What is biodegradable material?

Biodegradable plastic is a polymer material with excellent performance, which can be completely decomposed by environmental microorganisms after being discarded, and finally inorganicized to become a part of the carbon cycle in nature. The handbags produced by Wenzhou Xiaqila Packing Co., Ltd. have biological decomposition effects. Today, let us explain what biodegradable materials are?

Completely biodegradable materials can be completely decomposed by microorganisms and have a positive effect on the environment.

While creating modern civilization, humans also bring negative effects-white pollution. Disposable tableware, disposable plastic products, and agricultural mulch are difficult to recycle, and their treatment methods are mainly incineration and burial. Incineration will produce a large amount of harmful gases and pollute the environment; burial means that the polymers cannot be decomposed by microorganisms in a short time, which also pollutes the environment. The presence of discarded plastic film in the soil hinders the development of crop roots and the absorption of water and nutrients, reduces soil permeability, and leads to reduced crop yields; eating discarded plastic film will cause intestinal obstruction and death; synthetic fiber fishing nets and fishing lines that have been lost or abandoned in the ocean have caused considerable harm to marine life, so it is imperative to promote green consumption and strengthen environmental protection. Faced with increasingly depleted oil resources, trendy biodegradable materials are becoming a research and development hotspot as high-tech products and environmentally friendly products.

Biodegradable materials can be roughly divided into two categories according to their biodegradation process

One category is completely biodegradable materials, such as natural polymer cellulose, synthetic polycaprolactone, etc., whose decomposition mainly comes from: ① due to the rapid growth of microorganisms, resulting in the physical collapse of the plastic structure; ② due to the biochemical action of microorganisms, various hydrolysis under enzyme catalysis or acid-base catalysis; ③ free radical chain degradation caused by various other factors. The other type is biodegradable materials, such as a blend of starch and polyethylene. The decomposition is mainly due to the destruction of the additives and the weakening of the polymer chain, which degrades the polymer molecular weight to a level that can be digested by microorganisms, and finally decomposes into carbon dioxide (CO2) and water.

Semi-biodegradable plastics currently mainly include starch-modified (or filled) polyethylene PE, polypropylene PP, polyvinyl chloride PVC, polystyrene PS, etc. Studies have shown that starch-based biodegradable plastic bags will eventually enter the landfill without exposure to sunlight. Even if there is a biodegradation effect, the degradation that occurs is mainly biodegradation, but the polyethylene contained is difficult to decompose.

For solving environmental pollution, although starch-based plastics are more effective than disposable plastic products, since they still use non-biodegradable polyethylene or polyester materials as raw materials, in addition to the added starch that can be degraded, the remaining large amount of polyethylene or polyester will still remain and cannot be completely biodegraded. It is only decomposed into fragments and cannot be recycled. The situation is even worse after entering the soil, causing confusion in the treatment of waste. Therefore, completely biodegradable materials have become the research focus of degradable materials.

Polylactic acid was first developed by Shimadzu Corporation and Kanebo Corporation of Japan. It is a polymer obtained by polymerization with lactic acid as the main raw material. Lactic acid is a natural compound commonly found in animals, plants and microorganisms. It is very easy to decompose naturally. Its fiber has excellent performance, which is between synthetic fibers and natural fibers. It is more hydrophilic than polyester fiber and has a lower specific gravity than polyester fiber. It has excellent hand feel, drape and appearance, good resilience, excellent curl and curl retention, controllable shrinkage, strength of 62cN/tex, unaffected by ultraviolet light, can be dyed with a variety of dyes, outstanding processability, controllable thermal bonding temperature, crystal melting temperature as high as 120℃-230℃, and low flammability.

The main feature of lactic acid monomer is that it exists in two optically active forms. Polylactic acid technology uses this unique polymer property to control the crystal melting point of the product by controlling the ratio and distribution of D and L isomers on the polymer chain.

Poly-L-lactic acid (PLLC) is a polymer material synthesized by chemical methods using L-lactic acid fermented from bioresources such as starch and molasses as raw materials. PLLC is a thermoplastic material with similar plasticity to polystyrene and polyester. It has high crystallinity and rigidity and excellent tensile strength.