It is well known that starch can be metabolized by a variety of microorganisms to form fermentation products such as ethanol and methane.

PVA is also prone to biodegradation, but this process is extremely slow. Moreover, the number of microorganisms that degrade PVA is very limited relative to the number of microorganisms that degrade aliphatic polyester. Many researchers have studied the biodegradability of starch and PVA blends. It was found that the biodegradation rate of starch and PVA composite films is related to the content of PVA in the composite material.

The blend degrades significantly faster than pure PVA. It was found that the starch glycerol sample could degrade and lose up to 70% of its weight within 22 days. However, after adding PVA, the weight loss rate was only 59%, which also showed that the addition of PVA slowed down the degradation process of the sample. The degradation process of thermoplastic starch and PVA under anoxic conditions was studied, mainly simulating the exposure environment of household waste. It was found that PVA existed throughout the degradation process, while starch was almost completely degraded.

However, the content of PVA significantly affects the degradation rate of starch. The degradation process of modified starch and PVA blends was evaluated, and a bioactivity kinetic model was also established. The results showed that the degradation rate of PVA increased with the addition of starch. Based on the kinetic model, during the first-order reaction, the growth rate of microorganisms increases with the increase of starch content. characterized the biodegradability of PVA, starch, and cellulose films in the presence of cross-linking agents and without cross-linking agents. The results show that the composite membrane generally biodegrades within 30 days, while obtaining 50% to 80% of the minerals. Both pure PVA and cross-linked blends degrade relatively slowly.