乙醇胺-乙二醇复合体系引发对二氧环己酮开环聚合的研究

Studies on the ring opening polymerization of 1,4-dioxanone by 2-hydroxyethanolamine-glycol

以乙醇胺-乙二醇复合体系催化对二氧环己酮(PDO)开环聚合生成聚对二氧环己酮(PPDO)。系统研究了反应时间、温度及单体与催化剂摩尔比(n(M)/n(C))对产物的结构及热力学性能方面的影响。利用红外光谱(IR)、核磁光谱(1 H NMR)、X射线广角衍射(WAXD)乌氏粘度法及差示扫描量热法(DSC)对聚合产物的结构、特性粘度以及热力学性能进行初步探讨。结果表明,在反应时间为24h、温度为120℃及n(M)/n(C)=500∶1条件下生成的聚合产物性能最佳。乙醇胺-乙二醇复合引发体系能够有效地催化PDO开环聚合生成PPDO产物。

poly(1,4-dioxanone)(PPDO)were prepared by the polymerization of 1,4-dioxanone(PDO)without solvent using 2-hydroxyethanolamine-glycol as a non-metallic organic catalyst,which has not previously been reported.The effects of the operating parameters,including the reaction temperature,reaction time and the molar ratio of monomer to catalyst(n(M)/n(C)),on the properties of the synthesized PPDO were systematically investigated.The structure of the products was characterized by 1 H NMR,IR and wide-angle X-ray diffraction(WAXD).The intrinsic viscosity([η])was measured using a Ubbelohde viscometer.Thermodynamic properties were characterized by differential scanning calorimetry(DSC).The results indicated that the best polymerization conditions were 140 ℃ and 24 hwith n(M)/n(C)equal to 500∶1.Furthermore,the results demonstrated that 2-hydroxyethanolamine-glycol was an efficient and easily removed catalyst for the ring-opening polymerization of PDO.