Waste cooking oils as processing aids for eco-sustainable elastomeric compounding

Abstract

This work focuses on the replacement of mineral oils with bio-based waste cooking oils in rubber compounding. Two different waste cooking oils from potatoes and chicken frying process were analyzed by means of chemical and rheological tests to evaluate the chemical composition, the oxidative stability and the viscosity. Waste oils have been introduced in elastomeric compounds as substitute for typical processing aids (i.e. lubricants). Cure kinetics of rubber compounds was studied by rheological characterization. Mechanical properties of vulcanized samples were determined by means of tensile tests, hardness tests and dynamic mechanical analysis. The waste oils showed a rheological behavior very similar to the mineral oils conventionally employed in rubber manufacturing leading to almost the same processability of the resulting compound. The waste oils did not significantly affect the vulcanization kinetics of the rubber compound, as expected for conventional lubricants. Waste cooking oils and mineral oil show analogous influence on mechanical properties of cured compounds. At increasing oil content, the elongation at break and the tensile strength increased whereas the values of Elastic Modulus at 100% strain, the Storage Modulus and Shore A Hardness decreased with respect to the oil-free sample. These results are very promising, confirming the possibility to replace the mineral oils, in a good practice of circular economy.

Soybean Oil‐Based 3D Printed Mesh Designed for Guided Bone Regeneration (GBR) in Oral Surgery

“…[ 17 ] Among bio‐sources, vegetable oils are very promising for the production of bioplastics. Vegetable oils (i.e., olive oil, linseed oil, and soybean oil [ 18 ] ) are a mixture of unsaturated and saturated fatty acids and triglycerides (transesterification of glycerol with three chains of fatty acids) [ 19 ] that are generally liquid at room temperature (25 °C) due to the high content of unsaturated fatty acids. Vegetable oils do not present reactive chemical groups, and they cannot be employed as monomers in their pristine state for polymerization reactions.…”

Towards sustainable rubber compounds: The use of waste raw materials

“…McDonald's provides a frequent substitution of the cooking oils after a determined number of frying cycles focusing on environmental sustainability 44 . WCOs have been already characterized and successfully used in the production of rubber compounds in a previous work 29 . They showed a similar viscosity value (78 mPa s) of the neat oil and the presence of small percentages of saturated free fatty acids (7.28% of stearic acid) and octadecenal (C 18 H 34 O), a secondary oxidation product after the frying process.…”

“…WCO has been widely researched for the production of biodiesel, 27 biosurfactants, 25 or biopolymers 28 . It has been recently proven that WCOs can be used as processing aids during rubber compounding without affecting the mechanical and chemical properties of the vulcanized rubber 29 Elastomeric matrix is the major constituent of the compound and it affects the properties of the final composite material the most.…”

Ground tire rubber and coffee silverskin as sustainable fillers in EPDM compounds for rubber‐to‐steel bonded systems in roofing applications

“…The elastic modulus (M 100% ), the maximum strength (σ max ), and the shore A hardness values, reported in Table 2, highlight the high stiffness and tensile resistance 38,39 of all compounds, especially in the formulation containing both fillers (M 100 = 15.7 MPa). Although CSS and GTR have micrometric dimensions they show some interaction with the macromolecule of the rubber.…”