磺酸和酰胺基团对羧酸共聚物性能的影响

Effects of sulfonic and amide groups on the properties of carboxylic acid copolymer

通过在聚羧酸系减水剂分子结构中引入一定量的磺酸基团或酰胺基团,来探讨该羧酸共聚物对水泥基材料的分散效果、表观黏度、凝结时间及早强作用的影响规律。结果表明:磺酸基团或酰胺基团等摩尔取代羧基的量在20%以下时,该羧酸共聚物对浆体的分散作用明显增强,但同时浆体的表观黏度增大;磺酸基团或酰胺基团的引入,均显著缩短了浆体的初凝时间,而延长浆体的初凝、终凝时间差;磺酸基团等摩尔取代羧基量为20%时或酰胺基团等摩尔取代羧基量为15%时,该羧酸共聚物的增强效果最明显。

Effects of the dispersibility,apparent viscosity,setting time and early strength on the cement-based materials with the addition of carboxylic acid copolymer,which containing a certain amount of sulfonic groups or amide groups,were investigated.The results show that the dispersion of the pastes enhanced obviously,but apparent viscosity of the pastes increased when the equimolar substitution amount of the carboxyl groups by the sulfonic groups or amide groups is less than 20％ in the molecular structure of carboxylic acid copolymer.Although the initial setting timeof the pastes shortened significantly,the final and initial setting time difference prolonged by the introducing of the sulfonic groups or the amide groups.When the equimolar substitution amount of the carboxyl groups by the sulfonic groups or amide groups is less than 20％ and 15％ respectively,the most obvious strength enhancement effect of the carboxylic acid copolymers.