Composites based on low-density polyethylene combined with PETcoated SBS paperboard shavings

Abstract

In this study, polymer composites comprised of shavings of SBS paperboard coated with polyethylene terephthalate
(PET) and recycled low-density polyethylene (LDPE) were obtained. The tensile properties, flexural
strength, impact resistance and water absorption were determined according to the standards published
by the American Society for Testing and Materials (ASTM). The results show that the composites with the
highest concentration of LDPE were more resistant to absorption when exposed to water and humidity. As
regards density, a 19.5% increase of this property was verified for the 30% cellulosic fiber reinforced composite
relative to the pure LDPE density. In relation to the mechanical properties, these samples were found to
be very flexible in the elasticity test. The extrusion method provided adequate adhesion between the interfaces
of the matrix with the fiber. The composite showed a tensile strength of approximately 55% larger than
that originated by pressing. However, the values for the tensile, flexural and impact strength were lower than
expected due to the lack of homogeneity of the SBS paperboard shavings.
Keywords: packaging residue, mechanical properties and polymers.