Development of Bio-Based Polymers for Use in Asphalt

Asphalt binder is typically modified with poly type (styrene-butadiene-styrene or SBS) polymers to improve its rheological properties and performance grade. The elastic and principal component of SBS polymers is butadiene. For the last decade, butadiene prices have fluctuated and significantly increased, leading state highway agencies to search for economically viable alternatives to butadiene based materials. This project reports the recent advances in polymerization techniques that have enabled the synthesis of elastomeric, thermoplastic, block-copolymers (BCPs) comprised of styrene and soybean oil, where the “B” block in SBS polymers is replaced with polymerized triglycerides derived from soybean oil. These new breeds of biopolymers have elastomeric properties comparable to well-established butadiene-based styrenic BCPs. In this report, two types of biopolymer formulations are evaluated for their ability to modify asphalt binder. Laboratory blends of asphalt modified with the biopolymers are tested for their rheological properties and performance grade. Blends of asphalt modified with the biopolymers are compared to blends of asphalt modified with two commonly used commercial polymers. The viscoelastic properties of the blends show that biopolymers improve the performance grade of the asphalt to a similar and even greater extent as the commercial SBS polymers. Results shown in this report indicate there is an excellent potential for the future of these biopolymers as economically and environmentally favorable alternatives to their petrochemically-derived analogs

An update on the future prospects of Glycerol Polymers

Glycerol, a water‐soluble polyol, is currently used in a wide variety of markets, e.g., as a sweetener in drinks, as an additive in the food and cosmetic industry, or as an antifreeze agent, to name a few. The blooming biodiesel production has created an excess supply of glycerol by‐product. Researchers all around the world are actively exploring strategies to utilize this cheap and abundantly available biobased molecule. To date, glycerol‐based polymers have only been examined extensively for use in biomedical applications, however, the use of biobased crude glycerol is nonviable for such applications due to the presence of impurities such as methanol and residual fatty acids from the biodiesel production process. Thankfully, the increased volumes of glycerol generated from biodiesel production have stimulated the research on its use in various other industrial applications such as the production of commodity chemicals, polymers, etc. In this article, we summarize some of the efforts to valorize glycerol for polymeric applications such as polyurethanes, polyhydroxyalkanoates, and adhesives