Introducing covalently crosslinked network to polymer matrix can merge the advantages in reprocessing and durability of polymers.In this contribution,a series of high-performance vitrimeric elastomers were achieved vi...Introducing covalently crosslinked network to polymer matrix can merge the advantages in reprocessing and durability of polymers.In this contribution,a series of high-performance vitrimeric elastomers were achieved via polycondensation.The topological structures of polymers were tuned by varying the feeding ratios of bisacetoacetate,hex–substituted bisacetoacetate,bisamine and tris(2-aminoethyl)amine.With these structural manipulations,the vitrimeric elastomers presented great elastic recovery properties(strain recovery value up to 80%)benefiting from the introduction of long chain branch.Furthermore,the elastomers exhibited excellent reprocessing property,water vapor/oxygen barrier and adhesive properties.Specially,the elastomers could be degraded into monomer under acid conditions which enabled the elastomer synthesis again in closed loop recycling system.The ease of the polycondensation in this work to prepare highly elastic and recyclable vitrimeric elastomers demonstrated exciting opportunities for the synthesis of sustainable polymers.展开更多
以己二胺为原料利用界面反应制备了双氟酰胺单体1,6-N,N′-双(4-氟苯甲酰胺)己烷(BFBH),并与硫化钠、二氯二苯砜通过溶液缩聚制备了一系列新型半芳族聚酰胺共聚改性聚芳硫醚砜(Semi-PASS/A)树脂。通过核磁氢谱(1 H NMR)和红外光谱(FTIR...以己二胺为原料利用界面反应制备了双氟酰胺单体1,6-N,N′-双(4-氟苯甲酰胺)己烷(BFBH),并与硫化钠、二氯二苯砜通过溶液缩聚制备了一系列新型半芳族聚酰胺共聚改性聚芳硫醚砜(Semi-PASS/A)树脂。通过核磁氢谱(1 H NMR)和红外光谱(FTIR)表征了单体及聚合物的化学结构。结果表明,新型单体及聚合物成功制备。Semi-PASS/A树脂的特性黏度范围为0.43~0.55 dL/g,该共聚物具有优异的热性能,其玻璃化转变温度范围为202~215℃,5%热分解温度范围为396~429℃。玻璃化转变温度、热分解温度均随着聚合物中半芳族酰胺含量的增加而下降。平板流变结果表明,Semi-PASS/A的复数黏度相比于聚芳硫醚砜树脂(PASS)下降显著,PASS树脂的25470 Pa·s降低至Semi-PASS/A-10树脂(BFBH的摩尔分数为10%)的36.9 Pa·s。随着半芳族聚酰胺含量的增加,共聚物的复数黏度降低。此外,Semi-PASS/A树脂在高温(310℃)下的时间测试中,其熔体复数黏度随时间增加基本保持稳定,表明半芳族聚酰胺引入PASS树脂结构中不仅降低了聚合物的熔体黏度,同时还有效改善了PASS的熔体稳定性,极大地改善了PASS的熔体加工性能。展开更多
High molecular weight poly(1,4-butylene 2,5-furandicarboxylate-co-isosorbide 2,5-furandicarboxylate)copolyesters(PBSIF-x)were synthesized via melt-polycondensation of 2,5-furandicarboxylic acid(FDCA),with varying rati...High molecular weight poly(1,4-butylene 2,5-furandicarboxylate-co-isosorbide 2,5-furandicarboxylate)copolyesters(PBSIF-x)were synthesized via melt-polycondensation of 2,5-furandicarboxylic acid(FDCA),with varying ratios of isosorbide(ISB)and 1,4-butylene glycol(BDO)catalyzed by antimony trioxide(Sb_(2)O_(3)).The PBSIF-x structures were investigated using FTIR and~1H NMR,while the GPC analysis exhibited the copolyesters molecular weights with number average molecular mass(M_n)in the range of 11079-15153 g/mol.The DSC results show that PBSIF-x copolyesters have a single glass-transition temperature(T_(g))(77.45-110.96℃),increasing with the increase in ISB content,while TGA analysis demonstrates excellent thermal stability up to 320℃.From the thermal result,properties of PBSIF-x copolyesters are found to be within the interval of their parent homologues poly(butylene 2,5-furandicarboxylate)(PBF)and poly(isosorbide 2,5-furandicarboxylate)(PIF),which confirms the aromatic/aliphatic blending within the polymer matrix for enhanced polymer stability and performance.展开更多
基金supported by National Natural Science Foundation of China(NSFC,Nos.21971230,U19B6001,22201003)Excellent Research and Innovation Team Project of Anhui Province(No.2022AH010001)Anhui Province Key Laboratory of Environment-friendly Polymer Materials。
文摘Introducing covalently crosslinked network to polymer matrix can merge the advantages in reprocessing and durability of polymers.In this contribution,a series of high-performance vitrimeric elastomers were achieved via polycondensation.The topological structures of polymers were tuned by varying the feeding ratios of bisacetoacetate,hex–substituted bisacetoacetate,bisamine and tris(2-aminoethyl)amine.With these structural manipulations,the vitrimeric elastomers presented great elastic recovery properties(strain recovery value up to 80%)benefiting from the introduction of long chain branch.Furthermore,the elastomers exhibited excellent reprocessing property,water vapor/oxygen barrier and adhesive properties.Specially,the elastomers could be degraded into monomer under acid conditions which enabled the elastomer synthesis again in closed loop recycling system.The ease of the polycondensation in this work to prepare highly elastic and recyclable vitrimeric elastomers demonstrated exciting opportunities for the synthesis of sustainable polymers.
基金Funded by the Program(BG2021)of High-end Foreign Experts of The State Administration of Foreign Experts Affairs(SAFEA)the Young Talent Project of Hubei Provincial Department of Education,China(No.Q20201108)。
文摘High molecular weight poly(1,4-butylene 2,5-furandicarboxylate-co-isosorbide 2,5-furandicarboxylate)copolyesters(PBSIF-x)were synthesized via melt-polycondensation of 2,5-furandicarboxylic acid(FDCA),with varying ratios of isosorbide(ISB)and 1,4-butylene glycol(BDO)catalyzed by antimony trioxide(Sb_(2)O_(3)).The PBSIF-x structures were investigated using FTIR and~1H NMR,while the GPC analysis exhibited the copolyesters molecular weights with number average molecular mass(M_n)in the range of 11079-15153 g/mol.The DSC results show that PBSIF-x copolyesters have a single glass-transition temperature(T_(g))(77.45-110.96℃),increasing with the increase in ISB content,while TGA analysis demonstrates excellent thermal stability up to 320℃.From the thermal result,properties of PBSIF-x copolyesters are found to be within the interval of their parent homologues poly(butylene 2,5-furandicarboxylate)(PBF)and poly(isosorbide 2,5-furandicarboxylate)(PIF),which confirms the aromatic/aliphatic blending within the polymer matrix for enhanced polymer stability and performance.
