Search

The total production of global plastics is up to 400 million tons per year. Nearly 80% of the used plastics are directly landfilled or dumped in the environment, leading to the generation and release of microplastics, which poses a great threat to both environment and human health. How to recycle plastic waste efficiently and environmentally has become a common concern worldwide. Among the plastic waste recycling methods, chemical recycling such as pyrolysis can realize the transformation from polymer to high-value products. This paper summarizes the research and industrialization progress of four different plastic waste pyrolysis technologies, namely fast pyrolysis, catalytic pyrolysis, oxidative pyrolysis and hydro-pyrolysis. The challenges faced by the pyrolysis of plastic waste is discussed and the future development direction of various pyrolysis technologies is also outlooked. It is expected that some more efficient, environmentally friendly, and economical technologies of plastic waste pyrolysis can be explored in the future, to meet the growing demand for environmental protection and sustainable development.

To clarify the effects of plant growth promoting rhizobacteria (PGPR)on growth promotion and disease resistance of flue-cured tobacco, potential roles of previously isolated Bacillus velezensis F10 were studied through pot and plot experiments to investigate its growth promotion and control effects on tobacco bacterial wilt. The results showed that the growth of roots and aerial parts of tobacco plants under the biocontrol bacterium F10 treatment were significantly better than that of the control, and the activities of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) in tobacco leaves increased. The control effects of biocontrol bacterium F10 on tobacco bacterial wilt in pot and plot experiments were 60.49% and 54.91% respectively. The agronomic traits of flue-cured tobacco in fields treated with biocontrol bacterium F10 were significantly better than those of the control. The yield, output value, average price, proportion of high grade leaves, and proportion of high-to-mid grade leaves increased by 11.82%, 31.46% and 13.17% respectively. Biocontrol bacterium F10 has growth promoting effect on flue-cured tobacco and has good control effect against tobacco bacterial wilt, which significantly promotes the economic benefits of flue-cured tobacco. [ABSTRACT FROM AUTHOR]

This paper overviewed the recent research progress in the toughening modification of polyimides at home and abroad and also summarized the toughening modification methods including the hyperbranching toughening, toughening with flexible groups, diamine or dianhydride and structural modification. Hyperbranched polymers can reduce the entanglement of molecular chains due to a large number of end groups and highly branched 3D structure, and their flexible groups can improve the flexibility of molecule chains. Both of the molecular features can enhance the toughness of polyimides. The toughness of polyimides can also be improved by the new-designed diamine and dianhydride. Moreover, the change in structure of the original molecular chains can reduce the conjugates between molecular linkages and enhances the toughness of polyimides accordingly. Finally, the further research direction and development trend were prospected. The synergistic toughening method was highly recommended for polyimides by a combination of hyperbranched polymer and flexible groups with hyperbranched polymer and diamine, dianhydride. [ABSTRACT FROM AUTHOR]