The Degradation Behavior of TPS/LDPE Blend Mulch Films Prepared with Different Pro-oxidants (original) (raw)
Related papers
A z yoğunluklu polietilen (AYPE) tarımda yaygın olarak kullanılan plastiklerden biridir ve LDPE'den üretilen malç filmlerin bozunabilirliği termoplastik nişasta (TPN) eklenmesi ile artırılmaktadır. Bu çalışmada, bileşiminde %20'den %40'a kadar değişen oranlarda TPN bulunan TPN/LDPE karışımları çift vidalı karıştırıcı kullanılarak hazırlandı. TPN'nın ara yüzey yapışmasını geliştirmek ve matris içinde daha iyi dağılmasını sağlamak için, sitrik asit ve stearik asit uyumlulaştırıcıları ilave edildi. Bozunmayı hızlandırmak için kobalt(II) asetilasetonat pro-oksidan olarak kullanılmıştır. Malç filmler bozunması için 180 gün Coriolus versicolor (L.) Quél ve Postia plasenta (Fr.) M.J. Larsen & Lombard ile aşılanmış topraklara gömüldü. Filmlerin kimyasal yapılarındaki değişiklikler toprağa gömülmeden önce ve sonra FTIR spektroskopisi ile değerlendirildi. Tüm örneklerin ağırlık kaybı 180 gün biyobozunmadan sonra ölçüldü ve artan nişasta içeriği ile ağırlık kaybının hızlandığı görüldü. Uyumlaştırıcıların, malç karışımların ısıl, mekanik ve morfolojik özelliklerine etkileri TGA, mekanik testler ve SEM ile belirlenmiştir. Kobalt(II)asetilasetonat sitrik asit ile birlikte kullanıldığında TPN'nın filmlerdeki ısıl kararlılığı gelişmiştir. Aynı zamanda, sitrik asit ile hazırlanan filmler stearik asit ile kıyasla kopma anında daha yüksek uzama değerleri göstermiştir. Anahtar Kelimeler AYPE, termoplastik buğday nişastası, pro-oksidan, uyumlaştırıcı. A B S T R A C T L ow density polyethylene (LDPE) is one of the most widely used plastic in agriculture and the degradability of mulch film is increased by introducing thermoplastic starch (TPS) into the LDPE. In this study, TPS/LDPE blends were prepared by twin screw compounder and TPS content is varied from 20 to 40%. To improve the interfacial adhesion and dispersion of TPS, citric acid and stearic acid were added as compatibilizers. To accelerate the degradation cobalt(II)acetylacetonate was used as a pro-oxidant. The blended mulch films were buried in soil inoculated with Coriolus versicolor (L.) Quél. and Postia placenta (Fr.) M.J. Larsen & Lombard for 180 days for the degradation. The changes in the chemical structures of the films were evaluated by FTIR spectroscopy before and after soil burial treatment. The weight loss of all samples achieved after 180 days of biodegradation and increasing starch content speeded up the weight loss. The effects of compatibilizers on thermal, tensile and morphological properties of blends were determined by TGA, mechanical and SEM analysis. When cobalt(II)acetylacetonate used together with citric acid, the thermal stability of TPS in films was enhanced. It was also found that samples with citric acid exhibited higher elongation at break values compared to films with stearic acid.
2016
Az yoğunluklu polietilen (AYPE) tarımda yaygın olarak kullanılan plastiklerden biridir ve LDPE’den üretilen malç filmlerin bozunabilirliği termoplastik nişasta (TPN) eklenmesi ile artırılmaktadır. Bu çalışmada, bileşiminde %20’den %40’a kadar değişen oranlarda TPN bulunan TPN/LDPE karışımları çift vidalı karıştırıcı kullanılarak hazırlandı. TPN’nın ara yüzey yapışmasını geliştirmek ve matris içinde daha iyi dağılmasını sağlamak için, sitrik asit ve stearik asit uyumlulaştırıcıları ilave edildi. Bozunmayı hızlandırmak için kobalt(II) asetilasetonat pro-oksidan olarak kullanılmıştır. Malç filmler bozunması için 180 gün Coriolus versicolor (L.) Quél ve Postia plasenta (Fr.) M.J. Larsen & Lombard ile aşılanmış topraklara gömüldü. Filmlerin kimyasal yapılarındaki değişiklikler toprağa gömülmeden önce ve sonra FTIR spektroskopisi ile değerlendirildi. Tüm örneklerin ağırlık kaybı 180 gün biyobozunmadan sonra ölçüldü ve artan nişasta içeriği ile ağırlık kaybının hızlandığı görüldü. Uyumlaşt...
Effect of Pro-Oxidant Additives on Degradation of Mulch Film Based on Recycled Polyethylene
2015
The effect of pro-oxidant additives (Iron, Cobalt and Manganese stearates) on the biodegradation of recycle polyethelene mulching films was studied in both accelerated weather and natural exposure conditions. The degradation degree of film was determined by measuring mechanical properties and scanning electronic microscope (SEM). The results showed that the mechanical properties of film samples with pro-oxirant additives decreased rapidly, and that surface film with additives was degraded clearly compared to the films without additives after 30 cycles of accelerated weather. Reliability in terms of acceleration are 28 - 30 cycles of exposure and in the natural conditions reached 10-12 months.
Chemosphere, 2008
The objective of this work was to study the use of new biodegradable films in agriculture under open field conditions. Three biodegradable mulch films made from modified biodegradable polyester of different thicknesses and colors (black and white) and a conventional low density polyethylene (LDPE) mulch film were used to cover the beds of tomato plants. Changes in physical appearance of the films were recorded as well as changes in their mechanical, optical, and physical properties. Once tomato harvest was completed, the conventional LDPE mulch film was removed and all the tomato plants were cut using a mower. The biodegradable mulch films were plowed into the soil. The change in the appearance of the film was recorded and samples of each film after plowing were characterized according to the properties mentioned above.
