CA1142935A - Oligomers terminated by perfluoroalkyl containing mercapto groups, process for their manufacture and their use as surface tension depressants and additives in fire fighting compositions - Google Patents

Abstract

Abstract of the Disclosure The present invention relates to novel oligomers of the formula H, and mixtures thereof, wherein Rf is a perflouroalkyl group, E is a linkage group, repre-sents a hydrophilic monomer unit, represents a hydrophobic monomer unit, x and y represent the number of monomer units present in the novel oligomers. The sum of x and y is between 4 and 500 and

Description

~2~35 The instant invention relates to a new class of perfluoral~yl sulfide terminated oligomers having a backbone of from 8 to 1000 carbon atoms, in addition to those o~ the per~luoroalkyl sulide moiety, wherein the backbone of the oligomers are made up of hydrophilic monomer units or mixtures of hydrophili~ and hydrophobic monomer untis, a process for their manufacture, their use as surface tension depressants, and the in-corporation thereof into protein hydrolyzate compositions for fire fight-ing foams.

Protein fire-fighting foams are described by J.M. Perri ("Fire Fighting Foams" in J.J. Bikerman, ed., Foams; Theory and Industrial Appli-cations, Reinhold Publishing Corp., N.Y. 1953, pp. 189-242); also by N.O. Clark ~Spec. Report No. 6, D.S.I.R., H.M. Stationary Office, London, 1947). They comprise aqueous fire fighting foams derived from such protein bases as animal proteins, principally keratins, albumins, globulins derived from horns, hoofs, hair, feathers, blood, fish-scale, and vegetable proteins from soybean meal, pea flour and maize meal.

, In addition such compositions may contain as stabilizers metal salts of variable valency, solvents to impart low temperature performance capability, protective colloids and saponins.

Protein foams were developed as fire-fighting agents for high rlsk situations ;nvo1ving flammable liquids in bulk, in reflneries~ tank farms and wherever low Plash point fuels, such as aasoline, are stored.
The danger that long pre-burns may build up hot zones in deep fuel layers is ever present and under such circumstances s~andard protein foams, however applied, quickly become contaminated wi~h the fuel, burn themselves off and are therefore limited in their effectiveness.

-~ ~',, ... , . . .. , , ., . .. .. ... . , ., . , . . .... . , . .... --.. ~ .. .. .. .. . .. . . . . . .. .. . .. . .
. .

Such protein hydrolyzate type of fire-f;ghting foam was made more effective by the addition of fluorinated surfactants, as described in U.5.
Patent 3,475,333 and British Patent No. 1,245,124. These so-called fluoro-protein foam compositions are primarily used as 3% or 6% proportioning concentrates against fires in high risk situations involving bulk storage of flammable liquids. They are w;dely accepted by major oil and chemical companies as the superior foam extinguishing agent for the oil and petro-chemical industry. They also provide optimum foam properties for control-ling and extinguishing aircraft crash fires and for general use against hydrocarbon spill fires.

The Rf surfactants in the aforementioned patents are incorporated in order to impart improved properties to protein-type fire fighting foams by imparting better foam mobility, reduced extinguishing times, and reduced sensitiv;ty to hydrocarbon pick-up.

The Rf surfactants d~sclosed in U.S. 3,475,333 and Br. Pat. No.
1,245,1Z4 differ signif~cantly in structure from the oligomers of the ~nstant invention. Moreover, ~hile protein foams containing Rf surfactants as dlsclosed in the aforementioned patents are certainly beneficial in reducing extinguishing times in fighting hydrocarbon fires if compared with protein foams not containing such surfactants, the Rf surfactants tend to reduce the foam expansion as well as foam drainage time of the pro~ein foam, which are consider~d to be undesirable side effects because the area which can be covered with a given amount of protein foam concentrate is being reduced and because a fastPr draining foam shows decreased burnback resis-tance.

The present invention pertalns to novel perfluoroalkyl group terminated o1igomers derived From perfluoroalkyl mercaptans and hydrophilic and hydrophobic monomers ~ia free radical polymerization, and the use of such oli~omers as additives to protein foam type fire fighting composi-tions and as surface tension depressants for aqueous systems.

Generically, the novel oligomers may be represented by the following formula ~ E - S ~ Ml ~ M2 ~ H

wherein Rf is a straight or branched chain perfluoroalkyl of 4 to 18 carbon atoms, perfluoroalkyLoxyalkylene of 5 to 19 carbon atoms, or mixtures thereof, E is a straight or branched chain alkylene of 1 to 12 carbon atoms, -CON(R')-E'-, -SO~N(R')-E'-, -"-CON~R')-E'-, -E"-S-E'-, -E"-N(R')-E;
or -E"-SO2N(R')-E'-, where R' is hydrogen or alkyl OT 1 to 6 carbon atoms, E' is alkylene of 2 to 8 carbon atoms and E" is alkylene of 1 to 4 carbon atoms; -~-Ml-3- repr~sents a hydrophilic monomer unit derived from a hydro-philic -vinyl ~onomer and t M2-~- represents a hydrophobic ~onomer unit derived from a hydrophobic vinyl monomer, the sum of x and y is between 4 and about 500; and x is between 1 and 0.5, x is an integer of 4 to about 500, y is Y
~ero or an integer of up to 250. Preferably the sum of x and y is between 10 and about 200 and y is zero.

It is understood that the formula is not intended to depict the actual sequenGe o~ the oligomer units, since the units can be randomly dlstributed in the novel ol;gomer. It is also understood th~t the monomers from which the -~-Ml-3- and -~-M2-~- units are derived are known, per se.

