二异氰酸酯扩链聚2,5-呋喃二甲酸乙二酯

以2,4-甲苯二异氰酸酯(TDI)为扩链剂,对生物基聚2,5-呋喃二甲酸乙二酯(PEF)进行扩链,探讨了扩链剂用量(NCO/OH摩尔比)、反应时间、反应温度等因素的影响。采用红外光谱、核磁共振氢谱、元素分析、差示扫描量热法、X射线衍射分析了扩链PEF的分子结构、热性能和结晶性能。结果表明,当扩链剂用量n(NCO)/n(OH)=1~3,反应时间为30min,反应温度为230℃时扩链效果较好;扩链后PEF的特性黏度最高达1.24dL/g,重均相对分子质量(Mw)最高达28.8×104;扩链后PEF的结晶能力降低,热稳定性能相对提高。

Chain Extension of Poly(ethylene 2,5-furandicarboxylate) by Diisocyanate

A high molecular weight of bio-based poly (ethylene furandicarboxylate) was prepared by chain extension with 2,4-toluene diisocyanate (TDI).The effect of TDI dosage,chain extension time and temperature were studied to find out the appropriate chain extension condition.The molecular structure and element of PEF were characterized by FT-IR,1H-NMR and element analyzer.The crystallization and thermal properties of PEF were investigated via differential scanning calorimetry (DSC),thermal gravity analysis (TG) and XRD.It is found that the appropriate conditions for the chain extension synthesis are 230 ℃,30 min when NCO/OH mole ratio is at the range of 1 ～3.The maximum intrinsic viscosity [η] of extended PEF reaches 1.24 dL/g,and the maximum Mw reaches 2.9 × 106 g/mol.The crystallization capacity is decreased due to the chain extension.However,the thermal stability is improved due to the introduction of TDI.