NU 2015-120
Inventors
Regan J. Thomson*
Franz Geiger
Background
The generation of polymers from biorenewable sources is a key goal for the sustainable production of important materials. a-Pinene is one of the most common terpenes found in nature and is readily extracted from a variety of renewable feedstocks. Although it is currently a popular monomer for a variety of downstream polymers, a -Pinene is not suitable for metathesis polymerization reactions due to steric hindrance at the carbon-carbon double bond. Northwestern offers a novel method that converts a-pinene into a more useful and accessible derivative for which ring-opening metathesis polymerization (ROMP) may be used to create high molecular-weight polymers.
Abstract
Northwestern researchers have developed an alternative method for using a-pinene as a monomer precursor for ROMP, a process traditionally known to produce significantly fewer byproducts with higher catalytic rates compared to other types of catalyzed polymerizations. a-Pinene is the most abundant monoterpene present in nature and plays crucial roles in many biological, atmospheric, and industrial processes. Similar to other readily accessed and biorenewable terpenes, a-pinene is widely used in both the fine chemical and polymer industries. More specifically, the Lewis acid-catalyzed polymerization of a-pinene has found a variety of uses in industrial applications such as adhesives, plastics and rubbers. a-Pinene is not suitable for ROMP due to the congested methyl-substituted olefin that hampers the polymerization reaction. However, deleting the methyl substituent results in the less congested precursor, apopinene, which is suitable for subsequent polymerization reactions. Apopinene reacts with ruthenium-based metathesis catalysts to provide an all trans-polymer with a low polydispersity index and molecular weights in the 1100 to 15,600 g mol-1 range (9-127 monomer units). Northwestern researchers have developed a novel process to easily prepare apopinene in one-step from myrtenal or two-steps from a-pinene, both of which are naturally abundant. By utilizing this unique method, apopinene may find future use as a new biorenewable precursor for the sustainable production of ROMP-based materials and opens the opportunity to manufacture new families of polymers.
Stage of Development
Bench-scale proof of concept reactions have been performed with Grubbs I, II, and III catalysts.
Applications
Advantages
Publications
Strick B, Delferro M, Geiger F, Thomson R (2015) Investigations into Apopinene as a Biorenewable Monomer for Ring-Opening Metathesis Polymerization. ACS Sustainable Chemistry & Engineering. 3: 1278-1281.
IP Status
Issued US Patent No. 9,850,340