文献类型：期刊文献

英文题名：Cyanide-functionalized polyimides regulating the crosslinked network and mechanical performance of phthalonitrile-based composites

作者：Zhang, Yongcheng[1];Zhang, Wenhua[2];Jiang, Fengguang[1];Liu, Min[1];Zhou, Quan[1]

机构：[1]East China Univ Sci & Technol, Sch Mat Sci & Engn, Key Lab Specially Funct Polymer Mat & Related Tech, Minist Educ, Shanghai 200237, Peoples R China;[2]Shanghai Composite Mat Technol Co Ltd, Shanghai 201112, Peoples R China

年份：2026

卷号：250

外文期刊名：EUROPEAN POLYMER JOURNAL

收录：;EI(收录号：20261420425145);WOS:【SCI-EXPANDED(收录号:WOS:001732701300001)】；

基金：The authors gratefully appreciate the financial support from the National Natural Science Foundation of China (grant numbers 52473075, 52173074) and the Fundamental Research Funds for the Central Universities (No. JKD01261701) .

语种：英文

外文关键词：Cyanide-functionalized; Polyimide; Phthalonitrile resin; Thermo-oxidative stability; Mechanical Property

摘要：Phthalonitrile resins exhibit outstanding thermal resistance but suffer from intrinsic brittleness, which limits their application in high-performance composite structures. In this work, cyanide-functionalized polyimides with tailored molecular architectures were introduced as reactive modifiers to regulate the curing behavior, network structure, and mechanical performance of a phthalonitrile matrix resin. Three polyimides with different effective chain lengths were synthesized, and their terminal phthalonitrile groups enabled covalent co-crosslinking with an in-house-prepared phthalonitrile resin. Incorporation of 10 wt% polyimide modifier resulted in reactive composite resins with improved network uniformity and interfacial integrity. The modified resins retained excellent thermal and thermo-oxidative stability, with the highest Td5 reaching 547 degrees C in nitrogen and 542.3 degrees C in air. Quartz-fiber-reinforced composites based on the medium-chain-length polyimide-modified resin exhibited the most significant mechanical enhancement, with flexural strength and interlaminar shear strength increasing from 673.6 to 797.2 MPa and from 51.9 to 73.1 MPa, respectively. After long-term thermal aging at 400 degrees C in air, the modified composites maintained substantially higher residual mechanical properties than the unmodified system, indicating enhanced resistance to thermo-oxidative degradation and interfacial deterioration. Microstructural analyses demonstrated that polyimides with appropriate chain length promote uniform molecularscale interpenetration and effective chain entanglement with the phthalonitrile matrix, leading to a homogeneous crosslinked network and efficient stress transfer. This study establishes a clear structure-network-property relationship in polyimide-modified phthalonitrile composites and provides a practical molecular-design strategy for high-temperature composite materials.