Synthesis of sodium taurinate-modified maleic anhydride copolymer and its application as superplasticizer in cement pastes

Abstract

The petrochemical industry produces many intermediary products containing mixed olefinic components which have not been utilized efficiently. In the present work, maleic anhydride was copolymerized with C5 mixed olefins contained in light naphtha using the self-stabilized precipitation polymerization, yielding light naphatha-based maleic anhydride copolymer (MCP). Subsequently, MCP was amidated with sodium taurinate to append sulfonate groups and neutralized to obtain neutralized sodium taurinate-modified MCP (NTMCP) as a superplasticizer for cement pastes. The effects of amidation degree on the dispersing capacity and retarding effect of NTMCP were investigated systematically. NTMCP can enhance the fluidity and reduce the fluidity loss over time of cement pastes dramatically, with the 2 h fluidity reaching up to 250 mm. Moreover, NTMCP displayed a highly adjustable retarding property, and the initial setting time can be tuned from 180 to 1500 min by decreasing the amidation degree. The introduction of sulfonate ions improved the adsorption capacity and Ca²⁺ resistance of NTMCP remarkably, accounting for the improvement in fluidity and compressive strength. The performance and cost of the developed superplasticizer can be optimized further by forming a complex system with NTMCP and commercially available naphthalene sulfonate formaldehyde condensate (NSF) superplasticizers. Overall, our research has developed a facile and efficient strategy for converting mixed olefins into NTMCP with great application prospect as superplasticizer in cement pastes.