화력발전소 Bottom Ash가 첨가된 기능성 폴리우레탄 폼의 기계적 강도 개선 및 UV 내성 향상 연구

Abstract

Polyurethane is used in various commercial and technical applications due to its high strength, chemical resistance, good processability, and favorable mechanical properties. Specifically, in construction and maritime applications, polyurethane foam serves as a thermal insulator, necessitating high mechanical strength for diverse uses. However, a drawback of polyurethane is its tendency to yellow upon exposure to UV radiation, limiting its outdoor applications due to potential discoloration and degradation. To address these challenges, ongoing studies explore the incorporation of UV absorbers, carbon black, and Hindered Amine Light Stabilizers (HALS). In this study, we introduced mask fibers into polyurethane foam to enhance its compressive strength. Disposable masks were used as a fiber source, given the heightened interest in recycling these waste products, which significantly contribute to environment pollution. The polyurethane foam with mask fibers was produced by stirring urethane, bottom ash, expanded graphite, and mask fibers (different wt%) at 2500 rpm for 30 seconds, followed by drying at 50 oC. Thermal conductivity testing revealed that the polyurethane foam with mask fibers exhibited approximately 15% higher thermal conductivity than the original polyurethane foam. The compressive strength test confirmed that the strength increased with the amount of mask fibers addition, reaching a maximum of 0.274 MPa at 2 wt.%, representing a 40% increase compared to the original polyurethane foam. On the other note, for improve yellowing resistance, we blended TiO2 with polyurethane. The polyurethane foam with TiO2 was produced by stirring urethane, bottom ash, expanded graphite, anatase TiO2, and rutile TiO2 at 3000 rpm for 15 seconds, followed by drying at 50 oC. Thermal conductivity testing showed that the polyurethane foam with anatase TiO2 experienced a slight decrease or no significant change in thermal conductivity compared to the original polyurethane foam. In contrast, the polyurethane foam with rutile TiO2 exhibited a maximum increase of about 20%. Compressive strength testing revealed different outcomes: 0.784 MPa (86% increase) for the polyurethane foam with anatase TiO2 and 0.686 MPa (62% increase) for the polyurethane with rutile TiO2. UV-Vis measurements demonstrated increased absorption in the UV region for both anatase and rutile TiO2 added polyurethane foams. Additionally, after 24 hours of UV lamp irradiation, it was confirmed that the polyurethane foam with rutile TiO2 exhibited greater improvement in yellowing resistance compared to the polyurethane foam with anatase TiO2. In conclusion, we found that incorporating mask fibers into polyurethane can significantly enhances compressive strength at a low cost. Conversely, adding TiO2 to polyurethane enhances not only improves yellowing resistance but also enhances its physical and mechanical properties.