Thermal behavior of polyformates of milkweed and soybean oils

Authors: Harry O Kuru, Rogers; Biresaw, Girma; Xu, Jingyuan - James

Submitted to: Journal of Applied Polymer Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/11/2019
Publication Date: 8/5/2019
Citation: Harry-O'Kuru, R.E., Biresaw, G., Xu, J. 2019. Thermal behavior of polyformates of milkweed and soybean oils. Journal of Applied Polymer Science. 136(48):48225. https://doi.org/10.1002/app.48225.
DOI: https://doi.org/10.1002/app.48225

Interpretive Summary: Chemistry is perfused with serendipity and the effort to solve a seeming challenge leads to opportunity. In the process of trying to clean up a new material, another new unexpected product was generated. This communication is an effort to understand and explain what happened so the process could be reproduced consciously and deliberately. This process modifies vegetable oils to produce new environmentally friendly products.

Technical Abstract: Reprocessing neat vicinal polyformate esters of milkweed and soybean triglycerides in a silica-drying column with mild heating resulted in a light reddish-orange gel formation of the column eluate on cooling. Analysis of gel by 1H- and 13C-NMR showed characteristics of possible elimination, which include olefinic/aromatic moieties and formic acid. Rearrangement of triglyceride skeleton leads to crosslinking. FTIR spectrum of the gel suggested formation of olefinic species. Trial runs to reproduce the column results by heating aliquots of the neat vicinal polyformate under N2 with and without silica gel generated a gas that discharged basic phenolphthalein solution. Further heating gave a tacky off-white polymer that was chloroform insoluble. In contrast, the vicinal polyacetate derivatives of milkweed and soybean oils were stable under similar reaction conditions. From the rheological similarity of their power-law exponents, 0.63 and 0.70, respectively, MWF gel and SoyF gel can have similar behavior during processing.