What are the main biodegradable plastic bags made of?
Biodegradable plastics(1) natural polymer modification method. Starch, cellulose, chitin, lignin, seaweed and other natural polymers as raw materials, through chemical modification and copolymerization method, these molecules were modified to synthesize biodegradable plastics.(2) chemical synthesis. The simulation of natural polymer structure, starting from simple water molecules, in the polymer chain of plastic with active groups such as amide, peptidyl, ester compounds containing these radicals, similar to natural protein structure, fragments of grease, easily biodegradable.(3) microbial fermentation, many microorganisms can take some organic substances as carbon source, through metabolism, secrete, produce polyester polymer, these molecules are easy to degrade, and can be further recycled.
At present, developed a new biodegradable plastic, its composition is polyvinyl alcohol starch plus photosensitizer synthesis, polyvinyl alcohol was easy to degrade than polyethylene, adding photosensitizer can absorb sunlight to accelerate the degradation by plastic, starch can promote the degradation of plastic in soil speed. As a result, this new biodegradable plastic is easier to degrade than the former, and it decomposes into a substance of simple molecular structure, such as carbon and water, which is more environmentally friendly.
The degradable plastic bags made of polyethylene and starch, but this can only be degradable plastic plastic degradation into smaller chunks of plastic, plastic compositions did not completely disappear, so its degradation is limited.
