Polyamides with pendent optical absorbers and related methods

1. A method comprising:

esterifying a carboxyl-pendent optical absorber with a halogen-terminal aliphatic alcohol to yield a halogen-terminal alkyl-optical absorber; and

N-alkylating a polyamide with the halogen-terminal alkyl-optical absorber to yield a polyamide having an optical absorber pendent from a backbone of the polyamide.

2. The method of claim 1 , wherein the carboxyl-pendent optical absorber is selected from the group consisting of calcein; 5(6)-carboxyfluorescein; 6-carboxyfluorescein; 5(6)-carboxyfluorescein-N-hydroxysuccinimide ester; 2-pyrenepropanoic acid; 2-perylenepropanoic acid; 3,9-perylenedicarboxylic acid; 5(6)-carboxy-2′,7′-dichlorofluorescein; calcein blue; 2-[(3-carboxy-2-oxidonaphthalen-1-yl)diazenyl]-4-chloro-5-methylbenzenesulfonate disodium; 5-oxo-1-(4-sulfonatophenyl)-4-[(4-sulfonatophenyl)diazenyl]-4H-pyrazole-3-carboxylate trisodium; and any combination thereof.

3. A composition comprising:

a polyamide prepared by the method of claim 2 .

4. The method of claim 1 , wherein the polyamide is selected from the group consisting of polycaproamide, poly(hexamethylene succinamide), polyhexamethylene adipamide, polypentamethylene adipamide, polyhexamethylene sebacamide, polyundecamide, polydodecamide, polyhexamethylene terephthalamide, nylon 10,10, nylon 10,12, nylon 10,14, nylon 10,18, nylon 6,18, nylon 6,12, nylon 6,14, nylon 12,12, a semi-aromatic polyamide, an aromatic polyamide, any copolymer thereof, and any combination thereof.

5. The method of claim 1 , wherein the halogen-terminal aliphatic alcohol is X—(CH 2 ) n —OH where X is bromo or chloro and n is 2-18.

6. The method of claim 1 , wherein the halogen-terminal aliphatic alcohol is selected from the group consisting of 3-bromoethan-1-ol, 3-chloroethan-1-ol, 4-bromopropan-1-ol, 4-chloropropan-1-ol, 5-bromobutan-1-ol, 5-chlorobutan-1-ol, 6-bromopentan-1-ol, 6-chloropentan-1-ol, 7-bromohexan-1-ol, 7-chlorohexan-1-ol, and any combination thereof.

7. The method of claim 1 , wherein esterifying takes place at about 0° C. to about 70° C.

8. The method of claim 1 , wherein a molar ratio of the carboxyl-pendent optical absorber to the halogen-terminal aliphatic alcohol is about 5:1 to about 1:5.

9. The method of claim 1 , wherein a molar ratio of the halogen-terminal alkyl-optical absorber to the polyamide is about 500:1 to about 10:1.

10. The method of claim 1 , wherein N-alkylating takes place in the presence of a strong base.

11. The method of claim 10 , wherein the strong base comprises one or more of sodium t-butoxide, potassium t-butoxide, magnesium t-butoxide, calcium t-butoxide, sodium t-amylate, sodium 2-methyl-2-butoxide, sodium amide, potassium amide, lithium diethylamide, lithium diisopropylamide, sodium hydride, lithium hydride, triphenylmethyl lithium, triphenylmethyl sodium, naphthalene sodium, and triphenylmethyl potassium.

12. A composition comprising:

a polyamide having an optical absorber pendent from a backbone of the polyamide,

wherein the polyamide and the optical absorber are connected by an alkyl linker having 2 to 18 carbons, the alkyl linker being connected to the optical absorber by an intervening OC(═O) or C(≡O) O group; and

wherein the optical absorber is selected from the group consisting of a rhodamine, a fluorescein, a coumarin, a naphthalimide, a benzoxanthene, an acridine, a cyanine, an oxazine, a phenanthridine, a pyrrole ketone, a benzaldehyde, a polymethine, a triarylmethane, an anthraquinone, a pyrazolone, a quinophthalone, a carbonyl dye, a perinone, diketopyrrolopyrrole (DPP), a dioxazine dye, a phthalocyanine, an indanthrene, a benzanthrone, a violanthrone, a phthalocyanine dye, a quinacridone dye, an anthraquinone dye, an indigo dye, a thioindigo dye, a perinone dye, a perylene dye, an isoindolene dye, an aromatic amino acid, a flavin, a derivative of pyridoxyl, and a derivative of chlorophyll.