Cuphea as a Source of Fully Crop-Based Plasticizers for Poly(vinyl chloride)

A series of crop-based secondary amines that function as plasticizers were 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 designated as THF-2-AUD, HMF-2-AUD, and DFF-2-AUD, respectively. The plasticizers were blended at 22 wt % with poly­(vinyl chloride), and films of the blends were cast onto glass plates. The films were evaluated by mechanical properties, SEM, atomic force microscopy, microscope infrared spectroscopy, UV−visible transmittance, dynamic mechanical analysis, and thermogravimetric analysis. These results were compared to films made with the commonly utilized plasticizer di­(2-ethylhexyl)­phthalate (DEHP) and films made without plasticizer. The results suggest that these biobased plasticizers produce flexible films comparable to those made with the petroleum-based DEHP.