Functionalized carboxymethyl chitosan synthesis and its regulation mechanism on the temperature rise of cement slurry

Chemical admixtures offer a simple and effective approach to controlling cement hydration. However, achieving both cement paste dispersion and regulation of hydration temperature rise remains a challenge for existing admixtures. A crosslinked polymer (FCMC) was synthesized via copolymerization of acrylic acid and unsaturated carboxymethyl chitosan, and its structure was verified to match the intended design. The effects of FCMC on cement paste performance and its mechanism for regulating temperature rise were investigated. Results show that FCMC (0.2% dosage) significantly enhances cement paste fluidity (increased by 200%) and reduces the peak temperature (decreased by 42.15%) without notably affecting compressive strength. The adsorption and chelation effects of FCMC markedly inhibit crystal nucleation and growth, delay phase boundary reactions, and result in a denser structure with fewer defects. These findings contribute to the innovation and development of admixture structures and provide a theoretical basis for controlling temperature-induced cracking in concrete.