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Bucharest, Romania

Jecu L.,Romanian National Institute for Research and Development in Chemistry and Petrochemistry | Gheorghe A.,Romanian National Institute for Research and Development in Chemistry and Petrochemistry | Rosu A.,Romanian National Institute for Research and Development in Chemistry and Petrochemistry | Raut I.,Romanian National Institute for Research and Development in Chemistry and Petrochemistry | And 2 more authors.
Journal of Polymers and the Environment | Year: 2010

The aim of this work was to select a fungal strain with degradative potential upon PVA based materials. The polymeric materials tested were PVA films which contain different percentages of PVA, starch and glycerol. These materials are of interest for food packaging applications, which presume to solve the problems concerning accumulation, disposal and degradation. Eleven strains were tested in solid culture for the ability to use PVA based composites as carbon and energy sources. The fungal strain selected was cultivated in liquid medium with different compositions. The scanning electron microscopy (SEM) investigations revealed the effects of microorganism growth upon polymeric films. Significant changes in polymer surface aspects were observed depending on the medium culture composition, the presence of supplementary carbon source facilitating microbial growth and degradation process. © 2010 Springer Science+Business Media, LLC. Source


Popescu M.C.,Petru Poni Institute of Macromolecular Chemistry | Vasile C.,Petru Poni Institute of Macromolecular Chemistry | Macocinschi D.,Petru Poni Institute of Macromolecular Chemistry | Lungu M.,Science INCERPLAST SA | Craciunescu O.,Romanian National Institute for Research and Development for Biological Sciences
International Journal of Biological Macromolecules | Year: 2010

In this paper biomaterials based on various polyurethane formulations have been physically characterized by FT-IR spectroscopy, contact angle measurements, DSC, TG/DTG and SEM methods. It has been established that the transition temperatures of soft and hard segments of polyurethane (glass transition or melting) depend on the blend composition. The melting temperature varies from 54.2 to 81.9 °C for soft segments, and from 220 to 235 °C for hard segments. FT-IR spectrometry allows identifying the functional groups involved in interactions and consequently the changes in polymer chain mobility. From SEM images, is evident that polyurethanic film is porous and spongious. By adding of the others components such as hydrolyzed collagen, elastin, chondroitin sulfate or hyaluronic acid, a reduction of porosity of films was obtained. © 2010 Elsevier B.V. Source


Rapa M.,Science INCERPLAST SA | Grosu E.,Science INCERPLAST SA | Vuluga Z.,ICECHIM | Scheau A.,Science INCERPLAST SA | Stanescu C.,Science INCERPLAST SA
Materiale Plastice | Year: 2010

A biodegradable blend based on low-density polyethylene (LDPE) and 36 % starch that can be used for horticultural application was studied. The mechanical properties and the processing by molding injection were also studied. It is found that the starch helps to increase surface area on which the microorganism can attack the polymer matrix. The increase in the carboxyl index, which indicates the concentration of carboxyl blend, with time, also indicates the progress of biodegradation. Although this type of blend is not completely biodegradable it is preferred to those completely biodegradable which are expensive and with many processing problems. Source


Rapa M.,Science INCERPLAST SA | Grosu E.,Science INCERPLAST SA | Degeratu C.,Polytechnic University of Bucharest | Scheau A.,Science INCERPLAST SA | Stanescu C.,Science INCERPLAST SA
Materiale Plastice | Year: 2010

In this study, blends of biodegradable matrix as poly(3-hydroxybutyrate) (PHB) and fibers provided by renewable resources were prepared by a melt blending method. Improvement of the compatibility between fibers and polymer was studied using coupling agents: maleic anhydride (MA) respectively, succinic anhydride (SA). Mixtures with two types of fibers were investigated in terms of microscopy, torque, density, tensile strength, melting temperature and contact angle. It is found that the mechanical properties of PHB with cellulose fibers blends were better than PHB and wood fibers. Source


Rapa M.,Science INCERPLAST SA | Popa M.E.,University of Bucharest | Grosu E.,Science INCERPLAST SA | Geicu M.,University of Bucharest | Stoica P.,Science INCERPLAST SA
Romanian Biotechnological Letters | Year: 2011

Biodegradation studies of PHB with wood fibers/celluloze fibers composites were performed. These materials are of interest for food packaging applications, which presume to solve the problems concerning accumulation, disposal and degradation. The samples in the form of composite films were prepared by blending in BRABENDER Plastograph. Examined films were incubated in the presence of the Penicillium sp. isolated from soil. Degree of colonization and surface morphology of the films with an optical microscope were observed. The loss of mass was estimated. Fourier Transform Infrared (FTIR) spectroscopy was used to monitor the development of degradation products, the structural change by effect of microorganism on the samples. The results of the study have shown that Penicillium sp. was capable of degrading PHB samples. © 2011 University of Bucharest. Source

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