Thermoplastic polyurethane compositions comprising nitro-substituted polyester diols
This invention relates to the field of polymers. More specifically, the invention comprises thermoplastic polyurethane elastomers comprising polyesters comprising nitro-substituted dicarboxylic acids that are products obtained by decomposition of polyethylene. The thermoplastic polyurethane elastomers described herein exhibit higher glass transition temperatures and higher Shore A hardness compared to thermoplastic polyurethane elastomers synthesized from similar polyester diols made from virgin monomers that do not contain nitro substitution.
1. A thermoplastic polyurethane elastomer composition comprising the reaction product of
(a) a composition comprising at least one nitro-substituted polyester diol (NO 2 -PED), and at least one polyester diol that is not substituted by a nitro group, wherein the NO 2 -PED has the formula:
wherein n is 0-14, y is 1-100, X═H or NO 2 , and R is alkylenyl, alkylenyl with one or more CH 2 groups substituted by —O—, cycloalkylenyl, or arylenenyl, wherein at least one X is NO 2 ,
(b) at least one polyisocyanate, and
(c) at least one chain extender.
2. The composition of claim 1 , wherein R is alkylenyl.
3. The composition of claim 2 , wherein R is ethylenyl, propylenyl, isopropylenyl, butylenyl, pentylenyl, hexylenyl, heptylenyl, or octylenyl.
4. The composition of claim 1 , wherein R is alkylenyl, wherein one or more CH 2 groups are substituted by —O—.
5. The composition of claim 1 , wherein R is —(CH 2 ) o —O—(CH 2 ) o —, CH 3 —O—(CH 2 ) o —O—(CH 2 ) o — CH 3 , (CH 3 CH(OH)CH 2 ) 2 O, wherein o is 2-4.
6. The composition of claim 1 , wherein R is arylenenyl.
7. The composition of claim 1 , in which the NO 2 -PED before reaction has a number average molecular weight of 400-10,000 g/mol.
8. The composition of claim 1 , wherein the chain extender is a dihydroxyalkane or dihydroxycycloalkane.
9. The composition of claim 8 , wherein the chain extender is ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, neo-pentyl glycol, 1,4-cyclohexanedimethanol, 1,4-dihydroxycyclohexane, or mixtures thereof.
10. The composition of claim 1 , wherein the chain extender is an alkylene or aralkylene diamine.
11. The composition of claim 10 , wherein the chain extender is ethylene diamine, hexamethylene diamine, 1,4-cyclohexanylene diamine, or mixtures thereof.
12. The composition of claim 1 , wherein the chain extender is an aromatic diamine.
13. The composition of claim 12 , wherein the aromatic diamine is benzidine, dihydroxymethoxy hydroquinone, toluene diamine, diaminodiphenyl methane, phenylene diamine, or mixtures thereof.
14. The composition of claim 1 , wherein the chain extender is hydrazine.
15. The composition of claim 1 , wherein the chain extender is an amino alcohol.
16. The composition of claim 15 , wherein the chain extender is ethanolamine, N-methylethanolamine, N-butylethanolamine, N-oleoylethanolamine, N-cyclohexylisopropanolamine, or mixtures thereof.
17. The composition of claim 1 , wherein the chain extender is a substituted aromatic diamine.
18. The composition of claim 17 , wherein the chain extender is 4,4′-methylene-bis(o-chloroaniline), 4,4′-methylenebis(3-chloro-2,6-diethylaniline), or mixtures thereof.
19. The composition of claim 1 , wherein the thermoplastic polyurethane elastomer composition further comprises at least one crosslinking agent.
20. The composition of claim 19 , wherein the at least one crosslinking agent is glycerine, trimethylolpropane, diethanolamine, triethanolamine, or mixtures thereof.
21. The composition of claim 1 , wherein a ratio of polyisocyanate to active hydrogen containing group (the NCO index) is from 0.9-1.5.
22. The composition of claim 1 , wherein the at least one polyisocyanate is 4,4′-diisocyanatodiphenylmethane (4,4′-MDI), 2,4′-diisocyanato diphenylmethane (2,4′-MDI), p-phenylene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-diisocyanato cyclohexane, hexamethylene diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, 3,3′-dimethyl-4,4′-biphenyl diisocyanate, 4,4′-diisocyanato-dicyclohexylmethane, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, or mixtures thereof.
23. The composition of claim 1 , further comprising at least one additive comprising:
(a) a light stabilizer or a UV stabilizer;
(b) an inorganic filler or an organic filler;
(c) a silicate mineral, metal oxide, metal salt, clay, metal silicate, glass fiber, natural fibrous material, or a synthetic fibrous mineral;
(d) carbon black, fullerene, carbon nanotubes, biochar, melamine colophony, cellulose fibers, polyamide fibers, polyacrylonitrile fibers, polyurethane fibers, polyester fibers based on aromatic and/or aliphatic dicarboxylic acid esters, or carbon fibers; and
(e) an organic phosphate, metal polyphosphate, metal oxide, metal salt, or a cyanuric acid derivative;
wherein the additives are present in 0.5-30 percent by weight of the composition.
24. The composition of claim 1 , further comprising at least one flame retardant that is an organic phosphate, metal polyphosphate, metal oxide, metal salt, cyanuric acid derivative, or mixtures thereof; wherein the at least one flame retardant is present in 500 to 4000 ppm of the composition.
25. The composition of claim 1 , further comprising a foaming agent that is water, pentane, cyclopentane, or a hydrofluorocarbon, or mixtures thereof.
26. The composition of claim 1 , wherein the at least one nitro-substituted polyester diol comprises at least one C8-C20 dicarboxylic acid substituted with a single nitro group, and at least one polyol.
27. The composition of claim 26 , wherein the at least one polyol is a C 1-8 diol.
28. The composition of claim 1 , which comprises 20-80% by weight of the nitro-substituted polyester diol.