Poly-perfluoroalkyl substituted polyethyleneimine foam stabilizers and film formers
Poly-perfluoroalkyl substituted polyethyleneimine compositions are provided that act as foam stabilizers and film formers when used in fire-fighting foam concentrates. The polyethylene compositions are soluble in water, but have only low solubility in polar solvents. When aqueous film forming foam generated from these concentrates is applied to burning polar solvent the polyethyleneimine compositions precipitate at the polar solvent/foam interface and inhibit the collapse and destruction of the foam.
1. An aqueous film-forming firefighting composition comprising an effective amount of a foam stabilizing agent comprising a branched substituted polyamine wherein the amino groups of said polyamine are substituted with:
(a) —(CH 2 ) m (CF 2 ) n F, wherein m is 1-12 and n is 4-16; and
(b) a hydrophilic moiety selected from the group consisting of
—(CH 2 ) p CHOH(CH 2 ) q SO 3 − ,
(CH 2 ) p CHOH(CH 2 ) q NH 4 + and
(CH 2 ) p COO − ; wherein p and q independently are 1-6 and p+q is 2-8;
wherein said substituted polyamine has a weight average molecular weight M w of between about 5 kDa and 25 kDa prior to substitution; and
wherein said stabilizer has a fluorine content of about 15 to about 25%.
2. The aqueous film-forming firefighting composition according to claim 1 further comprising: an effective amount of a monomeric perfluoroalkyl surfactant; and an effective amount of at least one non-fluorinated surfactant.
3. The aqueous film-forming firefighting composition according to claim 1 further comprising an effective amount of one or more components selected from the group consisting of: a foam aid; a freeze protection composition; a composition comprising ion sequestering, buffer, and anti-corrosion components; a biocide and antimicrobial composition; an electrolyte composition; and a polysaccharide gum thickener.
4. The aqueous film-forming firefighting composition according to claim 1 , wherein said amino groups of said polyamine are further substituted with a siloxane moiety selected from the group consisting of (R 3 SiO) 2 Si(R)(CH 2 ) 3 OCH 2 CHOHCH 2 — and R 3 SiO[Si(R) 2 O] r Si(CH 2 ) 3 OCH 2 CHOHCH 2 —, wherein each R independently is lower alkyl, r=1-9, and wherein said foam stabilizing agent has a silicon content of about 0.1 to about 10%.
5. The aqueous film-forming firefighting composition according to claim 1 wherein n is 4-6.
6. The aqueous film-forming firefighting composition according to claim 5 , wherein n is 6.
7. The aqueous film-forming firefighting composition according to claim 1 , wherein m is 1 or 2.
8. The aqueous film-forming firefighting composition according to claim 1 , wherein p and q are 1 or 2.
9. The aqueous film-forming firefighting composition according to claim 4 , wherein said siloxane moiety is (Me 3 SiO) 2 Si(Me)(CH 2 ) 3 OCH 2 CHOHCH 2 — or C 4 H 9 Si(CH 3 ) 2 O[Si(CH 3 ) 2 O] r Si(CH 2 ) 3 OCH 2 CHOHCH 2 —.