1,720,981 research outputs found
Preparation, characterisation and field-testing of a biodegradable sodium alginate-based spray mulch
No full textAn innovative biodegradable coating that can be sprayed was developed and tested as suitable alternative to low density polyethylene films for soil mulching in horticulture. A mulch was created by spraying over the soil a sodium alginate water-based solution that, at the end of the cultivation cycle, could be tilled into the soil to be biodegraded. The mechanical and radiometric properties, the functionality of the spray coating, and its biodegradation were assessed by means of laboratory measurements and cultivation field tests. In the field, during the cultivation of strawberries, the spray coating was compared with a low density polyethylene mulching film and a straw mulch. The mechanical properties of the coating degraded when exposed in the field, but the coating kept its mulching effect for 6 months. The radiometric properties varied without regular trends, but the coating maintained its capacity to suppress weeds. The biodegradation tests showed that the spray coating samples biodegraded by 65% after 6 months into the soil
Physical Properties of Innovative Spray Biodegradable Coatings for Soil Mulching in Greenhouse Cultivation
No full textIn order to overcome the serious drawback of huge quantities of plastic
waste obtained at the end of the life of agricultural plastic mulching films,
researches on innovative biodegradable materials have been developing. The paper
examines a new sustainable approach in which a water solution of natural
biodegradable polymers is sprayed on a cultivation area in order to form a mulch
coating. The material used is a blend of two polysaccharides, such as Guar Gum and
Locust Bean Gum additivated with glycerol. A protected field experiment was
conducted to test the effectiveness of spray black biodegradable mulching coating in
a tomato crop in Southern Italy. Field performance and physical properties,
evaluated by means of laboratory tests, are compared to those of commercial low
density polyethylene and biodegradable starch based mulch films. The spray
mulching coating is opaque in the solar radiation range and behaved as a black
body. The tested spray coating showed much lower values of tensile stress and
elongation at break in comparison with the values of commercial low density
polyethylene and biodegradable starch based mulch films. Such innovative coatings
were characterised by functionality during their use in field. Results indicate that
the biodegradable spray coatings could be a sustainable alternatives to plastic films
based on fossil raw materials
Acid and base functionalization of ethylene propene rubbers, 3a): "Mechanical and dynamic mechanical characterization of the elastomer networks", Makromol.Chem. 190, 1457-1470 (1989)
No full textStarch-based Films and Spray Coatings as Biodegradable Alternatives to LDPE Mulching Films
No full textBiodegradable starch-based extruded mulching films and biodegradable sprayable water-born polysaccharides based coatings were prepared within two European Projects as an alternative to soil mulching films made of synthetic petro-chemical polymers. The biodegradable mulches, both films and coatings, had appropriate mechanical and physical properties to assure their functionality throughout the crop cycle in relation to the cultivation needs, the geographical region, and the season. The useful lifetime of the biodegradable films and coatings was fully comparable with the low density polyethylene films currently in use: the biodegradable films lasted up to 9 months, the biodegradable coatings up to 6 months. They satisfy the mulching task of weed control during the crop cycle reducing solar PAR radiation reaching the mulched soil and creating a physical barrier preventing airborne weed seeds
How poloxamer addition in hyaluronic-acid-decorated biodegradable microparticles affects polymer degradation and protein release kinetics
No full textPolymeric microparticles (MPs) designed for the intravitreal administration of therapeutic proteins result in a prolonged half-life in the vitreous and can delay or discourage the onset of adverse effects inevitably related to this route of administration. Hence, here we designed MPs composed of a polymeric blend based on poly(lactic-co-glycolic) acid and poloxamers, externally decorated with hyaluronic acid. The MPs are intended for intravitreal administration of bovine serum albumin. In detail, a systematic formulative study aiming to shed light on the complex relationship between protein release rate and MP degradation rate was carried out by means of calorimetric and gel permeation chromatography analyses. We found out that poloxamer addition caused a compact MP matrix, which led to a slight modification of the degradation kinetics and a reduction in the initial BSA initial release, which is of the utmost importance to ensure a relatively regular BSA release. It must also be underlined that for acid-labile molecules such as proteins, the poloxamer’s presence induced complex and hardly predictable effects on MP degradation/protein release, due to the dynamic balance between the time-evolving hydrophilicity of MPs and the influence of poloxamers themselves on the PLGA degradation rate
An overview of biodegradable films and spray coatings as sustainable alternative to oil-based mulching films
No full textThe use of plastic materials in agriculture causes the serious drawback of huge
amount of wastes to be disposed of. In order to overcome this problem a new
generation of biodegradable materials has been developed based on raw materials
coming from renewable source. These materials retain their physical and mechanical
properties during their lifetime and when they are integrated directly in the soil, the
bacterial flora transforms them in carbon dioxide or methane, water and biomass.
