In Silico Investigation of the Impact of Reaction Kinetics on the Physico-Mechanical Properties of Coconut-Oil-Based Rigid Polyurethane Foam

Abstract

Conventionally, designing rigid polyurethane foams (RPUFs) with improved physico-mechanical properties from new, bio-based polyols is performed by modifying foam formulations via experimentation. However, experimental endeavors are very resource-dependent, costly, cumbersome, time-intensive, waste-producing, and present higher health risks. In this study, an RPUF formulation utilizing a coconut-oil (CO)-based polyol with improved physico-mechanical properties was approximated through a computational alternative in the lens of the gel time of the RPUF formation. In the RPUF formation of most bio-based polyols, their very fast gel times negatively impact foam robustness. The computational alternative functioned by finding a CO-based RPUF formulation with a gel time in good agreement with a formulation based on commercial petroleum-derived polyol (control). The CO-based RPUF formulation with the best-fit catalyst loading was approximated by simulating temperature profiles using a range of formulations with modified catalyst loadings iteratively. The computational approach in designing RPUF with improved properties was found to effectively negate foam collapse (with a shrinkage decrease of >60%) and enhance foam strength (with a compressive strength increase of >300%). This study presents an economically and environmentally sustainable approach to designing RPUFs by enabling minimized utilization of material sources for experimentation and analysis and minimized dependence on waste-producing methods.

Valorization of Agricultural Rice Straw as a Sustainable Feedstock for Rigid Polyurethane/Polyisocyanurate Foam Production

“…The data presented in Table 3 show the impact of substituting V490 with RS-based polyol within the 0–50% range on the foaming reactions kinetics of RPUFs. This analysis highlights key parameters such as cream time, gel time, and maximum temperature ( T max ), 30 , 35 and has been conducted with three replicates, providing insights into the thermodynamic aspects of the foaming process. Significantly, both cream and gel times exhibit a consistent incremental increase as the proportion of RS-based polyol increases.…”

“…One of the most well-known PU products is rigid PU foam (RPUF), commonly employed in construction and insulation applications due to its exceptional insulating properties and structural integrity. − PU synthesis entails the reaction between hydroxyl (−OH) groups in polyols and –NCO groups in isocyanates, , (Figure ). The polyol types significantly influence the resulting PU properties. ,− Traditionally, polyols used in PU production are primarily derived from petroleum feedstocks.…”

An Iterative Method for the Simulation of Rice Straw-Based Polyol Hydroxyl Moieties

“…Further investigation in Figure 4 reveals a gradual decrease in temperature as the system approaches thermal equilibrium, indicating heat dissipation from the PU foam system during the cooling phase following the gelling process [19]. This observation suggests that heat is transferred from the PU foam system to the surroundings during the cooling phase, resulting in a gradual decrease in temperature.…”

“…One crucial aspect that profoundly affects the properties of these products is the reaction kinetics during the PU manufacturing process [14][15][16][17][18]. Alfeche et al (2023) successfully modeled the physicomechanical properties of rigid PU foam based on coconut oil, focusing on the gel reaction kinetics and gel time [19]. It was found that PU reaction kinetics are largely influenced by the chemical properties of the polyol, such as heat capacities, functionalities, and hydroxyl values.…”