Degradable plastics are mainly suitable for occasions that are not convenient for recycling. The three most important application fields are packaging, agriculture and biomedicine, of which packaging accounts for the largest proportion of 58%.
Although countries actively increase the proportion of plastic recycling, reduce the proportion of landfill, and limit the use of all kinds of disposable plastics, there are still occasions that need disposable use and are difficult to effectively recycle, collect and treat. Therefore, degradable plastics are different from traditional plastics.
Regionally, Europe is the main market for degradable plastics, accounting for 55% of the world, the Asia Pacific region accounts for 25% of the world, and North America accounts for 19%.
In terms of downstream applications, the application range of degradable plastics is expanding, including packaging, textile fiber, automobile transportation, etc.
In terms of materials, among PLA, PBS, PBAT, PLA and other polyester degradable plastics and starch based plastics, although starch based plastics are relatively cheap and can be completely degraded. However, they have short service life and poor mechanical properties, so their applications are limited.
At present, PLA and PBAT are the most widely used and produced degradable plastics. In terms of the proportion of the production capacity of degradable plastics in 2019, PLA accounts for 25% and PBAT 24%, accounting for nearly 50% in total.
In terms of production process, PLA has high technical barriers, and China still depends on import. Jindan technology, a domestic manufacturer, is still under commissioning. Compared with the production process, PBAT is relatively mature. There are two main types: one is the process technology provided by BASF and the other is the technology provided by the Institute of physics and chemistry of the Chinese Academy of Sciences.
On July 14, 2020, the Ministry of industry and information technology published an article «accelerating the pace of polyglycolic acid (PGA) biodegradable plastic industry in China», «Due to its good gas barrier, biocompatibility and degradability, PGA products have good application prospects in the fields of medical suture and tissue repair. In 2010, the technology of preparing PGA from coal based syngas made a breakthrough, and Shanghai Pujing chemical company started the construction of related projects in Baotou, Inner Mongolia in 2018.
As China is relatively rich in coal resources, if the coal-based synthetic PGA technology is mature, it will effectively reduce the cost of degradable plastics. On the other hand, because PGA has good degradability, it is more suitable for medical occasions, and there is a problem of insufficient performance in the field of packaging.
The plastic ban has become stricter, and the demand and capacity are racing