Preparation and properties of retarded cellulose-based polycarboxylic superplasticizers

Abstract

The use of biomaterials instead of petrochemical materials is a direction for the development of green chemical industry. This study adopts sustainable cellulose materials, as an alternative to Polyhydroxyl compound, and modifies it by hydrolysis and grafting of functional monomers, and then prepares green retarding cellulose-based polycarboxylic acid water reducing agent (CBPCS) with monomers such as AA and TPEG-2400 through aqueous solution free-radical polymerization reaction and discusses its performance and role. We also investigated the performance and mechanism of CBPCS. It was found that CBPCS could improve the cement hydrate strength in addition to its good slow-release and water-reducing properties. Adding 0.5% of this water reducing agent to cement, the water reduction rate reached 28.3%, the setting time was prolonged by 69 min, and the compressive and flexural strengths of cementitious sand at 3d, 7d and 28d were improved compared with that of unadulterated water reducing agent. XRD and SEM analyses also showed that CBPCS suppressed the hydration of C₃S, which confirmed its retardation property. In this study, the hydrolyzed cellulose greatly solved the problems of its poor water solubility and application limitations, and providing a low-cost and sustainable raw material for the development of green concrete water reducing agents in the future.