Understand degradable plastic materials

Biodegradable plastics, a polymer material degraded by microorganisms such as bacteria, fungi, and algae, are a standout product in the environmental protection field. Not only do they possess excellent performance, but they can also be completely decomposed by environmental microorganisms after disposal, ultimately achieving inorganicization and becoming an essential part of the natural carbon cycle. This material combines the biodegradability of "paper" with the durability of "synthetic plastics," making it an ideal high-performance eco-friendly polymer material.

Biodegradable plastics, a shining star in the environmental protection field, are gradually entering our daily lives. These materials not only exhibit outstanding performance but can also be completely decomposed by microorganisms in natural environments, achieving inorganic transformation and thus becoming a crucial link in the natural carbon cycle. They are categorized into fully biodegradable plastics and destructive biodegradable plastics, primarily including types such as PBAT and PLA, with natural polymers and aliphatic polyesters as their main components.

Biodegradable plastics, also known as biodegradable plastics, are plastics that can be completely degraded by microorganisms under specific conditions. These conditions include natural environments such as soil, sand, as well as environments in composting, anaerobic digestion, or aqueous culture media. Through microbial action, these plastics can ultimately degrade into carbon dioxide (CO2), methane (CH4), water (H2O), mineralized inorganic salts of the elements they contain, and new biomass. Depending on the raw material composition, biodegradable plastics can be further classified into two major categories: biobased biodegradable plastics and petrochemical-based biodegradable plastics.

Biodegradable plastics derived from biological sources are primarily categorized into four types: First, plastics directly processed from natural materials; Second, polymers formed through the combined action of microbial fermentation and chemical synthesis; Third, polymers synthesized exclusively by microorganisms; and Fourth, biodegradable plastics produced by blending the aforementioned materials or combining them with other chemically synthesized biodegradable plastics. In contrast, petrochemical-based biodegradable plastics refer to those synthesized through chemical methods by polymerizing petrochemical monomers, such as PBAT, polybutylene succinate (PBS), and polypropylene carbonate (PPC). Additionally, based on the degradation process, biodegradable plastics can be further classified into two major categories: fully biodegradable plastics and destructive biodegradable plastics. The latter primarily includes starch-modified or filled polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and polystyrene (PS).

Starch-based fully biodegradable plastics Completely biodegradable plastics are derived from natural polymers such as starch, cellulose, and chitin, produced through microbial fermentation or synthetic methods. These include thermoplastic starch-based plastics, aliphatic polyesters, polylactic acid (PLA), and starch-polyvinyl alcohol blends. Starch-based biodegradable plastics are now available in various forms, such as PLA, PHA, starch plastics, bioengineered plastics, and bio-compatible plastics (e.g., polyolefins and PVC). These materials are fully biodegradable in nature and environmentally friendly. In addition, there are other types of biodegradable plastics, such as polycaprolactone (PCL). This plastic exhibits excellent biodegradability, with a melting point of 62°C, and can be decomposed by microorganisms under aerobic or anaerobic conditions. It is commonly blended with materials such as starch and cellulose, or polymerized with lactic acid to enhance its performance. Additionally, polybutylene sebacate (PBS) and its copolymers are also important biodegradable plastics. Based on PBS, various high-molecular-weight polyesters can be manufactured, and industrial production has been achieved, which has a melting point of 114°C.

carbon dioxide copolymer China Inner Mongolia Mengxi Group Company has successfully established a carbon dioxide/epoxide copolymer resin plant through the technology of Changchun Institute of Applied Chemistry, with its products widely used in packaging and medical materials. Additionally, Jiangsu Taixing has also received good news: the low-molecular-weight carbon dioxide copolymer technology developed by Dr. Chen Liban from the Guangzhou Institute of Chemistry, Chinese Academy of Sciences, has been put into production here. Its product, low relative molecular weight carbon dioxide/epoxide copolymer, serves as a raw material for polyurethane foam materials, providing strong support for the packaging of household appliances and other products. Henan Tianguan Group has also kept up with the technological trend, adopting the technology of Professor Meng Yuezhong from Sun Yat-sen University to establish a pilot-scale carbon dioxide copolymer production line. Meanwhile, biodegradable materials such as chitin, polyamide, polyaspartic acid, polysaccharides, and cellulose are being actively developed, with the expectation of bringing more innovations in the future.