Biodegradable fire-fighting formulation
This invention relates to a formulation material and its method useful in forestry firefighting, the formulation material comprising: (a) an anhydride copolymer having a structural formula wherein a functional group X of said formula is at least one alkyl group selected from the family consisting of methyl, ethyl, and propyl groups! and (b) at least 0.1%, by weight, of at least one cross-linking agent for said anhydride copolymer, said agent selected from the group of cross-linking agents consisting of a biopolymer and a tannin, wherein a weight ratio of said anhydride copolymer to said cross-linking agent is at least 2:1, and wherein a total weight of said anhydride copolymer and said cross-linking agent, within the formulation, is at least 25% on an anhydrous basis.
1. An ambiently degradable aqueous gel formulation comprising:
(a) water; and
(b) a water-absorbent, ambiently degradable co-polymer having
(i) a first repeating, ambiently degradable base structure being formed of n first building blocks, each first building block having a carboxyl ion moiety (—COO − ) and a first carbonyl moiety, (—CO—) the first base structure being represented by:
(ii) a second repeating, ambiently degradable base structure being formed of n second building blocks, each second building block having a carboxyl moiety (—COOH) and a second carbonyl moiety (—CO—), the second base structure being represented by:
wherein functional groups R and R 1 in said base structures are alkyl groups independently selected at each instance from the family consisting of methyl (CH 3 ), ethyl (C 2 H 5 ), and propyl (C 3 H 7 ) groups,
the value of n in said first and second repeating base structures being selected such that the molecular weight of said co-polymer is than 50 000 Daltons(Da);
wherein each of the n building blocks of said first repeating base structure is crosslinked to a corresponding second building block of said second repeating base structure, via an ambiently biodegradable crosslinking structure, by means of at least two of:
said carboxyl ion and said first and second carbonyl moieties,
wherein said water is absorbed within said degradable copolymer,
and wherein the gel formulation has a viscosity in a range of 500 cps to 50,000 cps.
2. The formulation of claim 1 , wherein said crosslinking structure is attached to at least one of said first and second carbonyl moieties by means of a nitrogen atom.
3. The formulation of claim 2 , wherein said nitrogen atom is part of an amine group.
4. The formulation of claim 1 , wherein said crosslinking structure is attached to at least one of said first and second carbonyl moieties by means of an oxygen atom.
5. The formulation of claim 1 , disposed on an outdoor area having a length of at least 5 meters, and a width of at least 5 meters.
6. The formulation of claim 1 , further comprising a surfactant.
7. The formulation of claim 1 , further comprising at least one long-term fire retardant.
8. The formulation of claim 7 , said long-term fire retardant having a chemical anti-smoldering mechanism.
9. The formulation of claim 1 , wherein said nitrogen atom is part of an N—H group.
10. The formulation of claim 1 , wherein said cross-linking structure is attached to said first and second carbonyl moieties by means of a nitrogen atom.
11. The formulation of claim 4 , wherein said cross-linking structure includes a moiety selected from the group consisting of a polysaccharide moiety and a tannin moiety.
12. The formulation of claim 4 , wherein said cross-linking structure includes a bivalent cation.
13. The formulation of claim 1 , wherein the concentration of said water-absorbent polymer in said formulation is at least 60%, on an anhydrous basis.
14. The formulation of claim 1 , wherein the concentration of said water-absorbent polymer in said formulation is at most 30%, on a hydrated basis.
15. The formulation of claim 1 , disposed as a chemical firebreak on an outdoor area having a length of at least 5 meters, and a width within a range of 5 to 20 meters.
16. The formulation of claim 1 , at least partially disposed as a chemical firebreak on a swath of vegetation having a length of at least 5 meters, and a width within a range of 5 to 20 meters, said chemical firebreak containing 0.5 liters to 50 liters of the formulation, per square meter of said firebreak.
17. The formulation of claim 1 , disposed in a vicinity of a raging fire.
18. The formulation claim 1 , disposed in or around a forest or brush.
19. The formulation of claim 7 , said at least one long-term flame retardant being selected from the group consisting of brominated compounds, phosphorous compounds, organophosphorous compounds, chlorinated compounds, tin compounds, alumina hydrates, metal polyphosphates, borates and antimony oxides.
20. The formulation of claim 7 , said at least one long-term flame retardant being at most practically insoluble in water, at 20° C.
21. The formulation of claim 1 , the value of n in said first and second repeating structures being selected such that said molecular weight is greater than 100,000 Daltons (Da).
22. The formulation of claim 1 , the value of n said first and second repeating structures being selected such that said molecular weight is about 200,000 Daltons (Da).