Soy-based polyurethane foam for insulation and structural applications

Polyurethane (PU) foams are widely used as insulation materials due to their high insulation properties and low cost compared to conventional materials such as styrene and mineral wool. PU foams are traditionally fabricated with petroleum-based precursors. However, high crude price and higher carbon footprint has lead interest of researchers to synthesis PU foams using plant-based raw materials, that are inexpensive and renewable. In this dissertation, PU foams were fabricated using soy-based polyol and its thermal and mechanical properties were investigated. In the first part, of PU foam samples with different formulations were fabricated using soy-based polyol HB230, and varying amounts of blowing agent, catalyst and surfactant. The prepared samples were tested for density, mechanical properties, thermal insulation, and thermal stability. It was observed that soy-based polyol had comparable thermal and mechanical properties to petroleum-based foam. In the second part, PU foam samples were fabricated by blending HB230 polyol with soy-based crosslinker HB530, and petroleum-based polyol in varying ratios. Blended foam samples exhibited better thermal resistivity, compressive properties, and tensile strength of 8% higher, 512% higher, and 287% higher, respectively as compared to pure petroleum-based and pure HB230. In the third part, soy-based foams were optimized for maximum thermal insulation and mechanical strength by investigating the effects of different surfactants, used in varying amounts. The fabricated samples were investigated for effect of morphology on mechanical and thermal properties. It was observed that the cell size of the foam samples can be controlled by varying the surface tension of the reactants of the foam, resulting in variation of the properties --Abstract, page iv