Epoxy resin possesses poor flame retardancy and difficulty in both recycling and reprocess abilit... more Epoxy resin possesses poor flame retardancy and difficulty in both recycling and reprocess ability that largely limit its application. Herein, two vanillin based epoxy monomers, shorted as VAD-EP (A) and VDP-EP (P), containing both imine bonds and inherently fire retarding phosphorus elements, were synthesized via in situ condensation reaction with DDM and addition reaction with DOPO, followed by the epoxidation by epichlorohydrin. Epoxy vitrimer materials were then cured by D230 diamine hardener by adjusting the proportion of VAD-EP and VDP-EP monomer. When the mass ratio of VAD-EP and VDP-EP was 8:2, A8P2-D230 reached the fire retarding UL-94 V0 rating and LOI value of 27.0% with only 0.66% of phosphorus content, this behavior was ascribed to condensed phase and free radical scavenging mechanisms. When the mass ratio was 7:3, the tensile strength and elastic modulus of the A7P3-D230 epoxy were 75.5 MPa and 2.5 GPa, respectively, i.e. 48.6% and 18.8% higher than A10P0-D230 sample. ...
El objetivo principal de la presente investigacion ha sido desarrollar una nueva clase de materia... more El objetivo principal de la presente investigacion ha sido desarrollar una nueva clase de materiales nanocompuestos organicos-inorganicos basados en la capacidad de los copolimeros de bloque de auto-organizarse promoviendo la dispersion de nanoparticulas, asi como relacionar las diferentes morfologias obtenidas con las propiedades finales de los nanocompuestos. Para generar la nanoestructuracion de estos nanocompuestos basados en copolimeros de bloque, como el poli(estireno-b-isopreno-b-estireno) (SIS) y el poli(estireno-b-butadieno-b-estireno) (SBS) en nanoparticulas de plata, se han utilizado los conceptos de compatibilizacion y confinamiento. Es decir, las nanoparticulas inorganicas se confinaron en una sola fase del copolimero de bloque mediante tratamientos superficiales y su funcionalizacion fisica. En particular, se utilizaron surfactantes (el cloruro de tetrametilamonio, TMAC, y el dodecanotiol, DT) para favorecer la interaccion entre las nanoparticulas inorganicas y la matr...
Películas de mezclas de PLA-PHB para aplicaciones de envases alimentarios sostenibles
espanolEl desarrollo de envases basados en polimeros obtenidos a partir de fuentes renovables y c... more espanolEl desarrollo de envases basados en polimeros obtenidos a partir de fuentes renovables y con caracteristicas biodegradables ha cobrado especial interes en la industria del envase alimentario debido a que representan una alternativa prometedora para remplazar a los polimeros convencionales derivados del petroleo comunmente utilizados para este fin. El poli(acido lactico) (PLA) es el termoplastico biobasado y biodegradable de mayor interes a nivel industrial debido a que presenta una serie de caracteristicas ventajosas para su aplicacion como envase alimentario. Sin embargo, para la produccion de peliculas flexibles el PLA presenta algunas desventajas, tales como una baja flexibilidad y pobres propiedades barrera. Para aumentar su extensibilidad es necesario incorporar plastificantes. Para mejorar las propiedades barrera una estrategia sencilla y economicamente viable para la industria es mezclarlo con otro polimero mas cristalino, como el poli(hidroxibutirato) (PHB). En este s...
Diferentes rutas de procesado para reforzar poliuretanos con grafeno
espanolEn el presente trabajo se estudian diferentes nanocompuestos obtenidos a partir de una mat... more espanolEn el presente trabajo se estudian diferentes nanocompuestos obtenidos a partir de una matriz de un poliuretano lineal formado por estructuras de copolimeros de bloque de policaprolactona (PCL) y poli(L-acido lactico) (PLLA) reforzados con grafeno en diferentes proporciones en peso. En particular los nanocompuestos se obtuvieron utilizando tres metodos de procesado diferentes: “solvent casting”, extrusion y polimerizacion “in situ”. La dispersion de grafeno en la matriz polimerica se estudio por microscopia electronica de transmision. Se realizo un estudio del impacto que tienen, tanto los diferentes porcentajes de grafeno como las diferentes rutas de procesado en las propiedades electricas, termicas y mecanicas de los nanocompuestos. Por ultimo se estudio el comportamiento de memoria de forma en las muestras obtenidas mediante polimerizacion "in situ", demostrando que la inclusion del grafeno no deteriora las propiedades de memoria de forma intrinsecas de la matriz...
