Cuphea as a source of fully crop-based plasticizers for Poly(vinyl chloride)

Authors: Jackson, Michael - Mike; Selling, Gordon; Evans, Kervin; Wegener, Evan

Submitted to: ACS Sustainable Chemistry & Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/5/2024
Publication Date: 7/24/2024
Citation: Jackson, M.A., Selling, G.W., Evans, K.O., Wegener, E.C. 2024. Cuphea as a source of fully crop-based plasticizers for Poly(vinyl chloride). ACS Sustainable Chemistry & Engineering. https://doi.org/10.1021/acssuschemeng.4c01592.
DOI: https://doi.org/10.1021/acssuschemeng.4c01592

Interpretive Summary: Plasticizers are substances added to plastics, such as polyvinyl chloride (PVC or vinyl) to make them softer and more flexible. Petroleum-based DEHP is the most common plasticizer used in PVC products, but recent concerns regarding toxicity and potential endocrine disrupting activity have prompted efforts to find safer alternatives. ARS researchers in Peoria, Illinois, developed new biobased plasticizers from Cuphea seed oil, a newly developed industrial crop, and sugar derivatives that can be prepared from agricultural waste, such as corn cobs. These new biobased plasticizers perform comparably to DEHP with PVC testing for flexibility, strength, light transmittance, and degradation. Commercialization of these plasticizers offers potentially safer alternatives that also promote the development of new agricultural crops that could replace imported seed oils and petroleum used in the manufacturing of numerous products.

Technical Abstract: A series of crop-based secondary amines that function as plasticizers was prepared through the reductive amination (RA) of furans with 2-aminoundecane (2-AUD) using Pd/C as the catalyst for the reaction. The 2-AUD was itself prepared through the RA of 2-undecanone that can be prepared from the seed oil of Cuphea. The 2-AUD was added to furfural, 5-(hydroxymethyl)furfural (HMF), and 2,5-diformylfurfural (DFF) in a second RA to give the plasticizers. The plasticizers were blended at 22 wt% with poly(vinylchloride) and films of the blends were cast onto glass plates. The films were evaluated by mechanical properties, SEM, microscope infrared spectroscopy, UV-vis transmittance, dynamic mechanical analysis, and thermogravimetric analysis. These results were compared to films made with commonly utilized plasticizer di(2-ethylhexyl)phthalate (DEHP) and films made without plasticizer. The results suggest that these biobased plasticizers produce a flexible film comparable to that made with the petroleum-based DEHP.