Thermal behavior of polyformates of milkweed and soybean oils

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. Published 2019. This article is a U.S. Government work and is in the public domain in the USA. J. Appl. Polym. Sci. 2019 , 136, 48225.