Compositions of biodegradable natural and synthetic polymers
AssigneeRegents of the University of Minnesota
InventorsUtpal R. Vaidya, Mrinal Bhattacharya
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Abstract
A biodegradable interpolymer and composition is prepared by the reactive blending of a synthetic polymer having functional groups with a naturally occurring biodegradable polymer such as a carbohydrate or protein compound. During reactive blending, the synthetic polymer can undergo a chemical reaction with the biodegradable natural polymer which results in covalent and physical bonding between the two polymers, thereby forming an interpolymer. By this process, a biodegradable interpolymer composition is produced that is suitable for molding various articles.
Claims27
A biodegradable interpolymer comprising a continuous phase and a dispersed phase;
- wherein the dispersed phase is comprised of particulate microdomains that have at least a few covalent bonds with the continuous phase at an interface between the dispersed phase and the continuous phase;
- and one phase is an effective biodegradable amount of native or modified carbohydrate compound particles;
- and the other phase is a synthetic polymer having at least one functional group selected from the group consisting of carboxyls, hydroxyl, anhydride, epoxy, primary amines, secondary amines, tertiary amines, alky halides, oxazoline, isocyanate, nitro, acyl halides, alkoxy, thiols, esters, ethers, urethanes, carbodiimide, and urea;
- and
- wherein at least a few molecules of said synthetic polymer and at least a few molecules of said natural or modified carbohydrate compound are covalently bonded together at the interface between the dispersed phase and the continuous phase to form said covalent bonds between the particles and the synthetic polymer phase.
A biodegradable interpolymer composition comprising:
- (a) about 5 to 99 wt-% of native or modified carbohydrate compound particles and
- (b) about 1 to 95 wt-% of a synthetic polymer having at least one functional group;
- wherein one of said components (a) and (b) is present in the composition as a continuous phase and the other component is in a dispersed phase comprising a plurality of particulate microdomains having a diameter of about 0.01 to 100 microns, wherein said functional group of said synthetic polymer reacts with a hydroxyl, carboxyl or other functional group in said native or modified carbohydrate compound during reactive blending, thereby covalently bonding said synthetic polymer to said carbohydrate compound at an interface between the continuous phase and the dispersed phase, thereby forming a plurality of interpolymers which effectively provide a strong interaction between the continuous phase and the dispersed phase.
A biodegradable composition, comprised of a continuous phase and a dispersed phase, made by a process comprising reactively blending at an elevated temperature polysaccharide compound particles and a synthetic polymer having at least one functional group, to produce a chemical bond between at least a few molecules of said polysaccharide compound and said synthetic polymer at an interface between the dispersed phase and the continuous phase;
- and the dispersed phase is produced as particulate microdomains that have at least a few covalent bonds to the continuous phase at the interface.
A method of making a biodegradable interpolymer composition which comprises the steps of:
- (a) providing an effective biodegradable amount of carbohydrate compound particles;
- and
- (b) reactively blending at a temperature from about 25.degree. C. to about 300.degree. C. said carbohydrate compound particles with a synthetic polymer containing at least one functional group;
- to chemically bond together at least a few molecules of said synthetic polymer and said carbohydrate compound at an interface between a dispersed phase and a continuous phase so that the dispersed phase is produced as particulate microdomains that have at least a few covalent bonds to the continuous phase at the interface thereby forming the biodegradable interpolymer composition.
A biodegradable interpolymer comprising:
- (a) an effective biodegradable amount of particles of oxidized starch;
- and
- (b) a synthetic polymer having at least one functional group comprising oxazoline;
- wherein at least a few molecules of said synthetic polymer react with at least a few molecules of said oxidized starch on the particles at an interface between a dispersed phase and a continuous phase, and wherein said dispersed phase is comprised of particulate microdomains of the oxidized starch particles that have at least a few covalent bonds to the continuous phase at the interface.
A biodegradable interpolymer comprising:
- (a) an effective biodegradable amount of native or modified carbohydrate compound particles;
- and
- (b) a synthetic polymer having at least one functional group selected from the group consisting of carboxyls, hydroxyl, anhydride, epoxy, primary amines, secondary amines, tertiary amines, alkyl halides, oxazoline, isocyanate, nitro, acyl halides, alkoxy, thiols, esters, ethers, urethanes, carbodiimide, and urea;
- wherein said functional group of at least a few molecules of said synthetic polymer is reacted with a hydroxyl, carboxyl or other functional group of at least a few molecules of said native or modified carbohydrate compound on the surface of particles of said compound so that the particles have at least a few covalent bonds to said synthetic polymer.
Dependencies are inferred from the claim text.