Study of mechanical and physical properties of LLDPE-G-MA injection grade reinforced with coffee husk post-industrial waste

In this work, the evaluation of a post-industrial residue of coffee industry (coffee husk) as organic filler in functionalised linear low-density polyethylene matrix was investigated. The properties of these composites were compared with more widely used inorganic fillers, such as calcium carbonate and SiO2. All the composites were prepared by grafting of linear low-density polyethylene maleic anhydride and then by melt mixing of fillers. The rheological behaviour of the compounds during processing was established to evaluate the effects of a nanosized (SiO2), micron sized calcium carbonate and coffee husk fillers. Additionally, thermal, morphological and mechanical properties of the polymer composites were evaluated. The results indicated an increase in tensile modulus and tensile strength resulting from incorporation of fillers in the polymer matrix. Some relevant modifications of melting temperature and crystallinity degree for coffee husk composites were observed, but not observed for inorganic fillers composites. The properties of the composites prepared with coffee husk were comparable to those obtained with inorganic fillers, demonstrating that this coffee residue can be used as filler for obtaining composites for many possible applications.