At present, PBAT is used in supermarket shopping bags, take-out lunch boxes, agricultural mulch and other fields such as agriculture, commerce and medicine. With the introduction of the plastic limit order and the expansion of the green consumer market, PBAT has a good development prospect as an environmentally friendly material.
1. PBAT
Polybutyrate (short for polybutyrate adipate terephthalate, or PBAT) is a biodegradable and compostable (EN13432) biopolymer with similar properties like low density polyethylene (LDPE).
PBAT bioplastics is made from fossil resources. Its compounds (starch, PLA) have a biobased carbon content of up to > 30%. Typical applications (the largest volume product is flexible film for packaging, e.g. compostable shopping bags):
2.Biodegradable Plastics
Biodegradable plastics are plastics that degrade into small molecules or low-molecular compounds such as carbon dioxide and water under natural conditions such as soil and sand. Degradable plastics are mainly divided into photodegradable plastics, biodegradable plastics, and photobiodegradable plastics. Photodegradable plastics need sufficient light to degrade, which brings great limitations to production, so the promotion of photodegradable plastics is not good.
There are dozens of types of biodegradable plastics, and the varieties that can be mass-produced and industrially produced are mainly: polyhydroxy fatty acid esters synthesized by microbial fermentation, chemically synthesized polylactic acid (PLA), polycaprolactone, and diol dicarboxylate Acid aliphatic polyester (PBS), aliphatic/aromatic copolyester, CO2/epoxy compound copolymer (APC), polyvinyl alcohol (PVA), etc., natural polymer starch-based plastics and their biodegradable plastic blends Materials, plastic alloys, etc.
3.Preparation method of PBAT
Using adipic acid (AA), terephthalic acid (PTA), and butylene glycol (BDO) as monomers to synthesize poly(adipic acid/butylene terephthalate) in a certain proportion, the emphasis is on strict Control the esterification method, esterification time, polycondensation temperature, stabilizer, etc. of the reaction.
These key factors can directly affect the synthesis process and ultimately affect the performance of the product. In order to ensure the preparation of good PBAT resin, the best process conditions required are: co-esterification reaction mode, esterification time is 185 min, polycondensation temperature is 248-250 ℃, and stabilizer dosage is 70 μg/g.
4.Preparation technology of PBAT
There are three esterification methods for the preparation of PBAT: co-esterification, partial esterification and tandem esterification. The preparation flow chart and main process parameters are shown in Figure 1, Figure 2, and Figure 3.
5.Development status and application prospect of PBAT
As an environmentally friendly material with good performance, PBAT can reduce petroleum resource consumption and alleviate "white pollution", which is of great significance to my country's sustainable development.
At present, the global PBAT market demand is strong. Due to the high price of PBAT, my country has good raw material production conditions. PBAT products are mainly used for export, with high industry concentration, large potential market and good industrialization prospects.
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