基于乙炔基封端酰亚胺和氰酸酯树脂的互穿网络聚合物

以2，3，3'，4'-联苯四甲酸二酐和2，2'-双三氟甲基-4，4'-联苯二胺为单体、4-乙炔基邻苯二甲酸酐为封端剂合成了不同聚合度的聚酰亚胺低聚物（BETI），将其溶于双氛A型氰酸酯单体制备了改性氰酸酯树脂，对改性氰酸酯树脂的固化行为进行了详细探究，并对其固化物的热学性能、力学性能和介电性能等进行了表征与分析。结果表明:BETI对氰酸酯树脂的聚合有明显的催化作用，可以降低固化温度，缩短凝胶时间。基于BETI和氰酸酯树脂的互穿网络聚合物（IPN）的热性能和力学性能与纯氰酸酯树脂相比都有一定的提高。当加入质量分数30%、聚合度为19的BETI树脂时，固化物的玻璃化转变温度从297 ℃提高到309 ℃，热失重5%时温度从425 ℃提高到了431 ℃；拉伸强度从76 MPa提高到了94 MPa，冲击强度从24 kJ/m2℃提高到了31 kJ/m2。加入BETI后，聚合物的介电常数稍稍高于纯氰酸酯树脂。由于具有良好工艺性和材料性能，BETI改性氰酸酯树脂可作为基体树脂应用于航空航天等领域。 

Interpenetrating polymer networks derived from ethynyl-terminated imide oligomers and cyanate ester

Ethynyl-terminated oligomers (BETI) with different degrees of polymerization were synthesized using 2, 3, 3', 4'-biphenyltetracarboxylic dianhydride and 2, 2'-bis(trifluoromethyl) benzidine as the monomers and ethynylphthalic anhydride as the end-capper; modified cyanate ester resins were then formulated by dissolving BETI in bisphenol A dicyanate, and the properties of the blends and the resulting Interpenetrating Polymer Networks (IPNs) were investigated in terms of curing behavior, and thermal, mechanical, and dielectric properties. The results indicate that the trimerization of-OCN functionality could be catalyzed by the incorporation of BETI, as evidenced by significantly reduced curing temperatures and shorter gelation time. Moreover, IPNs show improved thermal and mechanical properties compared to pure polycyanurate. especially, when 30% weight BETI with the polymerization degree 19 was blended in pure cyanater ester resin, the class transition temperature, 5% weight loss temperature, tensile strength, and impact strength of the IPNs were increased from 297℃ to 309℃, 425℃ to 431℃, 76 MPa to 94 MPa, and 24 kJ/m2 to 31 kJ/m2, respectively. The dielectric constants of the IPNs are slightly higher than that of pure polycyanurate. The BETI-modified cyanate ester resins could be potentially used as matrix resin in aerospace industry due to their improved processability and material properties.