Polyurethanes, articles and coatings prepared therefrom and methods of making the same

A polyurethane comprising a reaction product of components comprising:

• (a) an isocyanate functional urethane prepolymer comprising a reaction product of components comprising:
• (i) about 1 equivalent of at least one polyisocyanate;
• and
• (ii) about 0.3 to about 0.4 equivalents of butanediol and
• (b) about 0.3 to about 0.7 equivalents of trimethylolpropane based upon the about 1 equivalent of at least one polyisocyanate (i);
• and
• (c) up to about 0.4 equivalents of butanediol or pentanediol based upon the about 1 equivalent of at least one polyisocyanate (i),
• wherein the reaction product components comprise less than about 5 weight percent of polyester polyol, less than about 5 weight percent of polycarbonate polyol and less than about 5 weight percent of polyether polyol, wherein the prepolymer (a), trimethylolpropane (b), and butanediol or pentanediol (c) (if present) are each preheated to and maintained at a temperature of at least about 120° C. to about 140° C. for at least about 10 minutes immediately prior to mixing together within a mixing chamber of a dynamic pin mixer, wherein the mixing chamber has a volume of about 62 cc to about 250 cc, the total flow rate of components into the mixing chamber is about 499 to about 4807 grams per minute, and wherein the residence time of the components in the mixing chamber is from about 0.1 seconds to about 5 minutes.

A polyurethane consisting of a reaction product of components consisting of:

• (a) an isocyanate functional urethane prepolymer consisting of a reaction product of components consisting of:
• (i) about 1 equivalent of at least one polyisocyanate;
• and
• (ii) about 0.3 to about 0.4 equivalents of butanediol;
• and
• (b) about 0.3 to about 0.6 equivalents of trimethylolpropane based upon the about 1 equivalent of at least one polyisocyanate (i);
• and
• (c) about 0.1 to about 0.4 equivalents of butanediol or pentanediol (c) based upon the about 1 equivalent of at least one polyisocyanate (i), wherein the prepolymer (a), trimethylolpropane (b), and butanediol or pentanediol (c) are each preheated to and maintained at a temperature of at least about 120° C. to about 140° C. for at least about 10 minutes immediately prior to mixing together within a mixing chamber of a dynamic pin mixer, wherein the mixing chamber has a volume of about 62 cc to about 250 cc, the total flow rate of components into the mixing chamber is about 499 to about 4807 grams per minute, and wherein the residence time of the components in the mixing chamber is from about 0.1 seconds to about 5 minutes.

A polyurethane comprising a reaction product of components comprising:

• (a) an isocyanate functional urethane prepolymer comprising a reaction product of components comprising:
• (i) about 1 equivalent of at least one polyisocyanate;
• and
• (ii) about 0.1 to about 0.5 equivalents of at least one diol selected from the group consisting of propanediol, butanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, sorbitol, mannitol, propylene glycol, neopentyl glycol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, and dibutyl 1,3-propanediol, and mixtures thereof;
• and
• (b) about 0.05 to about 0.9 equivalents of at least one polyol (b) based upon the about 1 equivalent of at least one polyisocyanate (i), the polyol (b) being selected from the group consisting of tetramethylolmethane, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, and mixtures thereof;
• and
• (c) up to about 0.45 equivalents of at least one diol (c) having 2 to 18 carbon atoms based upon the about 1 equivalent of at least one polyisocyanate (i),
• wherein the reaction product components comprise less than about 5 weight percent of polyester polyol, less than about 5 weight percent of polycarbonate polyol and less than about 5 weight percent of polyether polyol, wherein the prepolymer (a), polyol (b), and diol (c) (if present) are each preheated to and maintained at a temperature of at least about 120° C. to about 140° C. for at least about 10 minutes immediately prior to mixing together within a mixing chamber of a dynamic pin mixer, wherein the mixing chamber has a volume of about 62 cc to about 250 cc, the total flow rate of components into the mixing chamber is about 499 to about 4807 grams per minute, and wherein the residence time of the components in the mixing chamber is from about 0.1 seconds to about 5 minutes.