Polyvinyl alcohol (PVA) can be degraded by bacteria from various soil sources and its structure is somewhat similar to that of starch.It is an available way of blending polyvinyl alcohol (PVA) with starch to develop biodegradable materials.The high speed stirring is a suitable method while blending of PVA and starch to prepare the biodegradable materials with better properties required.The effect of high speed stirring on the properties of starch/PVA blend solution was studied by means of spectrophotometry

microscopy

molecule weight analysis and rheometry etc.The experimental results indicate that changes are found on the chains of PVA and starch after conducting high speed stirring

which causes a modification in the properties of starch/PVA blend solution.The degrading effect of high speed stirring on starch and PVA agrees to the common mechano-chemical degrading feature.The high speed stirring breaks the side chain of starch and eventually increases the amylose content in starch solution.The high speed stirring also lowers the Mw and widens the Mw distribution of PVA. The dispersion of starch in PVA is improved by high speed stirring and the interaction between starch and PVA is strengthened

resulting in an improvement of the mechanical properties

transparency and water-repellence of starch/PVA blend film.