The novel oligomers of this invention arP syn~hesized by polymer-izing a hydrophilic monomer or monomers of the type Ml with or without a hydrophobic monomer or monomers of the type M2 in the presence of an R~-mercaptan of formula

(2) Rf - E - SH

wherein R~ and E are as defined previously.

Rf mercaptans of formula (2) are described inter alia in U.S.
Patents 2,894,991; 2,961,470; 2,965,677; 3,088,849; 3,172,910; 3,5~4,663;

3,655,732; 3,686,283, 3,883,596, 3,886,201, 3,935,277; a~d 3,514,487.

Suitable Rf mercaptans cant alternatively, be eas~ly prepared by reacting an Rf acid halide, e.g. RfS02Cl or RfCOCI with an amlno mercap-tan, e.g. H-N(R')-E'-SH, in an Inert solvent.

The most pre~erred mercaptans are those of the formula Rf(C H2n)SH9wherein n is 1 to 12, such as RfCH2CH2SH(Rf - C6F13-C12F25) and further the mercaptans of the formùlae ~2~S

~F1,CH2CH2SCH2CH,SH
CaFl~CH2CH2SCH2CH2cH
CeF,7CH7CH20C~12CH2SH
C~FI7CH2CH~OCH~CH2CH~SH
C~FI7CH2CH2N(CH3)CH2CH,CH2SH
(CH3)2CF(CF2)~.CH~cH25H
C9F,tSO;~NHCH2CH2SH
C~FI,502N(rH3)CH,CH2SH
~7FI~CON~CH2CH2SH
CI~F~gOC6H~,SH
C6F, ,CH~CH2SO2NHCH.CH2SH
~"F " CH2C~12SO2N(CH3)CH~CH2SH .

Hydrophilic monomers of the type Ml which con-tain at least one hydrophilic group are known per se and many are commercially available, such as acrylic and methacrylic acid and salts thereof as well as hydro-philic groups containing derivatives such as their hydroxyalkyl esters, e.g., 2-hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl or 2,3 hydroxypropyl esters; also ethoxylated and polyethoxylated hydroxyalkyl esters, such as esters of alcohols of the formula (3) HO~ H2m--0~(CH2 ~CH2~)n--RL

wherein Rlrepresents hydrogen or methyl, m represents 2 to 5 and n repre-sents 1 to 20 or esters of analogous alcohols, wnerein a part of the ethyl-eneoxide units is replaced by propyleneoxide units. Further suitable esters are dialkylaminoalkyl acrylates and methacrylates, such as the 2-(dimethyl-amino)-ethyl-, 2-(diethylamino)-ethyl- and 3-(dimethylamino)-2-hydroxypropyl esters. Another class of hyJrophilic monomers are acrylamide and methacryl-amide as well as amides substituted by lower hydroxyalkyl, lower oxaalkyl-or lower dialkylaminoalkyl groups such as N-(hydroxymethyl)-acrylamide and ~ 3 S

-methacrylamide, N-(3-hydroxypropyl)-acrylamide, N-(2-hydroxyethyl)-meth-acrylamide, N-(l,l-dimethyl-3-oxabutyl)-acrylamide alld ~J-[l,l-dimethyl-Z-(hydroxymethyl)-3-oxabutyl)~-acrylamide; further hydrophilic monomers of interest are hydrazine derivatives, such as trialkylamine methacrylimide, e.g., trimethylamine-methacrylimide and dimethyl-(2-hydroxypropyl)amine methacrylimide and the corresponding derivatives of acrylic acid;
mono-olefinic sulfonic acids and thelr salts, such as sodium ethylene sulfonate, sodium styrene sulfonate and 2-acrylamido-2-methylpropanesulfonic acid; N-C2-(dimethylamino)-ethyl]-acrylamide and -methacrylamide, N-~3-~dimethylamino)-2-hydroxypropyl]-methacrylamide, or mono-olefinic derivatives of heterocyclic nitrogen-containing monomers, such as N-vinyl-pyrrole, N-vinyl-succinimide, l-vinyl-2-pyrrolidone, l-vinyl-imidazole, l-vinyl-indole, 2-vinyl-imidazole, 4(5)-vinyl-imidazole, 2-vinyl-l-methyl~imidazole, 5-vinyl-pyrazoline, 3-methyl-5-isopropenyl, 5-methylene-hydantoin, 3-vinyl-2-oxazolidone, 3-methacrylyl-2-oxazolidone, 3-methacrylyl-5-me-2-oxazolidone, 3-vinyl-5-methyl-2-oxazolidone, 2- and 4-vinyl-pyridine, 5-vinyl-2-methyl-pyridine, 2-vinyl-pyridine-1-oxide, 3-isopropenyl-pyrid;ne, 2- and 4^vlnyl-piperidine, 2- and 4-vinyl-quinoline, 2, 4-dimethyl-6-vinyl-s-triazine, 4-acrylyl-morpholine as well as the quaternized derivatlves o-f the above pyridines.

The abo~e listed hydrophilic monomers of type M1 can be used alone or in combination with each other as well as in combindtion with suitdble hydrophobic monomers of type M2.

