- Full starch degradation plastic
The National Plastic Products Quality Supervision and Inspection Center (Beijing) Weng Yunyi et al. tested corn starch powder, corn starch sheet, and corn starch film under controlled composting conditions according to GB/T 19277 (IDT ISO 14855). The decomposition rate is above 70%.
- Starch filled degradable plastic
National Plastic Products Quality Supervision and Inspection Center (Beijing) Weng Yunxuan and others, according to the mold erosion test of GB/T 17295 (MOD ISO 846). For films with different starch content, the potential degradation performance test experiment was carried out. After 28 days, the mass loss of PE film containing 50% potato starch and 50% corn starch has exceeded 30%, and the PE film containing 50% potato starch is basically broken down into small pieces. The average value of the film containing 15%-25% corn starch reached 11.4% after 28 days, but the PE film without starch basically did not grow mold after 28 days. It can be concluded that the addition of starch is definitely beneficial to mold growth. When the filling amount of starch exceeds 50%, the mold erosion effect of the product is definitely good, but when the starch content is 15% to 30%, the increase in starch content will not have a great impact on the degradation quality loss. The reason may be that the microbial attack point of the plastic in the degradation experiment did not increase with the rapid increase of starch content, so that the quality loss did not increase with the rapid increase of starch content.
The above experiments show that although the plastic products made of starch filled with traditional plastics cannot be biodegraded, they have partial degradation properties and are easily eroded by mold. Therefore, when developing products, attention should be paid to the required degradation performance requirements and the requirements for mildew resistance.