链段相容性对聚酯-聚醚多嵌段共聚物组成均一性的影响

<正> 由结晶型芳族聚酯为硬链段,无定型脂肪族聚醚为软链段的聚酯-聚醚多嵌段共聚物,是一类性能优良的热塑弹性体,本文研究链段相容性对这类聚合物组成均一性的影响,因此,合成了一系列不同链段结构的聚酯-聚醚多嵌段共聚物。 如硬链为聚对苯二甲酸乙二醇酯(PET)和丁二醇酯(PBT);软链段有聚乙二醇醚(PET)、聚丁二醇醚(PTMG)、聚二醇醚(PPG)和四氢呋喃同环氧丙烷的共聚醚二醇     

从聚酯合成聚酯-聚醚多嵌段共聚物

研究直接以聚酯为原料,合成聚酯-聚醚多嵌段共聚物。研究了反应机理、链段结构对反应的影响以及由此法制备的多嵌段共聚物的链段序列结构。实验结果表明,链段相容性对聚合物法的影响至为重要,链段相容性不仅决定了所得嵌段共聚物的组成均一性,而且还决定了某一链段结构的多嵌段共聚物能否用聚合物法制备。     

ω-氨基酸缩聚反应动力学研究

前曾报导9-氨基壬酸的缩聚,从开始到反应程度p增加到99％左右时止,均遵循二级反应。在这以后,由于体系粘稠的影响,迅速转为三级反应。本文报导在6-氨基己酸和11-氨基十一酸缩聚时,也出现同样现象,即在p逐渐到高于99％左右时,反应从二级转变为三级。可以说这一现象是AB型单体聚酰胺化的一般规律,从而澄清了文献中对这一问题的不同论点。     

RESEARCH ON THE POLYCONDENSATION KINETICS OF ω-AMINO-ACIDS*

In our previous report, it was discovered that the polycondensation of 9-amino-nonanoic acid follows second order from the beginning up to the extent of reaction, p, around 99%, and after which the reaction changes rapidly to third order. In this paper, we wish to report that this change of the reaction order from second to third occurred also in the polycondensation of 6-aminocaproic acid and 11-amino-undecanoic acid. The transition region lay again at p around 99%. It may be concluded that this is a general rule in the polycondensation of the ω-amino-acids (monomers of the A—B type), and the controversial results that appeared in the literature may be cleared up by our experiments.     

SYNTHESIS OF POLYESTER-POLYETHER MULTIBLOCK COPOLYMERS FROM POLYESTERS

A polymeric method was explored for the preparation of polyester-polyether multiblock copoly-mers using polyesters and polpethers as starting materials. The mechanism of the reaction and theeffect of the segment structure on it, the segment sequence of the block copolymers prepared havebeen studied. It has been shown that to the polymeric method the degree of compatibility betweenstarting polyester and polyether is of paramount importance, which determines not only the com-positional homogeneity of the block copolymers formed but also the success of the polymeric methodto get the block copolymers of the expected structure.