MARIA APARECIDA DA SILVA COLOMBO

MARIA APARECIDA DA SILVA COLOMBO

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Influence of reinforcing efficiency of clay on the mechanical properties of poly(butylene terephthalate) nanocomposite
2023 - COLOMBO, MARIA A.S.; DIAZ, FRANCISCO R.V.; KODALI, DEEPA; RANGARI, VIJAYA; GUVEN, OLGUN; MOURA, ESPERIDIANA A.B.
In contrast to traditional fillers, clay, in particular, natural smectite clay, represents an environmentally significant alternative to improve the properties of polymers. Compared to conventional nanofillers, smectite clay can effectively enhance the physical and mechanical properties of polymer nanocomposites with a relatively small amount of addition (<5 wt%). The present study focuses on investigating the reinforcing efficiency of different amounts (up to 5 wt%) of a natural Brazilian smectite clay modified (MBClay) on the mechanical properties of poly(butylene terephthalate) (PBT) nanocomposites and also evaluates the correlation between MBClay addition and the mechanical and thermal behaviors of the PBT/MBClay nanocomposites. Natural Brazilian clay modified by the addition of quaternary salt and sodium carbonate (MBClay) was infused into the PBT polymer by melt extrusion using a twin-screw extruder. It was found that the best properties for PBT were obtained at 3.7 wt% of modified BClay. Tensile strength at break exhibited increased by about 60%, flexural strength increased by 24%, and flexural modulus increased by 17%. In addition, an increase in the crystallinity percentage of PBT/BClay nanocomposite was confirmed by DSC and XRD analysis, and a gain of about 45% in HDT was successfully achieved due to the incorporation of 3.7 wt% of MBClay
Surface properties of electron irradiated polyamide 6,6
2005 - SEGURA PINO, E.; COLOMBO, M.A.S.
Biodegradable aliphatic aromatic copolyester/corn starch blend composite reinforced with cofee parchment hush
2013 - SILVA, VALQUIRIA A.; TEIXEIRA, JACIELE G.; GOMES, MICHELLE G.; ORTIZ, ANGEL V.; OLIVEIRA, RENE R.; SCAPIN, MARCOS A.; COLOMBO, MARIA A.; MOURA, ESPERIDIANA A.B.
Compatibilization of polyamide 6,6/linear low-density polyethylene blend by electron irradiation
2002 - SEGURA PINO, E.; COLOMBO, M.A.
Polymer blending is a growing scientific and commercial development activity. In most cases, polymeric blends are formed by thermodynamically immiscible components. Such blends require the use of compatibiliezers that, often, are copolymers, graft copolymers or any means that improve the dispersion and adhesion of blend phases. Compatibility of a polymer blend plays an important role in determining the blend properties for their end use. In this work, the compatibilization of the polyamide 6,6/low-density polyethylene blend, using electron radiation, was carried out. Samples for mechanical test, with 75/25 %wt/wt composition were melt mixed in an extruder and then injection-molded. These samples were electron irradiated to doses of 50, 100, 150, and 200kGy. The tensile measurements show that the strength at break increases with an increase of the radiation doses. On the other hand, the elongation at break shows a rapid standing decrease as a function of the doses. Comparing these results with those obtained with no irradiated samples we have found an improvement of the mechanical properties of the PA6,6/LLDPE blend. We consider that the carboxylic groups produced in the polyethylene chains, during irradiation, react with the end amine end groups of the polyamide, acting as an interfacial bonding stabilizing this blend system.
Mechanical properties of electron irradiated polyamide 6,6
2003 - SEGURA PINO, E.; COLOMBO, M.A.S.
Electron beam effects on gelatin polymer
2009 - INAMURA, PATRICIA Y.; SHIMAZAKI, KLEBER; SOUZA, CLECIA de M.; COLOMBO, MARIA A.; MOURA, ESPERIDIANA A.B.; MASTRO, NELIDA L. del
Estudo do efeito da radiacao ionizante sobre as propriedades mecanicas da poliamida 6,6
2004 - COLOMBO, MARIA A. da S.
Compatibilization of polyamide 6,6/linear low-density polyethylene blend by electron irradiation
2002 - SEGURA PINO, E.; COLOMBO, M.A.
Polymer blending is a growing scientific and commercial development activity. In most cases, polymeric blends are formed by thermodynamically immiscible components. Such blends require the use of compatibiliezers that, often, are copolymers, graft copolymers or any means that improve the dispersion and adhesion of blend phases. Compatibility of a polymer blend plays an important role in determining the blend properties for their end use. In this work, the compatibilization of the polyamide 6,6/low-density polyethylene blend, using electron radiation, was carried out. Samples for mechanical test, with 75/25 %wt/wt composition were melt mixed in an extruder and then injection-molded. These samples were electron irradiated to doses of 50, 100, 150, and 200kGy. The tensile measurements show that the strength at break increases with an increase of the radiation doses. On the other hand, the elongation at break shows a rapid standing decrease as a function ofthe doses. Comparing these results with those obtained with no irradiated samples we have found an improvement ofthe mechanical properties ofthe PA6,6/LLDPE blend. We consider that the carboxylic groups produced in the polyethylene chains, during irradiation, react with the end amine end groups of the polyamide, acting as an interfacial bonding stabilizing this blend system.
Gelatin/piassava composites treated by electron beam radiation
2010 - TAKINAMI, PATRICIA Y.I.; SHIMAZAKI, KLEBER; COLOMBO, MARIA A.; MOURA, ESPERIDIANA A.B. de; MASTRO, NELIDA L. del
Effect of electron beam irradiation on mechanical properties of gelatin/brazul nut shell fiber composites
2010 - INAMURA, PATRICIA Y.; SHIMAZAKI, KLEBER; COLOMBO, MARIA A.; ROSA, RICARDO de; MOURA, ESPERIDIANA A.B. de; MASTRO, NELIDA L. del