Ethylene vinyl acetate (EVA) copolymers are interesting materials for biomedical application such... more Ethylene vinyl acetate (EVA) copolymers are interesting materials for biomedical application such as medical packaging, medical devices, and pharmaceutical applications for over 35 years. EVA properties can be tailored and manipulated to develop novel materials with innovative biomedical applications. The addition of a small amount of nanosized particles can significantly affect the final properties of EVA and improve its physical and mechanical performance. EVA-based nanocomposites are a class of materials that merge the benefits of elastomeric-engineered plastics and the reinforcement effect of nanofillers. Nanocomposites based on EVA can be potential candidates for several biomedical applications, ranging from medical devices and medical packaging applications including thermoformed trays, containers, boxes, tubes, needle cover, bottle, blister packs, clamshells, and bottle caps. Thus the formulation of EVA-based nanocomposites that are biostable, easily processable, and with imp...
Uso de aditivos naturales en la industria del procesado de plásticos
espanolEn la actualidad hay un creciente interes en reemplazar los plasticos tradicionales por pl... more espanolEn la actualidad hay un creciente interes en reemplazar los plasticos tradicionales por plasticos mas sostenibles con la finalidad de producir un menor impacto medioambiental. Por lo tanto, la produccion y uso de los plasticos biobasados y biodegradables ha aumentado considerablemente. Los productos naturales, principalmente compuestos activos, extractos de plantas y aceites esenciales resultan aditivos sostenibles interesantes para la industria del procesado de plasticos, debido a que permiten mejorar tanto el proceso de transformacion de los plasticos, asi como tambien ofrecer propiedades funcionales al material final (propiedades antimicrobianas y/o antioxidantes). El uso de antioxidantes tiene un interes especial en la industria de los plasticos para evitar la degradacion termo-oxidativa durante el proceso de trasformacion. En este articulo se presentan los agentes antioxidantes comunmente utilizados en la industria de los plasticos y sus mecanismos de accion. Se proponen...
Aluminium joints have been used in order to investigate the effects of radiation on curing at roo... more Aluminium joints have been used in order to investigate the effects of radiation on curing at room temperature structural adhesives. For many applications, like space satellites, high energy physics experiments, and nuclear power plants, radiation can in fact be so high that the performances of many polymers can be completely compromised. The effects of different surface treatments, together with the effects of adhesive thickness, has been analysed in order to correctly design the tests. Mechanical tests on the so designed joints have been performed up to a ionising radiation dose of 4 MGy. The correlation between fracture mechanics and polymer degradation are discussed. Surface treatments can strongly influence the radiation behaviours of adhesive joints.
The alpha magnetic spectrometer (AMS) is a sophisticated instrument developed for the determinati... more The alpha magnetic spectrometer (AMS) is a sophisticated instrument developed for the determination of anti-matter nuclei in the outer space. Following specific requirements the silicon sensors are included in an array of several thin carbon fiber composite tubes of different length in various horizontal layers, which will be supported by an outcr vertical cylindrical structure also made in composite. A structural analysis of single tubes and of the complete structure has been performed using a fine element code. The main results of this study are reported in terms of maximum lateral displacement of tubes, suggesting the necessity to use shock absorbers between them; and in terms of vibration behavior expressed as the equivalent Von Misses stresses. The analysis shows that the designed structure accomplish with NASA specifications. where triangular elements were considered. The weight of electronic was considered increasing the density of the outer structure, where it is glued.
