BIODEGRADEABLE COMPOSITE AND METHOD OF PREPARATION THEREOF

1 . A polylactic acid (PLA)/biomass composite comprising: polylactic acid (PLA), a biomass material, a compatibilizer, a crosslinker, a chain extender, an antioxidant, and a nucleating agent, wherein the PLA, the biomass material, the compatibilizer, the crosslinker, the chain extender, the antioxidant, and the nucleating agent are present in the PLA/biomass composite at a concentration of 30-60% wt/wt, 20-70% wt/wt, 5-20% wt/wt, 0.1-3% wt/wt, 0.1-2% wt/wt, 0.1-1% wt/wt, and 1-10% wt/wt, respectively.

2 . The PLA/biomass composite of claim 1 , wherein the biomass material is selected from the group consisting of wood, bamboo, corncob, and combinations thereof.

3 . The PLA/biomass composite of claim 1 , wherein the compatibilizer is selected from polylactic acid grafted maleic anhydride (PLA-g-MAH); polybutylene adipate terephthalate grafted maleic anhydride (PBAT-g-MAH); a self-synthesized network-branched compatibilizing pellet represented by the by the chemical structure I or II:

or a pharmaceutically acceptable salt thereof, wherein: R 4 for each instance is independently hydrogen, a moiety of Formula III, or a moiety of Formula IV:

wherein q is a whole number selected from 650-6,500, with the proviso that at least 1 R 4 is the moiety of Formula III and at least two R 4 are the moiety of Formula IV; and combinations thereof.

4 . The PLA/biomass composite of claim 1 , wherein the crosslinker is selected from the group consisting of epoxidized soybean oil (ESO), neopentyl glycol diglycidyl ether (NGDE), diethylene glycol diglycidyl ether (DGDE), 1,4-butanediol diglycidyl ether (BDE), diglycidyl ether (DE), tannic acid (TA), gallic acid (GA), 3,4-dihydroxybenzaldehyde (DB), pyrogallol, and combinations thereof.

5 . The PLA/biomass composite of claim 1 , wherein the chain extender is selected from the group consisting of:

wherein each of R 1 and R 2 is independently H, CH 3 , or alkyl; R 3 is alkyl, and each of m, n, and p is independently 1-20; and combinations thereof.

6 . The PLA/biomass composite of claim 1 , wherein the antioxidant is selected from the group consisting of:

and combinations thereof.

7 . The PLA/biomass composite of claim 1 , wherein the nucleating agent is selected from the group consisting of: sebacic acid diphenyl dihydrazide, montmorillonite, calcium carbonate, and combinations thereof.

8 . The PLA/biomass composite of claim 3 , wherein the crosslinker is selected from the group consisting of epoxidized soybean oil (ESO), neopentyl glycol diglycidyl ether (NGDE), diethylene glycol diglycidyl ether (DGDE), 1,4-butanediol diglycidyl ether (BDE), diglycidyl ether (DE), tannic acid (TA), gallic acid (GA), 3,4-dihydroxybenzaldehyde (DB), pyrogallol, and combinations thereof; the chain extender is selected from the group consisting of:

wherein each of R 1 and R 2 is independently H, CH 3 , or alkyl; R 3 is alkyl, and each of m, n, and p is independently 1-20; and combinations thereof;

the antioxidant is selected from the group consisting of:

and combinations thereof; and the nucleating agent is selected from the group consisting of: sebacic acid diphenyl dihydrazide, montmorillonite, calcium carbonate, and combinations thereof.

9 . The PLA/biomass composite of claim 8 , wherein the PLA, the biomass material, the compatibilizer, the crosslinker, the chain extender, the antioxidant, and the nucleating agent are present in the PLA/biomass composite at a concentration of 30-60% wt/wt, 21.6-49.5% wt/wt, 8-12% wt/wt, 1.2-2% wt/wt, 0.6-1% wt/wt, 0.5-1% wt/wt, and 4-9% wt/wt, respectively.

10 . The PLA/biomass composite of claim 1 , wherein the compatibilizer is a self-synthesized network-branched compatibilizing pellet represented by the by the chemical structure I or II:

or a pharmaceutically acceptable salt thereof, wherein: R 4 for each instance is independently hydrogen, a moiety of Formula III, or a moiety of Formula IV:

wherein q is a whole number selected from 650-6,500, with the proviso that at least 1 R 4 is the moiety of Formula III and at least two R 4 are the moiety of Formula IV; and combinations thereof;

the crosslinker comprises tannic acid, gallic acid, 3,4-dihydroxybenzaldehyde, and pyrogallol; the chain extender comprises:

wherein each of R 1 and R 2 is independently H, CH 3 , or alkyl; R 3 is alkyl, and each of m, n, and p is independently 1-20;

the antioxidant comprises:

and the nucleating agent comprises sebacic acid diphenyl dihydrazide, montmorillonite, and calcium carbonate.

