Segmented copolymer compositions and coatings incorporating these compositions
Some variations provide a segmented copolymer composition comprising: fluoropolymer first soft segments that are (α,ω)-hydroxyl-terminated and/or (α,ω)-amine-terminated; polyester or polyether second soft segments that are (α,ω)-hydroxyl-terminated and/or (α,ω)-amine-terminated; isocyanate species possessing an isocyanate functionality of 2 or greater; and polyol or polyamine chain extenders or crosslinkers, wherein the molar ratio of the second soft segments to the first soft segments is less than 2.0. Exemplary segmented copolymers are disclosed. The segmented copolymer composition may be present in a low-friction, low-adhesion coating. Such a coating may be characterized by a coefficient of friction, measured at 90% relative humidity, less than 0.7. Such a coating may be characterized by an average kinetic delay of surface ice formation of at least 10 minutes at −10° C. These coatings are useful as bugphobic and icephobic coatings.
1. A segmented copolymer composition comprising:
(a) one or more first soft segments selected from fluoropolymers having an average molecular weight from about 500 g/mol to about 10,000 g/mol, wherein said fluoropolymers contain an oxygen atom connected to two alkyl or aryl groups, wherein at least one hydrogen atom of said alkyl or aryl group is replaced by a fluorine atom, and wherein said fluoropolymers are (α,ω)-hydroxyl-terminated and/or (α,ω)-amine-terminated;
(b) one or more second soft segments selected from polyesters or polyethers, wherein said polyesters or polyethers are selected from the group consisting of poly(oxymethylene), poly(ethylene glycol), poly(propylene glycol), poly(glycolic acid), poly(caprolactone), poly(ethylene adipate), poly(hydroxybutyrate), poly(hydroxyalkanoate), and combinations thereof, and wherein said polyesters or polyethers are (α,ω)-hydroxyl-terminated and/or (α,ω)-amine-terminated;
(c) a hard segment containing a reacted form of one or more isocyanate species possessing an isocyanate functionality of 2 or greater; and
(d) in said hard segment, a reacted form of one or more polyol or polyamine chain extenders or crosslinkers,
wherein the molar ratio of said second soft segments to said first soft segments is less than 2.0, and
wherein said first soft segments, said second soft segments, and said hard segments are microphase-separated.
2. The segmented copolymer composition of claim 1 , wherein said molar ratio of said second soft segments to said first soft segments is from about 0.1 to about 1.5.
3. The segmented copolymer composition of claim 1 , wherein said fluoropolymers are selected from the group consisting of perfluoropolyethers, polyfluoroacrylates, polyfluorosiloxanes, and combinations thereof.
4. The segmented copolymer composition of claim 1 , wherein said fluoropolymers include a fluoropolymer having the structure:
wherein:
X=CH 2 —(CH 2 —CH 2 —O) p —OH wherein p=0 to 50;
m=1 to 100; and
n=1 to 100.
5. The segmented copolymer composition of claim 1 , wherein said isocyanate species is selected from the group consisting of 4,4′-methylenebis(cyclohexyl isocyanate), hexamethylene diisocyanate, cycloalkyl-based diisocyanates, tolylene-2,4-diisocyanate, 4,4′-methylenebis(phenyl isocyanate), isophorone diisocyanate, and combinations or derivatives thereof.
6. The segmented copolymer composition of claim 1 , wherein at least one polyol or polyamine chain extender or crosslinker of said one or more polyol or polyamine chain extenders or crosslinkers possesses a functionality of 2 or greater.
7. The segmented copolymer composition of claim 6 , wherein said at least one polyol or polyamine chain extender or crosslinker is selected from the group consisting of 1,3-butanediol,1,1,4-butanediol, 1,3-propanediol, 1,2-ethanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, ethanol amine, diethanol amine, methyldiethanolamine, phenyldiethanolamine, glycerol, trimethylolpropane, 1,2,6-hexanetriol, triethanolamine, pentaerythritol, ethylenediamine, 1,3-propanediamine, 1,4-buatendiamine, diethyltoluenediamine, dimethylthiotoluenediamine, isophoronediamine, diaminocyclohexane, N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylenediamine, and homologues, derivatives, or combinations thereof.
8. The segmented copolymer composition of claim 1 , wherein said hard segment is present in an amount from about 5 wt % to about 60 wt %, based on total weight of said composition.
9. The segmented copolymer composition of claim 1 , wherein said segmented copolymer composition is present in a coating.
10. The segmented copolymer composition of claim 9 , wherein said coating is characterized by a coefficient of friction, measured at 90% relative humidity, less than 0.7.
11. The segmented copolymer composition of claim 9 , wherein said coating is characterized by an average kinetic delay of surface ice formation of at least 5 minutes at −10° C.