Cellulose acetate propionate (CAP), a high value-added chemical, is traditionally prepared using H₂SO₄ as catalyst. Replacement of the mineral acids by solid acids is current research focus for green and sustainable production of CAP. Herein, we reported the fabrication of novel solid acid catalyst HPW/Si(Et)Si-Dim-SO₃H (Si(Et)Si = ethyl-bridged organosilica and Dim = dihydroimidazole) by incorporating phosphotungstic acid (HPW) and sulfonic acid-based Brønsted acidic ionic liquids onto the organosilica nanospheres of the designed catalyst for efficient manufacture CAP via esterification. The results indicated that the as-prepared HPW/Si(Et)Si-Dim-SO₃H with 7.5% HPW loading showed the best catalytic performance at 45 °C in 3 h and the resulting CAP exhibited viscosity of 447 mPa s, Mw of 102,882 and DS of 2.69. Most importantly, the HPW/Si(Et)Si-Dim-SO₃H exhibited high catalytic stability over six consecutive cycles and the obtained products were stable too with similar DS, Mw and viscosity. As such, the designed heteropolyacids and sulfonic acid-bifunctionalized heterogeneous catalyst is highly promising for biomass conversion under mild conditions.

中文翻译：

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杂多酸和磺酸双官能化有机硅球体，用于高效生产高粘度醋酸丙酸纤维素

传统上，使用H ₂ SO ₄作为催化剂制备高附加值的乙酸丙酸纤维素（CAP）。用固体酸替代无机酸是绿色和可持续生产CAP的当前研究重点。在这里，我们报道了通过掺入磷钨酸（HPW）和磺酸制备新型固体酸催化剂HPW / Si（Et）Si-Dim-SO ₃ H（Si（Et）Si =乙基桥连有机硅和Dim =二氢咪唑）的布朗斯台德酸性离子液体在设计的催化剂的有机硅纳米球上，可通过酯化有效制备CAP。结果表明，所制备的HPW / Si（Et）Si-Dim-SO ₃HPW负载量为7.5％的H在45°C下3h表现出最佳的催化性能，所得CAP的粘度为447 mPa s，Mw为102,882，DS为2.69。最重要的是，HPW / Si（Et）Si-Dim-SO ₃ H在连续六个循环中显示出高催化稳定性，并且获得的产物也具有相似的DS，Mw和粘度。这样，设计的杂多酸和磺酸双官能化的非均相催化剂对于在温和条件下进行生物质转化非常有前途。