The Effects of Citric Acid and Stearic Acid Compatibilizers on the Degradation Behavior of TPS/LDPE Blends for Mulch Films Sitrik Asit ve Stearik Asit Uyumlaştırıcılarının TPN/AYPE Karışımı Malç Filmlerinin Bozunma Davranışı Üzerine Etkileri (original) (raw)
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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...
The Degradation Behavior of TPS/LDPE Blend Mulch Films Prepared with Different Pro-oxidants
Kısmen bozunabilen malç filmleri hazırlamak için az yoğunluklu polietilen (AYPE), termoplastik nişasta (TPN) ile çift vidalı ekstruder yardımıyla karıştırıldı. Bu çalışmada, demir(III) stearat ve manganez(II) stearat pro-oksidan olarak kullanılmışve farklı pro-oksidanların karışımların bozunması üzerindeki etkisi incelenmiştir. Malç filmler Coriolus versicolor (L.) Quel ile aşılanmış toprağa gömülerek 180 gün boyunca degrede edilmiştir. Filmlerin kimyasal yapıları FTIR spektroskopisi ile belirlenmiş ve tüm numunelerin ağırlık kaybı toprakta bozunma öncesi ve sonrası ölçülmüştür. İki farklı pro-oksidanın, malç karışımların ısıl ve germe özellikleri üzerine etkisi TGA ve mekanik analiz ile tespit edilmiştir. Demir (III) stearat ve sitrik asitin birlikte kullanılmasıyla sinerjik bir etki gözlenmiştir. Her ikisinin birlikte kullanıldığı karışımlarda TPN'nin yüksek ısıl kararlılık gösterdiği bulunmuştur. Ayrıca, mekanik özelliklerinde belirgin düzelme gözlenmiştir. Bununla birlikte, manganez(II) stearat sitrik asit ile birlikte kullanıldığında stearik asitli karışımlarına kıyasla daha zayıf mekanik özellikler göstermiştir. Anahtar Kelimeler AYPE, termoplastik nişasta, pro-oksidan, demir stearat, manganez(II) stearat. A B S T R A C T L ow density polyethylene (LDPE) was blended with thermoplastic starch (TPS) by twin screw compounder to prepare partially degradable mulch films. In the present study, ferric stearate and manganese(II) stearate were used as pro-oxidant and the effect of different pro-oxidants on the degradation of the blends were investigated. The blended mulch films were buried in soil inoculated with Coriolus versicolor (L.) Quél. for 180 days for the degradation. The chemical structures of the films were evaluated by FTIR spectroscopy and the weight loss of all samples was measured before and after soil burial treatment. The effects of two different pro-oxidants on thermal and tensile properties of blends were determined by TGA and mechanical analysis. A synergetic effect between ferric stearate and citric acid was observed. Using both in the blends resulted in higher thermal stability of TPS in the blends. Significant improvement of the mechanical properties was also observed. However, when manganese(II) stearate used together with citric acid a decrease in the mechanical properties was observed compared blends with stearic acid.
Boletim do Instituto de Pesca, 2018
O objetivo deste trabalho foi desenvolver e caracterizar filmes biodegradáveis de proteínas miofibrilares de aparas da filetagem da corvina (Micropogonias furnieri) utilizando ácido esteárico (AE) para melhorar suas propriedades tecnológicas. As proteínas extraídas foram liofilizadas, caracterizadas e utilizadas na elaboração dos filmes. As soluções filmogênicas foram secas em suporte de silicone a 35°C por 14 horas em estufa incubadora, de acordo com o método casting. A região com as melhores propriedades mecí¢nicas, físicas e de barreira dos filmes foi definida por planejamento fatorial completo. As proteínas miofibrilares liofilizadas (PML) apresentaram teor proteico de 96,03%. A análise dos resultados do planejamento experimental indicou que as melhores condições para elaborar o filme otimizado foram: 2,84% PML, 3,18% AE e 78,41% SDS (dodecil sulfato de sódio). Os filmes controles foram elaborados com 2,84% de PML e 30% de plastificante. O filme otimizado apresentou...
