Comportamento reológico de compósitos híbridos compatibilizados de polietileno/fibra de línter/argila montmorilonita

Abstract

The addition of two fillers in polymeric matrices has been shown as an alternative to the production of conventional polymer composites, as it allows to combine the properties of the individual components. Cotton línter fiber is a low cost, biodegradable cellulose rich textile waste. Montmorillonite clay (MMT) is an inorganic natural filler capable of improving properties such as modulus of elasticity, flammability and gas permeability of polymeric materials. Polyethylene is a polyolefin widely used mainly in the packaging industry, which represents a large part of the world production of plastics. The aims of this work was to present a study of the rheological behavior in linear viscoelastic region of polyethylene hybrid composites with cotton línter fibers and organically modified montmorillonite clay with and without PE-g-MA compatibilizing agent as well as to obtain morphology, analyze X-ray diffraction structure (XRD) and to investigate possible chemical interactions by Fourier transform infrared spectroscopy (FTIR). The results of rheological analysis revealed an increase in storage and loss modules, as well as complex viscosity with the addition of fillers. The compatibilizer proved to be determinant in the composites viscosity and storage module (G') and loss modulus (G'') crossing points when compared to non-compatible composites. Morphological analysis by scanning electron microscopy (SEM) revealed the presence of an agglomerated pigment in pure polyethylene, which had a strong influence on the material rheology. SEM also showed a better adhesion surface for liner and PE-g-MA composites. Both XRD and transmission electron microscopy (MET) analysis revealed evidence of agglomeration and exfoliation regions for the clay composite. Keywords: Polyethylene; montmorillonite clay; cotton linter; rheology