Materials Science and Engineering: R: Reports, 2017
The approach of simultaneously exploit the use of microscale elastomers/thermoplastics and nanosc... more The approach of simultaneously exploit the use of microscale elastomers/thermoplastics and nanoscale fillers for the modification of epoxy systems is presently an active research topic. Such hybrid modification of epoxy primarily helps to tailor multiple mechanical properties, without compromising other required properties. The current review reports about the development and properties of multicomponent epoxy systems modified with both elastomers/thermoplastics and nanofillers, on the basis of an updated literature survey. For a better understanding and comparison, the review initially provides a short discussion on key findings in binary blends of epoxy and elastomers/thermoplastic and binary epoxy nanocomposites. Successful studies dealing with multicomponent epoxy systems are also reported, where it is demonstrated that microscale modification individually, sometimes synergistically, enhances the fracture toughness of epoxy without affecting the properties optimized by nanoscale modification. The mutual role of microscale elastomer/thermoplastic and nanoscale filler on morphology, cure reaction, mechanical and thermal properties of epoxy multicomponent system is discussed. The complex interaction between the micro-and nano-phases determines phase separated morphologies in the multicomponent system, essentially related to the function of microscale modifiers in dispersion/intercalation/distribution of nanofillers and to the role of nanofillers in phase separation kinetics and mechanisms. The specific effect of nanofillers in phase separation mechanisms for epoxy blends, that place via nucleation and growth (NG) and spinodal decomposition, is analysed looking at the final morphology and hence performance of multicomponent system. Moreover, the fracture mechanism that operates in such multicomponent epoxy systems is discussed. Abbreviations: ABS, poly(acrylonitrile-co-butadiene-co-styrene); ATBN, amine-terminated poly(butadiene-co-acrylonitrile); BCPs, block copolymers; BF3.EA, boron trifluoride monoethylamine; CFRP, carbon-fibre reinforced-plastic; CNF, carbon nanofibers; CNT, carbon nanotubes; CRGO, chemically reduced graphene oxide; CRBN, carboxyl-randomized liquid butadiene-acrylonitrile rubber; CSR, core-shell rubbers; CTBN, carboxyl terminated poly(butadiene-co-acrylonitrile); CTPB, carboxylterminated polybutadiene; DDA, Dicyanodiamide; DDM, 4, 4 0 -diaminodiphenylmethane; DDS, 4, 4 0 -diaminodiphenyl sulfone; Epoxy/SiC/CTBN_M2, Epoxy hybrid by mixing CTBN in sonicated epoxy/SiC mixture; Epoxy/SiC/CTBN_M1, Epoxy hybrid by sonicating SiC nanofibers in epoxy/CTBN mixture; fCNT, N-octyl-functionalized CNT; ETBN, epoxy terminated poly(butadiene-co-acrylonitrile); FRP, fibre reinforced-plastic; GFRP, glass fibre reinforced plastic; GO, graphene oxide; GnP, graphene nanoplatelets; HBPs, hyperbranched polymers; HLNR, hydroxyl terminated liquid natural rubber; HNT, halloysite nanotube; HPEEK, hydroxylated poly (ether ether ketone); HPMM, high pressure mixing method; HTBN, hydroxyl-terminated poly(butadiene-co-acrylonitrile); HTPB, hydroxyl terminated polybutadiene; MA, maleic anhydride; MBS, methacrylated butadiene-styrene copolymer; M-NCDSUs, micro-nano constrained damping structure units; MMT, montmorillonite organoclays; MWCNTs, multiwalled carbon nanotubes; MWCNT-COOHs, carboxylic acid functionalised multi-walled carbon nanotubes; MWCNT-NH2s, amino-functionalized multiwalled carbon nanotubes; PA, polyamides; PCL, poly(e-caprolactone); PEEKMOH, poly ether ether ketone with pendant methyl groups; PEI, poly(ether imide); PEO, poly(ethylene oxide); PEO-PBO, poly(ethylene oxide)-bpoly-(butylene oxide); PEO-PEE, poly(ethylene oxide)-b-poly(ethyl ethylene); PEO-PEP, (ethylene oxide)-b-poly(ethylene-alt-propylene); PEO-PPO, poly(ethyleneoxide)-bpoly(propylene oxide); PEO-PPO-PEO, poly(ethyleneoxide)-b-poly(propylene oxide)-b-poly(ethylene oxide); PES, poly(ether sulfone); PMMA, poly(methyl-methacrylate); PMMA-PS, poly(methyl methacrylate
Fully bio-based and biodegradable active films based on poly(lactic acid) (PLA) blended with poly... more Fully bio-based and biodegradable active films based on poly(lactic acid) (PLA) blended with poly(3-hydroxy butyrate) (PHB) and incorporating lactic acid oligomers (OLA) as plasticizers and carvacrol as active agent were extruded and fully characterized in their functional properties for antimicrobial active packaging. PLA_PHB films showed good barrier to water vapor, while the resistance to oxygen diffusion decreased with the addition of OLA and carvacrol. Their overall migration in aqueous food simulant was determined and no significant changes were observed by the addition of carvacrol and OLA to the PLA_PHB formulations. However, the effect of both additives in fatty food simulant can be considered a positive feature for the potential protection of foodstuff with high fat content. Moreover, the antioxidant and antimicrobial activities of the proposed formulations increased by the presence of carvacrol, with enhanced activity against S.aureus if compared to E.coli at short and long incubation times. These results underlined the specific antimicrobial properties of these bio-films suggesting their applicability in active food packaging.
