Heat‐ and light‐induced thiol‐ene oligomerization of soybean oil‐based polymercaptan |
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| Authors: | Grigor B Bantchev Karl E Vermillion James C Lansing Girma Biresaw |
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| Affiliation: | 1. Bio‐oils Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture, 1815 N. University Street, Peoria, Illinois 61604;2. Functional Food Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture, 1815 N. University Street, Peoria, Illinois 61604 |
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| Abstract: | Polymercaptanized soybean oil (PMSO), the product of a thiol‐ene reaction between soybean oil and hydrogen sulfide, is a material of interest as a lubricant additive and polymer precursor. We investigated with gel permeation chromatography, nuclear magnetic resonance (one‐dimensional and two‐dimensional), gas chromatography–mass spectrometry, and viscometry the changes that occur with PMSO upon heating or ultraviolet irradiation. The observed changes were due to a further thiol‐ene reaction between the thiol groups and the residual unsaturation. The formation of oligomers was a result of new sulfide bridges. Additionally, tetrahydrothiophene moieties were detected. An almost linear increase of the average molecular weight (MW) and the polydispersity index (PDI) was observed upon heat treatment number‐average MW (  ) = 1180 Da, PDI = 1.32 for PMSO,  = 1720 Da, PDI = 2.17 for PMSO that was heated for 1000 h at 130 °C]. PDI correlated best with the z‐average MW. The  was the best predictor of the viscosity. For samples with close  , the higher PDI corresponded to a higher viscosity index. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46150. |
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| Keywords: | biomaterials dendrimers hyperbranched polymers and macrocycles lipids structure– property relationships viscosity and viscoelasticity |
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) = 1180 Da, PDI = 1.32 for PMSO, 
= 1720 Da, PDI = 2.17 for PMSO that was heated for 1000 h at 130 °C]. PDI correlated best with the z‐average MW. The 
was the best predictor of the viscosity. For samples with close 
, the higher PDI corresponded to a higher viscosity index. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46150.