|Cite this article as:|
|Haozhen Wang, Lin Lin, and Yingshu Liu, Eco-friendly physical blowing agent mass loss of bio-based polyurethane rigid foam materials, Int. J. Miner. Metall. Mater.,(2022). https://doi.org/10.1007/s12613-022-2502-8|
Through systematical experiment design, the physical blowing agent (PBA) mass loss of bio-based polyurethane rigid foam (PURF) in the foaming process was measured and calculated in this study, and different eco-friendly PBA mass loss was measured quantitatively for the first time. The core of the proposed method is to add water to replace the difference, and has a high fault tolerance rate for different foaming forms of foams. The method was proved to be stable and reliable through the standard deviations σ1 and σ2 of R1 (ratio of the PBA mass loss to the materials total mass except the PBA) and R2 (ratio of the PBA mass loss to the PBA mass in the materials total mass) in parallel experiments. It can be used to measure and calculate the actual PBA mass loss in the foaming process of both bio-based and petroleum-based PURF. The results show that the PBA mass loss in PURF with different PBA systems is controlled by its initial mass concentration ω, additionally R2 of the same PBA with different initial mass concentration ω is basically a fixed value. The main way for PBA to dissipate into the air is evaporation/escape along the upper surface of foam. This study further reveals the mechanism of PBA mass loss: the evaporation/escape of PBA along the upper surface of foam is a typical diffusion behavior. Its spread power comes from the PBA within the interface layer of the chemical potential and its chemical potential difference in the outside air. For a certain PURF system, R1 has a linear relationship with its PBA initial mass concentration ω, which can be expressed by the functional relationship Ri=ai ωi, where ai is a variable related to PBA's own attributes.