Flame retardant resin
The present disclosure provides to a novel flame retardant resin, wherein the resin is a reaction product of an epoxy material, a curing agent, and a partially esterified tannic acid of formula I, wherein TA represents a tannic acid moiety, R 1 represents an optionally substituted C 1 -C 6 straight or branched alkyl, an optionally substituted C 3 -C 6 cyclic ring, an optionally substituted phenyl group, or any combination thereof, and n is 2-10.
1. A flame retardant resin, wherein the resin is a reaction product of an epoxy material, a curing agent, and a partially esterified tannic acid of formula I,
wherein TA represents a tannic acid moiety, R 1 represents an optionally substituted C 1 -C 6 straight or branched alkyl, an optionally substituted C 3 -C 6 cyclic ring, an optionally substituted phenyl group, or any combination thereof, n is 2-10; and
wherein the partially esterified tannic acid refers to that about 8-40% of free hydroxy groups on the phenolic ring of the tannic acid (TA) are esterified.
2. The flame retardant resin of claim 1 , wherein R 1 is methyl group or a phenyl group.
3. The flame retardant resin of claim 1 , wherein the epoxy material comprises bisphenol A based epoxy material, bisphenol F based epoxy material, cycloaliphatic epoxy material, novolac epoxy material, or any combination thereof.
4. The flame retardant resin of claim 1 , wherein the curing agent comprise polyamine, aliphatic amine, polyamide, cycloaliphatic amine, aromatic amine, anhydride, imidazole, Lewis acid, or a combination thereof.
5. The flame retardant resin of claim 1 , wherein the partially esterified tannic acid has at least 3 wt % of the total weight of the epoxy material and the partially esterified tannic acid of formula I.
6. The flame retardant resin of claim 1 , wherein the partially esterified tannic acid has 3-10 wt % of the total weight of the epoxy material and the partially esterified tannic acid of formula I.
7. The flame retardant resin of claim 1 , wherein n is 3-8.
8. The flame retardant resin of claim 1 , wherein n is 5-6.
9. A method of using a partially esterified tannic acid as a flame retardant additive in preparing a flame retardant resin, wherein the method comprises:
providing a partially esterified tannic acid of formula I;
providing an epoxy material;
mixing the partially esterified tannic acid and the epoxy material; and
curing the mixture of the partially esterified tannic acid and the epoxy material with a curing agent to provide a flame retardant resin;
wherein TA represents a tannic acid moiety, R 1 represents an optionally substituted C 1 -C 6 straight or branched alkyl, an optionally substituted C 3 -C 6 cyclic ring, an optionally substituted phenyl group, or any combination thereof, n is 2-10; and
wherein the partially esterified tannic acid refers to that about 8-40% of free hydroxy groups on the phenolic ring of the tannic acid (TA) are esterified.