端羟基聚乳酸共聚物的合成及表征

以乳酸为原料,辛酸亚锡为催化剂,采用梯度升温法,在168℃、0.098 MPa下直接熔融缩聚合成端羟基改性聚乳酸共聚物聚（乳酸/1,4丁二醇）P（LA/BDO）]、聚（乳酸/二乙醇胺）P（LA/DEA）]和聚（乳酸/ε-己内酯）P（LA/CL）]。用乌氏黏度法、红外光谱（FT-IR）、核磁共振（1H-NMR）、差...

Synthesis and Characterization of Hydroxyl-Terminated Poly(Lactic Acid)

The hydroxyl-terminated modified polylactic acid copolymers of poly(lactic acid/1,4-butanediol)P(LA/BDO)],poly(lactic acid/diethanolamine)P(LA/DEA)] and poly(lactic acid/ε-caprolactone)P(LA/CL)]were synthesized via directly melt polycondensation with D,L-racemic lactic acid(D,L-LA) as raw material and stannous octoate as catalyst.The copolymerization reaction was performed at the temperature of 168 ℃ and the pressure of 0.098 MPa using linear heating method.The copolymers were characterized by viscosity-average molecular weight,Fourier transform infrared spectrum(FT-IR),1H nuclear magnetic resonance spectrum(1H-NMR),differential scanning calorimetry(DSC),thermogravimetric analysis(TGA) and X-ray diffraction(XRD).The results demonstrate that Tg of the hydroxyl-terminated copolymers is lower than that of PLA,reducing the rigidity of PLA with certain plasticization;The copolymers have good thermal stability for one-step decomposition;Compared with PLA,the crystallinity of P(LA/CL) and P(LA/BDO) decreases,and the flexibility increases.While P(LA/DEA) is amorphous polymer,this amorphous structure is conducive to the degradation.