Biodegradable hydrophobic composite materials and process for the preparation thereof

Patent metadata

Field	Value
Publication number	US-9556328-B2
Application number	US-201314435368-A
Country	US
Kind code	B2
Filing date	Oct 11, 2013
Priority date	Oct 12, 2012
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

The present invention relates to biodegradable hydrophobic composite materials and a process for the preparation of said hydrophobic biodegradable materials from the seaweed polysaccharides through grafting reaction with vinylated monomers e.g. vinyl acetate. The said composites can be used as a substitute for synthetic ropes for varied applications including seaweed cultivation in the open sea. The results of cultivation experiments showed that ropes are suitable for cultivation of seaweeds in the sea environment, and exhibit higher biomass yield as compared to synthetic ropes. The prepared composites are very flexible and can be used for making handles for carry bags and for the preparation of biodegradable designs, bowls, pots, jars, gift items, stud caps and bracelets.

First claim

We claim:

1. A hydrophobic biodegradable composite prepared from a seaweed derived polysaccharide through a grafting reaction with vinyl acetate comprising:
[a] seaweed derived polysaccharide in the range of 30 to 80 wt %;
[b] vinyl acetate in the range of 8 to 60 wt %; and
[c] plasticizer in the range of 2 to 15 wt %;

wherein, the plasticizer is selected from the group consisting of glycerol, ethylene glycol, and sorbitol; and
wherein moisture content of said composite is in the range of 5 to 15 wt %.

2. The composite as claimed in claim 1 , wherein the seaweed derived polysaccharide is selected from the group consisting of agar, agarose, alginate, and carrageenan.

3. The composite as claimed in claim 1 , wherein the seaweed derived polysaccharide is either used alone or as a blend of seaweed derived polysaccharides.

4. The composite as claimed in claim 1 , wherein the seaweed derived polysaccharide is agar and/or agarose.

5. The composite as claimed in claim 1 , wherein the plasticizer is glycerol.

6. A process for the preparation of the composites as claimed in claim 1 , the process comprising:
[a] dissolving 1 to 8 wt % of the seaweed derived polysaccharide or a blend of seaweed derived polysaccharides in distilled water by heating at a temperature in the range of 100 to 120 degrees Celsius for 5 to 30 minutes to obtain a homogeneous solution;
[b] adding 0.01 to 0.10 wt % potassium persulphate to the homogeneous solution as obtained in step [a] under stirring followed by addition of 2 to 16 wt % vinyl acetate and heating at a temperature in the range of 60 to 85 degrees Celsius in aqueous medium under reflux conditions for 3 to 7 hours under constant stirring to obtain a reaction mixture;
[c] adding 0.5 to 5.0 wt % plasticizer into the reaction mixture as obtained in step [b] and transferring the contents into a hollow or tubular device or mould to obtain a moulded composite;
[d] treating the moulded composite as obtained in step [c] with an organic solvent at a temperature in the range of 20 to 30 degrees Celsius to remove unreacted homopolymer followed by air drying to obtain the hydrophobic biodegradable composite.

7. The process as claimed in claim 6 , wherein the hollow or tubular device or mould is made of glass, plastic, steel, or wood.

8. The process as claimed in claim 6 , wherein the organic solvent is selected from the group consisting of isopropyl alcohol, acetone, methanol, ethanol, ethyl acetate, and tetra hydro furan.

Assignees

• Council Scient Ind Res

Inventors

• Meena Ramavatar
• Ghosh Pushpito Kumar
• Chejara Dharmesh
• Eswaran Karuppanan
• Siddhanta Arup Kumar
• Prasad Kamalesh
• Chaudhary Jai Prakash

Classifications

• B29C39/003

  characterised by the choice of material · CPC title

• C08L5/00 Primary

  Compositions of polysaccharides or of their derivatives not provided for in groups C08L1/00 or C08L3/00 · CPC title

• C08B37/0039 Primary

  Agar; Agarose, i.e. D-galactose, 3,6-anhydro-D-galactose, methylated, sulfated, e.g. from the red algae Gelidium and Gracilaria; Agaropectin; Derivatives thereof, e.g. Sepharose, i.e. crosslinked agarose · CPC title

• C08F251/00

  Macromolecular compounds obtained by polymerising monomers on to polysaccharides or derivatives thereof · CPC title

• C08B37/0042

  Carragenan or carragen, i.e. D-galactose and 3,6-anhydro-D-galactose, both partially sulfated, e.g. from red algae Chondrus crispus or Gigantia stellata; kappa-Carragenan; iota-Carragenan; lambda-Carragenan; Derivatives thereof · CPC title