Abstract
Silicon-containing arylacetylene(PSA)resins have broad application prospects because of their excellent heat resistance.However,im-proving their mechanical properties and interfacial bonding with reinforcement fibers while maintaining heat resistance is a challenge in engi-neering applications.Here,poly(diethynylbenzene-methylsilyl-3-benzonitrile)(DEB-CN)and poly(diethynylbenzene-methylsilyl-3,6-diethynylcar-bazole-3-benzonitrile)(DEC-CN)were synthesized via an isopropylmagnesium chloride lithium-chloride complex(i-PrMgClLiCl),overcoming the compatibility problem between cyano groups and Grignard reagents.The cyano and alkyne groups in the resin underwent cyclization to form pyridine,catalyzed by the-NH-moiety in DEC-CN,resulting in extremely high thermal stability(5％weight loss temperature:669.3 ℃,glass transi-tion temperature＞650 ℃).The combination of cyano dipole-dipole pairing and hydrogen bonding greatly enhanced the resin-fiber interface properties,while the generated pyridine promoted stress relief in the crosslinked network,substantially improving the mechanical properties of the cyano-silicon-containing arylacetylene resin composites.The flexural strength of quartz fiber cloth/DEC-CN composites was 298.2 MPa at room temperature and 145.9 MPa at 500 ℃,corresponding to 84.0％and 127.6％enhancements,respectively,over the cyano-free counterpart.These cyano-silicon-containing arylacetylene resins exhibited a dual reinforcement mechanism involving physical interfacial interactions and chemical crosslinking,achieving a good balance between thermal stability and mechanical properties.
维普
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