LUIZ GUSTAVO HIROKI KOMATSU
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Resumo IPEN-doc 27967 Nanocomposites foams of polypropilene modified by ionizing radiation containing CaCo3/ag° nanoparticles of bio-calcium carbonate-study of bactericidal effect2019 - PARRA, DUCLERC F.; SILVA, ORELIO L. da; KOMATSU, LUIZ G.; CARDOSO, ELIZABETH C.L.; LUGAO, ADEMAR B.This paper presents a study of high melting strengh polypropylene (HMSPP) foams by gamma irradiation with insertion of silver nanoparticles (AgNPs) adsorbed in carrier of CaCO3 (natural source) aiming bactericidal effect. The use of silver (Ag°) gives important antibacterial property since silver is highly toxic against bacterae. The HMSPP matrix was processed in a twin screw extruder under CO2 atmosphere and polypropylene nanocomposites (HMSPP-AgNC) were obtained in different concentrations of silver. The material was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), field emission scanning electron microscopy (FESEM), X-ray diffraction spectroscopy (XRD), cytotoxicity assay and reduction colony-forming-unit (CFU). The analyzed foams showed spherical clusters and homogeneous regions with good distribution of the silver nanoparticles. Furthermore, the HMSPP@AgNCs foams exhibited a antibacterial efficiency against E. coli and S. aureus due to the presence of the biocidal silver nanoparticles.Artigo IPEN-doc 27809 Effect of ionizing radiation applied to PLA used as compatibilizing agent in reinforced eGG shell PBAT/PLA bio-based composites2021 - CARDOSO, ELIZABETH C.L.; PARRA, DUCLERC F.; SCAGLIUSI, SANDRA R.; KOMATSU, L.G.H.; LUGAO, ADEMAR B.Bio-filler from eggshells as reinforcement of bio-based polymers are based on their benefits as adequate strength and stiffness, besides friendly, degradable and renewable environment. Eggshell is an agricultural waste considered as garbage, contributing to pollution; nevertheless, it can be transformed into bio-calcium carbonate, acquiring new values. As biodegradable polymers, there were chosen PLA (poly-lactic-acid) and PBAT (butylene adipate co-terephthalate), thermoplastics capable to be processed via conventional methods. PLA is a linear, aliphatic thermoplastic polyester, high in strength and modulus, but brittle. PBAT is a synthetic polymer, very flexible, based on fossil resources with high elongation at break, but low strength. It will be required the use of compatibilizers, for reducing interfacial tension exhibited by PLA/PBAT immiscible blend, considering their extreme glass transition temperatures: 62 ° C for PLA and – 30 ° C for PBAT. Herein it was used ionizing radiation for inducing compatibilization by free radicals, improving dispersion and adhesion of blend phases, without using chemical additives, at room temperature. PLA, acting as compatibilizer, was previously e-beam and gamma radiated, at 150 kGy. PBAT/PLA 50/50 blend with 15 phr of biofiller from avian eggs 125 μm particle size and both compatibilizers were homogeneized in a co-rotating twin-screw extruder, within a temperature profile 120 to 145 ° C, from hopper to die. Characterization involved: Differential Scanning Calorimeter, Thermogravimetric Analyses, Fourier Transform Infrared Spectroscopy, Wide Angle X-Ray Diffraction, Tensile Strength and Elongation at Break.Resumo IPEN-doc 27672 Ionizing radiation compatibilization in bio-based blends from PBAT/PLA reinforced with bio-eggshell2020 - CARDOSO, E.C.; PARRA, D.F.; SCAGLIUSI, S.R.; KOMATSU, L.G.; LUGAO, A.B.Plastics global annual production exceeds 300 million tons and 99% is originated from oil or fossil combustibles. The amount of plastics wastes utilized exceeds the amount into landfills, prejudicing effectively the environment. As an alternative, they are being slowly replaced by bioplastics, as PLA (poly-lactic acid) and PBAT (butylene adipate co-terephthalate). Food and dairy industries produce annually huge amounts of avian eggshells residues and their disposition presents a serious environmental risk. Bio-load from avian eggshells as polymers reinforcement is based in their higher benefits as resistance and rigidity besides being a friendly environmental material, degradable and renewable. PLA and PBAT are thermoplastics capable to be processed by conventional methods: nevertheless, due to their high interfacial tension, it is required the use of compatibilizers. In this work, additives and heat generally used as compatibilizers were replaced by e-beam radiation, at 150 kGy dose. PBAT/PLA blends were prepared at the weight ratio of 82 / 18 and 5.0 phr of PLA 150 kGy e-beam radiated, at 2.5, 5.0 and 10.0 phr of bio-eggshells. Samples were homogeneized in a co-rotating twin-screw extruder and further characterized for: DSC, TGA, FTIR, XRD and Mechanical essays.