Hydrophilic monomers of type Ml which require a comonomer for polymerization are maleates, fumarates and vinylethers; the following mono-mer combinations are, for instance, useful: di(hydroxyalkyl) maleat~s, 2.~3S

such as di(2-hydroxyethyl) maleate, and ethoyxlated hydroxyalkyl maleates, hydroxyalkyl monomaleates, such as 2-hydroxyethyl monomaleate and hydroxy-lated hydroxyalkyl monomaleate with vinyl ethers7 vinyl esters, styrene or generally any monomer whlch will easily copolymerize with maleates or fumar-atPs; hydroxyalkyl vinyl ethers, such as 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, with maleates, fumarates, or generally all mono-mers which will easily copolymerize with vinyl ethers.

Especially valuable hydrophilic monomers o~ type M1 are acrylic acid, methacrylic acid, acrylamide, diacetone acrylamide, acrylamidopro-pane sulfonic acid and sal-ts thereof, and hydroxyethyl methacrylate.
.

Hydrophobic monomers of the type M2 which do copolymerize with hydrophilic monomers of type Ml are known per se and include acrylates, methacrylates, maleates,fumarates and itaconates with one or more carbon atoms in the ester group, such as methyl, ethyl, propyl, isopropyl, butyl, hexyl, octyl, decyl, dodecyl, 2-ethylhexyl, octadecyl, cyclohexyl, phenyl, benzyl and 2-ethoxyethyl;

Vinyl esters wi`th 1 to 18 carbons in the ester group, such as v~nyl acetate, butyrate, laurate, stearate, 2-ethyl-hexanoate and benzoate;
vinyl chloracetate and isopropenyl acetate, vinyl carbonate derivatives;

Styrene and substituted styrenes such as o- and p-methyl, 3,4-dimethyl, 3,4-diethyl and p-chlorostyrene; alpha olefins which include substituted alpha olefins both straight and branched with up to 18 carbon atoms in the side chain including ethylene, propylene and butylene;

_ 9 _ Methyl vlnyl ether, isopropyl vinyl ether, isobu-tyl vinyl ether, 2-methoxyethyl vinyl ether, n-propyl vinyl ether, ~-butyl vinyl ether, isoamyl vinyl ether, n-hexyl vinyl ether, 2-ethylbutyl vinyl ether, diiso-propylmethyl vinyl ether, l-methylheptyl vinyl ether, n-decyl vinyl ether, n-tetradecyl vinyl ether, and n-octadecyl vinyl;

Vinyl chloridel vinylidene chloride, vinyl fluoride, Yinyldene fluoride, acrylonitrile, methacrylonitrile, tetrafluoroethylene, trifluoro-chloroethylene, hexafluoropropylene;

Dienes particularly 1,3-butadiene, isoprene, and chloroprene, 2-fluoro-butadiene, 1,1,3-trifluorobutadiene~ 1,1,2,3-tetrafluorobutadiene, l,1,2-trifluoro-3,4-dichlorobutadiene and tri- and pentafluorobutadiene and isoprene.

It is well known to the one skilled in the art that mercaptans act as so-called chain transfer agents in free-radical polymerization and copolymerization reaction. The prev1ously listed hydrophilic monomers of type M1 and hydrophobic monomers of type M2 will either homopolymerlze and/or copolymerize in the presence of a free-radical initiator and there^
fore readlly react with Rf-mercaptans of formula (2) forming the instant Rf-oligomers of formula (l) in high yield.
Preferred Rf-oligomers of formula ~1) are such wherein Rf is a branched or straight chain perfluoroalkyl group with 6 ; to 14 carbon atoms, E is ethylene, Rl iS -~-CH2-C~ CH2-C~-3- or -~-CH-CH-3-Tl T2 13 T4 l~Z~

~herein Tl is -COOMe; ~CONH2; -CONHR2;-CoNR2R3; -COMH-El-NR2R3;
-CO~IH-El-NR.R3R4X ; -CONHCH20H; -CONHCH20R2; -CONHE20H;
-CO(OEl)nORI;-COOCH2CHOHCH20H; -CONH-E2-SO3Me; -CON(ElOH)~ T2 is -OH; -OE20Rl; -(OEl)nORl; -SO3Me; -C6H4503Me;
~CO~
-N~ , pyridinium halide, -NHCOR~, -NH2 T3 ~ T~ are independently -COOMe; -CONH2; ~CO(OEl)nORl;
-CONH^E1-OH; -CON(EI-OH)2 Rl is hysrogen or methyl R2,R3,R4 are independently alkyl with 1 to 6 carbon atoms E1 is alkylene wlth 2 or 3 carbon atoms E2 is alkylene with 2 to 6 carbon atoms Me is : hydrogen or alkali metal X is halide and n is 1 to 20, ~: Rl -~-M2-~- is -~-CH2-C-~ CH2-CH-j~ or -~-CH-CH-3-GlG2 G3 G4 wherein Gl is -COORs; -OCOR2; CN; -OR5; -C6H~; -C6H4X
G7 i9 hydrogen, R2 or halide G3 and ~ are independently -COORs or combined can be -CO-O-CO-Rl,R2,X are as previously defined is alkyl with 1 to 18 carbon atoms, cycloalkyl, aryl or alkenyl with 6 to 18 carbon ato~s, the sum of x and y is between 4 and about 5QO; and Xxy is between 0.5 and 1. Preferably the~sum of x plus y is between 5 to 250 or 10 to 200.

- .~
. , , Z{3~35 More preferably, the sum of x and y ls between 10 and about 200, n10st preferably between 10 and about 100 and Xxy ~5 about û.5 to 1.

