Structural and mechanical properties of crosslinked drawn gelatin films

Differential scanning calorimetry and high angle X-ray diffraction analyses were performed on gelatin films, air dried at different values of constant elongation, crosslinked with glutaraldehyde and examined at constant relative humidity of 75%. Drawing induces a preferential orientation of the chain segments of gelatin parallel to the stretching direction, and a linear increase of the renaturation level, calculated as the ratio between the denaturation enthalpy of gelatin films and that of tendon collagen. The comparison with the results previously obtained on the mechanical properties of the films, puts into evidence the different contributions of orientation and renaturation on the improvement of the mechanical parameters on drawing. The results offer important information on the role of glutaraldehyde (GTA) crosslinking on the stability of collagenous materials.