The
influence of surface treatment of fibers on the properties of glass fiber/
PA 6,6 composites
CREPEC, Center for Applied Research on
Polymers and Composites,
Chemical Engineering Department,
Ecole Polytechnique, P.O.Box, Stn. Centre-Ville,
Abstract
The
influence of surface treatment of fibers on the morphology, mechanical and
thermal properties of injection molded samples of polyamide (PA) 6,6 composites
made with grafted and untreated glass fibers has been investigated. Changes in
properties due to weld line were also examined. Glass fiber polyamide
composites were prepared by melt blending using a twin-screw extruder and
tensile specimens with and without weld lines were prepared by injection
molding. The treated glass fiber composites were found to have much better
mechanical properties (tensile strength, tensile modulus, and impact energy)
compared to the untreated glass fiber composites. As expected, the tensile
properties of samples with a weld line were lower compared to the ones without
a weld-line for both treated and untreated fiber composites. The enhanced
properties of the grafted fiber composites are attributed to enhanced wetting
and stronger interaction between the polyamide and the grafted glass fibers, as
well as a better dispersion. These were confirmed by electron microscopy (SEM)
micrographs and by a significant increase of the glass transition temperature
for the treated glass fiber composite.
Key-words: Polyamide, polymerization
compounding, glass fiber, properties of composites.