Of special oligomers of interest are the formula r , 1 r l2 l R~E--S ~ Cl~2C~CH2C~H

X y where Rf is a straigh~ or branched chain perfluoroalkyl of 6 to 14 carbon atoms, E is -CH2CH2-Rl and R2 are independently hydrogen or methyl, T and G are each independently -CONH2, -COOH, 3 R ~ X ~ ~9 E' OH -CONH-E'-SO3H, -CONHCH20R 7, COOCH2CH 2 4 5 6 -CONHElN ~ R5 where R i9 ethyl and preferably methyl; X is chloride or bromide, El is straight or branched chain alkylene of 1 to 3 carbon atoms, R4, R5, and R6 are independently alkyl of 1 to 4 carbon atoms and R7 is hydrogen or alkyl of 1 to 4 carbon atoms, preferably hydrogen or methyl and x~y = ; to 500.

Preferably x is 5 to 4iO and y is zero.

Most preferred Rf-oligomers are of the formula (i) Rf-E {-Ml--~ H, wherein Rf is a straight or branched chain perfluoroalkyl ~Z~35 of 6 to 14 carbon atoms, preferably a linear perfluoroalkyl with 6 to 12 carbon atoms E is -CH2CH2-Ml ~ is ~ CH2CH ~ , ~ CH2CH ~ , ~ CH2C(CH3~ ~ , : -~-CH2-C~-3-, _~-CH2C(CH3)-~- ' and/or -~-CH~CH~
~ COOCH2CH20H OH
0~

and x is 5 to 250, preferably 10 to 200 and most preferably 15 to 50.

Most preferred Rf-oligomers used as protein foam additives have the above listed structure Rf-E-S t l~l ~ H wherein t Ml--~ i9 t C~I2CH--} and x varles from 5 to lOG, preferably 5 to 50 and most preferably 10 to 50.

The repeating units mentioned for ~- Ml--~ in formula (S) can be present in eombined form irl the oligomers that is e.g. ~wo di~ferent hydrophilic units can form an oligomer of Eormula (5) such as (6) RfCH2CH2S t CH2CH ~ ~2C (CH3) ~ _ H
COOH x COOCH2CH20H x (7) RfCH2CH2S ~ Cl~2CH ~ ~ ~ 2 CH t - H

NH I

CH20CH2CH(CH3)2 xl NH2 2 - 13 ~
(8) RfCH2CH2S ~ CH2CH ~ ~CH2C(CH3) t H
CONH2 xl COOH ~ x2 (9) RfCE2C~125~CH2 1 ~ [112CHl--~
CONH2 Xl COOH x a~d (10~ ~fC112C~25~C~2C ~ CO~2 ~

wherein the sum of xl+ x2 has the meaning of ~ m~ntioned in formula 5.
Preferably the sum of ~1 and x.2 is 10 to 50 and ~ore preferably 10 to.
20.

The poly~erization reaction is performed in an essentially water free rPaction medium, preferably in a lower alcohol such as ~ethanol or isopropanol, or acPtone on a lower celloso1ve which dissolve the reactants and catalyst.

Gsnerally the oligomerization temperature is maintained at a temperature between 20 and 60C, but temperatures up to 100C may be used as well. Optimum temperature may be readily determined for each oligomer-ization and will depend on the reaction, the relative reactivity of the monomers and the specific free-radical initiator used. In order to facili-tate the free-radical propagation necessary for an effective catalyst reaotion an oxygen-free atmosphere iâ desirable and the oligomerizations are carried out under ni~rogen.

(33S

The catalyst employed must be a ~ree-radical initiator, such as the peroxides, persulfates or azo compounds. These materials are well known in the art, However, particularly efficacious results arP obtained using organic peroxides and hydroperoxides, hydrogen peroxides, azo cata-lysts and water soluble persulfates. Specific examples include ammonium persulfate, lauroyl peroxide, tertbutyl peroxide and particularly the azo catalysts 2,2'-azobis(isobutyronitrile); 2,2'-azobis(2,4-d;methylvalero-nitrile); 2-tert-~utyla~o-2-cyanoproyane; l-tert-butyla~o-l-cyanocyclo-hexane; and 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile).

Catalytic amounts of initiator are used, that is between 0.01 and 0.5b by weight of monomers depending on the particular initiator and monomer system. With the preferred azo catalyst from 0.01 to 0.2~ by weight of azocatalyst per weight of monomers are used. Using greater amounts of initiator provides no significant advantage.

It is mos~ practical to synthesize the nove1 R~-o1igomers from monomers of type Ml and M~ in a one step polymerization reaction as pre-viously outlined. However, it is also possible, and under certain circum-stanc2s necessary, to synthesize the nove1 Rf-oltgomers in a two step synthesis. In this alternate synthesis method, hydrolyzable hydrophobic monome~s of type M2 are polymerized in the presence of an R~-mercaptan of formula ~2) yielding an Rf-oligo~er co~taining ~M2~monomer units.In a second step, such Rf-oligomers are hydrolyzed with a base, preferably alco-holic sodium or potassium hydroxide solution. In this hydrolysis procPss, selected -~-M2-~ monomer units are converted into hydrophilic -~-Ml-3-monomer units. In this way, vinyl ace-tate monomer units are converted into ~2~

1~ --vinyl alcohol monomer units or maleate ester units are converted into maleic acid salt units. Similarly, an Rf-oligomer containing maleic anhydride mono~er units can be hydrolyzed or amidized. This two step approach is7 however, more costly than the one step synthesis approach which is preferred and made possible due to the availability of a large number of commercially ava i l abl e hydroph i l i c monomers of type Ml .

