Helium gas barrier and water absorption behavior of bamboo fiber reinforced recycled polypropylene

Abstract

Helium gas permeability and water absorption behavior of the recycled polypropylene/short bamboo fiber composite membrane were investigated. The effects of short bamboo fiber content and fiber chemical treatment on gas permeability and water absorption properties of composites have been examined. Our research showed that the solubility coefficient of helium increased as the fiber content of the bamboo increases but the diffusivity coefficient seemed to decrease with increasing amount of bamboo fiber in the composite formulation due to the poor adhesion between bamboo fiber and polymer matrix. The structure of recycled polypropylene/bamboo fibers have also investigates by X-ray diffraction technique. The chemical treatment of the bamboo fiber by alkali solution increased fiber surface roughness within the composite; in consequence, a more homogeneous dispersion of these fibers appears in the polymer matrix. The process of absorption of water was found to follow the kinetics and mechanisms described by Fick’s theory. A considerable loss in mechanical properties of the water-saturated samples after 3 months of aging in water was observed and this reduction could be delayed by fiber chemical treatment. This study provided the useful information about the behavior of recycled polypropylene/bamboo fiber composite materials during their service life time.