Novel polyurethane viscoelastic foam modified with discarded luffa seed oil in accordance with cleaner production

In this study, abundant, inexpensive, and underutilized natural luffa seed oil (LSO) was used for modifying polyurethane viscoelastic foam (PVF) to prepare LSO-modified PVF (LSVF). Scanning electron microscopy and porosity measurement results show that the addition of LSO endowed LSVF with a rich porous structure and rough cell surface. With the increase in LSO addition, the cell diameter and porosity of LSVF increased from 0.33 to 0.58 mm and 50.68–87.69%, respectively. Addition of LSO increased the viscosity of LSVF reaction mixture system, thus prolonging the cell expansion time in foaming process. Moreover, the addition of LSO reduced the indentation hardness, compression deflection coefficient, and hysteresis loss rate, and improved the flexibility of LSVF. Notably, LSO could significantly improve the sound absorption performance of LSVF. LSVF-30 (30% LSO added amount) acted as a high-efficiency sound-absorbing material, and the LSVF containing LSO exhibited a significantly improved ability to absorb sound waves in the frequency range of 2000–5000 Hz (the most sensitive range for the human ear). Compared to LSVF-0 without LSO, the sound absorption performance of LSVF-30 in this frequency range improved by nearly 100% on average. The addition of LSO significantly improved the moisture dissipation of conventional PVF. The moisture dissipation rate of LSVF-30 increased by 17.67% in 72 h compared to that of LSVF-0. These results show that the addition of LSO is beneficial to improve the properties and service life of foam, reduce the polyurethane foam waste from the source, and help reduce environmental pollution.