In order to synthesize Rf-oligomers of formula (1) having the most desirable properties either as a protein foam additive or as a surface tension depressant for aqueous systems, it is necessary to balance the oleophobic and hydrophobic properties of the Rf-E-S- segment versus the hydrophilic properties of the -~-MI-3- monomer units and the hydrophobic properties of the -~-M2-3- monomer units in the oligomer.
In order to achieve a desired balance of properties it can be advantageous to have more than one type of -~-M~ units and more than one type af -~-M2-3- units present in the oligomer. However, it was also found that in many instances the Incorporation of hydrophobic -~-M2~- monomer units is not necessary at all to achieve the proper balance of oleophobic/hydro-phobic versus hydrophilic properties.

Further, by selecting the chain length of the Rf-group and the nature and ratio of the M1 and ~2 monomer units it was found that the foam expansion and drainage rate of the protein foam containing the perfluoro-aliphatic sulfide terminated oligomers of the instant invention can be modified. In addition to the ability of the artisan to use oligomers of the instant invention to modify the foam expansion of pro~ein fire fighting foams, the instant compositions can be tailored in such a way as to provide improved extinguishing times and the least sensi~ivity to hydrocarbon pickup with a given protein foam concentrate. For most applications of the novel Rf-oligomers it was found desirable to achieve a solubility in water or water-solvent mixtures of at least O.OlZ by weight Of Rf-oligomer. These very small amounts of Rf-oligomers already have a significant effect in protein foams.

It was also found that by selecting the proper M1 and M2 type monomers and, even more importantly, by varying the degree o~ polymerization, i.e. the weight ratio of the Rf-E-S segment versus the segment formed by -~_Ml ~ M2 ~ H, R~-oligomers can be prepared which reduce the surface tPnsion of aqueous systems to any desirable degree and as low as 16 dynes/cm.
While it is well known that classical fluorochemical surfactants as exempli-fied in U.S. patents 2,915,544, 3,274,244, 3,621,059 and 3,668,233 do reduce surface tens;ons of water as low as 15 dynes/cm, it is also well known that for many ?nd uses such extreme low surface tensions are not requlred which in many cases eliminates the use of the very hiyh priced fluorochemical surfactants. With the instant Rf-oligomers it is possible to tailor R~-oligomer compositions which provide any desirable surface tension in water between 76 dynes/cm and about 16 dynes/cm as exemplified later. This posslbilit~ to design Rf-oligomers providing any desirPd range of surface tension properties make the novel Rf-oligomers a very cost effi-cient class of surface tension depressants which have utilities in many fields of applications where commonly more expensive classical fluorochemi-cal surfactants are being used as additives. The novel Rf-oligomers can therefore be used in appllcations where improved wetting and spreading of liquids on difficult to wet substrates or substrates contaminated with oll or silicones is required. Application areas where these properties of aqueous systems containing R~--oligomers are required include:

Printing inks, paints, metal and can coatings, Floor, furntture and automobile polishes, Cleaners and grease removers, Photographic, insecticidal, herbicidal and bacteriostatic emulsions and dispersionst Pigment and dyestuff dîspersions and fiber, textilet and leather finishes, Consumer and personal care products such as hair sprays, shampoos ind conditianers, shaving creams and skin protection products, Oil recovery systems and fracturing fluids, and many other areas where classical fluorochemical surfactants are being used.

335;
-.18 -As stated before, the novel Rf-oligomers are particularly useful as additives to aqueous protein hydrolyzate foam concentrates used as fire fighting foams. Such so-called fluoroprotein foam concentrates ~ontaining the novelRf-oligomers show excellent foam e~pansion rations, as desirable slow foam drainage rate, and high tolerance to fuel contamination As a result such fluoroprotein foams do control and extinguish difficult to fight fuel fires and form a secure and longer lasting foam blanket which supresses the release of flammable vapors, has great stability and heat resistance, provides efective sealing against hot tank walls and has high resistance to reignition and burn back.

Other factors distinguishing superior fluoroprotein c~mpositions are the ext~nguishment o~ rim flres, smoothness of the foam blanket and minimal charrlng characteristics. The subject oligomeric surfactants confer these outstanding properties on fluoroprotein foam fire extinguishing agents. Such fluoroprotein foam concPntrates can be proportioned (diluted) directly ~ith fresh or sea water and show excellent long-term stability.
They can be applied directly to the surface on spill fires or by subsurface application methods as in tank farm protection systems. In such systems, the aqueous fluoroprote;n foam is introduced beneath the surface of the burning liquid and rlses to the surface where the foam spreads and extinguishes the fire.

Preferably such a processis used for e~tinguishing a burning hydrophobic liquid in a storage tank or containing vessel which com-prises introducing beneath the surface of the burning liquid an aqueous foam, which foam then rises to the surface of said liquid, said foam being prepared from an aqueous solution of a protein hy-drolyzate in a concentration sufficient to essentially completely stabilize the foam, said aqueous solution also containing from about 0.003 to 0.3% by weight of an oligomer according to formula (1) or formulae (4) to (10).

~Z'3~3~

In the process of ext~nguishing a f~re wherein the instant fluoro-protein foam fire-fight1ng compositions are used in conjunction ~lith a dry powdcr fire-extinguishing material, dry powder fire extinguishing ~aterial ;s first applied to a combustible materia1 (usually a flamnab1e liquld) to extinguish the fire and then the fluoroprotein foam composition, described supra, is applied to the surface to cover the cumbustible ~dterial to prevent reignition of said material by hot surfaces.

