Analysis of the Properties of Degradable Plastics (I)

Biodestructive plastics Biodamaged plastics are generally considered to be starch-based, aliphatic polyester-based, and natural-mineral-based. The three major types of starch-based bio-destructive starch-based bio-destructive plastics are also classified as physically modified starches and chemically modified. Starch series two. Physically Modified Starch: Starch is physically treated to increase its compatibility with plastic resins.
If the corn flour is treated with silane, the compatibility with polyethylene can be improved, and then an unsaturated oil oxidant (corn oil) is added, and the mixture is fully stirred and dried to make the water content below 12%, ie, the starch content is obtained. For 40-60% of the masterbatch, add it to low-density polyethylene, linear low-density polyethylene or high-density polyethylene, etc., to produce destructible plastic. After contact with the soil after use, micro-environment will consume it. The starch portion of the starch leaves a porous structure, and corn oil reacts with the metal education industry to form peroxides that break up the residue into small pieces.
MATERBI's composition is more than 60% of agricultural raw materials (most of which are cereal starches), less than 40% is poly-all material, non-toxic, hydrophilic but insoluble, with similar mechanical properties of low-density polyethylene. And can be processed using traditional thermoplastic process molding. PE9321 is a blend of low density polyethylene and starch that degrades in soil and water and can be used as a food packaging material and container. In addition, disrupted plastics in which starch is blended with polypropylene have also been developed.
Chemically Modified Starch: Currently the most commonly used modified starch in the production of polyethylene biodestructive films is a starch/ethylene/acrylic acid copolymer. The modified lake is blended with polyethylene and starch and can be used to make garbage bags and food sacks. The best formula is 40% corn flour, 30% polyethylene and 30% modified starch. It is expected that within 5 years, this film will account for 20% of all polyethylene films. U.S. PURDUE University developed a graft copolymer of starch and styrene, which can be used as a compatibilizer to make starch and polyphenylene hexene blend well. The blend containing 20-30% of starch has similar polystyrene-like properties. Performance but susceptible to damage by microorganisms. In addition, if a copolymer of maleic anhydride modified starch and polystyrene is used, starch and polystyrene can be well mixed, and a plastic with good biodestructive and chemical degradability can be obtained.
It has also been used to blend pretreated starch with ethylene acrylic acid copolymer (EAA) and biodestructive films can be made with the addition of 1-5% carbonic acid adjuvant. Although starch-based plastics are degradable, bacteria and other microorganisms can be introduced to harm human health. And its degradation products can contaminate water sources. In addition, its synthesis method is complex and difficult to process, and generally it decomposes before it is heated to the melting temperature of the plastic, thus limiting its expansion.
The addition of 30-70 parts by weight of talc or calcium carbonate to natural mineral-based bio-destructive plastics such as polycaprolactone can produce "environmentally harmonized plastics," particularly in the case of calcium carbonate. The organic acids produced after the decomposition of polycaprolactone, as well as organic acids such as formic acid, acetic acid, and butyric acid, and acid rain, are suitable for use as sheets and pots for Guilin. Therefore, this material has both biological and chemical destruction capabilities.
Photodegradable plastics Photodegradable plastics are virtually ultraviolet-degradable plastics in visible light. Research and development began in the 1970s. Most of the degradable plastics used today are photodegradable plastics. Its main manufacturing methods and applications are as follows:
Homopolymer of Photodegradable Monomer The photodegradable monomer refers to a monomer having a photosensitizing group as a photosensitizing group: -N=N-, -CH=N-, -CH=CH-,- C=C-, -NH-NH-, -S-, -NH-, -O-, >C=O and other groups, such as thermoplastic 1.2-polybutadiene synthesized with 1.2-butadiene can produce light The degradable plastic film not only has various properties of the plastic film, but also easily degrades in the light, and if different photosensitizers are added, the degradation time can be adjusted. In addition, the addition of 20% of this 1.2-polybutadiene to polyethylene also produces a plastic film that degrades within two months. Furthermore, polyisoprene and polyisobutylene oxide are also obtained as photodegradable products by chemical synthesis, and the products obtained by blending with polyethylene also have photodegradability. In addition, photolysis plastics such as polyvinyl phenyl ketone and polyvinyl ketone have been synthesized.
Copolymers of photodegradable monomers and other monomers as copolymers of photodegradable monomers and other monomers such as carbonyl-containing polyethylene, polypropylene, which have been synthesized by copolymerizing carbon monoxide or vinyl ketones with corresponding other monomers, Photodegradable plastics such as polystyrene, polyvinyl chloride, polyethylene terephthalate, amide, and the like; not only can be used alone, but also can be blended with the same type of resin in the manner of masterbatch to obtain a variety of optical limit solutions. Plastics can also control the end product degradation time by changing the blending ratio. (To be continued)