ELISABETH CARVALHO L. CARDOSO

ELISABETH CARVALHO L. CARDOSO

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Study of flexible films prepared from PBAT/PLA blends reinforced with bio-CaCO3
2016 - CARDOSO, ELIZABETH C.L.; BUENO, NELSON R.; OLIVEIRA, RENE R.; 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. The most widely used materials include polyethylene (PE) and polypropylene (PP), among others. However, petrochemical-based conventional packaging materials are non-biodegradable and cause serious environmental problems. Poly (lactic acid) (PLA), a linear aliphatic polymer is known as a biodegradable thermoplastic polymer with widely potential applications. However, its high brittleness and low toughness limits its application; blending PLA with PBAT (Poly (butylene adipate-co-terepthalate), an aliphatic-aromatic copolyester, was the solution found due to its high toughness and biodegradability. Nevertheless, differences between PLA and PBAT solubility parameter values lead to the formation of immiscible blends as well as reduction in their mechanical performance. CaCO3 from avian eggshells, when added in PLA / PBAT composites imparts optimization of mechanicals properties due to its characteristic as reinforcing filler. This study aims to evaluate the effects of PLA addition in PBAT/PLA blends especially concerned to mechanical and thermal properties of PLA / PBAT / CaCO3 flexible films. Composites were prepared by melt processing, using a twin-screw extruder (L/D - 25). Before blown film processing, the composites were cooled down for a better dimensional stability, pelletized and dried at 60 ± 2 ºC for 24 h. The mechanical and thermal properties of obtained films were investigated by tensile tests, DSC and TG / DTG. In addition, the morphology of blends and composites were also evaluated by XRD and SEM analyses. The results showed important increase in crystallinity and tensile strength at break of flexible films without severe loss in elongation percentage, due to CaCO3 additional in PBAT / PLA blend with higher PLA contents.
Biodegradability of PP/HMSPP and natural and synthetic polymers blends in function of gamma irradiation degradation
2012 - CARDOSO, ELISABETH C.L.; SCAGLIUSI, SANDRA R.; LIMA, LUIS F.C.P.; BUENO, NELSON R.; BRANT, ANTONIO J.C.; PARRA, DUCLERC F.; LUGAO, ADEMAR B.
Biodegradability and mechanical properties of PP/HMSPP and natural polymers bio-composites in function of gamma-irradiations
2013 - CARDOSO, ELISABETH C.L.; SCAGLIUSI, SANDRA R.; LIMA, LUIS F.C.P.; BUENO, NELSON R.; PARRA, DUCLERC F.; LUGAO, ADEMAR B.
Prediction of an effective physical foamability of LLDPE/LDPE blends from rheological assessment
2013 - CARDOSO, ELISABETH C.L.; SCAGLIUSI, SANDRA R.; BUENO, N.R.; LUGAO, ADEMAR B.
A influencia do metodo de preparacao de especimes na avaliacao da morfologia celular de espumas de polipropileno
2009 - CARDOSO, ELISABETH C.L.; LIMA, LUIS F.C.P.; PARRA, DUCLERC F.; LUGAO, ADEMAR B.; BUENO, N.R.; GASPARIN, ELEOSMAR
Estudo da processabilidade de polietileno de baixa densidade (LDPE) gama irradiado para a produção de espumas
2011 - CARDOSO, ELISABETH C.L.; SCAGLIUSI, SANDRA R.; BUENO, NELSON R.; GASPARIN, ELIOSMAR S.; ONO, LILIAN S.; MORAIS, GUILHERME F.; PARRA, D.F.; LUGAO, ADEMAR B.
Sterilized PP/HMSPP cushion foams for medical and food packaging applications
2009 - CARDOSO, ELISABETH C.L.; LIMA, LUIS F.C.P.; PARRA, DUCLERC F.; LUGAO, ADEMAR B.; BUENO, N.R.; GASPARIN, ELEOSMAR
Biodegradability of PP/HMSPP and natural and synthetic polymers blends in function of gamma irradiation degradation
2014 - CARDOSO, ELISABETH C.L.; SCAGLIUSI, SANDRA R.; LIMA, LUIS F.C.P.; BUENO, NELSON R.; BRANT, ANTONIO J.C.; PARRA, DUCLERC F.; LUGAO, ADEMAR B.
Polymers are used for numerous applications in different industrial segments, generating enormous quantities of discarding in the environment. Polymeric materials composites account for an estimated from 20-30% total volume of solid waste. Polypropylene (PP) undergoes crosslinking and extensive main chain scissions when submitted to ionizing irradiation; as one of the most widely used linear hydrocarbon polymers, PP, made from cheap petrochemical feed stocks, shows easy processing leading it to a comprehensive list of finished products. Consequently, there is accumulation in the environment, at 25 million tons per year rate, since polymeric products are not easily consumed by microorganisms. PP polymers are very bioresistant due to involvement of only carbon atoms in main chain with no hydrolysable functional group. Several possibilities have been considered to minimize the environmental impact caused by non-degradable plastics, subjecting them to: physical, chemical and biological degradation or combination of all these due to the presence of moisture, air, temperature, light, high energy radiation or microorganisms. There are three main classes of biodegradable polymers: synthetic polymers, natural polymers and blends of polymers in which one or more components are readily consumed by microorganisms. This work aims to biodegradability investigation of a PP/HMSPP (High Melt Strength Polypropylene) blended with sugarcane bagasse, PHB (Polyhydroxy-butyrate) and PLA (Poly-Lactic Acid), both synthetic polymers, at a 10% level, subjected to gamma radiation at 50, 100, 150 and 200 kGy doses. Characterization will comprise IR, DSC, TGA, OIT and Laboratory Soil Burial Test (LSBT).