Preparation of supramolecular network materials by means of amylose helical assemblies
Preparation of supramolecular network materials by means of amylose helical assemblies
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DOI：
10.1016/j.polymer.2018.02.023
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发表时间：
2018-03-28
期刊：
影响因子：
4.6
通讯作者：
Yamamoto, Kazuya
中科院分区：
文献类型：
--
作者：
Kadokawa, Jun-ichi;Shoji, Takuya;Yamamoto, Kazuya
直链淀粉是一种天然多糖，由于其左旋螺旋构象，其形成双螺旋和包合复合物组装体取决于客体化合物是否存在。直链淀粉是通过磷酸化酶催化的酶促聚合精确合成的。在这项研究中，我们研究了磷酸化酶催化的酶促聚合引发麦芽庚糖（聚合引物）接枝聚（γ-谷氨酸）在不同的进料比的客体聚合物，聚（ε-己内酯）（PCL）的存在下。在不存在PCL或存在少量PCL的情况下，反应混合物完全变成水凝胶形式，主要由直链淀粉双螺旋组成。另一方面，大部分由直链淀粉包合物组成的聚集体在反应混合物中形成，在更大量的PCL的存在下。分析结果表明，双螺旋交联点参与了较大网络结构的形成，而较小网络结构则由包合物交联点构成。这些结构在分子水平上分级构建了不同的宏观网络尺寸，导致了材料形态的差异。(C)2018爱思唯尔有限公司版权所有
Amylose, a natural polysaccharides, is a well-known functional material, because it forms double helix and inclusion complex assemblies depending on whether guest compounds are present or not, owing to its left-handed helical conformation. Amylose is precisely synthesized by phosphorylase-catalyzed enzymatic polymerization. In this study, we investigated the phosphorylase-catalyzed enzymatic polymerization initiated from maltoheptalose (primer for the polymerization)-grafted poly(gamma-glutamic acid) in the presence of different feed ratios of a guest polymer, poly(epsilon-caprolactone) (PCL). In the absence of PCL or presence of less amount of PCL, the reaction mixtures totally turned into hydrogel form, pre-dominantly composed of amylose double helixes. On the other hand, aggregates, which were largely composed of amylose inclusion complexes, were formed in the reaction mixtures in the presence of larger amount of PCL. The analytical results indicated that double helix cross-linking points participated into the formation of larger network structure, whereas smaller network structure was fabricated from inclusion complex cross-linking points. These structures on molecular level hierarchically constructed different macroscopic network sizes, leading to difference in the material forms. (C) 2018 Elsevier Ltd. All rights reserved.