Preparation and characterization of biodegradable paper coated with blends based on PHA.

摘要

Polyhydroxyalkanoates (PHAs) are intracellular biopolymers entirely biodegradable, synthesized by a wide range of bacteria as a carbon and energy reserve. They are good candidates for polymeric blends,which are suitable to prepare mulching films, pots and disposable shopping bags, among others. As a part of an ongoing project on the use of waste vegetable oils, several kinds of paper sheets coated with different blends based on PHA and other biodegradable polyesters were prepared and tested. In thermo-mechanical characterization tests, coated samples, wet and dry, showed an improvement in tensile stress and tearing compared to non-coated samples. Scanning electron microscopy analysis showed a partial holes occlusion that improved waterproof features. In greenhouse biodegradation tests, papers coated with a blend based on PHA buried in soil irrigated showed holes at the surface which proceeded to the inner part of the film. Paper coated pots were shown to be suitable for growing sour orange seedlings up to 4 months, whereas control paper bags showed bottom cracks within one month. When coated paper pots were transplanted in the soil, a full biodegradation was observed within 2 months.