Abstract

Macroporous viscoelastic poly(vinyl alcohol) (PVA) cryogels are formed via the cryogenic processing (freezing/incubation in the frozen state/defrosting) of concentrated solutions of the polymer. Such materials are of significant scientific and applied interest. This also concerns various complex and composite PVA cryogels containing soluble and insoluble (fillers) additives, respectively. Novel organo-inorganic hybrid PVA cryogels containing silica components have been obtained and studied in this work. These hybrid cryogels are formed via the interaction of sodium silicate with hydrochloric acid, which are introduced into an aqueous PVA solution immediately before its cryogenic processing. As a result, the transformation of the inorganic components occurs simultaneously with the cryotropic gelation of PVA. It has been found that the physicomechanical properties, heat endurance, and macroporous morphology of the obtained samples depend on the concentration of the inorganic additives and the temperature conditions of the cryogenic process. Moreover, it has been revealed that formed NaCl and additionally polarized hydrogen bonds between OH groups of PVA and silanol groups of in situ formed poly/oligo(silicic acids) have substantial effects on the characteristics of resulting hybrid cryogels.

中文翻译：

---

聚合物体系的低温结构研究。54.填充有原位形成的二氧化硅的杂化有机-无机聚乙烯醇冰晶

摘要

大孔粘弹性聚乙烯醇（PVA）冷冻凝胶是通过聚合物浓缩溶液的低温处理（冷冻状态/在冷冻状态下保温/除霜）而形成的。这些材料具有重大的科学和应用价值。这也涉及各种分别包含可溶和不溶（填充剂）添加剂的复杂和复合的PVA低温凝胶。已获得并研究了含有二氧化硅组分的新型有机-无机杂化PVA低温凝胶。这些杂化冰晶是通过硅酸钠与盐酸的相互作用而形成的，在低温处理之前，将其引入PVA水溶液中。结果，无机组分的转变与PVA的低温凝胶化同时发生。已经发现，所获得的样品的物理机械性能，耐热性和大孔形态取决于无机添加剂的浓度和低温过程的温度条件。此外，已经发现，形成的NaCl和PVA的OH基团与原位形成的聚/低聚（硅酸）的硅烷醇基团之间的另外极化的氢键对所得杂化冷冻凝胶的特性具有实质性影响。