Thermal and evolved gas analyses on Michael addition oligomers of acrylic acid
Thermal and evolved gas analyses on Michael addition oligomers of acrylic acid
复制标题
丙烯酸迈克尔加成低聚物的热分析和逸出气体分析
DOI：
10.1007/s10973-020-10412-8
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发表时间：
2021
影响因子：
4.4
通讯作者：
Miyake Atsumi
中科院分区：
文献类型：
--
作者：
Fujita Michiya;Izato Yu-ichiro;Miyake Atsumi
丙烯酸的迈克尔加成反应引起了丙烯酸的热失控，从而在化工行业中引起了许多爆炸和火灾事故。本研究的目的是在热分析和进化气分析的基础上，更好地了解失控聚合过程中丙烯酸Michael加成低聚物（MAO）的反应机理。丙烯酸的迈克尔加成反应发生在低于热聚合发生温度的温度下，引发热聚合的起始和相应的热失控，热失控后，与产物反应产生的压力MAO可引起罐体破裂。通过对MAO及其热聚合物的高敏反应量热法和演化气分析，探讨了MAO的热聚合和热分解反应机理。从calvet型量热计和热重-差示扫描量热-质谱-红外光谱（TG-DSC-MS-IR）的热分析结果看，MAO在180℃以上可以放热聚合，其热聚合物在195℃以上分解为丙酸、二氧化碳、乙烯和低分子碳氢化合物如甲烷、乙烷和环丙烷。研究发现，丙烯酸的Michael加成低聚不仅会因其产生热量而热引发自由基聚合，还会因MAO聚合物热分解产生较大压力而增加失控聚合后罐体爆炸的可能性。
Michael addition reaction of acrylic acid has caused thermal runaway of acrylic acid, thereby causing many explosion and fire accidents in the chemical industries. The aim of the present study is to gain a better understanding of the reaction mechanisms of Michael addition oligomers of acrylic acid (MAO) during a runaway polymerization on the basis of thermal and evolved gas analysis. The Michael addition reaction of acrylic acid occurs at a temperature lower than the temperature at which thermal polymerization occurs, triggering the initiation of thermal polymerization and the associated thermal runaway, and after the thermal runaway, the pressure generated by the reaction with the product, MAO, can cause tank rupture. We discussed the reaction mechanisms of MAO including thermal polymerization and thermal decomposition on the basis of high-sensitivity reaction calorimetry and evolved gas analysis of MAO and its thermal polymer. From the results of the thermal analysis using Calvet-type calorimeter and thermogravimetry–differential scanning calorimetry-mass spectrometry-infrared spectrometry (TG-DSC-MS-IR), MAO can be polymerized exothermically at more than 180 °C, and its thermal polymer decomposes to propanoic acid, carbon dioxide, ethylene and low-molecular hydrocarbons such as methane, ethane, and cyclopropane at more than 195 °C. Michael addition oligomerization of acrylic acid was found to not only thermally initiate free radical polymerization due to its heat generation but also increase the possibility of the tank explosion after runaway polymerization due to the large pressure generation induced by thermal decomposition of MAO polymer.