Recycling of carbon fiber reinforced composites is important for sustainable development and the circular economy.Despite the use of dynamic chemistry,developing high-strength recyclable CFRPs remains a major challeng...Recycling of carbon fiber reinforced composites is important for sustainable development and the circular economy.Despite the use of dynamic chemistry,developing high-strength recyclable CFRPs remains a major challenge due to the mutual exclusivity between the dynamic and mechanical properties of materials.Here,we developed a high-strength recyclable epoxy resin(HREP)based on dynamic dithioacetal covalent adaptive network using diglycidyl ether bisphenol A(DGEBA),pentaerythritol tetra(3-mercapto-propionate)(PETMP),and vanillin epoxy resin(VEPR).At high temperatures,the exchange reaction of thermally activated dithioacetals accelerated the rearrangement of the network,giving it significant reprocessing ability.Moreover,HREP exhibited excellent solvent resistance due to the increased cross-linking density.Using this high-strength recyclable epoxy resin as the matrix and carbon fiber modified with hyperbranched ionic liquids(HBP-AMIM+PF6-)as the reinforcing agent,high performance CFRPs were successfully prepared.The tensile strength,interfacial shear strength(IFSS)and interlaminar shear strength(ILSS)of the optimized formulation(HREP20/CF-HBPPF6)were 1016.1,70.8 and 76.0 MPa,respectively.In addition,the CFRPs demonstrated excellent solvent and acid/alkali-resistance.The CFRPs could completely degrade within 24 h in DMSO at 140℃,and the recycled CF still maintained the same tensile strength and ILSS as the original after multiple degradation cycles.展开更多
采用开环聚合法合成聚环氧氯丙烷中间体,再分别与N-甲基咪唑和吡啶反应合成了聚醚咪唑型离子液体(PIIL)与聚醚吡啶型离子液体(PPIL),并用红外与核磁进行结构表征。然后将合成的2种聚醚离子液体分别与酚醛树脂预聚物共混,制备了改性酚醛...采用开环聚合法合成聚环氧氯丙烷中间体,再分别与N-甲基咪唑和吡啶反应合成了聚醚咪唑型离子液体(PIIL)与聚醚吡啶型离子液体(PPIL),并用红外与核磁进行结构表征。然后将合成的2种聚醚离子液体分别与酚醛树脂预聚物共混,制备了改性酚醛树脂。研究了2种聚醚离子液体及其用量对改性酚醛树脂的拉伸剪切强度、冲击强度及游离醛释放量的影响。结果表明:聚醚型离子液体的添加明显改善了酚醛树脂的胶合性能和冲击强度,并降低了游离醛含量。聚醚咪唑离子液体改性酚醛树脂的性能优于聚醚吡啶型离子液体,其拉伸剪切强度从最初的1.15 MPa提高到6.94 MPa,冲击强度从最初的2.10 k J/m2提高到9.51 k J/m2,游离醛含量从最初的1.76%降低到0.14%。展开更多
采用阳离子开环聚合法先合成端羟基聚环氧氯丙烷(PECH)中间体,再将其与氯乙酸和N-甲基咪唑反应,制备端羧基聚醚咪唑离子液体([HOOC-PECH-MIM]Cl),并用红外和核磁谱图对其结构进行表征。用合成的端羧基聚醚离子液体与酚醛树脂预聚物共混...采用阳离子开环聚合法先合成端羟基聚环氧氯丙烷(PECH)中间体,再将其与氯乙酸和N-甲基咪唑反应,制备端羧基聚醚咪唑离子液体([HOOC-PECH-MIM]Cl),并用红外和核磁谱图对其结构进行表征。用合成的端羧基聚醚离子液体与酚醛树脂预聚物共混,制备了改性酚醛树脂。用GPC测定了[HOOC-PECH-MIM]Cl的分子量及其分布,研究了分子量对酚醛树脂拉伸与冲击性能的影响。结果表明,合成的端羧基聚醚离子液体是目标产物,且其对酚醛树脂具有优异的增强增韧效果,当端羧基聚醚离子液体分子量为1 379时,[HOOC-PECH-MIM]Cl与酚醛树脂预聚物质量比为1∶4,改性后的酚醛树脂的冲击强度由原来的3.28 MPa提高到12.04 MPa,拉伸强度由原来的0.93 k J/m2提高到10.18 k J/m2。