Degradable materials and degradable packaging bags

The ubiquitous plastic products have facilitated people’s lives, but the resulting plastic waste has caused a lot of pollution to the ecological environment. White pollution caused by plastic products especially plastic bags is harming the natural environment and people’s normal lives step by step.

In order to deal with “white pollution”, in addition to establishing environmental awareness and reducing the use of disposable plastic products, another important method is to replace ordinary plastics with degradable plastics. By optimizing the selection of production raw materials and production processes, degradable plastics can be gradually decomposed into fragments under the combined action of several days or months of sunlight and rain and microorganisms, and eventually all degraded.

Degradable materials can be generally divided into four categories: photodegradable plastics, biodegradable plastics, photo/biodegradable plastics, and water degradable plastics.

Photodegradable plastics are plastics with photosensitizers. Under the influence of sunlight, the plastics gradually decompose. But its disadvantage is that the degradation time is affected by sunlight and climate environment, so it cannot be controlled.

Biodegradable plastics refer to plastics that can be decomposed into low molecular compounds under certain conditions by microorganisms present in nature, such as bacteria, molds, and algae. Such plastics are convenient for storage and transportation and have a wide range of applications in packaging bags and plastic cups.

Water-degradable plastic is a plastic that dissolves in water because of the addition of water-absorbing substances.

With the development of modern biotechnology, biodegradable plastics have become a new hotspot in research and development. At present, the biodegradable plastics developed in China are mainly biopolyesters such as polylactic acid (PLA), polyhydroxy fatty acid esters (PHA), and carbon dioxide copolymers (PPC). Polylactic acid (PLA) is a new type of biological substrate and renewable biodegradable material. The main source is processed from corn, cassava, etc., starch is saccharified to obtain glucose, and then glucose and certain strains are fermented to produce high purity lactic acid, and then synthesize a certain molecular weight polylactic acid through chemical synthesis. It has good biodegradability, after use, it can be completely degraded by microorganisms in nature under specific conditions, and eventually generate carbon dioxide and water, which does not pollute the environment, which is very beneficial to protect the environment. Polyhydroxy fatty acid esters (PHA) are aliphatic copolyesters of different structures synthesized by microorganisms through fermentation of various carbon sources. They can be used not only in packaging materials, agricultural films, but also in pharmaceuticals, cosmetics, animal feed and other fields.

PLA is mainly used in fully degradable packaging bags. The main bio-based material of fully degradable packaging bags is composed of PLA+PBAT, which can be completely decomposed into water and carbon dioxide within 3-6 months under composting conditions (60-70 degrees).

Why add PBAT? Professional flexible packaging manufacturer Lucky Time Pack tells you that PBAT is a copolymer of adipic acid, 1,4-butanediol and terephthalic acid. It has excellent flexibility and can be used in molding processes. The purpose of blending PLA and PBAT is to improve PLA packaging’s toughness, biodegradation, and molding performance. PLA and PBAT are not compatible, so choosing a suitable compatibilizer can significantly improve the performance of PLA.

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