接枝改性对LNG储罐用碳纤维及复合材料界面性能的影响

Effect of Graft Modification on Interfacial Properties of Carbon Fiber Reinforced Composites for LNG Storage Tanks

对LNG储罐用碳纤维进行接枝改性处理,对比分析了氧化处理碳纤维和三聚氰胺接枝改性碳纤维与未改性碳纤维的表面结构、表面形貌、浸润性、拉伸性能和界面剪切性能。结果表明,对碳纤维进行氧化和接枝改性后,碳纤维表面成功接枝三聚氰胺,并以OC-NH、C-N和C=N化学键形式存在,当三聚氰胺接枝改性25min及以上时,碳纤维表面的纵向沟槽深度有不同程度减小。三聚氰胺接枝改性处理后,不同反应时间下三聚氰胺接枝改性后的碳纤维在水中和在二碘甲烷中的接触角有不同程度降低、表面能都有不同程度提高、单丝拉伸强度会有不同程度减小,且随着反应时间延长,在水中和在二碘甲烷中的接触角逐渐减小、表面能逐渐增大,单丝拉伸强度先减小后增大,反应时间为35min时改性碳纤维的单丝拉伸强度为3.75GPa。三聚氰胺接枝改性处理后,三聚氰胺接枝改性碳纤维复合材料的界面剪切强度会得到不同程度提高,且随着三聚氰胺接枝改性时间的延长,三聚氰胺接枝改性碳纤维复合材料的界面剪切强度逐渐增大。

Carbon fiber for LNG storage tank was grafted and modified.The surface structure,surface morphology,wettability,tensile property and interfacial shear property of oxidized carbon fiber,melamine grafted carbon fiber and unmodified carbon fiber were compared and analyzed.The results showed that,after oxidation and grafting on carbon fibers,melamine was successfully grafted on the surface of carbon fibers and existed in the form of OC-NH,C-N and C=N chemical bonds.When melamine was grafted for 25min or more,the longitudinal groove depth on the surface of carbon fibers decreased to varying degrees.After melamine grafting modification treatment,the contact angle of the carbon fiber grafted with melamine in water and in diiodomethane decreases to differentdegrees,the surface energy increases to differentdegrees,and the tensile strength of the monofilament decreases to differentdegrees.With the extension of the reaction time,the contact angle in water and in Diiodomethane decreases gradually,and the surface energy increases gradually,the monofilament tensile strength decreased first and then increased.When the reaction time was 35min,the monofilament tensile strength of the modified carbon fiber was 3.75GPa.After melamine grafting modification,the interfacial shear strength of melamine grafted carbon fiber composites will be improved in differentdegrees.With the extension of melamine grafting modification time,the interfacial shear strength of melamine grafted carbon fiber composites will gradually increase.