接枝磺化木质素高效减水剂的配伍性能研究

以酸析木质素为原料,通过接枝、磺化和缩合制得接枝磺化酸析木质素GSAL,研究了它与木质素磺酸盐和消泡剂的配伍性能。结果表明:GSAL分别与木质素磺酸盐及其改性产品复配,可得到减水剂GSAL1和GSAL2。当水灰比为0.29、掺量w(GSAL1)=0.6%时,水泥净浆流动度达243mm;掺量w(GSAL2)=0.8%时,水泥净浆初凝时间延长110min,终凝时间延长约7h。掺量w(GSAL1)=0.8%时,水泥净浆减水率为21.4%,砂浆3d和7d的抗压强度比分别为163%和143%,其对水泥的减水增强作用超过了萘系高效减水剂FDN。GSAL与消泡剂的复配产品起泡性降低,水泥净浆流动度、新拌砂浆密度和砂浆抗压强度比均增大,GSAL与磷酸三丁酯配伍后的综合性能最佳。

Research on Compatibility of Graft-sulfonated Lignin as Superplasticizers

A superplasticizer GSAL was synthesized from acid precipitated lignin through graft,sulfonation and polycondensation.The compatibility of GSAL with lignosulfonate and defoaming agents was studied.Two superplasticizers (GSAL1 and GSAL2) were prepared by combining GSAL with lignosulfonate and its modified product respectively.When w(GSAL1)=0.6%,the fluidity of the cement paste is 243 mm under the water to cement ratio of 0.29.When w(GSAL2)=0.8%,the initial setting time and final setting time of cement paste are retarded for 110 min and 7 h respectively.When w(GSAL1)=0.8%,the water reducing ratio of the cement paste is 21.4%,and the 3-day and 7-day compressive strength ratios of mortar are 163% and 143% respectively,indicating that its water reducing ability and strength improving effect are better than those of naphthalene sulfonate formaldehyde condensate(FDN).When defoaming reagents are added to GSAL,its foamability declines; the fluidity of the cement paste,the density of fresh mortar and compressive strength ratio of mortar all become larger.The over-all application performances of the combined product by mixing GSAL and tributyl phosphate are the best.