Protein foams are available commercially as concentrates for either 3~ or 6~ proportioning. This means that when these concentrates are used the 3% concentrate is mixed with fresh or sea ~ater in a ratio ~f 3 volumes of concentrate to 97 volumes of water. Similarly, the 6~ concen-trate is mlxed with fresh or sea ~ater in a ratio of 6 volumes of concen-trate to 94 volumes of water. Thus the subj~ct oligomers are lncorporated in a 3X type concentrate in amounts varying from about O.lX to about 10%.
Similarly, the oligomers are incorporated into a 6% type concentrate in amounts varying from abcut 0.2X to about 20X. The actual amount depends upon the ef~ects des1red.

The concentrates are as a rule diluted with water and then provide a protein hydrolyza~e aqueous foam-forming concentrate compo-sition for making a ire-fighting foam after dilution with from about 15 to about 35 times its volume of water which comprises a water solution of a protein hydrolyzate containing sufi-cient protein hydroly~ate to essentially completely stabilize the foam produced after dilution, and in dissolved or dispersed condition an oligomer according ~o formula (1) or formulae (4) ~o (lO), in concentration to give from about 0.003 to 0.3% by weight of said oligomer after dilution.

EXAMPLES

The following is a list of examples to illustrat0 the preparation and the usefulness of the oligomers of this invention. The examples are for illustrative purposes only and are not to be construed as limiting in any fashion.
In the followin~ examples, Rf refers to a mixture of perfluoroalkyl groups in approximately the following weight ratio unless otherwise indicated:

C6Fl3/C~FI7/CloF2l = essentially 34~/38X/23~

and may also contain Cl2F25. Still higher perfluoroalkyl groups may be present in small amounts.

Examples l to 73 illustrate the methods of preparation of the instant ollgomers. Examples 74 tol23 show how they can be used to modify the foam e~pansion ratio and drainage rate of protein foams. Finally, examplesl24 to 148exemplify utility of the oligomers ln resin and coating systems.

The preparat10n of the otigomers is straightforward and reaction occurs readily in the absence of air or oxygen as evidenced by the appearancè f solid which precipitates within a few hours in many cases. Oligomers have been characterized directly using HP~C (high performance liquid chromatography) techniques. Product formation is confirmed also by complete disappearance of mercaptan determined by iodine test and almost complete consumption of monomer as determined specifically by HPLC. Oligomers are characterized by their water solubility, aqueous surface tension reduction capabilities, and their effect upon protein foam characteristics.

2~33~

The structures indicated for the oligomer sho~ing single values for x~y is idealized. HPLC analysis shows such products to be co~posed of a distribution of compositions centered about the single value of x+y.

2~35 Example 1 ~ 22 -_ RfCH2CH~S-----CH2CH~H
CO:IH2_¦

To a 4 liter ~eactor are charged 0.73 kg of methanol, and then simul-taneously two reactor streams, one containing 0.64 kg acrylamide in 0.64 kg methanQl and the other 0.28 kg. RfCH2CH2SH, 0.28 kg methanol and 0.6 g 2,2'-azobis(2,4-dimethylvaleronitrile) as polymerisation initiator. These reactant ratios correspond to a l~mole RfC~2CH2SH to 15 moles acrylamide.
The two streams are added to ~he reactor over a pe~iod of 2 hrs. at.
58-63 C resulting in a continuous formation of telomeric proauc~ ~nile permitting safe, complete control of the exothermic oligomerization, At the end of the charge the reaction is held for 4 hrs. at 5~-63~ while an additional 0.06g charge of the initiator in methanol is added. The product is the diluted to 20~ actives with water, resulting in a clear solution sultable for use as an additive in fire-fighting applications.

High pressure liquid chromatography (HPLC) analys~s of the praduct1 us;ng ultraviolet (UV) (215 nm) detectlon and gradient, reversed phase elution technlques showed the presence of a dlstr1butlon of products under an envelope.

Consumptlon of acrylamide monomer was confirmed, again by HPLC analysis of the product us1ng UV detection and gradient elution techniques.

.

~; ; :
:~

The surface tension of the product follows:

~ Actives 0.001 0.01 0.1 Surface Tension 62 30 21 dynes/cm Rf_D;StrjbUt jOn %:C6, C8, CLO~ Cl2 34~ 36~ 23~ 5 ~Z~33~

Examples.~-7 R~CH2C~2S ~ C~C(C~3) - ~ : ~H
L COOCH~CHOHCHzN(CH3)3Cl ~

In a 118 ml glass bottles were added the RfCH2CH2SH, 3-trimethyl-ammonio-2-hydroxypropyl me~hacrylate chlorlde (THMA~34.5g methanol solvent for.25~ solids solution and 0.15. 2.,2'-azobis.(2,4-dimethylvaleronitrile).
The bottles were then purged with nitrogen, sealed and placed in a water shaker bath at 58aC for about 18 hours. Both the initial reaction mixture and final products were clear solutions in methanol.
~t the end of the reaction period, the contents of the bsttles were dried to give a solld product by heating for 20-hours in a 75C draft-oven-and finally for 5 hours at 40C i~ a vacuum oven at 0.2 mm. The resulting produc~ obtalnPd in essentially qua~titative yield ~re.re light amber brittlo solids.
, On Table l are given the experimenkal data for preparation of these various Rf oligomers. On Table 2 are yiven the surface tension values for the Rf oligomers both at 0.1% solids.