Química Nova, 2007
Recebido em 24/3/06; aceito em 15/9/06; publicado na web em 26/3/07 INFLUENCE OF PLASTICIZER ADDITION AND CROSSLINKING PROCESS ON MORPHOLOGY, WATER ABSORPTION AND MECHANICAL PROPERTIES OF SODIUM ALGINATE FILMS The effects of sorbitol and formaldehyde on the morphology, water absorption and mechanical properties of sodium alginate films were analyzed. The morphology of the films indicated the presence of small aggregates in the surface of uncrosslinked films, which disappeared with the crosslinking process. The water uptake and percentage of elongation increased with the addition of sorbitol in uncrosslinked films. At the same time, a decrease in tensile strength and Young's modulus occurred. The swelling ratio and water uptake of crosslinked alginate/sorbitol films decreased with an increase in sorbitol content suggesting an enhanced crosslinking density due to the presence of plasticizer.
The Effects of Citric Acid on Thermal and Mechanical Properties of Crosslinked Starch Film
Chemical engineering transactions, 2021
Plastic waste from film packaging is one of the major threats to environmental sustainability. The problem can be reduced by using a biodegradable raw material such as starch to replace the non-biodegradable petroleum-based plastic. However, starch is highly hydrophilic and brittle, which needs to be modified to improve these drawbacks. In this research, a mixture of tapioca starch (S) and glycerol (G) was crosslinked with citric acid (CA) at different ratios (0, 0.4, 0.6, 0.8, 1.0 wt% of dry basis). Effects of CA contents on the degree of crosslinking, thermal stability, and tensile properties were investigated. The sample that contained 0.6 wt% CA showed the highest degree of crosslinking (i.e. 56 %), good thermal stability, high modulus (10 MPa) and tensile strength (0.16 MPa), and low elongation at break (161 %) when compared with other samples. Samples that have higher CA contents (i.e. 0.8 wt% and 1.0 wt%) experienced the acid hydrolysis on the crosslinking site, reducing the ...
New Approach of Starch and Chitosan Films as Biodegradable Mulching
Revista Virtual de Química, 2019
Nova Abordagem dos Filmes de Amido e Quitosana como Mulching Biodegradável Resumo: Os polímeros amido e quitosana podem resultar em filmes biodegradáveis para reduzir a poluição por plástico no ambiente. A adição de quitosana pode melhorar as propriedades dos filmes de amido, bem como a adição de pigmentos auxilia no controle do crescimento de plantas invasoras. O objetivo do presente trabalho foi analisar o comportamento de filmes de amido/quitosana adicionados de pigmentos quando aplicados como mulching. Os valores de resistência a tensão na ruptura não variaram com a formulação, enquanto filmes adicionados com pigmentos foram mais flexíveis. A adição de quitosana reduziu em duas vezes a solubilidade dos filmes quando comparados aos filmes só de amido. Os filmes em contato com o solo apresentaram redução nas propriedades mecânicas, alterações no espectro no infravermelho e nas micrografias, no entanto os filmes não apresentaram fraturas visíveis por 45 dias. Os filmes de amido/quitosana serviram como mulching biodegradável.
2007
Manufacturing of biodegradable films from starch is important due to pollution problems caused by the widespread use of polyethylene. Films were made with oxidized banana starch and glycerol using thermal gelatinization, and casting; an evaluation was made of the color, solubility in water and the thermal behavior of the films. The oxidized starches presented more whiteness than the native ones, and this same pattern was observed in the films that were made. The films presented high values of luminosity L* (93), increasing when the oxidation levels of the starch increased. The solubility in water increased when the temperature and oxidation level of the starch increased. High concentrations of hypochlorite in the oxidation caused higher depolymerization of the starch. The addition of sunflower oil to the filmogenic solution produced the lowest value of solubility (17.6%), which can be associated to the hydrophobic character of oil. The addition of glycerol in the films decreased the...
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.
Journal of Materials Science, 2002
A synthetic approach for the realisation of lifetime controlled biodegradable films is described starting from existing biodegradable polymers. Polyvinylalcohol (PVOH) chains are bridged through functionalised polycaprolactone (PCL) crosslinks directly during extrusion and film lamination. The resulting films are water resistant and their degradation may start only when buried in the soil due to microbial attack of the PCL bridges. The influence of blend composition on the mechanical properties and water sensitivity has been analysed. A thermal annealing is necessary after extrusion in order to complete the crosslinking of the obtained film. A mathematical model has been applied on the film to simulate their "greenhouse" effect. It was found that such films, when used as mulching film in agriculture, have a very interesting thermal response allowing temperatures inside the soil of 40-50 • C, comparable to well known non biodegradable mulching films.