展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.U23A2069 and 51403242)the Natural Science Foundation of Hubei Province(No.2024AFB800)+5 种基金the Fundamental Research Funds for the Central Universities,South-Central Minzu University(Nos.CZY23017 and CZD24001)the Innovation Group of National Ethnic Affairs Commission of China(No.MZR20006)the Fund for Academic Innovation Teams of South-Central Minzu University(No.XTZ24012)Scientific Research Platforms of South-Central Minzu University(No.PTZ24013)the Open Fund for Key Lab of Guangdong High Property and Functional Macromolecular Materials,China(No.20240007)State Key Laboratory of New Textile Materials and Advanced Processing Technologies(No.FZ20230012)。
文摘Recycling of carbon fiber reinforced composites is important for sustainable development and the circular economy.Despite the use of dynamic chemistry,developing high-strength recyclable CFRPs remains a major challenge due to the mutual exclusivity between the dynamic and mechanical properties of materials.Here,we developed a high-strength recyclable epoxy resin(HREP)based on dynamic dithioacetal covalent adaptive network using diglycidyl ether bisphenol A(DGEBA),pentaerythritol tetra(3-mercapto-propionate)(PETMP),and vanillin epoxy resin(VEPR).At high temperatures,the exchange reaction of thermally activated dithioacetals accelerated the rearrangement of the network,giving it significant reprocessing ability.Moreover,HREP exhibited excellent solvent resistance due to the increased cross-linking density.Using this high-strength recyclable epoxy resin as the matrix and carbon fiber modified with hyperbranched ionic liquids(HBP-AMIM+PF6-)as the reinforcing agent,high performance CFRPs were successfully prepared.The tensile strength,interfacial shear strength(IFSS)and interlaminar shear strength(ILSS)of the optimized formulation(HREP20/CF-HBPPF6)were 1016.1,70.8 and 76.0 MPa,respectively.In addition,the CFRPs demonstrated excellent solvent and acid/alkali-resistance.The CFRPs could completely degrade within 24 h in DMSO at 140℃,and the recycled CF still maintained the same tensile strength and ILSS as the original after multiple degradation cycles.
文摘采用开环聚合法合成聚环氧氯丙烷中间体,再分别与N-甲基咪唑和吡啶反应合成了聚醚咪唑型离子液体(PIIL)与聚醚吡啶型离子液体(PPIL),并用红外与核磁进行结构表征。然后将合成的2种聚醚离子液体分别与酚醛树脂预聚物共混,制备了改性酚醛树脂。研究了2种聚醚离子液体及其用量对改性酚醛树脂的拉伸剪切强度、冲击强度及游离醛释放量的影响。结果表明:聚醚型离子液体的添加明显改善了酚醛树脂的胶合性能和冲击强度,并降低了游离醛含量。聚醚咪唑离子液体改性酚醛树脂的性能优于聚醚吡啶型离子液体,其拉伸剪切强度从最初的1.15 MPa提高到6.94 MPa,冲击强度从最初的2.10 k J/m2提高到9.51 k J/m2,游离醛含量从最初的1.76%降低到0.14%。
文摘采用阳离子开环聚合法先合成端羟基聚环氧氯丙烷(PECH)中间体,再将其与氯乙酸和N-甲基咪唑反应,制备端羧基聚醚咪唑离子液体([HOOC-PECH-MIM]Cl),并用红外和核磁谱图对其结构进行表征。用合成的端羧基聚醚离子液体与酚醛树脂预聚物共混,制备了改性酚醛树脂。用GPC测定了[HOOC-PECH-MIM]Cl的分子量及其分布,研究了分子量对酚醛树脂拉伸与冲击性能的影响。结果表明,合成的端羧基聚醚离子液体是目标产物,且其对酚醛树脂具有优异的增强增韧效果,当端羧基聚醚离子液体分子量为1 379时,[HOOC-PECH-MIM]Cl与酚醛树脂预聚物质量比为1∶4,改性后的酚醛树脂的冲击强度由原来的3.28 MPa提高到12.04 MPa,拉伸强度由原来的0.93 k J/m2提高到10.18 k J/m2。