Table 1 RfC'd2C~2Sd TH~
~=465 MW=238 Weight Weight ~lal ue of Example Moles ( q ) Moles ( q ~ ( x )_ 2 o . 007 3 . 3 0 . 035 8 . 3 5 3 0.004 1.9 0.04 9.5 10

4 0 . 0018 0 . 8~ 0 . 04S lO . 7 25 0 . 0006 0 . ~4 0 . 047 ' 1 . 2 7S

6 0 . 00024 0 . 110 . 04811 . 4 200 7 None 0 . 048 ll . 4 ---- 26.-Table 2 Surface Tension dynes/cm in deionized water at 25C
Product of Value of at 0.1%
Exa le (x) Solia~ o~

7s 33 .~

~Z.~35 Example 8 RfCH2CH2S~C112CH_____ LH
lONHC(CH3)2CH250~H~

Following the general procedure of Examples 2-7, 2.35 g (0.005 mole) of RfC~2CH2SH, 5.2 g (0.025 mole) of 2-acryloylamido-2-methylpropanesul~onic acid (AMPS) 22.7 g of methanol solvent and 0.06 g of aæo catalyst as in E~ample 1 were reacted. The final product was a white powdar (% F calculated at 20.5%; found L7.1%) which gave surface tension values (dynes/cm) in deionized water at 25C of 26 at 0.1% solids;
33 at 0.01% solids and 53 at 0.001% solids.

~ 2~3S

Example 9 ~CH2C~S~C~2CH~f CO r C (HCH3 )2 NH(cH2 )3 N(CH3 )2 CH2SO3H _ :
: Following the general .procedure of Examples 2-7, the follo-wing.materials were added in this order to an~236 ml bottle: 59.7 g iso-propanol solvent9 9.3 g (0~.045 mol) 2-acryloylamido-2-methylpropa~e-sul~onic acid, 7.7 g (0.045 mol) N-(3-dimethylaminopropyl)-methacrylæmide (DMAPMA) 8.3 g (0.015 mole) RfCH2CH2SH and finally 0.25 (0.001 m~le) azo catalyst as in Exampl2 1. The mixture became homogeneous on initial warming and was reac~ed for 19 hours at 60CC.. A whiee precipitate resulted at the end of the reaction. The contents of the bottle were placed in a blender with S00 ml of dry methyl ethyl ketone ~o give a pulverized powder which was isolated by filtration and dried for 2.5 hours at 50~C
under 0.2 ~m. vacuum. T~e oligomeric amphoteric product was i~olated as a water solu~le, white powder in a yield of 22.~ grams ~86.a% of theory), A water solution of the product foa~ed when sllaken.
~, ' '~ ',' :

3~
- 29 ~
The surface tension values (dynes/cm) in deionized water at 25C for this product were 33 at 0.1% solids, 3~
at 0 . 01~ solids, 45 at o . 001% solids and 63 at o . 0001% solids .
Exam~les 10-11 Rf~l2CH2S - - CH~CH - -H
(~3 . CH~ I~ x Using 236 ml bottles, Rf~H2~.H2~H, 4-vinylpyridine, sufficient isopropanol to give 30~ by weight solids solutions and 0 . 25 g(~ .OOl mole) o~ azo catalyst as in Example 1 were mixed. The bottles were purged with nitrogen, sealed and placed in a water shaker-~ath at 58C for 18 hours.
The initial mixtu~es were nearly homogeneous solutions.

I~ a second step, methyl iodide in an equal weight of isopropanol was then added to the xeaction mixtures in the bottle5and reaction continued for 1 hour at 60aC. The solid produc~ wereisolated by evaporating the solvent in a 75C
drat oven followed by 2 days at 75C under 50 ~m vacuum.
The products Iormed cloudy solutions in water which foamed when shaken.

On Table 3 are given the experimental data for the preparation of these various cationic oligomers.
On Table 4 are given the description of the products and surface tension values (dynes/cm) in deionl~ed water at 25C.

. ,:

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Examples 12-14 RfCH2CH2S - - CH~CH H
/N~

O=C CH2 _ x In the following ~anner with actual dmounts shown in Table 5, examples 12-14 were prepared in a 1000 ml, three-necked flask fitted with mechanical stixrer, thermometer, nitrosen inlet tube and drying tube w~re added in order RfCH2C~2SH, N-vinyl-2 pyrrolidone, cellosolve solvent and azo catalyst as in Example 1.
The systems were kept under nitrnqen and slowly heated to 60C with stixring being maintained at 59-63C for 17 hours.
The nominal 37.5~ solids solu~ionsin cellosolve were cooled to 30C and diluted with water with stirring. The result-ing clear light yellow solutions were ~iltered to insure clarit~y. Actual solids ( ac~lves ) content was obtained by evaporating the filtered solutionsin a 60C draft oven overnight.

...... . ...... ,.. ,.. , ... .. . , .......... . , ~ ,.. ... ...... .

~2~

~ 33 -On Table 5 are given specific experimental data for preparing these non-ionic oligomers ~lth various values of x.

