Chemistry

CLC number: TS206.4

Controllable Synthesis of Hydroxypropyl Starch and Its Application in Hollow Capsules

羟丙基淀粉的可控合成及其在空心胶囊中的应用

School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, Hubei, China

Received: 6 January 2025

Abstract

Hydroxypropyl starch (HPS) is widely used in various applications due to its unique functional properties, but optimizing its molecular characteristics for specific applications remains a challenge. This study aimed to optimize the process parameters for producing HPS capsules with desirable molecular and performance properties. The mass fraction of the etherification reagent, reaction pH, reaction temperature, and reaction duration were controlled to create HPS with varying degrees of substitution (DS). Acid solution degradation was used to prepare HPS of varying molecular weights (MW), and cold-gelation was employed to prepare hollow HPS capsules. A rigorous evaluation of performance indicators was conducted, and response surface methodology (RSM) was used to examine the effects of solid content, MW, and dipping temperature on capsule performance. Experimental results showed that these factors influenced performance in the following order: solid content > molecular weight > dipping temperature. Optimal parameters were identified as a solid content of 18%, an MW of 77 kDa, and a dipping temperature of 57 ℃, yielding capsules with a wall thickness of 0.086 mm, a disintegration time of 328 s, and moisture absorption of 8.594%. These findings provide valuable insights for the tailored design of HPS capsules, which could enhance their utility in industrial applications.

摘要

羟丙基淀粉(HPS)因其独特的功能特性被广泛应用于各个领域，但针对特定应用优化其分子特性仍具挑战性。本研究旨在优化制备具有理想分子特性和性能指标的HPS胶囊工艺参数。通过控制醚化剂质量分数、反应pH、反应温度和反应时间，制备了不同取代度(DS)的HPS；采用酸溶液降解法获得不同分子量(MW)的HPS，并运用冷凝胶法制备HPS空心胶囊。通过对性能指标的严格评估，采用响应面法(RSM)分析了固含量、分子量和蘸胶温度对胶囊性能的影响。实验结果表明，各因素对性能的影响程度依次为：固含量$>$分子量$>$蘸胶温度。最终确定最佳参数组合为固含量18%、分子量77 kDa、蘸胶温度57 ℃，此时制得的胶囊壁厚0.086 mm、崩解时间328 s、吸湿率8.594%。该研究为HPS胶囊的定制化设计提供了重要依据，有助于拓展其工业应用价值。