氨基硅烷偶联剂对PB-g-PS胶乳改性水泥砂浆性能的影响

Influence of amino silane coupling agent on properties of cement martars modified with PB-g-PS latex

通过半连续乳液接枝聚合反应合成了聚丁二烯接枝聚苯乙烯(PB/PS)质量比为50/50[聚丁二烯接枝聚苯乙烯(St)]共聚胶乳。在固定水灰质量比为0.45时,将偶联剂和胶乳掺入到水泥砂浆中,考察了偶联剂加入量和聚合物掺量对改性水泥砂浆的吸水情况、力学强度以及工作性能的影响。结果表明,偶联剂的加入对砂浆的性能产生明显影响,随着偶联剂的加入,改性砂浆的流动度与吸水量与普通砂浆相比均有很大改善;聚灰比为0时,偶联剂的掺入降低了水泥砂浆的抗折强度与抗压强度,随着偶联剂含量的增加,改性砂浆的抗折强度与抗压强度呈增加趋势;随着聚灰比的增加,改性砂浆的抗折强度逐渐下降,聚灰比大于10%后,复合改性砂浆的抗压强度均大于胶乳改性砂浆。

The PB-g-PS copolymer latex with a weight ratio of 50/50 was synthesized by semi-continuous emulsion grafting polymerization.In a fixed ratio of 0.45 water-cement,the effects of the addition of coupling agent and polymer on the water absorption,mechanical strength and working performance of the modified cement mortar were investigated.The study showed that the addition of coupling agent has a significant impact on the performance of mortar.With the addition of coupling agent,the fluidity and water absorption of modified mortar are greatly improved compared with ordinary mortar.The results showed that when the polymer-cement ratio is 0,the incorporation of the coupling agent reduces the flexural strength and the compressive strength of cement mortar.With the increase of content of the coupling agent,the flexural strength and the compressive strength of modified mortar tend to increase.With the increase of cement-cement ratio,the flexural strength of modified mortar is gradually reduced.The compressive strength of composite modified mortar is larger than that of the latex modified mortar when the cement-cement ratio is more than 10%.