水性SPEKK上浆剂改善CF/PEKK复合材料的力学性能

Water-based SPEKK sizing agent for improving the mechanical properties of CF/PEKK composites

由于碳纤维(CF)的化学惰性,导致了CF和聚醚酮酮(PEKK)的界面结合较差,限制了碳纤维增强聚醚酮酮(CF/PEKK)复合材料力学性能的发挥。本文通过将国产PEKK树脂进行磺化处理制备了磺化聚醚酮酮(SPEKK)水性上浆剂,以改善CF/PEKK复合材料的力学性能。通过调控SPEKK的磺化度使其能够形成稳定的水性乳液,对CF进行上浆改性,并通过真空热压制备了CF/PEKK复合材料。研究发现,当水性SPEKK乳液的浓度为0.5wt%时,改性后的CF/PEKK复合材料的弯曲强度、弯曲模量和层间剪切强度分别达到了1237 MPa、78 GPa和92 MPa,比未改性的CF/PEKK复合材料分别提升了35.5%、5.4%和26.0%。CF/PEKK复合材料力学性能的改善,可能归因于在CF表面引入的SPEKK通过与CF产生氢键、π-π相互作用及与PEKK树脂基体形成π-π相互作用、分子间扩散和缠结等显著增强了CF与PEKK的界面结合。采用水性SPEKK上浆剂对碳纤维表面处理,不会产生环境污染,工艺更加简单,且适合于碳纤维的工业化生产,对于发展国产高性能碳纤维增强热塑性复合材料具有重要意义。

The interfacial interactions between carbon fiber(CF)and polyetherketoneketone(PEKK)are poor due to the chemical inertness of CF,limiting the mechanical properties of carbon fiber reinforced polyetherketoneketone(CF/PEKK)composites.In this study,a water-based sizing agent of sulfonated polyetherketoneketone(SPEKK)was prepared by sulfonating domestic PEKK resin,in order to improve the mechanical properties of CF/PEKK composites.By regulating the sulfonation degree,the stable SPEKK aqueous emulsion was obtained and used for CF sizing modification.Subsequently,CF/PEKK composites were fabricated via vacuum hotpress technique.When the concentration of SPEKK aqueous emulsion was 0.5wt%,the flexural strength,flexural modulus and interlaminar shear strength of the modified CF/PEKK composites reached 1237 MPa,78 GPa,and 92 MPa,which were 35.5%,5.4%,and 26.0% higher than that of the unmodified CF/PEKK composites,respectively.Such enhancement in mechanical properties could be attributed to the introduced SPEKK on the CF surfaces,which could form hydrogen bonds and π-π interactions with CF,as well asπ-πinteractions and diffusion and entanglement with PEKK,significantly promoting the interfacial bonding between CF and PEKK.As a simpler process,CF surface modification with water-based SPEKK sizing agent is environmentally friendly and suitable for the industrial production,which is of great significance for the development of domestic high-performance carbon fiber reinforced thermoplastic composites.