The Boeing Company
Transparent polymers and methods for making the same

Abstract:

A novel copolymer is made from a thiol terminated hydrocarbon monomer and at least one additional monomer chosen from the compounds of i) a terminally unsaturated hydrocarbon monomer, ii) an isocyanate functionalized hydrocarbon monomer and iii) a silane monomer substituted with two or more C.sub.2 to C.sub.8 terminally unsaturated alkenyl groups or C.sub.2 to C.sub.8 terminally unsaturated alkynyl groups, wherein the copolymer is a linear polymer, branched polymer or crosslinked polymer network, with the following provisos: if the at least one additional monomer is either a) a terminally unsaturated hydrocarbon monomer that is not a polymer having 12 carbon atoms or more, or b) a silane monomer, then the thiol terminated hydrocarbon monomer includes a saturated hydrocarbon ring with two or more terminal thiol groups attached to the hydrocarbon ring; if the terminally unsaturated hydrocarbon monomer is polybutadiene, the polybutadiene contains from about 0 mol % to about 30 mol % of polymer units in the cis-1,4-butadiene form; and if the at least one additional monomer is an isocyanate functionalized hydrocarbon monomer, then a ratio of the molecular mass of the thiol terminated hydrocarbon monomer to the number of sulfur atoms in the thiol terminated hydrocarbon monomer ranges from 65 to 500.