Properties of chitosan films prepared under different drying conditions Original Research Article

Chitosan-based packaging films were prepared by employing wet casting followed by two methods of drying at 80, 90 and 100 °C, viz, oven drying (OD) and infrared drying (ID), and the film properties were compared with those prepared under ambient temperature drying (AD ∼ 27 °C). Thin layer drying protocols were developed to explain convective oven drying and radiative infrared drying and characteristic constants were determined. IR drying was found to be more efficient and uniform than OD. The latter showed a higher colour index, compared to ID and AD films. Tensile strength of ID films (49.58–52.34 MPa) was less than that of AD films (56.78–59.38 MPa), while percent elongation of the former was reduced by only ∼1%. No significant differences were observed in their burst strength values. Water vapour and oxygen transmission rate values were slightly reduced in OD and ID films compared to those of AD films. X-ray diffraction pattern of OD films showed a different crystallinity nature.