聚合物改性粉煤灰的合成及其对水泥基复合材料性能的影响

发布时间：2018-03-03 22:25

本文选题：粉煤灰　切入点：水泥基复合材料　出处：《合肥工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：水泥基复合材料具有抗压强度高、耐久性好、价格低廉等特点,因而广泛应用于公路、桥梁、铁路、隧道、城建等领域,与其优点并存的还有天然存在的脆性问题。聚合物常被用来改善这种脆性问题,但物理掺加依靠增大分子间作用力的方式对相界面过渡区组成结构改善作用有限,且聚合物与粗、细骨料及水化胶凝材料之间物相相容性不好,这在很大程度上阻碍了水泥基复合材料抗折性能的提升。粉煤灰是一种理想的混凝土矿物掺合料,本研究通过化学手段,将高亲水性聚合物直接接枝在粉煤灰表面,得到聚合物改性粉煤灰,来提升水泥基复合材料的抗折强度。具体工作方法及内容如下：(1)通过酸碱溶液处理法,对粉煤灰进行表面羟基化处理,然后用有机硅烷偶联剂KH-570对羟基化粉煤灰进行偶联改性得到KH-570偶联改性粉煤灰,与聚乙二醇单甲醚丙烯酸脂(MPA,自制)聚合改性得到聚乙二醇单甲醚丙烯酸酯改性粉煤灰,来提升水泥基复合材料的抗折强度。(2)通过Piranha溶液(20%双氧水、98%浓硫酸)处理法,对粉煤灰进行表面羟基化处理,然后用有机硅烷偶联剂KH-570对羟基化粉煤灰进行偶联改性得到KH-570偶联改性粉煤灰,与丙烯酰胺聚合改性得到聚丙烯酰胺改性粉煤灰,来提升水泥基复合材料的抗折强度。(3)通过酸碱溶液处理法,对粉煤灰进行表面羟基化处理,然后用有机硅烷偶联剂KH-566对羟基化粉煤灰进行偶联改性得到KH-566偶联改性粉煤灰,与丙烯酸聚合改性得到聚丙烯酸改性粉煤灰,来提升水泥基复合材料的抗折强度。
[Abstract]:Cement based composites are widely used in highway, bridge, railway, tunnel, urban construction and other fields because of their high compressive strength, good durability and low price. Polymer is often used to improve the brittleness problem, but physical admixture by increasing the intermolecular force has limited effect on the structure improvement of the transition zone of the phase interface. The compatibility of polymer with coarse, fine aggregate and hydrated cementitious materials is poor, which greatly hinders the improvement of flexural properties of cement matrix composites. Fly ash is an ideal mineral admixture for concrete. In this study, high hydrophilic polymer was grafted directly on the surface of fly ash by chemical means to obtain polymer modified fly ash. To enhance the flexural strength of cement based composites. The specific working methods and contents are as follows: (1) the surface hydroxylation of fly ash is treated by acid and alkali solution treatment. Then the hydroxylated fly ash was modified by organic silane coupling agent KH-570 to obtain KH-570 coupling modified fly ash and poly (ethylene glycol monomethyl ether acrylate) modified fly ash was polymerized to obtain polyethylene glycol monomethyl ether acrylate modified fly ash. To improve the flexural strength of cement matrix composites. The surface hydroxylation of fly ash was treated by Piranha solution of 20% hydrogen peroxide and 98% concentrated sulfuric acid. Then the hydroxylated fly ash was modified by KH-570, and then the KH-570 modified fly ash was modified by KH-570. The modified fly ash was polymerized with acrylamide to obtain polyacrylamide modified fly ash. To improve the flexural strength of cement matrix composites, the surface hydroxylation of fly ash was treated by acid-base solution treatment, and then the hydroxylated fly ash was modified by organic silane coupling agent KH-566 to obtain KH-566 coupling modified fly ash. Polyacrylic acid modified fly ash was prepared by polymerization with acrylic acid to improve the flexural strength of cement based composites.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ536.4;TB332

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