耐高温低介电常数苯并噁唑芳炔树脂的合成及性能

Synthesis and Properties of Benzoxazole Arylalkyne Resin with High Temperature Resistance and Low Dielectric Constant

以2-氨基-4-溴苯酚、4-氰基苯甲醛、对溴苯甲醛和(三甲基硅烷基)乙炔为原料,采用偶联法成功合成了2种新型的热固性苯并噁唑树脂—苯并噁唑芳炔腈树脂(PBON)以及苯并噁唑芳炔树脂(PBOA)。采用差示扫描量热(DSC)、宽频介电和热重分析(TGA)分别研究了PBON和PBOA的热固化过程、介电性能和固化物的耐热性,并研究了PBON和PBOA的溶解性。研究表明,树脂单体在常规溶剂中的溶解性良好,可采用四氢呋喃进行溶解和加工。PBON固化物质量损失5%的热分解温度(T_(d5))为596℃,900℃残碳率为69.7%;PBOA固化物的T_(d5)为592℃,900℃残碳率为79.5%。2种树脂的固化物都具有优异的热稳定性,同时在1 MHz下的介电常数均小于2.5,介电损耗因子均小于0.06。

Using 2-amino-4-bromophenol,4-cyanobenzaldehyde,p-bromobenzaldehyde and(trimethylsilyl)acetylene as raw materials,two new thermosetting benzoxazole resins,benzoxazole arylalkyne nitrile resin(PBON)and benzoxazole arylalkyne resin(PBOA),were successfully synthesized by coupling method.The thermal curing process of PBON and PBOA was studied by differential scanning calorimetry(DSC).The heat resistance of the cured PBON and PBOA was analyzed by thermogravimetric analysis(TGA).The dielectric properties of the cured PBON and PBOA were studied by broadband dielectric method.The solubility of PBON and PBOA was also studied.Results show that two monomers have good solubility in ordinary solvents,such as tetrahydrofuran(THF)and dimethyl sulfoxide.The viscosity of THF solution of PBON and PBOA is 870 mPa·s and 430 mPa·s,respectively.The viscosity of THF solution of both resins is low,which is suitable for processing by solvent method.Both of the cured PBON and PBOA have excellent thermal stability.The decomposition temperature of 5%mass loss(T_(d5))of the cured PBON is 596℃,and the carbon yield ratio at 900℃(Yc,900)is 69.7%in nitrogen.For the cured PBOA,T_(d5) is 592℃and Yc,900 is 79.5%in nitrogen.Both of the cured resins have good mechanical properties,and can be used as structural parts.The flexural strength of the cured PBON at room temperature is 48.2 MPa,which is slightly lower than that of the cured PBOA,which is 59.5 MPa.However,the flexural modulus of the cured PBOA is almost equal to that of the cured PBON.The dielectric constant of the two cured resins at 1 MHz is lower than 2.5 and the dielectric dissipation factor of them is lower than 0.06.