11 . The PLA/biomass composite of claim 10 , wherein the PLA, the biomass material, the compatibilizer, the crosslinker, the chain extender, the antioxidant, and the nucleating agent are present in the PLA/biomass composite at a concentration of about 50% wt/wt, about 32% wt/wt, about 8% wt/wt, about 1.3% wt/wt, about 1% wt/wt, about 0.7% wt/wt, and about 7% wt/wt, respectively.

12 . A method of preparing the PLA/biomass composite of claim 1 , the method comprising: melt blending PLA, the biomass material, the compatibilizer, the crosslinker, the chain extender, the antioxidant, and the nucleating agent; optionally pelletizing and optionally drying thereby forming the PLA/biomass composite.

13 . The method of claim 12 , wherein the biomass material is selected from the group consisting of wood, bamboo, corncob, and combinations thereof.

14 . The method of claim 12 , wherein the compatibilizer is selected from polylactic acid grafted maleic anhydride (PLA-g-MAH); polybutylene adipate terephthalate grafted maleic anhydride (PBAT-g-MAH); a self-synthesized network-branched compatibilizing pellet represented by the by the chemical structure I or II:

or a pharmaceutically acceptable salt thereof, wherein: R 4 for each instance is independently hydrogen, a moiety of Formula III, or a moiety of Formula IV:

wherein q is a whole number selected from 650-6,500, with the proviso that at least 1 R 4 is the moiety of Formula III and at least two R 4 are the moiety of Formula IV; and combinations thereof.

15 . The method of claim 12 , wherein the crosslinker is selected from the group consisting of epoxidized soybean oil (ESO), neopentyl glycol diglycidyl ether (NGDE), diethylene glycol diglycidyl ether (DGDE), 1,4-butanediol diglycidyl ether (BDE), diglycidyl ether (DE), tannic acid (TA), gallic acid (GA), 3,4-dihydroxybenzaldehyde (DB), pyrogallol, and combinations thereof.

16 . The method of claim 12 , wherein the chain extender is selected from the group consisting of:

wherein each of R 1 and R 2 is independently H, CH 3 , or alkyl; R 3 is alkyl, and each of m, n, and p is independently 1-20; and combinations thereof.

17 . The method of claim 12 , further comprising: contacting PLA with a compound of Formula V or VI:

or a pharmaceutically acceptable salt thereof, wherein: R 5 for each instance is independently hydrogen or a moiety of Formula IV:

with the proviso that at least 3 R 5 is the moiety of Formula IV, thereby forming the compatibilizer, wherein the compatibilizer is a self-synthesized network-branched compatibilizing pellet represented by the by the chemical structure I or II:

or a pharmaceutically acceptable salt thereof, wherein R 4 for each instance is independently hydrogen, a moiety of Formula III, or a moiety of Formula IV:

wherein q is a whole number selected from 650-6,500, with the proviso that at least 1 R 4 is the moiety of Formula III and at least two R 4 are the moiety of Formula IV.

18 . The method of claim 17 , wherein the method comprises melt blending PLA and the compound of Formula V or VI, thereby forming the self-synthesized network-branched compatibilizing pellet; and melt blending the self-synthesized network-branched compatibilizing pellet with PLA, the biomass material, crosslinker, antioxidant, and nucleating agent, optionally pelletizing, and optionally drying thereby forming the PLA/biomass composite.

19 . The method of claim 18 , wherein the PLA and the compound of Formula V or VI are melt extruded at 160-190° C. thereby forming the network-branched compatibilizing pellet; and the network-branched compatibilizing pellet, PLA, the biomass material, antioxidant, and nucleating agent are melt extruded at 190-220° C.; optionally pelletizing and optionally drying thereby forming the PLA/biomass composite.

20 . The method of claim 17 , wherein the crosslinker comprises tannic acid, gallic acid, 3,4-dihydroxybenzaldehyde, and pyrogallol; the chain extender comprises:

wherein each of R 1 and R 2 is independently H, CH 3 , or alkyl; R 3 is alkyl, and each of m, n, and p is independently 1-20;

the antioxidant comprises:

and the nucleating agent comprises sebacic acid diphenyl dihydrazide, montmorillonite, and calcium carbonate.