Biodegradable films can be made using natural polymers, such as starch, cellulose,
chitosan, alginate and galactomannans. These materials can be obtained by means of
thermoextrusion process, solvent casting and spraying technique. Mulch coatings can
be 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 a focused overview on the formulation development, processing understanding,
field performance and mechanical properties of these innovative materials
for soil mulching is presented, in comparison to oil-based non renewable films. During
their using time in field, the biodegradable mulches showed suitable mechanical
properties if compared to the low density polyethylene films. At the end of their lifetime
the biodegradable materials were shattered and buried into the soil together with
plants. The film residues disposed of in the soil biodegraded in almost 1 month for the
water borne coatings and in about 12 months for the biodegradable starch- based
extruded films
Chapter 3: An Overview on Innovative Biodegradable Materials for Agricultural Applications
No full textThe world consumption of plastic materials in agriculture amounts yearly to 6.5 million tons, among which more then 10 % refers to plastic films for soil mulching. The use of plastic materials causes the serious drawback of huge quantities of waste to be disposed off and in the last decades the growing environmental awareness has been prompting the development of a new generation of materials created starting with raw materials from renewable origin. These materials have to retain their physical and mechanical properties while in use and have to be biodegradable or compostable at the end of their life, degrading via micro-organisms into carbon dioxide or methane, water and biomass.
Within the EU Projects “BIOPLASTICS” and “BIO.CO.AGRI”, several biodegradable materials for soil mulching were prepared using natural polymers, such as starch, cellulose, chitosan, alginate and glucomannan, as pre-competitive research products. These innovative materials were obtained by thermal film forming processes, casting and spraying techniques. Real scale field cultivation tests were carried out from 2001 to 2005 in order to study the relevant physical and mechanical properties, the degradation process, the morphological behaviour and the performance in the field of these materials in comparison to commercial oil based non renewable raw materials.
In this paper a focused overview on the formulation development, processing understanding, field performance and mechanical and radiometric properties of these innovative materials for mulching agricultural application is presented in comparison to oil based non renewable materials. The radiometric properties and their effect on the temperature condition and on weed control in the mulched soil were evaluated. The biodegradable materials could be the environmentally friendly alternatives to synthetic petro-chemical polymers and could contribute to a sustainable agriculture.The world consumption of plastic materials in agriculture amounts yearly to 6.5 million tons, among which more then 10 % refers to plastic films for soil mulching. The use of plastic materials causes the serious drawback of huge quantities of waste to be disposed off and in the last decades the growing environmental awareness has been prompting the development of a new generation of materials created starting with raw materials from renewable origin. These materials have to retain their physical and mechanical properties while in use and have to be biodegradable or compostable at the end of their life, degrading via micro-organisms into carbon dioxide or methane, water and biomass.
Within the EU Projects “BIOPLASTICS” and “BIO.CO.AGRI”, several biodegradable materials for soil mulching were prepared using natural polymers, such as starch, cellulose, chitosan, alginate and glucomannan, as pre-competitive research products. These innovative materials were obtained by thermal film forming processes, casting and spraying techniques. Real scale field cultivation tests were carried out from 2001 to 2005 in order to study the relevant physical and mechanical properties, the degradation process, the morphological behaviour and the performance in the field of these materials in comparison to commercial oil based non renewable raw materials.
In this paper a focused overview on the formulation development, processing understanding, field performance and mechanical and radiometric properties of these innovative materials for mulching agricultural application is presented in comparison to oil based non renewable materials. The radiometric properties and their effect on the temperature condition and on weed control in the mulched soil were evaluated. The biodegradable materials could be the environmentally friendly alternatives to synthetic petro-chemical polymers and could contribute to a sustainable agriculture
Mechanical properties decay and morphological behaviour of biodegradabile films for agricultural mulching in real scale experiment
No full textThe 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 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
Natural and Synthetic Hydroxyapatite Filled PCL: Mechanical Properties and Biocompatibility Analysis
No full textHydroxyapatite (Ca10(PO4)6(OH)2) is one of the most biocompatible
ceramics because it is similar to the mineral constituents of human bone and teeth. Composites of hydroxyapatite (HA) and biodegradable polymers such as polycaprolactone (PCL) are interesting materials for medical applications, especially for bone replacement. With the aim to improve the properties of biodegradable polyester-based devices, we have prepared and characterized novel composites made of polycaprolactone and natural or synthetic hydroxyapatite.
The composites were screened for cytocompatibility by a direct contact method, in view of the future application of these hydroxyapatite filled PCL polymers as scaffolds for bone engineering. Primary cultures of human bone marrow mesenchymal stem cells (MSC) were selected as the most appropriate models to study the in vitro performance of these materials. The results showed that all materials have good biocompatibility and allow expression of the osteoblastic features. Scanning electron microscopy provided direct evidence of intense cell adhesion and proliferation on the tested materials
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