Analysis of the performance of degradable plastic (middle)

Copolymerized polyethylene, polypropylene, polystyrene, or polyvinyl chloride having a carbon monoxide content of about 1% has been used for the production of a plastic film, and the resulting plastic film is not degraded in stock, but is degraded under direct sunlight. Another example is Canada's ECOPLASTICS, which uses an olefin monomer and vinyl ketone to produce a masterbatch called ECOLYTE, and blends with similar resins to produce a variety of photodegradable products. Its products include coffee cups, beef patties and meat. Dish, nursery with brown mulch and so on.
Blends of photodegradable plastics and other polymers Photodegradable plastics blended with other polymers is a simple and adaptable method. For example, 1.2-polybutadiene, polyisobutylene, polyisoprene, and the like can be blended with polyethylene. The above-mentioned ECOLYTE is blended with the same resin.
Each photo-degradable plastic light made by adding a photosensitizer is a kind of substance that easily absorbs light energy, and generates free radicals in the non-photodegradable plastic, thereby accelerating the photodegradation process of the plastic. This method has the advantages of simple process and low cost. Therefore, photodegradable plastics produced by this method account for most of the photodegradable plastics. Photosensitizers include inorganic and organic compounds.
Inorganic photosensitizers The inorganic photosensitizers for operation mainly include hydroxy salts, oxides, complexes, and complexes of transition metal ions such as copper, manganese, iron, cobalt, nickel, chromium, or ruthenium. Such as iron thiocarbamate, iron acetylacetonate, ferrocene and its derivatives, cesium octylate, barium stearate, and other stearates, as well as metal ions such as iron, zinc, manganese, nickel, ruthenium, and cobalt. Compound and so on. In addition, commonly used inorganic fillers such as calcium carbonate can reduce the interaction between plastic molecules and also promote photodegradation.
For example, in China, the use of heavy calcium carbonate in polyethylene, ultraviolet light absorbers and a small amount of surfactant can produce 1-4 days degradation of the plastic film, its decomposition can promote crop growth. The above-mentioned transition metal ion compounds such as iron, cobalt, nickel, and ruthenium are the most widely used and most important photosensitizers, and are particularly suitable for use in polyolefin photodegradable products. In addition, iron disulfide and dibutyl disulfide carbamate have been commercially produced in foreign countries and iron dibutyl dithiocarbamate has been introduced as a light enhancer and nickel dibutyl dithiocarbamate or Cobalt as a stabilizer for photodegradation of polyolefins. CABOT Plastics' PE 9323 masterbatch is an organometallic mixture that can continue to degrade even in the absence of light. POLYGRADE is a mixture of starch masterbatch and ferric ion masterbatch.
Organic photosensitizers as organic photosensitizers mainly include aromatic ketones such as benzophenone, acetophenone, hexachloroacetone, anthraquinone, naphthalene and triphenylamine, and various organic peroxides. Such photosensitizers have different selectivities to plastics, such as benzophenone and N-bromosuccinamide, which are effective for polyethylene and polypropylene, and have poor effects on polystyrene.
The modified photo-degradable plastics are suitably modified for non-photodegradable plastics and can also provide light-descent capability. If the polyethylene film is irradiated with an electron accelerator in the presence of oxygen, the solid energy introduces an oxygen group in the polyethylene film and has a photodegradability, and if a small amount of paraffin or oleic acid is added to the polyethylene, the polyethylene can be made. Degraded faster under UV irradiation. In another example, a small amount of low molecular weight polyethylene and a film degraded within 2 to 2.5 months are added to the recycled polyethylene.
Bio-biodegradable plastics Bio-photo-degradation is both a micro-organism and a photo-degradable plastic. So far there are few, such as starch / polyolefin / photosensitizer, starch / low density polyethylene / photosensitizer, starch master batch / Yan ion photosensitizer and other components prepared by a variety of products. To sum up, the following research and development profile shown in Table 2 can be obtained:
Table 2. Overview of research and development of degradable plastics

Product name and development unit Biodegradable plastics Biodegradable microorganisms, synthetic polymers
3HB-3HV copolymer
3HB-4HB Copolymer BIOPOL (ICI) (Tokyo Institute of Technology) (Japan Forest Research Institute) Natural Polymer Polysaccharides (U.S. Army NATICH Institute) Chemical Synthesis, Polymer

(To be continued)