Kinetic study of alkyl methacrylate polymerization in nanoporous confinement over a broad temperature range
Kinetic study of alkyl methacrylate polymerization in nanoporous confinement over a broad temperature range
复制标题
DOI：
10.1016/j.polymer.2020.122868
复制
发表时间：
2020-09
期刊：
影响因子：
4.6
通讯作者：
Qian Tian;Haoyu Zhao;S. Simon
中科院分区：
文献类型：
--
作者：
Qian Tian;Haoyu Zhao;S. Simon
采用差示扫描量热法研究了纳米约束对过氧化二叔丁基（DtBP）引发甲基丙烯酸乙酯（EMA）和甲基丙烯酸正丁酯（BMA）自由基聚合的影响。两种本体单体的有效速率相似，尽管BMA在95° C下反应快约11%。对于nanocolented的情况下，初始反应速率的单体限制在受控的孔隙玻璃的孔隙中的增强，在原生孔中观察到更大的影响相比，在其中的原生硅烷醇转化为三甲基甲硅烷基的孔。在纳米约束下，自动加速的开始也发生得更早，其中转化率和达到自动加速所需的时间分别减少x g el和t g el，并且原生孔的变化更大。诱导时间遵循Arrhenius行为，并在纳米约束下增加。在160° C以上的聚合温度下，随着接近上限温度，解传播变得重要，并且在纳米限制下似乎比在本体中更明显。
The effect of nanoconfinement on the free radical polymerization of ethyl methacrylate (EMA) and n-butyl-methacrylate (BMA) with di-tert-butyl peroxide (DtBP) initiator is investigated over a wide temperature range from 80 to 190° C using differential scanning calorimetry. The effective rates are similar for the two bulk monomers although the BMA reacts approximately 11% faster at 95° C. For nanoconfined cases, the initial reaction rate for monomer confined in the pores of controlled pore glass is enhanced, with larger effects observed in native pores compared to pores in which the native silanol was converted to trimethyl silyl. The onset of autoacceleration also occurs earlier under nanoconfinement, with decreases in both the conversion and the time required to reach autoacceleration, x g e l and t g e l, respectively, and larger changes for the native pores. The induction time follows Arrhenius behavior and increases under nanoconfinement. At polymerization temperatures above 160° C, depropagation becomes important as the ceiling temperature is approached and seems to be more pronounced under nanoconfinement than in the bulk.