Algin is known as biodegradable natural polymer from marine plants. PVA/Algin blend films were prepared by solution blending method for the purpose of useful biodegradable polymer. Characteristics properties of PVA/Algin blend films such as DSC, Elongation, Tensile strength and Morphological change by SEM were determined. Tensile strength and Elongation were rapidly reduced as increasing the blend ratio of Algin. PVA/Algin blend films were found that phase separation was occured as more than 25wt% increasing the blend ratio of Algin. Blend films were observed to be less partially compatibility than 10wt% increasing the blend ratio of Algin by DSC, mechanical properties and SEM. Also, PVA/Algin blend films at the laboratory soil test(Pot Test) were completely degraded in months with four kinds of soils by microorganisms.

The biodegradable characteristics of poly-β-hydroxybutyrate(PHB) film by fungi and soil burial are investigated. As the results of the American Standards for Testing and Materials(ASTM) method, the growth of Aspergillus niger was apparent on the PHB containing plate. This suggests that PHB was utilized as the sole carbon source by Aspergillus niger and ASTM method may have applications as measuring means of biodegradability of polyhydroxyalkanoic acid(PHA). PHB film was studied by monitoring the time-dependant changes in weight loss of PHB film under 30℃ and relative humidity 80 % during pot-test. As the results of pot-test, PHB film was decomposed about 87 % in 30 days by soil microorganisms. PHB film was more slowly degraded than PHB/HV film.