JULYANA GALVÃO SANTANA
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Capítulo IPEN-doc 25625 Development of biocomposite materials from biodegradable polymer and bio-hydroxyapatite derived from eggshells for biomedical applications2019 - REIS, PEDRO R.S.; SANTANA, JULYANA G.; OLIVEIRA, RENE R.; RANGARI, VIJAYA K.; LOURENÇO, FELIPE R.; MOURA, ESPERIDIANA A.B.Nowadays, significant advances have been made in the development of biodegradable polymeric materials for biomedical applications. This study aims to prepare and characterize composite materials based on PLA/PBAT, a biodegradable polymer blend, reinforced with bio-hydroxyapatite (bio-HAp). First, bio-HAp was obtained from eggshell residues by the wet precipitation method. PLA/PBAT blend with 1.5 wt% of bio-HAp was prepared by melt extrusion and injection molding process. Part of composite samples was irradiated with gamma radiation dose of 25 kGy, at room temperature and presence of air. The effects of the bio-HAp addition into the biodegradable blend were investigated by mechanical tests, XRD, DSC, FESEM, and cytotoxicity “in vitro” analysis and the correlation between the properties was discussed. In addition, the microbiological tests were carried out at irradiated and non-irradiated composite samples in order to evaluate the efficiency of the radiation dose of 25 kGy at composite materials sterilization.Capítulo IPEN-doc 25004 Mechanical, thermal, morphology and barrier properties of flexible film based on polyethylene-ethylene vinyl alcohol blend reinforced with graphene oxide2017 - SANTANA, JULYANA G.; ORTIZ, ANGEL; OLIVEIRA, RENE R.; RANGARI, VIJAY K.; GUVEN, OLGUN; MOURA, ESPERIDIANA A.B.Ethylene-vinyl alcohol (EVOH) copolymers are widely used in the food packaging industry as gas barrier properties to oxygen, organic solvents, and food aromas. EVOH is very sensitive to moisture and its gas barrier ability deteriorates in high relative humidity conditions. This work aims to prepare flexible films based on melt-blending high density polyethylene (HDPE) and ethylene-vinyl alcohol (HDPE/EVOH/EVA blend) reinforced with graphene oxide (GO). The HDPE/EVOH/EVA/GO flexible films were prepared by twin-screw extrusion and blown film extrusion processing. The flexible films samples were characterized by tensile tests, TG, DSC and FE-SEM analysis and the correlation between properties was discussed. In addition, the oxygen permeability tests were performed at 23 °C, 0 and 90% relative humidity using an OX-TRAN (MOCON Inc.).