Copolymers from photochemical thiol-ene polycondensation of fatty dienes with alkyl dithiols

Authors: Moser, Bryan

Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: 2/13/2019
Publication Date: 5/7/2019
Citation: Moser, B.R. 2019. Copolymers from photochemical thiol-ene polycondensation of fatty dienes with alkyl dithiols. American Oil Chemists' Society Annual Meeting & Expo. Program Book p. 86.

Interpretive Summary:

Technical Abstract: Photochemical thiol-ene polycondensation of unsaturated monomers based on renewable 9-decenoic acid with various alkyl dithiols readily afforded copolymers in high yield. Monomers were prepared by acid-catalyzed condensation of 9-decenoic acid with diols such as ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, 9-decenol, and 2-allyloxyethanol to give fatty dienoic esters. These dienes were then polymerized with 1,2-ethanedithiol, 1,3-propanedithiol and 1,4-butanedithiol in the presence of catalytic 2,2-dimethoxy-2-phenylacetophenone as photoinitiator to afford a family of twelve novel linear copolymers. Physical properties such as molecular weight, polydispersity index, degree of polymerization, glass transition temperature, melting point, crystallization onset temperature, and thermal stability were measured. Number average molecular weights ranged from 11–45 kDa, melting points were 25 deg C or greater, crystallization onset temperatures ranged from -15 to 55 deg C, glass transitions varied from -26 to 17 deg C, and thermal stabilities were greater than 330 deg C (temperature corresponding to 10% mass loss by DSC). Determination of mechanical properties such as tensile strength and Young’s modulus are planned for future studies. In summary, thiol-ene chemistry is a useful tool for rapid production of renewable polymers utilizing mild, solventless reaction conditions.