Biodegradable products and classification
A, injection class
1, use: disposable tableware and other daily necessities, such as: knife, fork, spoon, plate, bowl, chopsticks, flower POTS, etc.
2, products processing methods: same as general injection molding method.
3, degradation of performance: ISO14851 tests, in the natural environment, about 10 days later began to degradation, degradation of 70% or more in 90 days.
Second, the blister class
1. Application: mainly for hot forming products, such as: one-time drink cup, cold box, convenient food containers, all kinds of tablets, pills, grain, bell type packaging.
2, products processing methods: start with grain as raw material, using general extrusion machined piece of material, sheet according to the membrane shape after thermoforming produce all kinds of products.
3, degradation of performance: ISO14851 tests, in the natural environment, about 10 days later began to degradation, degradation of 70% or more in 90 days.
Three, film class
1. Purpose: agricultural film, all kinds of packaging film, all kinds of bags.
2, products processing methods: blow molding based on general blown film machine, made from a variety of products.
3, degradation of performance: ISO14851 tests, in the natural environment, about 10 days later began to degradation, degradation of 70% or more in 90 days.
Four, foaming class
1. Purpose: shockproof materials.
2, degradation of performance: ISO14851 tests, in the natural environment, about 10 days later began to degradation, degradation of 70% or more in 90 days.
Biodegradable materials
Biodegradable plastics
By microbial synthesis of biodegradable plastics, referred to as "bioplastics, including biological polyester, cellulose, poly (amino acid and polysaccharide, is a kind of nature can be completely in the microbial degradation of plastics.
Microbial or glycogen storage of plant and animal fat, is a kind of aliphatic polyester, known as the biological polyester, microbial nutrients. When there is no carbon source, the polyester can be decomposed into acetyl coenzyme as the energy of life activities.
Polylactic acid (PLA), also known as ester on poly stated, based on microorganism fermentation lactic acid as monomer chemical synthesis. Degradation can be automatically after use, will not pollute the environment.
Polylactic acid can be made into excellent mechanical properties of fiber and film, its strength in general and nylon fiber and polyester fiber. Polylactic acid can be hydrolyzed into lactic acid and acetic acid in biological body, and the metabolic enzymes to CO2 and H2O, it can be used as medicinal materials. Japan, the United States has used plastic processed into surgical suture, poly (lactic acid) (PLA) artificial bone, artificial skin. Polylactic acid is also used to produce packaging container, agricultural film, fiber with clothes and quilts, etc.
Starch plastic starch over 90%, can add other components are fully biodegradable, Japan's sumitomo corporation, the United States have so far Wamer - lambert company, Italy Ferrizz company claimed that the success of starch content was 90% ~ 100% of the total starch plastics, in January (~ 1 year) completely biodegradable and leave no trace, no pollution, can be used to make all kinds of containers, bottles, film and garbage bags, etc.
The starch plastic principle is to make the production of starch molecules allosteric and disordering, formed with thermoplastic starch resin, so also known as the thermoplastic starch plastics. Its forming process can continue to use the traditional plastic processing equipment.
Using starch as raw materials to develop the potential advantage of biodegradable plastics, starch in various environments are completely biodegradable ability; Plastic degradation of starch molecules or after ashing, to form carbon dioxide gas, not poison soil or air; Take the appropriate technology to after the thermoplastic starch can be used in the manufacture of plastic materials mechanical properties; Starch is a renewable resource, take on, exploit the use of starch is conducive to rural economic development.
To be sure, the vast majority of China's current production of starch plastics will be filling type starch plastics, namely in a biodegradable polymer material, adding a certain proportion of starch by physical properties of starch biodegradation and causes the entire material collapse, prompted a large number of end group exposed so that the oxidative degradation, but after the "collapse" of the rest of the PE, PVC, etc all can't degradation has been residues in soil, accumulate over a long period, of course, will cause pollution, therefore belongs to this kind of product abroad for elimination.
