Accession Number : ADA551650


Title :   Preparation of Novel Hydrolyzing Urethane Modified Thiol-Ene Networks


Descriptive Note : Journal article


Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV


Personal Author(s) : Mackey, Nicole M ; Confait, Bridget S ; Wynne, James H ; Buchanan, J P


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a551650.pdf


Report Date : 25 Oct 2011


Pagination or Media Count : 19


Abstract : Novel tetra-functional hydrolyzing monomers were prepared from the reaction of TEOS and select alkene-containing alcohols, ethylene glycol vinyl ether or 2-allyloxy ethanol, and combined with trimethylolpropane tris(3-mercaptopropionate) (tri-thiol) in a thiol-ene click polymerization reaction to produce clear, colorless thiol-ene networks using both radiation and thermal-cure techniques. These networks were characterized for various mechanical characteristics, and found to posses Tg's (DSC), hardness, tack, and thermal stability (TGA) consistent with their molecular structures. A new ene-modified urethane oligomer was prepared based on the aliphatic polyisocyanate Desmodur(registered name) N 3600 and added to the thiol-ene hydrolyzable network series in increasing amounts, creating a phase-segregated material having two Tg's. An increase in water absorption in the ene-modified urethane formulations leading to a simultaneous increase in the rate of hydrolysis was supported by TGA data, film hardness measurements, and an NMR study of closely related networks. This phenomenon was attributed to the additional hydrogen bonding elements and polar functionality brought to the film with the addition of the urethane segment. SEM was utilized for visual analysis of topographical changes in the film's surface upon hydrolysis and provides support for surface-driven erosion. Coatings prepared in this study are intended for use as hydrolyzing networks for marine coatings to protect against ship fouling.


Descriptors :   *HYDROLYSIS , *SURFACE CHEMISTRY , *THIOLS , ANTIFOULING COATINGS , MONOMERS , POLYMERIC FILMS , REACTION KINETICS , REPRINTS , URETHANES


Subject Categories : Organic Chemistry
      Physical Chemistry
      Polymer Chemistry


Distribution Statement : APPROVED FOR PUBLIC RELEASE