Bio-based films formed by poly(lactic acid) (PLA) and poly(3-hydroxybutyrate) (PHB) plasticized w... more Bio-based films formed by poly(lactic acid) (PLA) and poly(3-hydroxybutyrate) (PHB) plasticized with an oligomer of the lactic acid (OLA) were used as supporting matrices for an antibacterial agent (carvacrol). This paper reports the main features of the processing and physico-chemical characterization of these innovative biodegradable material based films, which were extruded and further submitted to filmature process. The effect of the addition of carvacrol and OLA on their microstructure, chemical, thermal and mechanical properties was assessed. The presence of these additives did not affect the thermal stability of PLA_PHB films, but resulted in a decrease in their crystallinity and in the elastic modulus for the active formulations. The obtained results showed the effective presence of additives in the PLA or the PLA_PHB matrix after processing at high
Epoxy resin possesses poor flame retardancy and difficulty in both recycling and reprocess abilit... more Epoxy resin possesses poor flame retardancy and difficulty in both recycling and reprocess ability that largely limit its application. Herein, two vanillin based epoxy monomers, shorted as VAD-EP (A) and VDP-EP (P), containing both imine bonds and inherently fire retarding phosphorus elements, were synthesized via in situ condensation reaction with DDM and addition reaction with DOPO, followed by the epoxidation by epichlorohydrin. Epoxy vitrimer materials were then cured by D230 diamine hardener by adjusting the proportion of VAD-EP and VDP-EP monomer. When the mass ratio of VAD-EP and VDP-EP was 8:2, A8P2-D230 reached the fire retarding UL-94 V0 rating and LOI value of 27.0% with only 0.66% of phosphorus content, this behavior was ascribed to condensed phase and free radical scavenging mechanisms. When the mass ratio was 7:3, the tensile strength and elastic modulus of the A7P3-D230 epoxy were 75.5 MPa and 2.5 GPa, respectively, i.e. 48.6% and 18.8% higher than A10P0-D230 sample. ...
El objetivo principal de la presente investigacion ha sido desarrollar una nueva clase de materia... more El objetivo principal de la presente investigacion ha sido desarrollar una nueva clase de materiales nanocompuestos organicos-inorganicos basados en la capacidad de los copolimeros de bloque de auto-organizarse promoviendo la dispersion de nanoparticulas, asi como relacionar las diferentes morfologias obtenidas con las propiedades finales de los nanocompuestos. Para generar la nanoestructuracion de estos nanocompuestos basados en copolimeros de bloque, como el poli(estireno-b-isopreno-b-estireno) (SIS) y el poli(estireno-b-butadieno-b-estireno) (SBS) en nanoparticulas de plata, se han utilizado los conceptos de compatibilizacion y confinamiento. Es decir, las nanoparticulas inorganicas se confinaron en una sola fase del copolimero de bloque mediante tratamientos superficiales y su funcionalizacion fisica. En particular, se utilizaron surfactantes (el cloruro de tetrametilamonio, TMAC, y el dodecanotiol, DT) para favorecer la interaccion entre las nanoparticulas inorganicas y la matr...
