Cell structure control and performance of rigid polyurethane foam with lightweight, good mechanical, thermal insulation and sound insulation

Lightweight and excellent mechanical properties rigid polyurethane foams (RPUFs) play an irreplaceable role in aerospace, construction and transportation fields. Microstructure is an important factor in controlling properties of RPUFs. In this study, RPUFs with different cell structures were fabricated by adjusting foaming agent. The relationship between cell structure parameters (cell size, wall thickness, closed cell rate and cell anisotropy) and density was determined based on SEM analysis. The compressive, bending, impact, heat insulation and sound insulation properties were tested. The results showed that cell structure was related to mechanical properties, which was reflected in the linear relationship between log (density) and log (mechanical properties). RPUF0.4 with a density of 148 kg/m3 possessed excellent compressive strength, flexural strength, flexural modulus and impact strength of 2.89 MPa, 2.60 MPa, 35.41 MPa and 1.06 kJ/m2. Thermal and sound insulation properties were depended on cell size and closed cell rate, the thermal conductivity of RPUFs ranged from 0.0398 to 0.0515 W/(m & sdot;K), and the sound transmission loss of RPUF1.4 exceeded 25 dB in 500-5000 Hz. The comprehensive properties were regulated by adjusting cell structure, which provides a theoretical basis for the design of RPUFs with specific properties.