高分散性丁苯胶乳的制备及其对水泥的改性

添加传统丁苯胶乳进行改性，大大提高了水泥的力学性能，但是改性后的水泥材料流动性能差，抗压性能损失较多。为了提高添加丁苯胶乳后水泥的流动性及降低抗压性能损失，本文对丁苯胶乳进行改性，以苯乙烯与聚丁二烯作为核层、带有苯环的对苯乙烯磺酸钠作为壳层，制备出核壳型丁苯（SSBR）胶乳。把新合成的SSBR胶乳加入水泥后，对水泥力学性能进行表征，由于SSBR胶乳中与磺酸根相连的是苯环刚性链，空间位阻效应明显，添加8% SSBR胶乳水泥浆的流变指数增大为0.898，分子链强度大，水泥石的7天抗压强度损失量为2.31%，损失不明显，同时抗折强度提高17%。对SSBR胶乳改性水泥石材料力学性能的作用机理进行探究，结果表明，SSBR胶乳填充作用明显，吸附作用较强，增大水泥浆流动性能，且胶乳粒子可以与Ca²⁺络合，形成三维网状空间立体结构，从而达到增强水泥石力学性能强度，提高水泥石韧性的目的。

Preparation of highly dispersible SSBR latex and modification of cement

Adding traditional styrene butadiene latex can greatly improve mechanical properties of the cement. However, the modified cement material has poor fluidity and loss of compressive performance. In order to improve the fluidity of the cement after adding styrene butadiene latex and reduce the loss of compressive performance, the styrene-butadiene latex was modified, styrene and polybutadiene were used as the core layer, and sodium p-styrene sulfonate with benzene ring as the shell layer to prepare the SSBR latex. After adding newly synthesized SSBR latex to the cement , the mechanical properties of the cement were characterized. Since the benzene ring rigid chain is connected to the sulfonate in the SSBR latex, the steric hindrance effect is obvious, and the fluidity index of the cement slurry with 8% SSBR latex increased to 0.898. The molecular chain strength was large, the 7-day compressive strength loss of cement stone was 2.31%, at the same time, the flexural strength was increased by 17%. The mechanism of the mechanical properties of SSBR latex modified cement-based materials was explored. The results showed that SSBR latex has obvious filling effect, strong adsorption effect, and increases the fluidity of cement slurry, and it can complex with Ca²⁺ to form a three-dimensional network structure, increase the strength of the mechanical properties of the cement stone, improve the toughness, so as to achieve the purpose of enhancing the mechanical properties of the cement stone.