Películas de mezclas de PLA-PHB para aplicaciones de envases alimentarios sostenibles
espanolEl desarrollo de envases basados en polimeros obtenidos a partir de fuentes renovables y c... more espanolEl desarrollo de envases basados en polimeros obtenidos a partir de fuentes renovables y con caracteristicas biodegradables ha cobrado especial interes en la industria del envase alimentario debido a que representan una alternativa prometedora para remplazar a los polimeros convencionales derivados del petroleo comunmente utilizados para este fin. El poli(acido lactico) (PLA) es el termoplastico biobasado y biodegradable de mayor interes a nivel industrial debido a que presenta una serie de caracteristicas ventajosas para su aplicacion como envase alimentario. Sin embargo, para la produccion de peliculas flexibles el PLA presenta algunas desventajas, tales como una baja flexibilidad y pobres propiedades barrera. Para aumentar su extensibilidad es necesario incorporar plastificantes. Para mejorar las propiedades barrera una estrategia sencilla y economicamente viable para la industria es mezclarlo con otro polimero mas cristalino, como el poli(hidroxibutirato) (PHB). En este s...
Diferentes rutas de procesado para reforzar poliuretanos con grafeno
espanolEn el presente trabajo se estudian diferentes nanocompuestos obtenidos a partir de una mat... more espanolEn el presente trabajo se estudian diferentes nanocompuestos obtenidos a partir de una matriz de un poliuretano lineal formado por estructuras de copolimeros de bloque de policaprolactona (PCL) y poli(L-acido lactico) (PLLA) reforzados con grafeno en diferentes proporciones en peso. En particular los nanocompuestos se obtuvieron utilizando tres metodos de procesado diferentes: “solvent casting”, extrusion y polimerizacion “in situ”. La dispersion de grafeno en la matriz polimerica se estudio por microscopia electronica de transmision. Se realizo un estudio del impacto que tienen, tanto los diferentes porcentajes de grafeno como las diferentes rutas de procesado en las propiedades electricas, termicas y mecanicas de los nanocompuestos. Por ultimo se estudio el comportamiento de memoria de forma en las muestras obtenidas mediante polimerizacion "in situ", demostrando que la inclusion del grafeno no deteriora las propiedades de memoria de forma intrinsecas de la matriz...
Ethylene vinyl acetate (EVA) copolymers are interesting materials for biomedical application such... more Ethylene vinyl acetate (EVA) copolymers are interesting materials for biomedical application such as medical packaging, medical devices, and pharmaceutical applications for over 35 years. EVA properties can be tailored and manipulated to develop novel materials with innovative biomedical applications. The addition of a small amount of nanosized particles can significantly affect the final properties of EVA and improve its physical and mechanical performance. EVA-based nanocomposites are a class of materials that merge the benefits of elastomeric-engineered plastics and the reinforcement effect of nanofillers. Nanocomposites based on EVA can be potential candidates for several biomedical applications, ranging from medical devices and medical packaging applications including thermoformed trays, containers, boxes, tubes, needle cover, bottle, blister packs, clamshells, and bottle caps. Thus the formulation of EVA-based nanocomposites that are biostable, easily processable, and with imp...
Uso de aditivos naturales en la industria del procesado de plásticos
espanolEn la actualidad hay un creciente interes en reemplazar los plasticos tradicionales por pl... more espanolEn la actualidad hay un creciente interes en reemplazar los plasticos tradicionales por plasticos mas sostenibles con la finalidad de producir un menor impacto medioambiental. Por lo tanto, la produccion y uso de los plasticos biobasados y biodegradables ha aumentado considerablemente. Los productos naturales, principalmente compuestos activos, extractos de plantas y aceites esenciales resultan aditivos sostenibles interesantes para la industria del procesado de plasticos, debido a que permiten mejorar tanto el proceso de transformacion de los plasticos, asi como tambien ofrecer propiedades funcionales al material final (propiedades antimicrobianas y/o antioxidantes). El uso de antioxidantes tiene un interes especial en la industria de los plasticos para evitar la degradacion termo-oxidativa durante el proceso de trasformacion. En este articulo se presentan los agentes antioxidantes comunmente utilizados en la industria de los plasticos y sus mecanismos de accion. Se proponen...
