A biodegradable linear bio-based polyester of poly(hexylene succinate) was effectively prepared in non-metal sulfonic acid-functionalized Brønsted acidic ionic liquids (SFBAILs) as both the catalyst and the polymerization medium, and the processes of polycondensation and post-polycondensation in SFBAILs were also investigated. In addition, the side reactions which were detrimental to the growth of M_w of poly(hexylene succinate) were evaluated and the synthesis mechanism of poly(hexylene succinate) catalyzed by SFBAILs was discussed with the help of DFT calculations. The result shows that both the imidazole ring and the sulfonic group on cations of SFBAILs play an important role in the catalytic process.

中文翻译：

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实现聚琥珀酸己二醇酯生物基聚酯的非金属路线：磺酸功能化布朗斯台德酸性离子液体的制备条件、副反应和机理

以非金属磺酸功能化布朗斯台德酸性离子液体（SFBAILs）为催化剂和聚合介质，有效制备了可生物降解的线型生物基聚（丁二酸己二醇酯）聚酯，并在缩聚和后缩聚过程中进行了研究。还对 SFBAIL 进行了调查。此外，还评估了不利于聚琥珀酸己二醇酯M _w增长的副反应，并借助DFT计算讨论了SFBAILs催化聚琥珀酸己二醇酯的合成机理。结果表明，SFBAILs 的咪唑环和阳离子上的磺酸基在催化过程中发挥着重要作用。