How Much PBAT Content in Biodegradable Plastic Bags Is Appropriate?
Now the use of biodegradable plastic bags are mainly made of PLA + PBAT blown film. What is the content of PBAT in the bag, the quality of the bag is good, share the proportion of PBAT with PLA is how to match out.
Due to the poor film-forming properties of PLA and the brittle blown film, the method of blending with PBAT biodegradable material solution is used. PBAT is an aliphatic-aromatic copolyester synthesized from adipic acid, terephthalic acid and 1,4-butanediol as monomers. This polyester material is biodegradable and has good film-forming properties. The bags made have good tensile properties and flexibility.
After repeated and repeated tests, it was confirmed that when the PBAT content was low, the film-forming property was not good, and the film surface was not smooth and appeared uneven. With the increase of PBAT content, the apparent morphology of the film was improved, and the film-forming property was good and the glossiness was also good.
The PLA/PBAT blended films with different PBAT contents were observed by scanning electron microscopy to observe the surface microscopic morphology. When the PBAT content was 20%, it could be seen that there were obvious voids and the denseness of the film was poor. When the PBAT content was 40%, the film was more dense. When the content reaches 50%, the microscopic morphology is uniform, dense and smooth, which is analyzed because the PLA/PBAT blend system is partially compatible, and the blend system with 20% PBAT content may be a single-phase continuous morphological structure. When the PBAT content is 40%, the two phases may form a staggered morphological structure, which is dispersed and has a large boundary area. When the PBAT content is 50%, the PLA/PBAT blending system is reversed; PBAT is the continuous phase and PLA constitutes the dispersed phase, so that the properties of the produced films mainly depend on the properties of PBAT, and the toughness of the films is improved.