聚(对苯二甲酸-1,3-丙二酯)环状低聚物的合成、表征和开环聚合反应

Synthesis, Characterization and Ring-opening Polymerization of Poly(trimethylene terephthalate) Cyclic Oligomers

探索了由对苯二甲酰氯和 1 ,3-丙二醇在“假高稀”条件下合成聚 (对苯二甲酸 -1 ,3-丙二酯 ) ( PTT)环状低聚物的可行性 .通过柱色谱分离了环状低聚物和线形低聚物 ;用核磁共振、质谱和元素分析表征了产物的化学结构 ;用 GPC和 HPLC研究了不同大小环的分布 ,发现在本文实验条件下合成的 PTT环状低聚物主要由二、三、四、五和七聚体构成 ,其中环状三聚体含量最多 ,没有发现环状六聚体的存在 .PTT环状低聚物的熔程为 92 .3～ 2 2 2 .6℃ ,熔融后是无色、透明的低粘度液体 .于 2 5 0℃将 PTT环状低聚物分别在辛酸亚锡、 1 -乙基 -3-氯四丁基锡氧烷、钛酸四丁酯和三氧化二锑催化下进行开环聚合反应 ,制备了特性粘数为0 .1 8～ 0 .4 9d L/

Cyclic oligomers of poly(trimethylene terephthalate)(PTT) were prepared by reaction of 1,3 propanediol with terephthaloyl chloride(TPC) under diluted conditions and separated from the linear products by silica gel column. The structures of PTT oligomeric cyclics were confirmed by means of 1H NMR, mass spectrometry, and elementary analysis. Cyclic dimer, trimer, tetramer, pentamer and heptamer were further separated by gel permeation chromatography and high performance liquid chromatography. They were found to constitute most of the cyclics mixtures with a preponderance of the cyclic trimer. The cyclic oligomers melt at 92.3~222.6 ℃, providing liquids of low viscosity. Ring opening polymerization was carried out by heating the sample mixtures at 250 ℃ for 15 minutes in the presence of conventionally used catalysts, such as Sn(Oct) 2, 1 ethoxy 3 chlorotetrabutyldistannoxane, \{Ti(OBu) 4\} and antimony oxide. The inherent viscosity of PTT prepared via ring opening polymerization was as high as 0.49 dL/g.