68 / 2021-06-06 21:04:34

All-green degradation, high elongation, without chemical modification reinforced films based on cellulose nanofibers and poly (butylene adipate-co-terephthalate)

CNFs; PBAT; reinforced composite films; degradable;

In the past 70 years, over 8 billion tons of plastics have been produced, and among all the plastic products, films have brought particularly intricate problems due to the huge consumption. The most of them cannot be fully degraded and produce more tiny plastic particles, including difficult to recycle due to special additives. Looking for an all-green degradable and excellent mechanical film to replace plastic film product is an effective way to solve the white pollution. Here, in my study, all-green degradable and excellent mechanical films have been designed by cellulose nanofibers (CNFs) and poly (butylene adipate-co-terephthalate) (PBAT) in free chemical modification manner. The preparation of the films mainly includes three steps: using mechanical approach to prepare CNFs, using the CNFs with SiO2 NPs to prepare the CNFs films and the CNFs films immersed in PBAT to prepare the CNFs/PBAT reinforced composite films. In this process, the CNFs and PBAT two continuous phases bound by direct high-temperature, in which chemical modification is not required, ensuring the all-green reliability of the prepared films. Remarkably, the contact angles of water on the CNFs/PBAT reinforced composite films surface are basically more than 80° significantly higher than that of the CNFs films without PBAT (36.5 ~ 55°). The CNFs/PBAT reinforced composite film with SiO₂ NPs (4wt%) not only shows the maximum average elongation of 9.3% that is over 3.72times higher than that of the CNFs film (SiO₂ NPs 0wt%), but also exhibits excellent bending flexibility with the folding resistance of nearly 3times (~1210times) that is an order of magnitude higher than that of the CNFs film with SiO₂ NPs 0wt% (~444times). Meanwhile, its underlying mechanism for the improved performance has also been explored. Importantly, the CNFs/PBAT reinforced composite straws, prepared by the reinforced films, also show excellent performance, such as high hydrophobicity, without any special chemical irritating smell. In short, although the comprehensive performances of the CNFs/PBAT reinforced composite films have been significantly improved, any modification chemical treatment is not required, which exhibit huge potential in replacing plastics with all-green degradable composite materials.