水溶性AM/AA/AMPS共聚物的高温水解

Hydrolysis of AM/AA/AMPS Copolymer at High Temperature

研究了丙烯酰胺 (AM) /丙烯酸 (AA) /2 -丙烯酰胺 - 2 -甲基丙磺酸 (AMPS)共聚物 (P3A)在 90℃的水解反应 .结果表明 ,共聚物这时的水解反应不遵循单调动力学模式 ,而具有 2个反应阶段 ,它们分别属于分子间和分子内反应机制 .在第 1阶段 ,AM单元发生水解反应占主要地位 ,它受氢氧根离子浓度控制 ,反应速度强烈取决于 p H值 ,在第 2阶段 ,AMPS单元水解是主要反应 ,由于邻近 AA单元的分子内催化作用 ,反应速度和 p H关系不大 .

The hydrolysis of acrylamide/acrylic acid/2 acrylamido 2 methylpropane sulfonic acid(AM/AA/AMPS) copolymer(P3A) at 90 ℃ was studied. The results show that the polymer hydrolysis doesn't obey the monotonic kinetic model and there are two reaction stages, involving inter and intra molecular reaction mechanisms, respectively. In the first stage the hydrolysis of AM units occurs predominately and the reaction rate much depends on the pH value for the reaction is controlled by direct attacking of hydroxide ions. Whereas in the latter stage the hydrolysis of AMPS units is the main reaction and the reaction rate is less related to the pH due to the intermolecular catalysis by the adjacent AA units. The effects of composition and chain conformation of copolymers on the hydrolysis reaction also have been discussed.