摘要
采用3种不同核壳比(聚丁二烯与聚苯乙烯的质量比为70/30,50/50和30/70)的聚丁二烯接枝聚苯乙烯胶乳改性水泥砂浆,考察了聚灰比(聚合物与水泥质量比)和核壳比对改性水泥砂浆流动度、抗压强度、抗折强度及吸水速率的影响,并通过扫描电子显微镜表征了改性水泥砂浆及其乳胶膜的微观结构。结果表明,在相同核壳比下,随聚灰比的增加,改性水泥砂浆的流动度呈增大趋势,抗压强度和抗折强度均呈现先降低后增加,然后又下降的趋势;在相同聚灰比下,改性水泥砂浆的流动度随核壳比的增加而减小,核壳比为70/30的胶乳改性水泥砂浆的抗压强度最低,吸水速率最高,而核壳比为50/50的胶乳改性水泥砂浆的抗折强度最高,吸水速率最低;胶乳改性水泥砂浆的结构更加致密,孔洞被氢氧化钙晶体和乳胶膜封闭,水泥水化物和乳胶膜完全结合形成互穿网络结构。
Three different core-shell ratios （mass ratio of polybutadiene to polystyrene was 70/30,50/50 and 30/70） of polybutadiene grafted polystyrene （PB-g-PS） latex were used to modify cement mortar.The effects of core-shell ratios and the polymercement ratios on the flowability,compressive and flexural strengths and water absorption rate of PB-gPS latex modified cement mortar were investigated,and the microstructures of modified cement mortar and its emulsion film were characterized by scanning electron microscope.The results showed that at the same core-shell ratio,with increasing polymer-cement ratio,the flowability of modified cement mortars increased,and both the compressive and flexural strengths decreased first and then increased and again decreased.At the same polymer-cement ratio,with increasing core-shell ratio,the flowability of modified mortars decreased and the compressive strength of the cement mortar modified by latex with core-shell ratio 70/30 was the lowest,and water absorption rate was the highest.The cement mortar modified by latex with core-shell ratio 50/50 had the highest flexural strength and the lowest water absorption rate.The structure of latex modified cement mortar was more compact,and the pores in cement mortar were closed by calcium hydroxide crystal and latex film.The cement hydrates was combined with latex film completely to form interpenetrating network structure.
出处
《合成橡胶工业》
CAS
CSCD
北大核心
2013年第6期474-479,共6页
China Synthetic Rubber Industry
基金
吉林省科技发展基金资助项目(20120256)
关键词
聚丁二烯接枝聚苯乙烯胶乳
改性
水泥砂浆
流动度
抗压强度
抗折强度
吸水速率
微观结构
polybutadiene grafted polystyrene latex
modification
cement mortar
flowability
compressive strength
flexural strength
water absorption rate
microstructure
