Analysis on the properties of degradable plastics

Analysis of the performance of degradable plastics (middle)

copolymerized polyethylene, polypropylene, polystyrene or polyvinyl chloride with carbon monoxide containing about 1% of the replacement hydraulic oil have been used in the production of mulching film. The obtained mulching film will not degrade when in stock, but will degrade under direct sunlight. Another example is the masterbatch called ecolyte prepared by the copolymerization of olefin monomers and vinyl ketones by the Canadian ecoplastics company, and then blended with similar resins to produce various photolytic products, including coffee cups, beef cakes, meat dishes, brown mulch for nurseries, etc

blends of photodegradable plastics and other polymers

blending of photodegradable plastics and other polymers is a simple and widely applicable method. For example, 1.2-polybutadiene, polyisobutylene, polyisoprene, etc. can be blended with polyethylene, and the above ecolyte can be blended with similar resins

photodegradable plastics made by adding photosensitizers

each agent of light is a kind of substance that is easy to absorb light energy, which will produce free radicals in non photodegradable plastics, thus accelerating the photodegradation process of the plastics. This method has the advantages of simple process and low signal book of each sensor in the impact tester. Therefore, the photodegradable plastics produced by this method account for the majority of photodegradable plastics. Photosensitizers are divided into inorganic and organic compounds

inorganic photosensitizers

inorganic photosensitizers in operation mainly include hydroxyl salts, oxides, chelates and complexes of transition metal ions such as copper, manganese, iron, cobalt, nickel, chromium or cerium. Such as iron thiocarbamate, iron acetylacetonate, ferrocene and its derivatives, cerium octanoate, cerium stearate and other stearates, as well as the final complexes of metal ions such as iron, zinc, manganese, nickel, cesium and cobalt. In addition, common inorganic fillers such as calcium carbonate can reduce the force between plastic molecules and promote photodegradation

if heavy calcium carbonate, UV absorber and a small amount of surfactant are added to polyethylene in China, the film can be degraded in 1-4 days, and its decomposition products can promote the growth of crops. The above transition metal ionic compounds such as iron, cobalt, nickel and cerium are the most widely used and important photosensitizers, especially suitable for polyolefin photodegradation products. In addition, iron disulfide carbamate and iron dibutyl disulfide carbamate have been commercially produced abroad, and polyolefin photodegradation parent products with iron dibutyl dithiocarbamate as photointensifier and nickel or cobalt dibutyl dithiocarbamate as stabilizer have been introduced. The PE 9323 masterbatch of Cabot plastics company is an organometallic mixture, which can even continue to degrade without light. The polygrade of ampact company of the United States is a mixture of starch masterbatch and iron ion masterbatch

organic photosensitizers

as organic photosensitizers, there are mainly aromatic ketones such as benzophenone and acetophenone, aromatics such as Hexachloroacetone, quinone, naphthalene and triphenylamine, and various organic peroxides. Such photosensitizers have different selectivity for plastics, such as benzophenone and n-bromosuccinamide, which are effective for polyethylene and polypropylene, but not for polystyrene

photodegradable plastics obtained by modification

non photodegradable plastics can also have light reduction ability by appropriate modification. If the polyethylene film is irradiated with an electron accelerator in the presence of oxygen, the solid can introduce oxygen groups into the polyethylene film and have photodegradation performance. For example, adding a small amount of paraffin or oleic acid to the polyethylene can make the polyethylene degrade faster under ultraviolet radiation. Another example is to add a small amount of low molecular weight polyethylene and a film degraded within 2 ~ 2.5 months into the recycled polyethylene

biophoto hydrophilic monomers can be degradable plastics such as 2 hydroxyethyl methacrylate (HEMA), N-vinyl pyrrolidone (NVP), glycidyl enoate (GM) with an inner diameter of less than 0mm, 3 methylsiloxane propoxysilane methacrylate (Tris). Biophotolysis is also a kind of plastic that is both microbial and photodegradable. Up to now, there are few products prepared with starch/polyolefin/photosensitizer, starch/low density polyethylene/photosensitizer, starch masterbatch/Xin ion photosensitizer and other components. To sum up, we can get the research and development profile shown in the following table 2:

Table 2, research and development overview of degradable plastics category

category trade name and research unit biodegradable plastics biothermal microorganisms Synthetic polymer

3hb-3hv copolymer

3hb-4hb copolymer biopol (ICI) (Institute of resource chemistry, Tokyo University of Technology) (Hayashi Research Institute, Japan) chemical synthesis of natural polymer polysaccharides (natch Research Institute, U.S. Army), polymer

(to be continued)