PA phenolic epoxy resin conductive adhesive had a tensile shear strength of 20.18MPa, a volume resistivity of 7.44×10^-4Ω·cm and a residual carbon content of 68.89%. Compared with the conductive adhesive made of commercially available E-51 epoxy resin, the self-made silicon-modified BPA-PA phenolic epoxy resin conductive adhesive increased tensile shear strength by 5.73MPa and reduced volume resistivity by 3.86×10^-4Ω·cm with increasing amount of residual carbon by 7.49%.