The structure and properties of viscoelastic polyurethane foams with fillers from coffee grounds

Abstract

The subject of the research presented in this article are viscoelastic polyurethane foams (VPF) made using a fillers from coffee grounds. The foams were made with varying content of coffee fillers. Foams and fillers were characterized by means of techniques such as infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry and cone calorimeter. The changes in the microstructure of the foams were analyzed using a scanning electron microscope. Foam properties in the compression test was assessed. As a result, it was concluded that the use filler from coffee grounds causes a significant reduction in compression set of foams after compression by 75% and by 90% of the height of the samples. It was shown that these changes are caused by changes in the chemical structure of the macromolecules of these foams but also in their structure. After addition the filler, all foams have permanent deformations with a value below the permissible limit of 10%. Addition of 20% by mass of filler caused by a decrease in the rate of heat release and the rate of smoke release during foam combustion.

Spent coffee grounds: An intriguing biowaste reinforcement of thermoplastic starch with potential application in green packaging

“…The greater flame‐retardant character of TPS/SCG blends was the outcome of introducing additional carbon supply from SCG. [ 57 ] These data conclusively supplemented the results from TGA and UL‐94 analyses.…”

Spent Coffee as a Composite Filler for Wastewater Treatment

“…The measurements were carried out with the refractive index specific to the cellulose (1.47) laser setting, which allows for the analysis of the full geometrical and morphological characteristics of powders. Detailed results of SCG research were presented in a different study [ 37 ].…”

Valorization of Spent Coffee Grounds as Precursors for Biopolymers and Composite Production

“…More recently, SCG (10–40 wt.%) were added to a viscoelastic PU foam composite, leading to a reduction in the foam growth time (11% for 10 wt.% SCG), and an increase in the foam density with increasing filler content (24% for 30 wt.% of SCG). The compression tests after 75% and 90% of the original deformation show that PU/SCG composites presented lower values of permanent deformation (about 2–3%), compared to neat PU (10% and 85%), which were below the acceptable limit of 10% [ 15 ].…”

“…The residues of SCG can be directly used as fillers in composites (mainly polymer matrices), or after chemical modifications (the extraction of the molecules of interest). Typical examples of polymer matrices are synthetic polymers, such as polyurethane [ 15 ] and polypropylene [ 16 , 17 , 18 ], or biopolymers, such as polylactic acid (PLA) [ 19 , 20 , 21 ]. The resulting materials have been proposed for various applications, such as for packaging (mostly food), disposable products (single-use products/composting), and 3D printing [ 15 , 21 , 22 ].…”

“…Typical examples of polymer matrices are synthetic polymers, such as polyurethane [ 15 ] and polypropylene [ 16 , 17 , 18 ], or biopolymers, such as polylactic acid (PLA) [ 19 , 20 , 21 ]. The resulting materials have been proposed for various applications, such as for packaging (mostly food), disposable products (single-use products/composting), and 3D printing [ 15 , 21 , 22 ]. The development of SCG composites is proposed as a sustainable pathway because it reduces the amount of SCG waste in the environment [ 22 ] while creating added-value products, which can even accelerate the degradation process of a biodegradable matrix [ 23 ].…”