Kinetic insights into metaphosphoric acid-catalyzed water-crosslinking reactions in silane-grafted polyolefin system
Kinetic insights into metaphosphoric acid-catalyzed water-crosslinking reactions in silane-grafted polyolefin system
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DOI：
10.1080/10426507.2022.2046573
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发表时间：
2022-03
期刊：
影响因子：
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通讯作者：
Shohei Tanaka;Kenta Adachi
中科院分区：
文献类型：
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作者：
Shohei Tanaka;Kenta Adachi
摘要研究了聚磷酸(PPA)在硅烷接枝聚烯烃体系中催化的水交联反应。PPA以一种平衡混合物的形式存在，它由几个磷酸齐聚物组成。这些低聚物的分布取决于PPA的五氧化二磷含量(%P2O5)。结果表明，PPA的催化活性高于聚合物工业中最常用的催化剂二月桂酸二丁基锡。PPA催化活性的差异主要归因于磷酸低聚物在PPA中的分布；随着高浓缩磷酸低聚体含量的增加，PPA的催化活性增强。理论计算结果表明，高凝聚低聚物能与水分子氢键形成稳定的水合物，从而提高了PPA的催化活性。这一发现将加深对开发高活性、环保的聚合物体系中交联反应催化剂的理解。图形摘要
Abstract Polyphosphoric acid (PPA)-catalyzed water-crosslinking reaction in silane-grafted polyolefin system was investigated. PPA exists as an equilibrium mixture comprising several phosphoric acid oligomers. Distribution of these oligomers depends on the phosphorus pentoxide content (%P2O5) of the PPA. Our results revealed that the PPA presented a higher catalytic activity than dibutyltin dilaurate, which is a catalyst most commonly used in polymer industry. The difference in catalytic activities of PPAs was primarily attributed to the distribution of the phosphoric acid oligomers in PPA; as the degree of highly condensed phosphoric acid oligomers increased, the catalytic activities of PPAs were enhanced. From the theoretical results, we concluded that the highly condensed oligomer could form the stable hydrate via hydrogen bond with a water molecule, leading to the enhanced catalytic activity of PPA for the hydrolysis reaction. This finding will add to the understanding in the development of the highly active and eco-friendly catalysts for the crosslinking reaction in polymer systems. Graphical Abstract