Heterogeneous Synthesis and Characterization of Cellulose Acetate Propionate

Cellulose acetate propionate(CAP) was synthesized through heterogeneous esterification of cellulose.Cellulose acetate propionate with various degree of substitution was synthesized in acetic acid/acetic anhydride/propionic anhydride system with sulfuric acid as catalyst.The product was identified by means of FT IR.The effect of ratio of acetic anhydride/propionic anhydride,molecular weight of cellulose,amount of catalyst and esterification time on viscosity,thermal properties and dissolubility of CAP was studied.The suitable conditions were obtained as follows: molecular weight of wood cellulose was DP=1926,amount of catalyst was 10%(wt) to cellulose,reaction temperature was 40℃,and reaction time was 3 h.