What are the common degradable materials?

What are degradable materials?

Degradable materials are mainly based on plastics, adding photosensitizers, modified starches, degradants and other raw materials, through which the stability of traditional plastics is reduced, and their degradation speed in the natural environment is accelerated to reduce the impact on the natural environment. Pollute. According to different degradation methods, it can be divided into biodegradable materials, photodegradable materials, thermally degradable materials, and mechanically degradable materials.


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Common degradable materials mainly include PLA and PBAT.

PLA polylactic acid is currently the most widely used degradable material, also known as polylactide, which is made of raw starch materials. The general principle is that the starch raw material is saccharified to obtain glucose and then fermented by glucose and certain strains to produce high-purity lactic acid and then synthesize polylactic acid with a certain molecular weight by chemical synthesis.

PBAT is also a widely used degradable material that has been researched and used. It is called polybutylene adipate or terephthalate, which is a copolymer of butylene adipate and butylene terephthalate. Combining the characteristics of PBA and PBT, it has not only good ductility and elongation at break but also good heat resistance and impact performance. In addition, it also has excellent biodegradability.

Food packaging bag

At present, the green and environmentally friendly packaging materials widely used in my country are mainly divided into paper product materials, natural biological materials, degradable materials, and edible materials.

The more mature ones are mainly traditional degradable materials, such as starch-based, polylactic acid, PVA film, etc.; other new degradable materials, such as cellulose, chitosan, protein, and other degradable materials, also have great development potential. Compared with single-use traditional packaging, recyclable and degradable packaging can reduce greenhouse gas emissions by 80%.

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Degradable in fast food, this material not only has the functions and characteristics of traditional plastics but also can be split, degraded and restored in the natural environment through the action of microorganisms in soil and water or through the action of ultraviolet rays in sunlight. , and finally, re-enter the ecological environment in a non-toxic form and return to nature.

Example: In the catering industry, you may often see degradable packaging, degradable lunch boxes, sugarcane pulp dinner plates, fully degradable paper cups, etc.

Cosmetic packaging materials

PLA material has good processability and biocompatibility and is currently the main biodegradable packaging material for cosmetics. The PLA material has good rigidity and mechanical resistance, making it a good material for rigid cosmetic packaging.

Cellulose and its derivatives are the most commonly used polysaccharides used in packaging production and are the most abundant natural polymers on earth. Consists of glucose monomer units linked together by B-1,4 glycosidic bonds, which enable the cellulose chains to form strong interchain hydrogen bonds. Cellulose packaging is suitable for the storage of non-hygroscopic dry cosmetics.

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Starch materials are polysaccharides composed of amylose and amylopectin, mainly derived from cereals, cassava, and potatoes. Commercially available starch-based materials consist of a mixture of starch and other polymers, such as polyvinyl alcohol or polycaprolactone. These starch-based thermoplastic materials have been used in a wide range of industrial applications and can meet the conditions of extrusion application, injection molding, blow molding, film blowing, and foaming of cosmetic packaging. Suitable for non-hygroscopic dry cosmetic packaging.

Chitosan has the potential as a biodegradable packaging material for cosmetics due to its antimicrobial activity. Chitosan is a cationic polysaccharide derived from the deacetylation of chitin, which is derived from crustacean shells or fungal hyphae. Chitosan can be used as a coating on PLA films to produce flexible packaging that is both biodegradable and antioxidant.

Naturally Degradable Clothing Materials

Biodegradable fabrics refer to pure cotton fabrics that can be completely decomposed by microorganisms in nature without any impact on the environment. They are also called "green" fabrics.

The total carbon emissions of the clothing industry exceed the sum of the emissions of all international flights and shipping, accounting for 10% of global carbon emissions, and are the second most polluting industry after the oil industry. Therefore, in terms of environmental protection, international brands such as Nike and Adidas have already made many attempts.

In 20 years, Xtep launched the polylactic acid windbreaker, becoming the first enterprise in the industry to overcome the problem of polylactic acid coloring and realize the mass production of polylactic acid products. At that time, the proportion of polylactic acid in the entire windbreaker fabric was 19%. A year later, in today's polylactic acid T-shirts, this proportion has risen sharply to 60%. It is understood that clothes made of polylactic acid fibers can be naturally degraded within one year if they are buried in the soil in a specific environment. The use of bio-based polylactic acid fibers can reduce the harm to the environment from the source.

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Kapok fibers are now used in biodegradable, all-natural clothing. Kapok fiber is often found in bedding labeled hypoallergenic and can be part of an allergen-free bedroom. As a natural fiber, kapok is an excellent alternative to petroleum-based materials, such as polyester and foam, that are commonly used in pillows. In addition, it is biodegradable and washable, and because kapok fiber is so light, one-eighth the weight of cotton, it is now being developed as a wearable material.

Simplifyber, a New York-based company, has invented a new method of manufacturing garments and accessories, using cellulose liquid directly to make garments and shoe uppers in one piece. A sustainable, fully biodegradable, and low-resource solution that skips 60% of the traditional processes of spinning, weaving, cutting, and sewing while allowing 35% less material to end up in waste. Simplifyber is also the first company in the world to use this technology.

Summary

A large part of what we now call degradable plastics is biodegradable plastics. Biodegradable plastics are currently mainly divided into four categories, PLA (polylactic acid), PBS (polyester), PBAT (polyester), and PHA (polyhydroxyalkanoate).

PLA is widely used in packaging, the textile industry, agricultural mulch film, 2biomedical polymer, and other industries; PBS can be used in packaging film, tableware, foam packaging material, daily necessities bottle, medicine bottle, agricultural film, pesticide and fertilizer slow-release materials, and other fields; PBAT is widely used in the field of disposable packaging film and agricultural film because of its good film-forming performance and easy film blowing; PHA degradable plastics have high thermal deformation temperature and good biocompatibility, and can be used in disposable products, medical Equipment surgical gowns, packaging bags and compost bags, medical sutures, repair devices, bandages, orthopedic needles, anti-adhesion films, and stents, etc.

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Degradable materials have their advantages in performance, practicability, degradability, and safety. In terms of performance, degradable plastics can reach or exceed the performance of traditional plastics in some specific areas; in terms of practicality, degradable plastics have similar application performance and hygienic performance to similar traditional plastics; After use, they can be degraded quickly in the natural environment (specific microorganisms, temperature, humidity), and become fragments or non-toxic gases that are easily used by the environment, reducing the impact on the environment; in terms of safety, degradable plastics degrade The substances produced or left in the process are harmless to the environment and will not affect the survival of humans and other organisms.

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