5-furandicarboxylate) (PEF) was synthesized via direct esterification method based on 2
5-furanicarboxylica acid and ethylene glycol.Stannous oxalate was used as catalyst.The results showed that the direct esterification method was a straightforward and convenient effective way for preparing PEF.The results of Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (1H-NMR) confirmed the expected PEF structure.The results of Ubbelohde viscosity method and gel permeation chromatography (GPC) declared the relationship between intrinsic viscosities and weight-average molecular weight was []=2.8210-6 Mw0.99 [dL/g
25℃
phenol-tetrachloroethane (1∶1
W/W)]; The results of differential scanning calorimeter (DSC) displayed that the glass transition (Tg) of PEF was 84℃ which was 16 K higher than that of poly(ethylene terephthalate) (PET) and the melting temperature (Tm) of PEF was 211℃ which was 43 K lower than that of PET.The results of thermogravimetric analysis (TGA) showed that the PEF was thermally stable up to 373℃.PEF had good thermal properties and was similar to that of PET.The results of coaxial cylinder viscometer showed that the PEF melt was a pseudoplastic Newtonian fluid and its Non-Newtonian index increased with decreasing of relative molecular weight and increasing of temperature.Non-Newtonian index was about 0.85 (melting temperature=230~250℃
rate of shear=2.1710-2~1.14102 s-1).
关键词
25-呋喃二甲酸聚25-呋喃二甲酸乙二醇酯直接酯化法合成与表征
Keywords
25-Furandicarboxylic acidPoly(ethylene 25-furandicarboxylate)Direct esterification methodSynthesis and characterization