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Plastic films play an important role in China's agricultural production. However, the large-scale use of plastic film has also caused very serious agricultural film pollution. Biodegradable polymers have received much attention because of the environmental pollution caused by the traditional plastic mulching film. The most typical copolymer is poly (butylene adipate co butylene terephthalate) (PBAT). Poly (Butylene Adipate-co-Terephthalate) (PBAT) is a kind of aliphaticaromatic polyester with excellent biodegradability and mechanical processing properties. Therefore, it has been rapidly developed and widely used in the industry. However, the degradation period of the agricultural film depends on certain requirements. Currently, the degradable materials available in the market do not meet the needs of all crops due to their degradation period. In this paper, the basic properties, degradation process and methods to delay the degradation of PBAT are reviewed for improving the degradation period of the plastic film that is prepared by using this kind of material. The degradation process includes photodegradation, biodegradation, and hydrolysis. The methods of delaying the degradation process include adding a chain extender, light stabilizer, antihydrolysis agent and antibacterial agent, providing a theoretical basis for the research and development of biodegradable film with a controllable degradation cycle. The future research and development of biodegradable polymers will mainly focus on controllable degradation rate, stable degradation cycle, new materials, and reducing research and development costs.

Diatomite is a kind of natural material with adsorption capacity and it’s widely used in industry. The main purpose of this paper is to study the influence of hydrochloric acid concentration and modification time on the modification effect of diatomite. This article describes a modified method of diatomite, which can not only reduce the purification cost, but also improve the separation efficiency of solanesol. The results show that when the concentration of hydrochloric acid is 3mol/L and the treatment time is 50 minutes, the modification effect of diatomite is the best. The determination of the optimum technological conditions is conducive to the separation and purification of Solanesol by diatomite, and lays a foundation for the further development and utilization of diatomite.

Calcium sulfate whisker (CSW) is a kind of fiber crystal material with high orientation structure. The major goal of this research is to study the changes of mechanical properties and light transmittance of PE greenhouse film with different proportions of CSW. The experimental results show that the mechanical properties and light transmittance of PE/CSW films are enhanced compared with the pure PE. For PE/2%CSW, it shows a 18.6% increase in tear strength, a 3.1% increase in luminous transmittance and 17.7% increase in haze. The PE/5%CSW demonstrates a 12.8% higher in tensile strength, a 20.5% higher in tear strength, a 23.9% lower in luminous transmittance and a 53.0% higher in haze. This article gives a new formula to strengthen the mechanical properties of PE greenhouse films and finds the direction for the research and development of astigmatic covering film.