Peroxide-periodate co-modification of carboxymethylcellulose to prepare polysaccharide-based tanning agent with high solid content

Abstract

Dialdehyde carboxymethylcellulose (DCMC) solution generally has quite low solid content, which inevitably limits its industrial application. In this work, carboxymethylcellulose sodium (Na-CMC) was pre-degraded using H2O2 followed by periodate oxidation for preparing DCMC with high solid content as practical tanning agent. Pre-degradation conditions optimization showed that H2O2 dosage most impacted the tanning effect of DCMC, and the Mw and viscosity of Na-CMC underwent remarkable reduction. FT-IR and 1H NMR illustrated that aldehyde group was successfully introduced into DCMC after periodate oxidation. Under the optimized conditions, the solid content of DCMC could be improved to around 30%. This DCMC could endow tanned leather with high shrinkage temperature and satisfactory fiber dispersion. Besides, DCMC tanned leather had comparable physical and organoleptic properties to those of leathers tanned by chrome tanning agent and commercial polyaldehyde tanning agent TWT. This suggests the prospect of DCMC with high solid content as useful tanning agent.