Clarification of the Mechanism of Thermoreversible Sal-Gel Transition of Non-crystalline Polymer/Diluents

阐明非晶聚合物/稀释剂的热可逆盐凝胶转变机制

• 批准号: 03452264
• 负责人: IZUMI Yoshinobu
• 金额: $ 3.97万
• 依托单位: Yamagata University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03452264/
• 关键词: Atactic polystyrene; Carbon disulfide; Physical gel; Soft crosslink; Neutron Scattering; Ball-drop method; DSC; Intrinsic Viscosity; 非晶性高分子; 中性子小角散乱; 中性子広角回析; 中性子準弾性散乱; 電荷移動錯体

In the present work, the results of the neutron scattering, the ball-drop method, DSC, and the intrinsic viscosity on atactic polystyrene (aPS)/carbon disulfide (CS_2) system were presented to reveal the mechanism of the sol-gel transition. The pregel is formed by the interchain association among aPS chains even in the sol. Through the analysis of the viscosity in the limits of both infinite dilution and high molecular weight, the aPS chain behaves as a kind of globular coil, which is induced by the strong interchain association. The critical scattering exponents along the sol-gel transition curve change from 3.3 to 2.0, as the concentration increases. The result suggests that the cross-linking region has a soft structure, i.e., it behaves like a fluid nodule. The results on the wide-angle neutron scattering suggest that the gel structure largely depends on the preparation temperature of the gel. The soft crosslinking region originates from the participation of the solvent molecule in the formation of the crosslinks. As a conclusion, present physical gel may be the phase separating gel with soft corsslinks.

本文采用中子散射、球滴法、DSC和特性粘数等方法研究了无规聚苯乙烯（aPS）/二硫化碳（CS_2）体系的溶胶-凝胶转变机理。即使在溶胶中，aPS链之间也通过链间缔合形成预凝胶。通过对无限稀释和高分子量范围内粘度的分析，认为aPS链表现为一种球状卷曲，这是由链间强缔合作用引起的。溶胶-凝胶转变曲线上的临界散射指数沿着由3.3变为2.0。结果表明，交联区具有软结构，即，它表现得像一个液体结节。广角中子散射的结果表明，凝胶的结构在很大程度上取决于凝胶的制备温度。软交联区源于溶剂分子参与交联的形成。因此，目前的物理凝胶可能是具有软交联的分相凝胶。

项目成果

和泉 義信: "Conformation of atactic polystyrene in carbon disulfide observed at a low temperature" Physica B. 180&181. 539-541 (1992)

Yoshinobu Izumi：“低温下观察到的二硫化碳中无规聚苯乙烯的构象”Physica B. 180&181 (1992)。

和泉 義信: "Quasielastic neutron scattering on the sol-gel-glass transition of atactic polystyrene in carbon disulfide" Physica B. 180&181. 542-544 (1992)

Yoshinobu Izumi：“二硫化碳中无规聚苯乙烯溶胶-凝胶-玻璃转变的准弹性中子散射”Physica B. 180&181 (1992)。

Y. Izumi, et al: "Quasielastic neutron scattering on the sol-gel-glass transition of atactic polystyrene in carbon disulfide" Physica B. 180 & 181. 542-544 (1992)

Y. Izumi 等人：“二硫化碳中无规聚苯乙烯溶胶-凝胶-玻璃转变的准弹性中子散射”Physica B.180

和泉 義信: "Neutron Scattering Evidence of Polymer Branching Caused by Physical Gelation II" Rept.Prog.Polym.Phys.Jpn. 35. 61-62 (1992)

Yoshinobu Izumi：“物理凝胶化引起的聚合物支化的中子散射证据 II”Rept.Prog.Polym.Phys.Jpn 35. 61-62 (1992)

Y. Izumi, et al: "Conformation of atactic polystyrene in carbon disulfide observed at a low temperatures" Physica B. 180 & 181. 539-541 (1992)

Y. Izumi 等人：“低温下观察到的二硫化碳中无规聚苯乙烯的构象”Physica B.180