Types of degradable plastics and specific introductions

1.Application status of degradable plastics:

2.Degradable Plastics:

Degradable plastics. Degradable plastics refer to plastics that can degrade on their own in a relatively short period of time and under natural conditions.

Degradable plastics are generally divided into four categories: (1) photodegradable plastics - photosensitizers are mixed into plastics to gradually decompose the plastics under sunlight. It belongs to an earlier generation of degradable plastics, and its disadvantage is that the degradation time is difficult due to sunshine and climate change, so the degradation time cannot be controlled; (2) Biodegradable plastics - refers to plastics that can be completely decomposed into low-molecular compounds under the action of microorganisms in nature (such as bacteria, molds and algae).

It is characterized by convenient storage and transportation, as long as it is kept dry, does not need to avoid light, and has a wide range of applications, it can not only be used for agricultural mulch film, packaging bags, but also widely used in the field of medicine; (3) Photobiodegradable plastics - a type of plastic that combines photodegradation and microbial degradation, which has the characteristics of photodegradable and microbial degradation plastics at the same time; (4) Water-degradable plastic - add absorbent substances to the plastic, which can be dissolved in water after use, which is mainly used in medical and sanitary appliances (such as medical gloves, etc.), which is convenient for destruction and disinfection. Among the four types of degradable plastics, biodegradable plastics have received more and more attention with the development of modern biotechnology and have become a new generation of hot spots in research and development. OK?

Degradable plastics refer to plastics that add a certain amount of additives (such as starch, modified starch or other cellulose, photosensitizers, biodegradants, etc.) in the production process, and the stability is reduced, and it is easier to degrade in the natural environment.

The advantages are: environmental protection and hygiene - degradable plastic is generally considered to be a kind of plastic that can be decomposed into low molecular matter through sunlight radiation or microorganisms in the soil, in addition to being degradable, it should also have the performance of easy processing and meeting the requirements of use. The harmful effect of sunlight on polymer materials is the comprehensive effect of ultraviolet light and oxygen, so it is called photooxidative degradation.

In the case of polyolefins, photooxidation often causes chain breakage or cross-linking of polymers, accompanied by the formation of some oxygen-containing functional groups, such as ketones, carboxylic acids, peroxides and alcohols. Its degradation is mainly due to catalyst residues in polymers, as well as the initiation of peroxides and carbonyl groups introduced during processing.

Biodegradable polymer materials refer to a class of functional polymer materials that can be degraded or enzymatically hydrolyzed in living organisms, and the generated small molecule substances are absorbed by the body and excreted from the body. At present, there are three main categories of biodegradable polymers that have been researched and developed: natural polymers, microbial synthetic polymers and chemically synthesized polymers. Among them, natural degradable polymers include starch, cellulose, glycans, chitin, chitosan and its derivatives; The biodegradable polymers synthesized by microorganisms include polylactic acid (PLA), polyhydroxyalkyl alcohols, poly(-malate), etc., and the synthetic degradable polymers include polyvinyl alcohol (PVA), polylactic acid (PLA), poly-hydroxylates, polycaprolactones (PCL), etc.

Biodegradable plastics are generally divided into four main types:

1. Photodegradable plastics.

A photosensitizer is added to the plastic to gradually decompose the plastic under sunlight. It belongs to an earlier generation of degradable plastics, and its disadvantage is that the degradation time is difficult due to sunshine and climate change, so the degradation time cannot be controlled;

2. Biodegradable plastics.

Under the action of microorganisms, plastics can be completely decomposed into low-molecular-weight compounds. It is characterized by convenient storage and transportation, as long as it is kept dry, does not need to avoid light, and has a wide range of applications, it can not only be used for agricultural mulch film, packaging bags, but also widely used in the field of medicine; With the development of modern biotechnology, biodegradable plastics have received more and more attention and have become a new generation of hot spots for research and development.

3. Photobiodegradable plastics.

A class of plastics that combine photodegradation and microorganisms, it has the characteristics of photodegradable plastics with both light and microorganisms. The fourth type of water-degradable plastic adds absorbent substances to the plastic, which can be dissolved in water after use, and is mainly used for medical and health appliances (such as medical gloves), which is convenient for destruction and disinfection.

What does degradable packaging bag mean is not a new word, so what are the classifications of degradable plastics? Next, let pchouse take you to understand.

At present, degradable plastic bags are divided into the following four categories:

1. A biodegradable plastic bag adds absorbent material to the plastic, discards and dissolves in water. It is mainly used in medical and health equipment (such as medical gloves), which are easily damaged and sterilized.

2. Photodegradable plastic bags are mixed with photosensitizers to make the plastic gradually decompose in the sun. It belongs to the earlier generation of degradable plastics, and its disadvantage is that due to sunlight and climate change, the degradation time is difficult to **, so the degradation time cannot be controlled.

3. Biodegradable plastic bags are composed of microorganisms, including bio-polyester, bio-cellulose, polysaccharides and polyurethane. It is a biodegradable plastic bag that can be distinguished by microorganisms in nature.

4. Photodegradable plastic bags are the product of the combination of photodegradation and microorganisms. It has the dual properties of photodegradation and microbial degradation.