Original Article
  • Effect of Coffee Grounds on Mechanical Behavior of Poly Propylene Composites
  • Vinitsa Chanthavong*, M. N. Prabhakar**, Dong-Woo Lee**, Jung-Il Song***†

  • * Department of Smart Manufacturing Engineering
    ** The Research Institute of Mechatronics
    *** Department of Mechanical Engineering

  • This article is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


Spent coffee grounds (SCG) are a ubiquitous byproduct of coffee consumption, representing a significant waste management challenge, as well as an untapped resource for economic development and sustainability. Improper disposal of SCG can result in environmental problems such as methane emissions and leachate production. This study aims to investigate the physicochemical properties of SCG and their potential as a reinforcement material in polypropylene (PP) to fabricate an eco-friendly composite via extrusion and injection molding, with SCG filler ratios ranging from 5-20%. To evaluate the effect of SCG on the morphological and mechanical properties of the bio-composite, thermogravimetric analysis, SEM, tensile, flexural, and impact tests were conducted. The results demonstrated that the addition of SCG lead to a slight increase in brittleness of the composite but did not significantly affect its mechanical properties. Impressively, the presence of a significant organic component in SCG contributed to the enhanced thermal performance of PP/SCG composites. This improvement was evident in terms of increased thermal stability, delayed onset of degradation, and higher maximum degradation temperature as compared to pure PP. These findings suggest that SCG has potential as a filler material for PP composites, with the ability to enhance the material's properties without compromising overall performance.

Keywords: Spent coffee ground, Bio-composite, Polypropylene, Thermal stability and mechanical analysis

This Article

Correspondence to

  • Jung-Il Song
  • *** Department of Mechanical Engineering

  • E-mail: jisong@changwon.ac.kr