聚硅炔酰亚胺树脂及其复合材料的制备与性能

Preparation and Performance of Poly(silicon-alkyne imide)Resins and Their Composites

首先通过材料基因组方法(MGA)设计筛选得到了一种具有高耐热性的乙炔基封端聚酰亚胺(ATPI),然后以2,3,3',4'-二苯醚四甲酸二酐、3,4'-二氨基二苯醚、3-氨基苯乙炔3种单体为原料合成了ATPI。利用傅里叶变换红外光谱、核磁共振氢谱对ATPI的化学结构进行了表征。通过ATPI与甲基乙烯基含硅芳炔(PSA)树脂共聚,得到聚硅炔酰亚胺(PSI)树脂。利用差示扫描量热仪分析了PSI树脂的热固化行为,确定了其固化工艺。采用热重分析表征了PSI固化物的耐热性,结果显示其质量损失5%的热分解温度(T_(d5))及800℃残碳率(Y_(r800))分别为573℃和85.9%。万能拉力机测试得到PSI浇注体的弯曲强度达到49.8 MPa,比PSA树脂提升了1.5倍。通过模压及热压罐成型工艺分别制备了石英纤维及T800碳纤维增强的PSI复合材料。T800碳纤维增强的复合材料弯曲强度和层间剪切强度(ILSS)分别为1553 MPa和84.1 MPa,在350℃处理100 h后,ILSS基本保持不变,复合材料具有良好的耐热性及力学稳定性。石英纤维增强的复合材料弯曲强度和ILSS分别为539 MPa和37.5 MPa。用网络分析仪对石英纤维增强的复合材料的介电性能进行了表征,500℃处理后材料的介电常数与常温下的数值相近,复合材料的高温介电稳定性较好。

Silicon-containing arylacetylene resin has excellent heat resistance and low-temperature curing properties.Its main defects are the brittleness of the cured resin and poor interface adhesion with the reinforcement.Polyimide(PI)resin has good thermal and mechanical properties,and excellent interfacial adhesion with reinforcement.The idea of copolymerizing PI and silicon-containing arylacetylene resin is proposed aiming to develop a high-temperature resistant composite matrix resin with excellent heat resistance and low temperature curing properties,and good adhesive property with the reinforcement.First,a highly heat-resistant acetylene-terminated polyimide(ATPI)was designed and screened by a material genome approach(MGA).And then ATPI was synthesized by 3,4'-oxydiphthalic anhydride,3,4-oxydianiline and 3-ethynylaniline.The chemical structure was investigated by means of Fourier transform infrared spectrometer(FT-IR)and hydrogen nuclear magnetic resonance(1H-NMR).By copolymerizing ATPI and poly(vinylsilylene ethynylenephenylenethynylene)(PSA)resin,poly(silicon-alkyne imide)(PSI)resin was prepared.The thermal curing behavior of PSI resin was investigated by differential scanning calorimetry(DSC),and the curing process was designed based on the result of DSC.The thermal stability of the cured PSI resin was analyzed by thermogravimetric analysis(TGA).The results showed that the decomposition temperature of 5%mass loss(T_(d5))and carbon yield ratio at 800℃(Y_(r800))of the cured PSI resin were 573℃ and 85.9%respectively in nitrogen.The mechanical property of the cured PSI resin was characterized by universal testing instruments.The flexural strength of the cured PSI resin was up to 49.8 MPa,which was 1.5 times higher than that of PSA resin.Next,quartz and T800 carbon fiber reinforced PSI composites were prepared by compression molding or heat pressure tank molding process.The flexural strength and interlaminar shear strength(ILSS)of reinforced composites were measured by universal testing instruments.The flexural strength and ILSS of T800 carbon fiber reinforced composite reached 1553 MPa and 84.1 MPa,respectively.After 350℃ treated for 100 h,ILSS could remain basically unchanged.The T800 carbon fiber composite material had good heat resistance and mechanical stability.The flexural strength and ILSS of quartz fiber reinforced composite were 539 MPa and 37.6 MPa,respectively.The dielectric property of quartz fiber reinforced composite was also studied.After 500℃ treated for 5 min,the dielectric constant of the material was basically unchanged compared with that at room temperature.The dielectric property of the quartz fiber composite material was stable at high temperature.