Search results for " polymer degradation"

showing 5 items of 5 documents

Frequency-Downconversion Stability of PMMA Coatings in Hybrid White Light-Emitting Diodes

2015

We report on the properties of a poly(methyl methacrylate)-based coating used as a host for an organic dye in hybrid white light-emitting diodes. The device is composed by a pump source, which is a standard inorganic GaN/InGaN blue light-emitting diode (LED) emitting at around 450 nm, and a spin-coated conversion layer making use of Lumogen® F Yellow 083. Under prolonged irradiation, the coating exhibits significant bleaching, thus degrading the color rendering performance of the LED. We present experimental results that confirm that the local temperature rise of the operating diode does not affect the conversion layer. It is also proven that, during the test, the photostability of the orga…

Materials scienceInfraredSettore AGR/13 - Chimica Agraria02 engineering and technologyengineering.materialSettore ING-INF/01 - Elettronica01 natural sciencesCoating0103 physical sciencesMaterials ChemistryElectrical and Electronic EngineeringPhotodegradationDiode010302 applied physicschemistry.chemical_classificationSpin coatingbusiness.industryPMMA hybrid LEDs Lumogen polymer degradation photostability spin coatingPolymer021001 nanoscience & nanotechnologyCondensed Matter PhysicsElectronic Optical and Magnetic MaterialsColor rendering indexchemistryengineeringOptoelectronics0210 nano-technologybusinessLayer (electronics)Journal of Electronic Materials

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Stability improvement of PMMA and Lumogen® coatings for hybrid white LEDs

2014

Hybrid white LEDs employing perylene-based dyes for the frequency down-conversion of blue light, generated by a standard inorganic source, suffer from colour rendering variations due to the degradation of the organic molecule under prolonged irradiation. To avoid such inconvenient, proper encapsulation of the dyes in resins or other polymer matrices can prevent their accelerated ageing; nevertheless, embedding polymers can also exhibit significant bleaching caused by chemico-physical agents. Among all, polymethyl methacrilate (PMMA) is one of the most used materials for the fabrication of hybrid LEDs' colour conversion coatings, therefore its stability needs to be investigated.

PMMA white LEDs hybrid LEDs perylene-based dyes Lumogen® polymer degradation LED optical characterization spin coating.Settore ING-INF/01 - Elettronica

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Photo-Oxidative and Soil Burial Degradation of Irrigation Tubes Based on Biodegradable Polymer Blends

2019

: Irrigation tubes based on biodegradable polymers were prepared via an extrusion-drawing process by Irritec and compared to conventional pipes made of high-density polyethylene (HDPE). A commercial polylactide/poly (butyleneadipate-co-butyleneterephthalate) (PLA/PBAT) blend (Bio-Flex&reg

biodegradable polymers; rheological properties; irrigation pipes; soil burial test; polyesters; Bio-Flex®; Mater-Bi®; polymer degradation; photo-oxidationIrrigationMaterials sciencePolymers and PlasticsBio-Flex®polymer degradationIrrigation pipePolyester02 engineering and technologyMater-Bi®polyesters010402 general chemistry01 natural sciencesArticlelcsh:QD241-441chemistry.chemical_compoundPolymer degradationlcsh:Organic chemistryBiodegradable polymerRheological propertieIrradiationirrigation pipeschemistry.chemical_classificationsoil burial testGeneral ChemistryPolymerPolyethylene021001 nanoscience & nanotechnologyBiodegradable polymerphoto-oxidation0104 chemical sciencesrheological propertiesChemical engineeringchemistrybiodegradable polymersDegradation (geology)Bio-Flex®High-density polyethylene0210 nano-technologyMater-Bi®Polymers

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Comparative Investigation on the Soil Burial Degradation Behaviour of Polymer Films for Agriculture before and after Photo-Oxidation

2020

Polymer films based on biodegradable polymers, polyethylene (PE) and modified PE with oxo-degradable additive were prepared by film blowing. Carbon black (1%) was added to all the films. Commercial biodegradable Ecovio&reg

polyethyleneEcovio®Materials sciencemulch filmsPolymers and Plasticspolymer degradation02 engineering and technologyMater-Bi®010402 general chemistry01 natural sciencesArticlelcsh:QD241-441chemistry.chemical_compoundPolymer degradationlcsh:Organic chemistrySoil retrogression and degradationbiodegradable polymers; mulch films; soil burial test; Ecovio®; Mater-Bi®; polylactide; poly(butyleneadipate-co-butyleneterephtalate); polyethylene; polymer degradation; photooxidationchemistry.chemical_classificationsoil burial testGeneral ChemistryPolymerCarbon blackPolyethyleneBiodegradation021001 nanoscience & nanotechnologyBiodegradable polymerphoto-oxidation0104 chemical sciencesSettore ING-IND/22 - Scienza E Tecnologia Dei MaterialichemistryChemical engineeringbiodegradable polymerspolylactidepoly(butyleneadipate-co-butyleneterephtalate)Biodegradable polymers Ecovio® Mater-Bi® Mulch films Photo-oxidation Poly(butyleneadipate-co-butyleneterephtalate) Polyethylene Polylactide Polymer degradation Soil burial testDegradation (geology)Ecovio®poly(butyleneadipate-co-butyleneterephtalate)0210 nano-technologyMater-Bi®Polymers

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Influence of Calcium Carbonate Nanoparticles on the Soil Burial Degradation of Polybutyleneadipate-Co-Butylenetherephthalate Films.

2022

A polybutyleneadipate-co-butylenetherephthalate (PBAT) sample, commercially known as Ecoflex®, was processed via melt extrusion with CaCO3 nanoparticles coated with a hydrophobic coating. Blown films of PBAT and two composites with nanofiller (2% and 5%wt) were prepared and degradation tests in soil at 30 °C up to 180 days were carried out with weight loss measurements. Furthermore, biodegradation test according to ISO 14851 was carried out at 30 °C. The effect of CaCO3 on soil burial degradation was assessed by surface wettability and SEM. ATR-FTIR and XPS analyses highlighted chemical modifications induced by soil degradation. CaCO3 nanoparticles decreased surface wettability …

soil burial testGeneral Chemical Engineeringpolymer degradationEcoflex®Settore CHIM/05 - Scienza E Tecnologia Dei Materiali Polimericibiodegradable polymers; soil burial test; Ecoflex®; poly(butyleneadipate-co-butyleneterephtalate); calcium carbonate; nanoparticles; polymer degradationSettore ING-IND/22 - Scienza E Tecnologia Dei MaterialiSettore CHIM/03 - Chimica Generale E Inorganicabiodegradable polymersGeneral Materials Sciencecalcium carbonatenanoparticlespoly(butyleneadipate-co-butyleneterephtalate)Settore CHIM/02 - Chimica FisicaNanomaterials (Basel, Switzerland)

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