An experimental study on castor oil-based flexible PU foam coated with silica hydrogel for acoustic and fire resistance applications

• Published in: Hyperfine interactions 2024-06, Vol.245 (1), Article 97
• Main Authors: Selvaraj, Vinoth Kumar, Subramanian, Jeyanthi, T, Senthil Muthu Kumar, Raja, S., S, Vignesh, K, Anto Kumar
• Format: Article
• Language: English
• Subjects: Absorptivity; Acid resistance; Acoustics; Atomic; Castor oil; Condensed Matter Physics; Fire resistance; Hadrons; Heavy Ions; Hydrochloric acid; Hydrogels; Immersion coating; Molecular; Nuclear Physics; Optical and Plasma Physics; Physics; Physics and Astronomy; Polyurethane foam; Silicon dioxide; Sodium silicates; Sound transmission; Sublimation; Surfaces and Interfaces; Thin Films; Weight loss; Weight reduction
• ISSN: 3005-0731; 0304-3843; 3005-0731; 1572-9540
• DOI: 10.1007/s10751-024-01940-y

This research explores the production of flexible polyurethane foam using castor oil with varying densities, treated via dip coating with sodium silicate and hydrochloric acid to form a protective silica hydrogel. This treatment enhances the foam’s acoustic and fire resistance properties. The sound absorption coefficient (SAC) is measured using an impedance tube per ASTM E 1050-12, and the noise reduction coefficient (NRC) is calculated. Specimen S5 shows superior performance with an NRC of 0.336 for coated and 0.283 for non-coated conditions, a significant 19% improvement. TGA revealed that non-coated foam showed initial sublimation at 240 °C and substantial degradation with a 75% weight loss at 400 °C, while coated samples like S5 began to decay at 300 °C, showing only a 25% weight reduction at 400 °C. These results highlight the influence of foam density on acoustic enhancement, making the foam ideal for automotive interiors by providing a quieter and safer environment for passengers.