Kinetics of Acetylation of Cellulose with Mono-, Di- and Tri-bromoacetic Acids and Thermo-analytical Studies of the Products

Abstract

<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">The bromoacetylation of cellulose with mono-, di- and tri-bromoacetic acids has been studied kinetically in the temperature range 303.16-353.16 K. The energies of activation for the reactions of mono-, di- and tri-bromoacetic acids with cellulose have been found to be 18.94, 21.15 and 26.79 kJ mol^-1 respectively. The treated samples were subjected to DTA and TGA studies. The values of heats of decomposition for these samples increase from 0.36 to 1.04 kJ/g with increase in the concentration of bromine from 0.38 to 3.13 %. From the average percentage char yield of the treated samples and other temperature - dependent parameters, like the entropy and the free energy of activation for the pyrolytic degradation of the modified cellulose samples obtained by TGA, the flame-retarding abilities of mono-, di- and tri-bromoacetylated celluloses have been evaluated.</span>