Aluminium joints have been used in order to investigate the effects of radiation on curing at roo... more Aluminium joints have been used in order to investigate the effects of radiation on curing at room temperature structural adhesives. For many applications, like space satellites, high energy physics experiments, and nuclear power plants, radiation can in fact be so high that the performances of many polymers can be completely compromised. The effects of different surface treatments, together with the effects of adhesive thickness, has been analysed in order to correctly design the tests. Mechanical tests on the so designed joints have been performed up to a ionising radiation dose of 4 MGy. The correlation between fracture mechanics and polymer degradation are discussed. Surface treatments can strongly influence the radiation behaviours of adhesive joints.
The alpha magnetic spectrometer (AMS) is a sophisticated instrument developed for the determinati... more The alpha magnetic spectrometer (AMS) is a sophisticated instrument developed for the determination of anti-matter nuclei in the outer space. Following specific requirements the silicon sensors are included in an array of several thin carbon fiber composite tubes of different length in various horizontal layers, which will be supported by an outcr vertical cylindrical structure also made in composite. A structural analysis of single tubes and of the complete structure has been performed using a fine element code. The main results of this study are reported in terms of maximum lateral displacement of tubes, suggesting the necessity to use shock absorbers between them; and in terms of vibration behavior expressed as the equivalent Von Misses stresses. The analysis shows that the designed structure accomplish with NASA specifications. where triangular elements were considered. The weight of electronic was considered increasing the density of the outer structure, where it is glued.
Materials Science and Engineering: R: Reports, 2017
The approach of simultaneously exploit the use of microscale elastomers/thermoplastics and nanosc... more The approach of simultaneously exploit the use of microscale elastomers/thermoplastics and nanoscale fillers for the modification of epoxy systems is presently an active research topic. Such hybrid modification of epoxy primarily helps to tailor multiple mechanical properties, without compromising other required properties. The current review reports about the development and properties of multicomponent epoxy systems modified with both elastomers/thermoplastics and nanofillers, on the basis of an updated literature survey. For a better understanding and comparison, the review initially provides a short discussion on key findings in binary blends of epoxy and elastomers/thermoplastic and binary epoxy nanocomposites. Successful studies dealing with multicomponent epoxy systems are also reported, where it is demonstrated that microscale modification individually, sometimes synergistically, enhances the fracture toughness of epoxy without affecting the properties optimized by nanoscale modification. The mutual role of microscale elastomer/thermoplastic and nanoscale filler on morphology, cure reaction, mechanical and thermal properties of epoxy multicomponent system is discussed. The complex interaction between the micro-and nano-phases determines phase separated morphologies in the multicomponent system, essentially related to the function of microscale modifiers in dispersion/intercalation/distribution of nanofillers and to the role of nanofillers in phase separation kinetics and mechanisms. The specific effect of nanofillers in phase separation mechanisms for epoxy blends, that place via nucleation and growth (NG) and spinodal decomposition, is analysed looking at the final morphology and hence performance of multicomponent system. Moreover, the fracture mechanism that operates in such multicomponent epoxy systems is discussed. Abbreviations: ABS, poly(acrylonitrile-co-butadiene-co-styrene); ATBN, amine-terminated poly(butadiene-co-acrylonitrile); BCPs, block copolymers; BF3.EA, boron trifluoride monoethylamine; CFRP, carbon-fibre reinforced-plastic; CNF, carbon