The aim of this work was the development and characterization of polymer-based nanocomposite materials to be employed as barrier coatings for packaging and optoelectronic devices. The following systems were analyzed: • Lumeta, produced by the functionalization of a commercial chlorotrifluoroethylene vinyl ether (CTFEVE) copolymer, Lumiflon LF-910LM, with a 2-isocyanatoethyl methacrylate (IEM) to obtain a photo-curable material. • Lumata-layered filler nanocomposites, obtained by dispersing a nanolayered silicate inside Lumeta, which acts as matrix. Two different layered silicate were mixed with Lumeta: Dellite 43B and Dellite 72T • Lumeta-particles nanocomposites, produced by mixing nanometric particles of fumed silica inside Lumeta. • Hybrid organic-inorganic sol-gels, based on LumetaSil. LumetaSil is a resin produced using triethoxysilyl propyl isocyanate (IPTES) and 2-isocyanatoethyl methacrylate (IEM) as functionalizing agents. The heat necessary for the thermally-activated crosslinking, caused by the functionalization with IPTES, was provided by the exothermicity of the photo-curing process. LumetaSil resin was used to produce hybrid organic-inorganic sol-gels with two different silica content. Two different sol-gels were developed, classified according to the content of silica: LumetaSil h-Si (high silica, L23Si77) and LumetaSil l-Si (low silica, L40Si60). Therefore, a total of six different coatings was studied. All these systems were diluted in a determined solvent with a determined ratio dry polymer mass over solvent mass. Each system was characterized by a proper solution formulation process. To obtain coatings, a photoinitiator was added to the solution before deposition. After deposition, the coatings are subjected to UV curing inside a chamber filled with inert gas (N2) to ensure evaporation of solvent. The coatings obtained with this procedure were then characterized with optical microscopy, solvent rub test, x-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, UV-vis spectroscopy, optical contact angle measurements and rheological analysis. The latter was also used on liquid solutions without the presence of the photoinitiator. All the developed systems showed optical characteristics that makes them eligible for applications in optoelectronics and outdoor applications. The nanocomposite coatings are limited to low concentrations of the nanofiller (max. 4% wt. with respect to dry polymer mass). Thermal characterizations showed that LumetaSil-based gels are not suitable to be used in outdoor applications due to thermally-induced deformations and physical damages that may occur when the coating is heated to temperatures slightly higher than room temperature. TGA analysis results proved that Lumeta-fumed silica nanocomposites are characterized by easier solvent evaporation, therefore their permeability must be higher than the ones of the other studied systems. After these characterizations, the coatings Lumeta, Lumeta- Dellite 43B and Lumeta-Dellite 72T were subjected to swelling tests to try to find some indications on the permeability of the coatings. The behavior exhibited by Lumeta samples when submerged inside a solvent showed that bulky molecules can penetrate the coatings in very low amount. Besides, layered nanocomposites showed a lower permeability than the permeability showed by pristine Lumeta. In conclusion, Lumeta-nanoclay systems show good enough thermal and optical properties to be employed as barrier coatings on optoelectronic devices and in packaging applications. Nanocomposite systems are limited to coatings containing low concentration of nanofiller (max. 4% wt. with respect to dry polymer mass).
L’obiettivo di questo lavoro di tesi è stato lo sviluppo e la caratterizzazione di materiali nanocompositi a base polimerica da impiegare come film barriera per packaging o dispositivi elettroluminescenti. I seguenti sistemi sono stati analizzati: • Lumeta, prodotto dalla funzionalizzazione di un copolimero commerciale clorotrifluoroetilene vinil etere, Lumiflon LF-910LM, con 2-isocianatoetil metacrilato (IEM) per ottenere un materiale foto-reticolabile. • Nanocompositi Lumeta-filler a strati, ottenuti disperdendo un silicato a strati nanometrici dentro il Lumeta, che agisce da matrice. Due diversi silicati a strati sono stati miscelati con Lumeta: Dellite 43B e Dellite 72T. • Nanocompositi Lumeta-particelle, prodotti miscelando particelle nanometriche di fumed silice dentro il Lumeta. • Sol-gel ibridi organici-inorganici, basati sul LumetaSil. LumetaSil è una resina prodotta usando trietossisilil propil isocianato (IPTES) e 2-isocianatoetil metacrilato (IEM) come agenti funzionalizzanti. Il calore necessario a far avvenire la reticolazione termica, causata dalla funzionalizzazione con IPTES, è stata fornita dall’esotermicità del processo di foto-reticolazione. LumetaSil è stato usato per produrre sol-gel ibridi organici-inorganici con due diversi contenuti di silice. Due diversi sol-gel sono stati sviluppati, classificati in base al contenuto di silice: LumetaSil h-Si (alto contenuto di silice, L23Si77) and LumetaSil l-Si (basso contenuto di silice, L40Si60). Di conseguenza, un totale di sei diversi film è stato studiato. Tutti questi sistemi sono stati diluiti in un determinato solvente con un determinato rapporto massa di polimero secco su massa di solvente. Ogni sistema è stato caratterizzato da un appropriato processo di formulazione. Per ottenere i film, un fotoiniziatore è stato aggiunto alla soluzione prima della deposizione. Dopo la deposizione, i film sono stati sottoposti a reticolazione sotto raggi UV dentro una camera piena di gas inerte (azoto) per far evaporare il solvente. I film ottenuti tramite questa procedura sono stati poi caratterizzati con microscopia ottica, test