中国塑料 ›› 2021, Vol. 35 ›› Issue (7): 43-48.DOI: 10.19491/j.issn.1001-9278.2021.07.007

• 材料与性能 • 上一篇    下一篇

吐温⁃80对PB⁃g⁃PSG乳液改性水泥砂浆性能的影响及作用机理

王国安, 赵文杰()   

  1. 长春工业大学化学工程学院,长春 130012
  • 收稿日期:2020-10-22 出版日期:2021-07-26 发布日期:2021-07-21
  • 基金资助:
    吉林省教育厅科学技术研究项目(JJKH2021731KJ)

Influence of Twain⁃80 on Property of PB⁃g⁃PSG Emulsion⁃modified Cement Mortar and Its Mechanisms

WANG Guoan, ZHAO Wenjie()   

  1. Institute of Chemical Engineering,Changchun University of Technology,Changchun 130012,China
  • Received:2020-10-22 Online:2021-07-26 Published:2021-07-21
  • Contact: ZHAO Wenjie E-mail:zhaowenjie@ccut.edu.cn

摘要:

以聚丁二烯(PB)接枝苯乙烯(St)和甲基丙烯酸环氧丙酯(GMA)为主要原料制备了水泥砂浆改性剂PB?g?PSG乳液,将吐温?80作为稳定剂加入至PB?g?PSG乳液,再将乳液与水泥、标准砂混合制备了改性水泥砂浆;通过扫描电子显微镜(SEM)、水泥胶砂流动度测定仪和激光粒度分析仪等仪器观察了改性水泥砂浆的微观形貌,并研究了吐温?80及PB?g?PSG乳液含量对改性水泥砂浆流动性、力学性能、保水率以及吸水性的影响,同时探讨了吐温?80对PB?g?PSG乳液的作用机理。结果表明,改性水泥砂浆的保水效果优异,保水率的最大值为99.3 %;改性水泥砂浆的吸水质量随吐温?80含量的增加先降后增;改性水泥砂浆的流动性增强,其抗压强度随PB?g?PSG乳液含量的增加而逐渐降低,且小于未改性的水泥砂浆,其抗折强度随PB?g?PSG乳液含量的增加先增后降,且基本高于未改性的水泥砂浆,当PB?g?PSG乳液含量为10 %(质量分数,下同)时,抗折强度最高,为9.52 MPa;PB?g?PSG乳液对水泥水化物具有黏合及桥接作用,二者能够形成互穿网络结构;吐温?80分子结构中的亲水基团能够将水吸附在PB?g?PSG乳液粒子的表面并形成一层很厚的水化层,使乳胶粒子之间被隔离而避免了凝聚的发生。

关键词: 吐温?80, 聚丁二烯, 苯乙烯, 接枝, 甲基丙烯酸环氧丙酯, 改性, 水泥砂浆

Abstract:

A cement mortar modifier, PB?g?PSG emulsion, was prepared with polybutadiene grafted styrene and glycidyl methacrylate as main raw materials and Tween?80 as a stabilizer, and cement mortar was modified by mixing cement and standard sand with PB?g?PSG emulsion and Tween?80. The micromorphology of the modified cement mortar was observed, and the effect of contents of Tween?80 and PB?g?PSG emulsion on the fluidity, mechanical properties, water retention rate and water absorption of the modified cement mortar were studied using scanning electron microscope, cement mortar fluidity tester and laser particle size analyzer. Meanwhile, the effect mechanism of Tween?80 for PB?g?PSG emulsion was analyzed. The results indicated that the modified cement mortar exhibited an excellent water retention with a maximum water retention rate of 99.3 %. The water absorption quality of modified cement mortar decreases at first and then increases with an increase in the Tween?80 content. The compressive strength of the modified cement mortar decreased gradually with an increase in the content of PB?g?PSG emulsion and was less than that of the unmodified cement mortar. The flexural strength of the modified cement mortar increased at first and then tended to decrease, which was essentially higher than that of the unmodified cement mortar. The modified cement mortar achieved the highest flexural strength of 9.52 MPa at a content of PB?g?PSG emulsion of 10 wt%. The PB?g?PSG emulsion can generate an adhesion and bridging effect on cement hydrate, and an interpenetrating network structure can be formed between them. The hydrophilic group in the Tween?80 molecules can adsorb water on the surface of PB?g?PSG emulsion particles and form a thick layer of hydration. In this case, the latex particles can be isolated from each other, avoiding the occurrence of condensation.

Key words: Twain?80, polybutadiene, styrene, grafting, epoxy propyl methacrylate, modification, cement mortar

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