Chapter 6 - High-performance polyurethanes foams for automobile industry

Abstract

Polyurethane (PU), one of the most researched materials in existence, is seen in the automobile industry without much surprise. This chapter describes physicomechanical and microstructural properties such as density, cellular structure, mechanical properties, and morphology of PU foams. Those properties are presently exploited or can be potentially used to meet automotive industries’ demands and objectives. For instance, the low density of PU foams decreases the vehicle's overall weight and gas consumption. This, in turn, improves the vehicle's performance and reduces greenhouse gas emissions. PU foams possess a broad range of mechanical behaviors, which allows them to be either flexible or rigid. Such properties can offer vehicles with mechanical shock protection. Besides the risk of collision, vehicles may also come in contact with fire in certain situations. Despite the inherently inferior flame resistance of PU foams, an extensive discussion is made in this chapter about the flame-retardant rigid PU foams obtained from an essential oil named carvone, derived from caraway and spearmint. Aluminum trihydroxide (ATH) and aluminum hypophosphite (AHP) were used as flame-retardants during the preparation of the PU foams. Standard testing methods were used in PU foam characterizations, which suggested their high suitability for automobile applications. The PU foams showcased an average density of about 40kg/m3, compressive strength in the range of 210 –150kPa, closed-cell content above 95%, and a significant reduction in self-extinguishing time of the flame from 87 to 5.2s, making them very suitable for use in automobiles.