INVESTIGADORES
ARANGUREN Mirta Ines
artículos
Título:
Analysis of the Creep Behavior of polypropylene-Woodflour Composites
Autor/es:
NUÑEZ, ADRIÁN J.; MARCOVICH, NORMA E.; ARANGUREN, MIRTA I.
Revista:
POLYMER ENGINEERING AND SCIENCE
Referencias:
Año: 2004 vol. 44 p. 1594 - 1603
ISSN:
0032-3888
Resumen:
The creep behavior of composites prepared from woodflour and polypropylene has
been analyzed. The woodflour content was varied from 0% to 60%. The compatibility
between filler and matrix was varied by adding a non-commercial polypropylenemaleic
anhydride copolymer (PPMAN) to the mixture. Short-term and long-term creep
tests of woodflour/polypropylene composites at different temperatures were carried
out. The effects of filler content, addition of compatibilizing agent and temperature
were discussed. The creep deformation was generally reduced with woodflour addition,
except at very high filler concentrations because of filler-wetting and dispersion
problems. Low temperatures and addition of PPMAN also reduced the creep deformation.
The creep compliance was modeled using the Bürgers model and a power law
equation. The parameters were found from the best fitting of experimental data using
an optimization method. The Bürgers model was found to provide a good description
of the linear viscoelastic behavior. The mathematical description obtained from the
short-term creep was utilized to predict the dynamic mechanical behavior of the
composites with very good agreement between experimental and calculated values.
Attempts to use the time-temperature-superposition principle to predict long-term
creep from high temperature results were not successful because of the aging of the
samples during creep at low temperatures. However, there was a good superposition
of the short-term and long-term data at temperatures close to 70°C80°C. The reason
for this behavior is a relaxation of the PP matrix that takes place in that temperature
range and erases any previous aging of the material.
Polym. Eng. Sci. 44:15941603, 2004. © 2004 Society of Plastics Engineers.