di attacco da parte di un solvente, diffrazione ai raggi x, calorimetria differenziale a scansione, analisi termogravimetrica, spettroscopia UV-vis, misure di angolo di contatto e analisi reologica. Quest’ultima è stata fatta su soluzioni liquide senza la presenza del fotoiniziatore. Tutti i sistemi sviluppati hanno mostrato proprietà ottiche che li rendono idonei per applicazioni in elettronica ottica e applicazioni all’aperto. I film nanocompositi sono limitati a basse concentrazioni di nanoadditivo (massimo 4% in peso rispetto alla massa di polimero secco). Caratterizzazioni termiche hanno mostrato che i gel basati su LumetaSil non sono adatti ad applicazioni all’aperto perché deformazioni e danni fisici indotti termicamente potrebbero manifestarsi se il film è riscaldato a temperature leggermente superiori alla temperatura ambiente. I risultati dell’analisi TGA hanno dimostrato che i nanocompositi Lumeta-fumed silice sono caratterizzati da una più facile evaporazione del solvente, quindi le loro permeabilità devono essere più alte di quelle degli altri sistemi studiati. Dopo queste caratterizzazioni, i film Lumeta, Lumeta-Dellite 43B e Lumeta-Dellite 72T sono stati sottoposti a test di rigonfiamento per provare a ricavare qualche indicazione sulla permeabilità dei film. Il comportamento esibito dai campioni di Lumeta quando sommersi dentro ad un solvente hanno mostrato che molecole grosse possono penetrare i film in quantità molto piccole. Inoltre, i nanocomnpositi a strati di silice hanno mostrato da una permeabilità minore di quella esibita dal Lumeta semplice. In conclusione, i sistemi Lumeta-nanoargille mostrano proprietà termiche e ottiche buone abbastanza da essere impiegati come film barriera su dispositivi elettroluminescenti e in applicazioni di packaging. I sistemi nanocompositi sono limitati a film contenenti basse concentrazioni di nanoadditivo (massimo 4% in peso rispetto alla massa di polimero secco)
Development and characterization of polymer-based nanocomposite coatings
BARILLARI, DAVIDE
2015/2016
Abstract
The aim of this work was the development and characterization of polymer-based nanocomposite materials to be employed as barrier coatings for packaging and optoelectronic devices. The following systems were analyzed: • Lumeta, produced by the functionalization of a commercial chlorotrifluoroethylene vinyl ether (CTFEVE) copolymer, Lumiflon LF-910LM, with a 2-isocyanatoethyl methacrylate (IEM) to obtain a photo-curable material. • Lumata-layered filler nanocomposites, obtained by dispersing a nanolayered silicate inside Lumeta, which acts as matrix. Two different layered silicate were mixed with Lumeta: Dellite 43B and Dellite 72T • Lumeta-particles nanocomposites, produced by mixing nanometric particles of fumed silica inside Lumeta. • Hybrid organic-inorganic sol-gels, based on LumetaSil. LumetaSil is a resin produced using triethoxysilyl propyl isocyanate (IPTES) and 2-isocyanatoethyl methacrylate (IEM) as functionalizing agents. The heat necessary for the thermally-activated crosslinking, caused by the functionalization with IPTES, was provided by the exothermicity of the photo-curing process. LumetaSil resin was used to produce hybrid organic-inorganic sol-gels with two different silica content. Two different sol-gels were developed, classified according to the content of silica: LumetaSil h-Si (high silica, L23Si77) and LumetaSil l-Si (low silica, L40Si60). Therefore, a total of six different coatings was studied. All these systems were diluted in a determined solvent with a determined ratio dry polymer mass over solvent mass. Each system was characterized by a proper solution formulation process. To obtain coatings, a photoinitiator was added to the solution before deposition. After deposition, the coatings are subjected to UV curing inside a chamber filled with inert gas (N2) to ensure evaporation of solvent. The coatings obtained with this procedure were then characterized with optical microscopy, solvent rub test, x-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, UV-vis spectroscopy, optical contact angle measurements and rheological analysis. The latter was also used on liquid solutions without the presence of the photoinitiator. All the developed systems showed optical characteristics that makes them eligible for applications in optoelectronics and outdoor applications. The nanocomposite coatings are limited to low concentrations of the nanofiller (max. 4% wt. with respect to dry polymer mass). Thermal characterizations showed that LumetaSil-based gels are not suitable to be used in outdoor applications due to thermally-induced deformations and physical damages that may occur when the coating is heated to temperatures slightly higher than room temperature. TGA analysis results proved that Lumeta-fumed silica nanocomposites are characterized by easier solvent evaporation, therefore their permeability must be higher than the ones of the other studied systems. After these characterizations, the coatings Lumeta, Lumeta- Dellite 43B and Lumeta-Dellite 72T were subjected to swelling tests to try to find some indications on the permeability of the coatings. The behavior exhibited by Lumeta samples when submerged inside a solvent showed that bulky molecules can penetrate the coatings in very low amount. Besides, layered nanocomposites showed a lower permeability than the permeability showed by pristine Lumeta. In conclusion, Lumeta-nanoclay systems show good enough thermal and optical properties to be employed as barrier coatings on optoelectronic devices and in packaging applications. Nanocomposite systems are limited to coatings containing low concentration of nanofiller (max. 4% wt. with respect to dry polymer mass).| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/134443