Polyols and Polyurethanes from Protein-Based Feedstocks

Abstract

Feedstocks that have high protein contents, such as soy protein, are promising materials for extensive polyol and polyurethane (PU) applications, such as foams, films, and coatings, due to the characteristic structures and properties of proteins. Currently, most research has been focused on the direct use of these protein-based feedstocks in combination with polymers for PU production. Although proteins have multiple reactive functional groups, such as amino and carboxyl groups, reports on the modification of protein-based feedstocks for the production of liquid polyols are limited. This chapter reviews sources, compositions, structures, and processing of protein-based feedstocks; synthetic methods and properties of protein-based polyols; and performance and applications of the derived PUs.

Synthesis of Biobased Polyols from Soybean Meal for Application in Rigid Polyurethane Foams

“…These are primarily used in human and animal nutrition, but they are also used in the production of bioplastics 16,25 and other industrial products, for example, adhesives and composites. 19,22,26 Other biomass resources such as Jatropha meal (a byproduct of biodiesel production) and distiller's dried grains with solubles (DDGS, a byproduct of ethanol production from corn via the dry milling process) can also be used for synthesis of industrial products. However, the crude protein content of soymeal is approximately 40−50% higher than the crude protein content of Jatropha meal or DDGS.…”

“…Plant oils used for polyol synthesis include canola oil, castor oil, rapeseed oil, and soybean oil, with soybean oil most commonly used. − Soybean comprises 18% soybean oil and 82% soybean meal or soymeal. Approximately 68% of the total soybean oil consumed in the United States is used in food applications, and rest of it is used in the production of biodiesel , and industrial products such as polyols. , There are many studies on polyol synthesis from plant oils, but very few studies report the use of soymeal for polyols synthesis. − …”

“…In certain studies, soymeal or soy protein isolate has been incorporated in polyurethane foams as an additive to improve their mechanical and thermal properties. , Soymeal is primarily used as an animal feed. , Soymeal proteins have been extracted and concentrated to provide protein-rich components, that is, soy protein concentrate (SPC, 70% of proteins) and soy protein isolate (SPI, 90% of proteins). These are primarily used in human and animal nutrition, but they are also used in the production of bioplastics , and other industrial products, for example, adhesives and composites. ,, Other biomass resources such as Jatropha meal (a byproduct of biodiesel production) and distiller’s dried grains with solubles (DDGS, a byproduct of ethanol production from corn via the dry milling process) can also be used for synthesis of industrial products. However, the crude protein content of soymeal is approximately 40–50% higher than the crude protein content of Jatropha meal or DDGS …”