nanofibers; CNT, carbon nanotubes; CRGO, chemically reduced graphene oxide; CRBN, carboxyl-randomized liquid butadiene-acrylonitrile rubber; CSR, core-shell rubbers; CTBN, carboxyl terminated poly(butadiene-co-acrylonitrile); CTPB, carboxylterminated polybutadiene; DDA, Dicyanodiamide; DDM, 4, 4 0 -diaminodiphenylmethane; DDS, 4, 4 0 -diaminodiphenyl sulfone; Epoxy/SiC/CTBN_M2, Epoxy hybrid by mixing CTBN in sonicated epoxy/SiC mixture; Epoxy/SiC/CTBN_M1, Epoxy hybrid by sonicating SiC nanofibers in epoxy/CTBN mixture; fCNT, N-octyl-functionalized CNT; ETBN, epoxy terminated poly(butadiene-co-acrylonitrile); FRP, fibre reinforced-plastic; GFRP, glass fibre reinforced plastic; GO, graphene oxide; GnP, graphene nanoplatelets; HBPs, hyperbranched polymers; HLNR, hydroxyl terminated liquid natural rubber; HNT, halloysite nanotube; HPEEK, hydroxylated poly (ether ether ketone); HPMM, high pressure mixing method; HTBN, hydroxyl-terminated poly(butadiene-co-acrylonitrile); HTPB, hydroxyl terminated polybutadiene; MA, maleic anhydride; MBS, methacrylated butadiene-styrene copolymer; M-NCDSUs, micro-nano constrained damping structure units; MMT, montmorillonite organoclays; MWCNTs, multiwalled carbon nanotubes; MWCNT-COOHs, carboxylic acid functionalised multi-walled carbon nanotubes; MWCNT-NH2s, amino-functionalized multiwalled carbon nanotubes; PA, polyamides; PCL, poly(e-caprolactone); PEEKMOH, poly ether ether ketone with pendant methyl groups; PEI, poly(ether imide); PEO, poly(ethylene oxide); PEO-PBO, poly(ethylene oxide)-bpoly-(butylene oxide); PEO-PEE, poly(ethylene oxide)-b-poly(ethyl ethylene); PEO-PEP, (ethylene oxide)-b-poly(ethylene-alt-propylene); PEO-PPO, poly(ethyleneoxide)-bpoly(propylene oxide); PEO-PPO-PEO, poly(ethyleneoxide)-b-poly(propylene oxide)-b-poly(ethylene oxide); PES, poly(ether sulfone); PMMA, poly(methyl-methacrylate); PMMA-PS, poly(methyl methacrylate
Fully bio-based and biodegradable active films based on poly(lactic acid) (PLA) blended with poly... more Fully bio-based and biodegradable active films based on poly(lactic acid) (PLA) blended with poly(3-hydroxy butyrate) (PHB) and incorporating lactic acid oligomers (OLA) as plasticizers and carvacrol as active agent were extruded and fully characterized in their functional properties for antimicrobial active packaging. PLA_PHB films showed good barrier to water vapor, while the resistance to oxygen diffusion decreased with the addition of OLA and carvacrol. Their overall migration in aqueous food simulant was determined and no significant changes were observed by the addition of carvacrol and OLA to the PLA_PHB formulations. However, the effect of both additives in fatty food simulant can be considered a positive feature for the potential protection of foodstuff with high fat content. Moreover, the antioxidant and antimicrobial activities of the proposed formulations increased by the presence of carvacrol, with enhanced activity against S.aureus if compared to E.coli at short and long incubation times. These results underlined the specific antimicrobial properties of these bio-films suggesting their applicability in active food packaging.
Bio-based films formed by poly(lactic acid) (PLA) and poly(3-hydroxybutyrate) (PHB) plasticized w... more Bio-based films formed by poly(lactic acid) (PLA) and poly(3-hydroxybutyrate) (PHB) plasticized with an oligomer of the lactic acid (OLA) were used as supporting matrices for an antibacterial agent (carvacrol). This paper reports the main features of the processing and physico-chemical characterization of these innovative biodegradable material based films, which were extruded and further submitted to filmature process. The effect of the addition of carvacrol and OLA on their microstructure, chemical, thermal and mechanical properties was assessed. The presence of these additives did not affect the thermal stability of PLA_PHB films, but resulted in a decrease in their crystallinity and in the elastic modulus for the active formulations. The obtained results showed the effective presence of additives in the PLA or the PLA_PHB matrix after processing at high
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Papers by Jose Kenny