Assessment of aliphatic–aromatic copolyester biodegradable mulch films. Part I: Field study
Chemosphere, 2008
The objective of this work was to study the use of new biodegradable films in agriculture under open field conditions. Three biodegradable mulch films made from modified biodegradable polyester of different thicknesses and colors (black and white) and a conventional low density polyethylene (LDPE) mulch film were used to cover the beds of tomato plants. Changes in physical appearance of the films were recorded as well as changes in their mechanical, optical, and physical properties. Once tomato harvest was completed, the conventional LDPE mulch film was removed and all the tomato plants were cut using a mower. The biodegradable mulch films were plowed into the soil. The change in the appearance of the film was recorded and samples of each film after plowing were characterized according to the properties mentioned above.
How Performance and Fate of Biodegradable Mulch Films are Impacted by Field Ageing
Journal of Polymers and the Environment, 2017
Three black biodegradable films based on PBAT-blends (PBAT/PLA, PBAT/PPC and PBAT/Starch) were tested for vine mulching in real field conditions. The impact of field ageing on their morphology, mechanical performance and ultimate biodegradation was investigated on films exposed at the soil surface or buried into the soil in order to assess the respective contribution of the main related ageing factors i.e. UV radiations and microorganisms. The fact that the soil-facing surface of films exhibited holes 18 months after installation suggested that the biodegradation process could occur above-soil even without previous burying step. However, the early loss of integrity of the biodegradable materials was attributed to UV radiations since beyond a certain threshold the photochemical modifications undergone by the material were too high to sustain its integrity. Whatever the material tested the deterioration of mechanical properties was correlated with the crosslinking of polymer chains inducing the formation of a gel fraction. Considering that the major part of the three materials studied is made of PBAT, the nature of the other polymer constituting the blend would not have a significant impact on the ageing mechanism of the material. Biodegradation analyses conducted in compost medium indicated that field ageing had a low impact on the percentages of mineralization whether the materials had been previously aged or not.
Journal of Agricultural Engineering, 2013
The use of plastic mulching films in horticulture causes the serious drawback of huge amount of wastes to be disposed of at the end of their lifetime. Several pre-competitive research products based on raw materials coming from renewable sources were recently developed to be used as biodegradable materials for soil mulching. Biodegradable materials are designed in order both to retain their mechanical and physical properties during their using time and to degrade at the end of their lifetime. These materials can be integrated directly in the soil in order to biodegrade because the bacterial flora transforms them in carbon dioxide or methane, water and biomass. The innovative materials can be obtained using natural polymers, such as starch, cellulose, chitosan, alginate and glucomannan. Biodegradable extruded mulching films were performed by means of thermo-plasticizing process. Spray mulch coatings were realized directly in field, by spraying water solutions based on natural polysaccharides, thus covering the cultivated soil with a protective thin geo-membrane. In this paper an overview on the formulation development, processing understanding, field performance, mechanical and radiometric properties of these innovative materials for soil mulching is presented. In field the biodegradable mulching films showed suitable mechanical properties if compared to the low density polyethylene films. The radiometric properties and their effect on the temperature condition and on weed control in the mulched soil were evaluated too. At the end of their lifetime the biodegradable materials were shattered and buried into the soil together with plants.
Polymer Testing, 2021
The use of plastic much films has been fundamental to promoting food production in many regions of the world. However, concern is growing about the progressive accumulation of plastic residues in soil after crop harvest and its subsequent impact on soil health and potential to enter the food chain. Although biodegradable films have been developed to prevent these problems, it is still unclear whether they are environmentally benign. Here we evaluated the physical and chemical breakdown of four commercial poly(butylene adipate-co-terephthalate) based biodegradable mulch films (BMF1, BMF2, BMF3 and BMF4) in an agricultural soil over a 26-month period. Based on visual examination, degradation followed the series BMF4 > BMF1, BMF2 > BMF3. Importantly, microplastic residues (fragments <5 mm) still remained in the soil of all 4 plastic types after 2 years, suggesting that they are likely to accumulate over time if used on an annual basis. Viscosimetry, Fourier transform infrared (FTIR) spectroscopy and Thermogravimetric Analysis (TGA) were used to characterise the breakdown process. Our results indicated that the degradation of the mulch film after burial in agricultural soil may be linked to the nature of the polymer but also to its manufacturing formulation. Although the peak changes of polyester in the infrared spectrum were not distinct, the plastic films showed other signs of degradation including a reduction in intrinsic viscosity after burial in soil. The different degradation rates of BMF1 and BMF2 at the molecular level may be due to the different CaCO 3 contents. In conclusion, under field conditions, we show that slight variations in the formulations of commercial biodegradable mulch films leads to very different persistence rates in soil. Further, we conclude that their slow rate of degradation will ultimately lead to their progressive accumulation in soil if used repeatedly.
Polymer Degradation and Stability, 2006
The use of plastic materials in agriculture causes the serious drawback of huge quantities of waste. The introduction of biodegradable materials, which can be disposed directly into the soil, can be one possible solution to this problem. Biodegradable materials are actually innovative materials; therefore, their physical properties must be evaluated in relation to their functionality during the use in field. In the present research results of experimental tests carried out on biodegradable films used in strawberries protected cultivation are presented. The decay of some relevant physical parameters of biodegradable films during the cultivation period was monitored by laboratory tests (SEM analysis, mechanical tensile tests and infrared reflectance spectroscopy). Infrared spectroscopy clearly indicated that the mechanical degradation starts from the starch component of the material. Tensile tests showed that the value of elongation at break of biodegradable materials decreased in some cases by 300% after 10 days of field application.