ABSTRACT
This research aimed to optimize the production conditions for geopolymer matrices by investigating the combination of heat curing conditions and the incorporation of recycled ceramic fines (CFs) as a partial replacement material for fly ash (FA). The obtained physical and mechanical properties of the composites confirmed the positive impact resulting from increasing the curing temperature from 65 °C to 85 °C and using CFs in the amount of 37.5% as a replacement for FA. The results were from laboratory tests performed to evaluate compressive strength, bending strength, bulk density, and water absorption of the geopolymer mixes. In addition, microscopic observations and porosity assessment were also performed, which confirmed that a further increase in the replacement of FA by CFs causes an increase in the porosity of the mixes and, thus, a decrease in all the assessed properties that are relevant to their practical use.
ABSTRACT
The poly(lactic acid) (PLA) biodegradable polymer, as well as natural, siliceous reinforcement in the form of diatomaceous earth, fit perfectly into the circular economy trend. In this study, various kinds of commercial PLA have been reinforced with diatomaceous earth (DE) to prepare biodegradable composites via the extrusion process. The structure of the manufactured composites as well as adhesion between the matrix and the filler were investigated using scanning electron microscopy (SEM). Differential scanning calorimetry (DSC) analyses were carried out to determine crystallinity of PLA matrix as function of DE additions. Additionally, the effect of the ceramic-based reinforcement on the mechanical properties (Young's modulus, elongation to failure, ultimate tensile strength) of PLA has been investigated. The results are discussed in terms of possible applications of PLA + DE composites.
