# Degradation of Low-Density Polyethylene Greenhouse Film Aged in Contact with Agrochemicals
#### Greenhouse Plastic Film Aging  
PE-LD film is commonly used as a greenhouse covering material because of its good mechanical properties, chemical resistance, and affordability. However, its chemical structure may be heavily impacted by weathering circumstances, which alters the film's mechanical and physical characteristics. The interconnection among the different aging factors of plastic material and its resilience to degradation phenomena remains a poorly investigated issue, which requires a suitable scientific approach, aimed at introducing innovative solutions, capable of enhancing the durability of a greenhouse plastic film. The worsening of a plastic's visual perception, as well as of its mechanical performance, radiometrical properties, physical characteristics, or chemical structure, is in general referred to as its \"degradation\". The Ultraviolet (UV) component of solar radiation is, within atmospheric conditions, the primary element that contributes to the rapid deterioration of agricultural plastics [20; 21]. Additionally, other variables may play a considerable role. These include temperature and the relative humidity of the internal air; mechanical stress imposed by wind, rain, hail, and snow or related to the installation (stretching) phase; interaction with air's oxygen/dust, atmospheric pollutants, and rainwater; interactionswith supporting structures or agricultural soil; exposure to agrochemicals, etc. Describing, measuring, and controlling plastic degradation are all problems made more difficult by several environmental, chemical, and technological aspects [22; 23]. When the primary mechanical characteristics of an agricultural plastic film--mainly, its percentage elongation at break--fall below 50% of the original measure when new, the material is considered as having reached the end of its service life. Indeed, this value is generally considered as the indicator that this material has finished its working life and has to be removed before its mechanical characteristics become so poor that its removal and further mechanical recycling could be impossible. Therefore, the primary recycling attributes consist of having adequate mechanical characteristics, in comparison to the plastic material when it was new. In order to characterize the deterioration of a PE-LD film, [PERSON] et al. [24] examined the quantitative criteria that may be used, coming to the conclusion that the variance in the percentage elongation at break is the primary determinant of the final evaluation of a greenhouse plastic film's degradation. This is how weathering conditions--particularly sunlight, in the 290-400 nm range--alter a PE-LD film's chemical structure and, consequently, its mechanical and physical properties. [PERSON] et al. [25] conducted some experimental tests using artificial and natural aging in Northern Algeria at four different greenhouses, simulating conditions of temperature and UV-A radiation, in order to comprehend the mechanisms of natural and artificial aging processes of a triple-layer film made of PE-LD used as greenhouse cover. Mechanical characteristics significantly decreased with aging, according to the data, and this might be due to the structural alteration of the plastic film. The results revealed that the maximum loss of yellow-color additives occurred after 2981 h under the natural aging process and after 2440, 1096, 1340, and 121 h under the four considered artificial aging conditions, respectively. Several research studies agreed on how the degradation process of PE-LD films used as greenhouse covers involves a wide number of interrelated phenomena, including chemical deterioration brought on by interactions with air pollutants and agrochemicals, photo-degradation brought on by reactions aided by UV light, and ultimately mechanical degradation brought on by bond ruptures brought on by mechanical stress [26; 27].