Abstract
Due to changes and challenges in environmental and material properties, continuous improvements to the resin products used for mining and structural support are constantly required. UPE resin has been employed in this field for decades, with a limited selection of fillers, promoters, and initiator additives suitable for ensuring product stability and performance to meet end-user requirements. Furthermore, the limitations in the choice of additives, as well as the mineralogy and particle size grading of specific fillers, can degrade from outstanding to subpar the resin's chemical, physical, thermal, and mechanical properties. Nanotechnology has been identified to enhance the desired properties of UPR, primarily the chemical and mechanical properties, by addressing the limitations of the current system.
UPE resin was promoted by adding 0.1 wt% of dimethyl-para-toluidine the amine promoter (DMPT), and 2.0 % benzoyl peroxide (BPO) as an initiator. Nanocomposite samples were prepared with varying quantities of TiO2 and Ag nanomaterials to investigate the effect of nanomaterial incorporation and their respective quantities. The liquid resin nanocomposites were tested for vinyl polymerization and tensile strength. For other tests, a premix of 18.0 wt% UPE resin and 82.0 wt% calcium carbonate fillers with two different gradings at 60:40 ratio of coarse to fine, was prepared at a constant resin-to-filler ratio. The nanocomposites were prepared by mechanical mixing for 20 minutes per sample and analysed using various techniques to measure resin viscosity (pipeline viscosity) on an extensometer, set time and AVP at elevated temperatures, using a Brookfield viscometer with an RVT spindle #3 at 10 rpm. For microstructural analysis, SEM was used to observe changes in surface roughness and the presence of nanoparticles.
The absence of cracks or voids on the nanocomposite surface indicated adequate crosslinking. Structural changes at the molecular level of the resin were measured using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and Raman spectroscopy. The presence of nanoparticles was detected through M—OH vibrations on FTIR, the appearance of new phases on XRD, and the narrowing and shifting of peaks on Raman spectroscopy. The set time and vinyl polymerization of the resin were not affected by the addition or increase in nanoparticle content. However, significant changes were observed in the resin's pipeline viscosity, with nanoparticles causing an increase in this property over a 90-day product shelf life. Thermogravimetric analysis was conducted to evaluate the thermal stability of the nanocomposite at different nanoparticle concentrations. To measure the cure profile of UPE resin and nanocomposites, the chemical exothermic reaction was tested, and the peak exotherm was recorded as a function of time...