Homogenous synthesis of sodium cellulose sulfates with regulable low and high degree of substitutions with SO3/Py in N,N-dimethylacetamide/LiCl

• Published in: European polymer journal 2019-10, Vol.119, p.181-188
• Main Authors: Muhitdinov, Bahtiyor, Heinze, Thomas, Turaev, Abbaskhan, Koschella, Andreas, Normakhamatov, Nodirali
• Format: Article
• Language: English
• Subjects: Cellulose; Chemical reactions; Chemical synthesis; Cotton; Degree of polymerization; Degree of substitution; Depolymerization; Homogenous sulfation; Lithium chloride; Polymerization; Reagents; Sodium; Sodium cellulose sulfate; Substitution reactions; Sulfates; Sulfation; Sulfur trioxide
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2019.07.030

[Display omitted] •SCS samples with DS of 0.23–2.56 were prepared with SO3/Py in DMA/LiCl.•The method is very appropriate to prepare SCS with low and high DS values.•Celluloses with low and high DPw values exhibited similar reactivity for sulfation.•DS value is tunable by the amount of the sulfating reagent or time and temperature.•The reaction produced SCS with low chain degradation and high yield. Synthesis possibility of cellulose sulfates with a low and high degree of substitution (DS) by direct homogenous sulfation of cotton cellulose in N,N-dimethylacetamide/lithium chloride (DMA/LiCl) using SO3/pyridine (Py) complex was studied comprehensively. The sulfation reactions were carried at different temperatures, time durations, amount of the sulfating reagent and celluloses with varying weight average degree of polymerization (DPw). It was found that the method is very appropriate to prepare sodium cellulose sulfate (SCS) with low and high DS from celluloses having wide range DPw. Completely water-soluble SCS samples with regulable DS values from 0.23 to 2.56 were obtained. Suitable conditions were proposed to gain high sulfate content and the samples with DS values of 2.16–2.32, and yield of 69.4–77.8% could be prepared in these conditions. Celluloses with low and high DPw values exhibited similar reactivity for sulfation. Precipitation of the product and drastic depolymerization in the polymer chain have not occurred during the reaction.