JULIO HARADA
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Artigo IPEN-doc 30269 Evaluation of graphene incorporation for mechanical properties of polypropylene composites2023 - HARADA, JULIO; MARCONDES, CLAUDIO A.; PEREIRA, MARIA da C.C.; SILVA, LEONARDO G.A.Graphene nanoparticles (GnP) was selected as an alternative reinforcement, nanofillers, to enhance the mechanical properties of polypropylene (PP-homo and PP-copolymer) and using compatibilizer, maleic anhydride graphitized with polypropylene (PP-g-MA) in a twin-screw extruder. The effect of GnP loading and the use of the PP-g- MA compatibilizer were studied. The influence on the mechanical properties of tensile strength, elongation, IZOD impact strength, and melting temperature in PP-homo and PP-copolymer were investigated and compared. Their improvement was observed up to a certain amount, depending on whether it is a homopolymer or copolymer. The PP copolymer has a greater affinity with graphene and the compatibilizer due to the elastomeric comonomer present in the copolymer.Resumo IPEN-doc 29549 Electron beam processing to improve biodegradable polymers and for industrial wastewater treatment and recycling2022 - CALVO, W.A.P.; MUNHOZ, P.M.; SOMESSARI, S.L.; DUARTE, C.L.; SPRENGER, F.E.; FEHER, A.; LAINETTI, F.F.; GASPAR, R.R.; NASCIMENTO, F.C.; SILVA, L.G.A.; HARADA, J.; BRAGA, A.; RODRIGUES, M.; SAMPA, M.H.O.Radiation technology has been used to control environmental pollution. The aim of these studies was to apply the electron beam radiation technology for controlling plastic pollution and environmental protection.Artigo IPEN-doc 28339 Influence of electron beam irradiation on the mechanical properties of pbat/pla polymeric blend2021 - MUNHOZ, PEDRO M.; NASCIMENTO, FERNANDO C.; SILVA, LEONARDO G. de A. e; HARADA, JULIO; CALVO, WILSON A.P.The aim of this research was to evaluate the changes in the mechanical properties of poly(butylene adipate co-terephthalate)/poly(lactic acid) (PBAT/PLA) polymeric blend after the radiation process at different radiation doses. The irradiation was performed in an electron beam accelerator, with 1.5 MeV of energy and 25 mA electric current. The samples were irradiated with doses of 5, 10, 15, 25, 50, 65 and 80 kGy. Both irradiated and non-irradiated samples were characterized by Izod pendulum impact resistance and tensile strength at rupture. The results showed an increase of 44% in relation to Izod impact resistance at a dose of 65 kGy. However, the module of elasticity decreased 56% and tensile strength at rupture decreased 55% at the same radiation dose. In relation to elongation, significant alterations caused by electron beam irradiation was not observed. Therefore, it can be concluded that irradiated blends could be used to make environmentally friendly products, which could absorb impact energy.Artigo IPEN-doc 26286 Poly (butylene adipate co-terephthalate)/poly (lactic acid) (PBAT/PLA) blend characterization processed by electron beam2019 - MUNHOZ, PEDRO M.; SILVA, LEONARDO G. de A. e; HARADA, JULIO; NASCIMENTO, FERNANDO C.; CALVO, WILSON A.P.The aim of this research was to check the changes in the mechanical and thermal properties of poly(butylene adipate co-terephthalate)/poly(lactic acid) (PBAT/PLA) polymeric blend, which commercial name is Ecovio®, after radiation processing in different absorbed doses. PBAT and PLA are biodegradable polymers and the Ecovio® polymeric blend consists of at least 80% of polymers from renewable resources. The irradiation was performed in a Radiation Dynamics Inc. electron beam accelerator, with 1.5 MeV of energy and electric current of 25 mA. Samples were prepared for micrograph, mechanical and thermal analyses. These samples were irradiated with absorbed doses of 5 kGy, 10 kGy, 15 kGy, 25 kGy and 50 kGy. The samples, after irradiation, were submitted to experiments of ultimate strength, tensile strength, ultimate elongation, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The results showed a good interaction between the components of the polymeric blends and the radiation effect on polymeric blend promoted changes in PBAT and PLA polymers, increasing tenacity of these biopolymers and consequently facilitating yarn formation in processing. In conclusion, these irradiated blends could be used to make environmental friendly products.Artigo IPEN-doc 24948 Characterization of biodegradable mulch black films incorporated with organics fertilizers and rice husk ash2017 - HARADA, JULIO; AMORIM, CAMILA A.; BRAGA, PAULA L.; MACHADO, LUCI D.B.; OLIVEIRA, RENE R.; CABRAL NETO, ABNER; MACEDO, JOSE R.N.; SILVA, LEONARDO G.A.; ROSA, DERVAL S.The effects of organic fertilizer, rice husk ash, both from renewable resources, were evaluated. Both of them were incorporated in biodegradable black mulch films. Morphological, mechanical and thermal properties based on PBAT/PLA composites with 2 % wt. of carbon black were investigated. In addition, the formulations were prepared with 1 % wt. to 2 % wt. rice husk ash and 2 % wt. to 4 % wt. % organic fertilizer The samples were produced by melt extrusion process, using a twin screw extruder machine and blown film extrusion process. As can be seen the properties of biodegradable mulch film samples were investigated by tensile tests, XRD, FTIR, TG, MEV analyses. Correlation between properties were discussed. According to the results it is possible to apply this composite as film for agricultural protection.Artigo IPEN-doc 24873 Investigação das propriedades dos compósitos formados por resina uretânica elastomérica e vermiculita processada2017 - OLIVEIRA, JOSE M.D.; COELHO, ANTONIO C.V.; BARBERATO, FERNANDA; HARADA, JULIO; SILVA, LEONARDO G.A.; CABRAL NETO, ABNERNa tentativa de melhorar a tensão de ruptura da resina uretânica elastomérica (TPU), foi estudada adição de vermiculita processada a esta resina. Os compósitos resultantes foram avaliados em microscopia eletrônica de varredura (MEV), Calorimetria Exploratória Diferencial (DSC), e análise termogravimétrica (TGA). Os resultados de tensão de ruptura obtidos para os compósitos formados pela resina uretânica elastomérica e vermiculita processada apontam para a necessidade estudos complementares de compatibilização e de processamento.Artigo IPEN-doc 23652 Effects of carbon black incorporation on morphological, mechanical and thermal properties of biodegradable films2016 - HARADA, JULIO; MACEDO, JOSE R.N.; MACHADO, GLAUSON A.F.; VALENZUELA-DIAZ, FRANCISCO; MOURA, ESPERIDIANA A.B.; ROSA, DERVAL S.This work evaluates the effects of carbon black incorporation on morphological, mechanical and thermal properties of biodegradable films. The biodegradable composite films based on PBAT/PLA blend and PBAT/PLA blend containing 2 wt. % of carbon black were prepared by me lt extrusion, using a twin screw extruder machine and blown extrusion process. The properties of biodegradable film samples were investigated by tensile tests, XRD, MFI, TGA, DSC and FE-SEM analysis and the correlation between properties was discussed.