HYPERBRANCHED ALIPHATIC POLYESTERS
HYPERBRANCHED ALIPHATIC POLYESTERS
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DOI：
10.1021/ma00109a049
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发表时间：
1995-02-27
期刊：
影响因子：
5.5
通讯作者：
HULT, A
中科院分区：
文献类型：
--
作者：
MALMSTROM, E;JOHANSSON, M;HULT, A
以2,2-二（羟甲基）丙酸（AB(x)型重复单元）和2-乙基-2-（羟甲基）-1,3-丙二醇（核心分子）为原料，采用酸催化在熔融状态下合成了理论上计算摩尔质量为1200- 44300的超支化脂肪族聚酯。合成过程为伪一步反应，每代对应的化学计量量依次加入。所得聚合物在室温下呈玻璃状，微黄色固体，末端基团为羟基。在模型化合物的帮助下，用C-13-NMR测定了聚酯的分支度，发现其接近80%。该材料在氮气气氛中表现出良好的热稳定性。玻璃化转变温度用DSC测定，发现约为40℃，对摩尔质量的变化相对不敏感。
Hyperbranched, aliphatic polyesters of theoretically calculated molar masses 1200-44 300 were synthesized in the molten state from 2,2-bis(hydroxymethyl)propionic acid (repeating unit of AB(x) type) and 2-ethyl-2-(hydroxymethyl)-1,3-propanediol (core molecule) using acid catalysis. The synthesis procedure was a pseudo-one-step reaction where stoichiometric amounts corresponding to each generation were added successively. The resulting polymers were glassy, slightly yellow solids at room temperature with hydroxyl groups as terminal groups. The degree of branching of the polyesters was determined with the help of model compounds using C-13-NMR and was found to be near 80%. The material exhibited good thermal stability as analyzed with TGA in a nitrogen atmosphere. Glass transition temperatures were determined using DSC and were found to be about 40 degrees C and to be relatively insensitive to variations in molar mass.