Repositório do Conhecimento Institucional do Centro Universitário FEI
 

Engenharia de Materiais

URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/17

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2022 - 20232

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Data inicial: 2020Periódico: search.filters.ispartof.Journal of Applied Polymer Science

Resultados da Pesquisa

Agora exibindo 1 - 2 de 2
  • N/D
    Artigo 6 Citação(ões) na Scopus
    Effect of injection molding conditions on the properties of polyamide 6/calcium carbonate nanocomposite
    (2023-05-12) AUGUSTO, T. A.; CARASTAN, D. J.; SANTOS, A. N. B.; BONSE, B. C.
    © 2023 Wiley Periodicals LLC.The application range of polyamide 6 in lightweight part applications can be significantly increased by using appropriate processing parameters and by incorporating additives. Therefore, specimens were manufactured at varying mold temperatures and injection velocities to study the effect of injection molding parameters on the properties of polyamide 6 and its nanocomposite with nano-calcium carbonate. Mechanical properties, degree of crystallinity, density, heat deflection temperature, and melt flow index were measured to assess the effect of injection molding conditions on material properties. Mold temperature was the process factor that most affected polyamide 6 and polyamide 6/nano-calcium carbonate properties. Increasing this parameter increased density, impact strength, flexural strength, flexural modulus, and heat deflection temperature. The nanocomposite's degree of crystallinity, tensile modulus, and melt flow index also increased. High injection velocity reduced only the impact strength of the nanocomposite. The findings indicate that by modifying injection parameters, it is possible to improve mechanical properties and processing efficiency of polyamide 6 and its nanocomposites, bringing them closer to their maximum potential. Incorporating the nanofiller increased almost all properties except for impact strength and elongation at break. Nano-calcium carbonate provided considerable advantages to polyamide 6 mechanical performance and processability while increasing sample weight by only 1.5%.
  • N/D
    Artigo 6 Citação(ões) na Scopus
    PA6/PA66/talc composite: Effect of reprocessing on the structure and properties
    (2022-04-05) DOMINGO, G. D.; SOUZA, A. M. C.
    In this study the effect of repeated injection molding cycles on the structure and properties of polyamide 6/polyamide 66/talc (PA6/PA66/talc - 35/35/30) composite was investigated for samples subjected to one, four, and seven processing cycles. Their morphology (scanning electron microscopy), structure (Fourier transform infrared spectroscopy), melt viscosity (melt flow index [MFI]), mechanical (tensile, flexural, impact, and fatigue tests), and thermal properties (differential scanning calorimetry and thermogravimetric analysis tests) were analyzed. The increase in MFI value and the decrease in the maximum decomposition temperature of PA6, observed by TG analysis, for samples subjected to seven processing cycles, indicated a possible reduction in molar mass of the PA6/PA66 matrix. These samples presented a decrease in degree of crystallinity of PA6 and PA66, which was more pronounced for PA6. The reprocessing of the composite did not present changes in the mechanical properties up to the fourth processing cycle, except for fatigue life which presented a 59% reduction. Samples subjected to seven processing cycles presented a decrease in tensile and flexural strength as well as in tensile and flexural modulus. Charpy impact strength of the samples did not significantly change upon reprocessing. The micrographs of the fatigue fractured surfaces indicated that the weak talc-matrix interaction and talc-matrix debonding became more evident with increasing processing cycles.