The effect of different variables on the accelerated and natural weathering of agricultural films

Espí, Enrique; Salmerón, A.; Fontecha, A.; García, Y.; Real, A. I.

doi:10.1016/j.polymdegradstab.2006.12.016

Cited by 21 publications

(14 citation statements)

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“…21,48,[78][79][80] Sulfur containing and halogenide pesticides were found to cause decrease in performance of HAS. 78 A large number of alkoxy radicals are formed due to the interaction of sulfur and the HAS.…”

Section: Effect Of Pesticidesmentioning

confidence: 98%

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Stability of Uv Stabilizers

2015

Handbook of UV Degradation and Stabilization

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Section: Effect Of Pesticidesmentioning

confidence: 98%

“…21 Stability of agricultural films is frequently the most affected by this action. 80 bility is similar, but it widely differs when differently stabilized formulations are affected by pesticides.…”

Section: Effect Of Pesticidesmentioning

confidence: 99%

Stability of Uv Stabilizers

2015

Handbook of UV Degradation and Stabilization

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“…Although the aging process can be greatly accelerated through the use of accelerated weathering chambers, this option was ruled out, because real outdoor exposure is difficult to reproduce in such conditions (Espí et al, 2007). The representativeness, and therefore the usefulness, of results obtained with accelerated weathering chambers for prediction of durability is discussed (Mallon et al, 2002;Adams, 2000).…”

Section: Polymer Weatheringmentioning

confidence: 99%

“…Additionally, some polymers are commercialised in the shape of small-celled honeycomb structures to be used as insulators, which may be useful to obtain adequate flow regimes in photocatalytic reactors (Wong et al, 2007). However, the easy thermal-and photo-degradation of polymers, beneficial to obtain self-degrading or self-sterilizing properties, poses a difficulty for the synthesis of durable, UV-transparent and photocatalytically active materials (Espí et al, 2007;Shang et al, 2003;Kubacka et al, 2007;Zhao et al, 2007;Cho and Choi, 2001). Many polymers show maximum sensitivity for bond dissociation in the range of 290-400 nm and consequently are photostabilized for commercial use at the expense of their UV transmittance (Feldman, 2002;Allen et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of several commercial polymers as support for TiO2 in photocatalytic applications

2014

Global NEST Journal

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This work is aimed to select the best synthetic polymers available in the market with high transmittance in the TiO2 activation range that can be coated with the semiconductor and withstand the photocatalytic oxidation conditions. Among eleven commercial organic polymers with different additives and processing techniques, only polypropylene, polystyrene, sheet moulding processed poly (methyl methacrylate) and rigid polyvinyl chloride presented transmittances higher than 80% at 360 nm , which allows irradiation there through. The selected polymers were coated without a calcination step with anatase-TiO2 obtained by sol-gel. Their weathering was studied during 150 days of exposure to solar radiation, with and without the TiO2 layer. It was observed that only poly (methyl methacrylate) retains the titania and the good optical and mechanical properties after the natural weathering, and thus is the best candidate for immobilization of TiO2 for air photocatalytic treatment applications.

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“…Film lifespan is also affected by agrochemicals commonly sprayed by the growers due to a generation of by products that lead to a deterioration of the covering materials together with a variation in their mechanical and physical properties (Khan and Hamid, 1995;Espí et al;Rull and Marin, 2006). The degradation due to agrochemicals depends on their active principles, application method and frequency, ventilation and greenhouse structure (Dilara and Briassoulis, 2000).…”

Section: Introductionmentioning

confidence: 99%

Effects of agrochemicals, ultra violet stabilisers and solar radiation on the radiometric properties of greenhouse films

Vox

Schettini

2013

J Agricult Engineer

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Agrochemicals, based on iron, sulphur and chlorine, generate by products that lead to a degradation of greenhouse films together with a decrease in their mechanical and physical properties. The degradation due to agrochemicals depends on their active principles, method and frequency of application, and greenhouse ventilation. The aim of the research was to evaluate how agrochemical contamination and solar radiation influence the radiometric properties of ethylene-vinyl acetate copolymer greenhouse films by means of laboratory and field tests. The films, manufactured on purpose with the addition of different light stabiliser systems, were exposed to natural outdoor weathering at the experimental farm of the University of Bari (Italy; 41° 05' N) in the period from 2006 to 2008. Each film was tested for two low tunnels: one low tunnel was sprayed from inside with the agrochemicals containing iron, chlorine and sulphur while the other one was not sprayed and served as control. Radiometric laboratory tests were carried out on the new films and on samples taken at the end of the trials. The experimental tests showed that both the natural weathering together with the agrochemicals did not modify significantly the radiometric properties of the films in the solar and in the photosynthetically active radiation wavelength range. Within six months of experimental field tests the variations in these radiometric characteristics were at most 10%. Significant variations, up to 70% of the initial value, were recorded for the stabilised films in the long-wave infrared radiation wavelength range. IntroductionThe radiometric properties of covering greenhouse films influence both the energy balance of the greenhouse and the crop behaviour (Kittas and Baille, 1998;Papadakis et al., 2000;Vox et al., 2010). The microclimate of the protected volume modifies the growing conditions of the crop in comparison with the external climatic conditions according to the quantity and quality of the solar radiation passing through the covering. The stability over time of the radiometric properties of the film during the crop cultivation cycle is an important goal for growers.Physical and mechanical properties decrease when the plastic film covering degrades in the field by discolouration, cracking of the surface, and stiffening. The average service life of plastic greenhouse films depends on parameters related both to the film itself and to the environment in which the film is used (Briassoulis, 2005;Briassoulis and Schettini, 2003;Desriac, 1991; Briassoulis, 1998, 2000;Khan and Hamid, 1995;Martin-Closas et al., 2008;Ruiz et al., 2006), varying from 3-6 months, for one cultivation season, to a maximum of 3-4 years in the Mediterranean area. The ultra violet (UV) radiation in the solar spectrum absorbed by the plastic films is one of the factors that have the biggest influence on the ageing and degradation process (Nijskens et al., 1990;Dilara and Briassoulis, 1998). The UV radiation, especially the UV-B and UV-A radiation that occurs in the ...

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The effect of different variables on the accelerated and natural weathering of agricultural films

Cited by 21 publications

References 1 publication

Stability of Uv Stabilizers

Stability of Uv Stabilizers

Evaluation of several commercial polymers as support for TiO2 in photocatalytic applications

Effects of agrochemicals, ultra violet stabilisers and solar radiation on the radiometric properties of greenhouse films

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