Study of the preparation and degradable characteristics of CaCO_3-PE film

摘要

The CaCO_3-polyethylene (PE) film was prepared by filling method, and the filling amount of calcium carbonate in film was 20%(w/w). The effects of natural weathering, ultraviolet light irradiation on the tensile strength, breaking elongation and molecular weight of the CaCO_3-PE film was investigated comparing with the photosensitizer-PE film. After being located in the open air for 30 d, the average tensile strength, average breaking elongation and the mean molecular weight of CaCO_3-PE film decreased 80.6%, 99.3% and 25.3%, respectively, as for the photosensitizer-PE film, the corresponding items decreased 18.8%, 45.0% and 11.7%, respectively. After ultraviolet light irradiation for 120 h, the average tensile strength of CaCO_3-PE film decreased 29.9%, the average tensile strength of the photosensitizer-PE film, however, increased 20.5%. The average breaking elongation of CaCO_3-PE film and photosensitizer-PE film decreased 97.3% and 84.1% respectively, the mean molecular weight of both films decreased 66.7% and 26.6% respectively. After covered by soil for 200 d, the weight loss of the CaCO_3-PE film and photosensitizer-PE was 2.15% and 0.22%, respectively. The results showed that the degradability of CaCO_3-PE film is superior to the photosensitizer-PE film.