New approach to predict the solubility of polymers Application: Cellulose Acetate at various DS, prepared from Alfa "Stipa - enassicima " of Eastern Morocco

Cellulose triacetate (CA, DS~3) was prepared starting from Alfa "Stipa-tenassicima" cellulose, acetic anhydride in acetic acid/toluene and perchloric acid which was used as catalyst. Cellulose acetate samples having various DS were elaborated by saponification reaction in alkali medium. The synthesized product was characterized by FTIR. Substitution degree (DS) of CA was directly determined by a classical titration method, it can also be obtained using the ratio of the areas of the carbonyl ester A(C=O) peak and the hydroxyl A (O—H) peak detected on FTIR spectra. We have studied and discussed in the context of usage in modification reactions, the solubility of the CA samples by varying their DS. This investigation was based on the determination of the Flory-Huggins interaction parameters (Xsp) using the partial Hansen solubility parameters (HSP). HSP of Cellulose and the CA samples were calculated from the Van-Krevlen-Hoftyze (VKH) method and the T. Lindvig approximation. We have focused our work on predicting and controlling family solvents of CA with various DS, in order to facilitate and to optimize the homogenous modification reaction conditions. From results on a range of CA samples, it is conclude that their prediction solubility taking the value of DS into account is possible, and then the surface modification can relatively be easily realized. We have shown that the theoretical study is in good agreement with the experimental tests.