Quantitative contrasts in the copolymerization of acrylate- and methacrylate-based comonomers
Quantitative contrasts in the copolymerization of acrylate- and methacrylate-based comonomers
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DOI：
10.1021/ma0616864
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发表时间：
2006-11-28
期刊：
影响因子：
5.5
通讯作者：
Reed, Wayne F.
中科院分区：
文献类型：
--
作者：
Alb, Alina M.;Enohnyaket, Pascal;Reed, Wayne F.
聚合反应自动连续在线监测（ACOMP）用于定量评估自由基共聚过程中丙烯酸酯和甲基丙烯酸酯家族共聚单体的反应性、平均组成漂移和分布以及摩尔质量和特性粘度演变。在后一种情况下，N-甲基丙烯酰氧基琥珀酰亚胺（MASI）引起了人们的主要兴趣，因为它有望作为一种起始材料，通过后聚合改性可以生产高度定制的聚合物。结果发现，MASI 与丙烯酸酯（如丙烯酸丁酯 (BA)）的反应活性比相差很大，并且与甲基丙烯酸甲酯 (MMA) 和 BA 的反应活性比相当。相比之下，MMA/MASI 的反应活性比更接近，这与文献中 MMA 与其他甲基丙烯酸酯共聚的总体趋势一致。虽然从化学角度来看这在直观上是合理的，但这种全面的在线表征证实，至少可以使用更广泛的 MMA 知识库对 MASI 共聚行为进行一些预测。 BA/MASI 共聚与 MMA/MASI 共聚之间的差异还体现在重均摩尔质量和特性粘度随着转化率的增加而异常增加。这项工作建立了可用作基于 MASI 的开发的通用工具的先例和方法，并为监测 MASI 的 ATRP 共聚以及水解和衍生化等聚合后修饰铺平了道路。
Automatic continuous online monitoring of polymerization reactions (ACOMP) was used to assess quantitatively the reactivity, average composition drift and distributions, as well as molar mass and intrinsic viscosity evolution of comonomers from the acrylate and methacrylate families during free radical copolymerization. In the latter case, N-methacryloxysuccinimide (MASI) was of chief interest because of its promise as a starting material from which highly tailored polymers can be produced by postpolymerization modifications. It was found that the reactivity ratios of MASI with an acrylate, such as butyl acrylate (BA), were widely separated and comparable to the case of methyl methacrylate (MMA) and BA. In contrast, reactivity ratios for MMA/MASI were closer together, consistent with general trends in the literature for MMA copolymerization with other methacrylates. While this is intuitively reasonable from a chemical point of view, this comprehensive online characterization confirms that at least some predictions about MASI copolymerization behavior can be made using the much wider knowledge base for MMA. The disparity between BA/MASI copolymerization compared to MMA/MASI is also seen in the unusual increase in weight-average molar mass and intrinsic viscosity as conversion increases. This work establishes the precedents and methodologies that can be used as a general tool in MASI-based developments and paves the way toward monitoring ATRP copolymerization of MASI, as well as postpolymerization modifications such as hydrolysis and derivitization.