Effects of Carboxyls Attached at Alkyl Side Chain Ends on the Lamellar Structure of Hydrogels
Effects of Carboxyls Attached at Alkyl Side Chain Ends on the Lamellar Structure of Hydrogels
复制标题
DOI：
10.1021/ma010625x
复制
发表时间：
2001-07
期刊：
影响因子：
5.5
通讯作者：
T. Miyazaki;T. Kaneko;J. Gong;Y. Osada
中科院分区：
文献类型：
--
作者：
T. Miyazaki;T. Kaneko;J. Gong;Y. Osada
两种由三种单体组成的水溶胀性水凝胶（丙烯酸硬脂酯（C18 A）-共-丙烯酸正烷基酯（CnA）-共-丙烯酸（AA））和聚（16-丙烯酰氧基十六烷酸（AHA）-co-CnA-co-AA）（n是侧链的碳原子数：n = 14，16，18，20，22），并用广角X射线衍射（WAXD）和小角X射线衍射（SAXD）对其结构进行了表征。两种凝胶均与层状结构形成晶体结构。在聚（C18 A-co-CnA-co-AA）凝胶的情况下，层状厚度d2和熔融温度Tm都随着n的增加而增加，表明C18 A和CnA形成分子混合的结晶域。另一方面，poly（AHA-co-CnA-co-AA）凝胶的d2远小于poly（CnA-co-AA）凝胶的d2，并且Tm与n无关是恒定的。对于聚（AHA-共-C18 A-co-AA）凝胶，在0.8的AHA组成下观察到Tm的突然降低。这些结果表明，烷基侧链末端的羧基对AHA的结构有重要影响。
Two kinds of water-swollen hydrogels composed of three monomerspoly(stearyl acrylate (C18A)-co-n-alkyl acrylates (CnA)-co-acrylic acid (AA)) and poly(16-acryloyloxyhexadecanoic acid (AHA)-co-CnA-co-AA) (n is the number of carbon atoms of side chains: n = 14, 16, 18, 20, 22)were synthesized, and their structures were investigated by wide-angle X-ray diffraction (WAXD) and small-angle X-ray diffraction (SAXD). Both gels formed the crystalline structure with the lamellae. In the case of poly(C18A-co-CnA-co-AA) gels, both the lamellar thickness, d2, and the melting temperature, Tm, increased with the increase in n, suggesting that C18A and CnA form molecularly mixed crystalline domains. On the other hand, d2 of poly(AHA-co-CnA-co-AA) gels was much smaller than that of poly(CnA-co-AA) gels, and Tm was constant regardless of n. An abrupt decrease in Tm was observed for poly(AHA-co-C18A-co-AA) gels at an AHA composition of 0.8. These results indicate that carboxyls attached at alkyl side chain end of AHA signif...