Positively and negatively charged xylan films

Xylan was 2-hydroxypropylsulfonated and/or 2-hydroxypropylquaternized for film application. All the products were water soluble with molar masses of the derivatives between Mn of 3.8 and 948.9 kg/mol with polydispersity index D from 1.7 to 26.8. At the range from 100 to 250 ?m of thickness the material developed reproducible mechanical properties. When mixed solutions of quaternized and sulfonated samples were used for film preparation, they disrupted although their thickness was 234 ± 18 ?m as determined by SEM. The thermal and thermo-oxidative stability of the mixed derivative increased in comparison to unmodified xylan film as determined by TG and DTA analysis. The measured tensile strength values were the best on quaternized films (64.3 MPa) while the Young's modulus values were higher on hydroxypropylsulfonated xylan film (3350 MPa). The mixed derivative gave values close to average between the two derivatives and according to SEM observation also the smoothest surface on the fracture.