ELISABETH CARVALHO L. CARDOSO

ELISABETH CARVALHO L. CARDOSO

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Study of flexible films prepared from PLA/PBAT blend and PLA E-beam irradiated as compatibilizing agent
2017 - CARDOSO, ELIZABETH C.L.; OLIVEIRA, RENE R.; MACHADO, GLAUSON A.F.; MOURA, ESPERIDIANA A.B.
Plastics global annual production exceeds 250 million tons and more than 40% of the total plastic production is used as packaging materials. In recent years polymeric materials derived from biomass have received great attention due to scarce petroleum resources and environmental concerns. PLA is one of the most extensively studied bio-based and bio-compostable aliphatic polyesters; nevertheless, high brittleness and low toughness limits its application. Blending PLA with PBAT (Poly(butylene adipate-co-terephthalate)), an aliphatic-aromatic copolyester, was the solution found due to its high toughness and biodegradability. Differences between PLA and PBAT solubility parameter values lead to the formation of immiscible blends as well as reduction in their mechanical performance besides a poor morphology; so, 5% of pre-irradiated PLA and a previous compatibilized PLA/PBAT (EcovioTM) were added to PLA/PBAT blends in order to improve miscibility phases. Investigations were accomplished on phase morphology (SEM), mechanical properties, thermal behavior and X-ray diffractions (XRD).
Development of bio-based foams prepared from PBAT/PLA reinforced with biio-calcium carbonate compatibilized by electron beam radiation
2016 - CARDOSO, ELIZABETH C.L.; SEIXAS, MARCUS V.S.; WIEBECK, HELIO; OLIVEIRA, RENE R.; MACHADO, GLAUSON A.F.; MOURA, ESPERIDIANA A.B.
Effect of gamma radiation on the mechanical and degradation properties of bromobutyl rubber compounds
2015 - SCAGLIUSI, SANDRA R.; CARDOSO, ELISABETH C.L.; LUGAO, ADEMAR B.
Characterization of mechanical properties of PP/HMSPP blends with natural and synthetic polymers subjected to gamma-irradiation
2015 - CARDOSO, E.C.L.; SCAGLIUSI, S.R.; LUGAO, A.B.
Hydrocarbon polymers, as PP, made from cheap petrochemical feedstock are important in many branches of industry. However, they have an undesirable influence on the environment and cause problems due to waste deposition and utilization. Polymeric materials composites account for an estimated from 20 to 30% of total volume of solid waste disposed. Thus, there is a tendency to substitute such polymers by those ones that undergo biodegradable processes. Polypropylene (PP) is a commodity, with high melting point, high chemical resistance, low density, with a balance between physical and mechanical properties and easy processing at low cost. Nevertheless, PP shows limitations for some special applications in automotive industry and civil construction. In order to minimize this deficiency, related to rheological behavior of polymer melt, especially referring to viscosity in processing temperature, a 50% mixture with HMSPP (High melt Strength Polypropylene) was used. PP/HMSPP was blended with 10, 15, 30 and 50% of natural (sugarcane bagasse) and synthetic polymers (PHB and PLA) aiming to partially biodegradable materials. The admixtures were subjected to gamma-irradiation at 50, 100, 150 and 200 kGy and then further assessed by mechanical tests in order to evaluate their degradability.