Light degradable plastics
Light degradable plastics refers to the degradation of plastic can occur under the action of light.
Light degradable plastics, for example
According to the manufacturing methods light degradable plastics can be divided into synthetic degradable plastics and add degradable plastics.
A carbon monoxide copolymer (E/CO), ethylene /
Photodegradation is characterized by the main chain rupture. The photodegradation rate and degree of E/CO related to the amount of chain containing ketone group, the higher the content, the faster the degradation, degree. Texas scientists have outdoor exposure experiments have been carried out to E/CO, in sunny June, E/CO in just a few days can fastest degradation.
B, vinyl class/vinyl ketone (Ecolyte) copolymer
Ecolyte ketone group on the molecular side chain in natural light can occur under the action of decomposition. Ecolyte photodegradation performance is better than that of E/CO, but the cost is higher also.
Disadvantages of this kind of polymer is once you see the light begins to occur degradation, almost no induction period, need to add antioxidants in order to achieve the purpose of adjusting the induction period.
Add light degradable plastics
Add light degradable plastics is adding a small amount of photosensitizer in polymer, is light oxidation degradation of catalyst in low concentration, the sunlight (uv) irradiation and react, make polyolefin polymer fracture.
In PE, PP and other polymers added ketone and amine, photosensitizer can obtain good degradability of light.
Add light degradable plastics of low cost, simple production technology, covering mulch use effect is good. But its degradation characteristics is a completely exposed surface degradation, buried in the soil is a part of the degradation was poor. The degradation of such light degradable plastics can be controlled in induction period more than two months. But less controllable degradation time.
The development of degradable plastics
Biodegradable plastics in the us and Japan markets including biodegradable polyester, such as, biodegradable poly (lactic acid) (PLA) PET, polybutylene succinate/acid ester, poly hydroxybutyric acid ester/valerate, PE succinic acid ester, polyester and acid amine has been lactone/mixture; Starch and its mixture; And joined to enhance degradation ability of other plastic additives. Growth is the cause of environmental protection, an increase in the amount of plastic, another reason is to reduce the cost of production. By expanding production and economies of scale, the manufacturers to reduce their price. However, because of biodegradable resin high cost and existing all kinds of plastic firmly occupy the market is biodegradable plastics in the way of the market.
Environmental degradation plastics is a kind of new varieties, foreign development environment degradation plastic began in the 70 s, when the main development of degradable plastics, optical aims to solve the plastic waste, especially the pollution to the environment of disposable plastic packaging products, to the 80 s, the development of research to give priority to with biodegradable plastics, and have appeared in the renewable resources instead of oil, such as planting trees, starch and cellulose animals such as chitin as raw material to produce biodegradable plastics. In addition, also developed with microbial fermentation production of biodegradable plastics, kind of had clinical application of medical plastic, the degradation of a living body, such as polylactic acid are attracted the attention of the people, want to use it to solve the problem of plastic pollution of the environment, but, for this type of plastic is classified as environmental degradation plastic has different opinions, the Japanese society of degradable plastics, opinion cannot be classified as environmental degradable plastics
But from the perspective of degradable plastics is a kind of new plastic solution, should also include the raw body degradable plastics, degradable plastics from use and might as well be classified and divided into the environment (natural) degradable plastics and raw body (environment) degradable plastics. The latter has on medicine for surgical suture, artificial bone, etc. China's development of degradable plastics research basic synchronization with the world. But China research and development of degradable plastics in agricultural film. China is an agricultural country. Membrane of the consumption of the world's first, to solve the problem of residual of accumulation in farmland mulch effect on the damage of plant root system growth and crop yield, and residual film interfere problem of machine-cultivated operation of agricultural machinery. Began in the 70 s that the development of the photodegradation plastic mulch, around 1990, a fill in general plastic starch biodegradable plastics, at the same time, on the basis of optical plastics, the development and at the same time filled with starch film with the function of light degradation and biodegradation.
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