中国塑料 ›› 2024, Vol. 38 ›› Issue (8): 8-12.DOI: 10.19491/j.issn.1001-9278.2024.08.002

• 材料与性能 • 上一篇    下一篇

纳米蒙脱土复合改性酯化淀粉及其性能研究

张馨鹏, 徐军, 杜夕彦, 郭宝华()   

  1. 清华大学化学工程系,北京 100084
  • 收稿日期:2023-12-11 出版日期:2024-08-26 发布日期:2024-08-19
  • 通讯作者: 郭宝华(1963—),男,教授,从事生物可降解聚酯合成与功能化,聚合物合金材料与纳米复合材料,医用组织工程材料等研究,bhguo@tsinghua.edu.cn
    E-mail:bhguo@tsinghua.edu.cn
  • 基金资助:
    国家重点研发计划(2021YFD1700700)

Study on modification and properties of starch esterified composite nano montmorillonite

ZHANG Xinpeng, XU Jun, DU Xiyan, GUO Baohua()   

  1. Department of Chemical Engineering,Tsinghua University,Beijing 100084,China
  • Received:2023-12-11 Online:2024-08-26 Published:2024-08-19
  • Contact: GUO Baohua E-mail:bhguo@tsinghua.edu.cn

摘要:

淀粉具有独特的束簇凝聚态结构,分子主链上存在大量的羟基,强烈的分子间氢键限制了分子链的自由运动,使得天然淀粉很难直接进行热塑性加工,为了改善淀粉的加工性,本文采用不同比例乙酰乙酸叔丁酯(t⁃BAA)与淀粉在二甲基亚砜(DMSO)为溶剂的条件下进行酯交换反应,引入乙酰乙酸基弱极性基团改性淀粉的羟基,以减弱淀粉分子之间的强氢键作用。进一步通过纳米改性蒙脱土(MMT)的加入,使得酯化淀粉的热稳定性得到进一步提升,结果表明:得到了取代度在0~1.57的酯化淀粉,并且成功将蒙脱土的层间距从1.53 nm扩大到2.02 nm,甚至呈现出部分剥离状态,且在不添加增塑剂的情况下实现热塑性加工并降低了其亲水性。

关键词: 淀粉, 蒙脱土, 纳米复合材料, 热塑性加工, 酯化改性

Abstract:

The presence of a large number of hydroxyl groups on the molecular backbone of starch endows the strong intermolecular hydrogen bonding interaction that limiting the free movement of the molecular chain,thus making it difficult for starch to achieve thermoplastic processing. That limits large⁃scale application of starch in plastic products. In this work, the esterification reaction of tert⁃butyl acetoacetate (t⁃BAA) with starch at different ratios was carried out in dimethyl sulfoxide (DMSO) solvent environment, so that the weak polar groups of acetoacetyl were introduced to modify the hydroxyl groups of starch to break the strong hydrogen bonds between starch molecules. And with the addition of modified montmorillonite (MMT), the thermal stability of esterified starch was further promoted. The results indicated that the esterified starch with a degree of substitution of 0~1.57 was obtained, and the interlayer spacing of montmorillonite was successfully expanded from 1.53 nm to 2.02 nm, even showing a partial peeling state. Moreover, the thermoplastic processing was realized without adding plasticizer and its hydrophilicity was reduced, realizing the starch to achieve the thermoplastic processing without adding any other plasticizer, and then getting hydrophobic surface.

Key words: starch, montmorillonite, nanocomposite, thermoplastic processing, esterification reaction

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