部分交联聚丙烯酰胺的合成机理

Mechanism of Forming Partially-Crosslinked Polyacrylamide

采用水溶液聚合合成出一种新型部分交联结构的聚丙烯酰胺。通过实时红外追踪、二维红外相关光谱分析和动态流变测试,揭示了由三官能度功能单体形成支化结构的反应历程和交联反应受动力学控制的独特机理。因支化活性链端偶合终止形成部分交联聚丙烯酰胺的反应,受急剧增大的体系黏度的影响,使支化活性端链的运动受到不同程度的抑制,耦合终止难以发生,部分支化链得以保留。这为深入理解部分交联的聚丙烯酰胺结构的形成机理和有效调控部分交联聚丙烯酰胺的支化和交联的比率提供了依据。

Partially-crosslinked polyacrylamide has been s3nathesized via aqueous solution polymerization. Based on methods of real time infrared monitoring, two-dimensional infrared correlation spectroscopy analysis and dynamic theology measurement, an unusual complex formation mechanism of the partially-crosslinked polyacrylamide under the multi-functional initiator system is clearly rerealed. A process forming branched structures from three functional monomer （DA） is exhibited, which supports by 2D FT-IR analysis. Furthermore, an interesting reaction process dominated by dynamics factors was proposed. Cross-linking reaction from great number of coupling terminations will be generated from the active branched end chains which can be inhibited in different extent from sharply accretion of systemic viscosity. It will result in part of the branched structures being reserved. Consequently, the rate of branched and cross-linked structures in partially-crosslinked polyacrylamide can be determined by the system viscosity and also by content of the functional monomer.