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Synthesis of chitosan-modified poly(methyl methacrylate) by emulsion polymerization

机译：乳液聚合法合成壳聚糖改性的聚甲基丙烯酸甲酯

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Emulsion polymerization of methyl methacrylate (MMA) in the presence of chitosan was studied and a reaction mechanism was proposed. It was proved in the companion article that potassium persulfate (KPS) free radicals can degrade chitosan chains into chain free radicals. Therefore, it is possible to produce a chitosan copolymer when the monomer and the KPS initiator are added into the chitosan solution. According to the proposed mechanism, concentrations of different species such as the initiator, total free radicals, and degraded chitosan chain were calculated with the reaction time. All the results a-reed with the experimental observation. The results showed that the polymerization rate varied with 0.83- and 0.82-order of the total free-radical concentration and chitosan repeating unit concentration, respectively. It was also verified that chitosan played multiple roles in the reaction system. If the monomer was added into the chitosan solution before the addition of KPS, chitosan served mainly as a surfactant. Consequently, the polymer particle number was increased with the chitosan addition and so was the polymerization rate. However, if the monomer was added into the solution where the chitosan was already degraded by KPS, the polymerization rate was decreased with the predegradation time of chitosan. In both cases, the final polymer particles consisted of the poly(methyl methacrylate) (PMMA) homopolymer and the chitosan-PMMA copolymer. (C) 2002 Wiley Periodicals, Inc. [References: 11]
机译：研究了在壳聚糖存在下甲基丙烯酸甲酯（MMA）的乳液聚合反应，并提出了反应机理。配套文章中已证明过硫酸钾（KPS）自由基可将壳聚糖链降解为链自由基。因此，当将单体和KPS引发剂加入到壳聚糖溶液中时，可以生产壳聚糖共聚物。根据提出的机理，随反应时间计算出不同种类的浓度，例如引发剂，总自由基和降解的壳聚糖链。所有结果均与实验观察一致。结果表明，聚合速率分别以总自由基浓度和壳聚糖重复单元浓度的0.83和0.82级变化。还证实了壳聚糖在反应体系中发挥了多种作用。如果在添加KPS之前将单体添加到壳聚糖溶液中，则壳聚糖主要用作表面活性剂。因此，随着壳聚糖的添加，聚合物颗粒数增加，并且聚合速率也增加。但是，如果将单体加入已经通过KPS降解壳聚糖的溶液中，则聚合速度会随着壳聚糖的预降解时间而降低。在两种情况下，最终的聚合物颗粒均由聚（甲基丙烯酸甲酯）（PMMA）均聚物和壳聚糖-PMMA共聚物组成。 （C）2002 Wiley Periodicals，Inc. [参考：11]

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