Table 5 Example l2 l3 l4 RfC~2C~2SH graTns 69.8 21.3 5.1 moles 0.15 0.046 0.013 N-vinyl-2-pyrrolidone grams 200 203.5 174 moles 1.8 1.83 1.56 Ethyl Cellosolve grams 450 375 300 Azo catalyst grams O.67 0.57 0.45 moles 0.0027 0.0023 O. 0018 Water (dilution) grams l~O 300 420 x (approximate) 12 40 120 Nominal Composition (wt. %) Ethyl Cellosolve 50 41.7 33.3 Water 20 33.3 46.7 Solids (actives) 30 25 20 Fluorine conten-t of solids %
Calculated 17.2 6.3 2.2 Found 15.6 5.5 1.8 Surface Tension dynes/cm in -~-deionized water at 25C of solids at O.OQl% 56 59 65 0.01% 27 27 46 0.1% l9 20 21 .... .. . . .. . . . . . .. ., . . .. _., , .-- . . .

3~i xamples l5-l7 Using the general procedure of Examples l2 l4, additional samples of non-ionic oligomer with vary}ng values of x were prepared.

Table 6 ExamDle l5 l6 l7 ._ _ RfCH2CH2S~ grams 12.4 6.0 3.4 moles 0.027 0.013 0.00?
N-vinyl-2-pyrrolidone grams 355.5 355.5 361 moles 3.2 3.2 3.25 Ethyl Cellosolve grams 613 602 607 Azo catalyst grams 0.92 0.90 0.91 moles 0.0037 0.0036 0.0037 Water (dilution) grams 859 844 851 x (approximate) 120 Z50 4S0 Calculated % solids (actives) Z0 20 20 Surface Tension dynes/cm in deionized water at 25C of solids at 0.001% ' 66 63 6a 0.01% ~2 S1 59 0.1% 2~ 27 32 , ~Z~35 Exarnples 18-24 Using the general procedure of Examples 12-14,RfCH2CH~8H, N-vinyl-2-pyrrolidone, sufficient acetone solvent ~o give 25% solids solution and azo catalyst as in Example 1 were reacted at 60aC for 18 hours.

On Table 7 are listed the experime~tal data for these non~ionic oligomers which were prepared as white solids in essentially quantitative yield.

~2~5 - 36.-Table 7 Exam~le 18 l9 20 21 22 23 24 RfCH~CH SH
gram~ 9.3 7.0 4.6 1.~ 0.~2 0.31 0.20 moles0.020.015 0.010.003 0.0013 0.0007O.OOOg ~-vinyl-2 P'Irrolidone grams11.1 16.7 16.7 10.0 11.1 11.1 11.6 ~ol~s0.10 0.15 0.15 0.09 0.1 0.1 0.105 Acetone grams 61 71 64 34 35 34 36 Azo Catalyst grams0.20 0.20 0.20 0.15 0.15 0.15 0.15 moles 0.00080.0008 0.0008 0.00060.00060.0006 0.0006 x (approximate) 5 10 15 30 75 150 250 Surface Ten-sion dynes/cm at 25~C in deionized water o~
solids at 0.001% 46 48 48 55 6~ 64 0.0}% 20 22 23 23 42 48 0.1%* 17 18 18 18 . 18 20 21 * Poly(vinylpyrrolidone) alone at 0.1% = 65 dynes/cm ~Z~335 EXamD1eS ZS 28 RfCi-i2CH2S~CH2CH~CH2C (CH3 ) - 1 H
L COOH ~ l IOOCH2CH20H ~

Using the general procedure of Example 9, RfC~2CH2SH, acrylic acid, 2 hydroxyethyl methacrylate (both are hydrophilic monomers) sufficient acetone solvent to give 30% solids solutions and azo catalyst as in E~ample 1 were reacted at 60C for 19 hours. After eva-poration of solvent, the products were isolated in essentially quanti-tative yield as white solids soluble in an aqueous ethyl cellosolve solution.

On Table 8 are given the experimental data for preparing these oligomeric materials.

2~35 T~le 8 ~xam~le 25 26 27 28 . . . _ C~2CH2S~ grams 9.3 9.3 9.3 9,3 moles 0.02 0.02 0.02 0.02 Acrylic acid grams 2.9 5.8 8.7 11.5 moles 0.04 0.08 0.12 0.16 2-hydroxyethyl meth-asrylate (HEMA) grams 20.8 15.6 10.4 5.2 moles 0.16 0.12 0.08 0.04 Acetone grams 77 72 66 61 A~o Catalyst grams ,0.25 0.25 0.25 0.25 moles 0.001 0.001 0.001 a . oo xl(approximate) 2 4 6 8 ~approximate) a 6 4 2 Su~face Tension dynes/cm at 2S~C in deioni2ed water of solids at 0.01% 27 27 35 43 0.1% 23 23 23 23 Examples 29-31 _ _ RfCH2CH2S--~CH2C _~

t,~ H2CH20H x Uslng the general procedure of Example 1, RfCH2C~2SH, 2-hydroxyethyl methacrylate, acetone solvent and 0.25 gram (0.001 mole) of azo catalyst as in Example 1 were reacted for 17 hours at 60C. Sufficlent acetone solvent was used to give 30% solids solutions. The products were iso1ated as white crystalline solids in essentially qu~ntitative yield. The solids were soluble in aqueous ethyl cellosolve solution.

On Table 9 are given the experimental data for preparing these oligomeric materials.

Table 9 .

Exam~le 29 30 31 RfCH2CE12SE~ grams9 . 3 7, o 4 . 6 moles0 . 02 0 . 015 0 . 01 2-Hydroxyethyl meth-acrylate (HEMA) grams 13.0 19.5 l9.S
moles0.10 0.15 0.15 Aceto~ie grams52 62 56 x ( approxlmate ) 5 lO 15 . .

,f~35 Exam~les 32-35 RfCH2CH25--_CH2CH _ --CH2CH--~ H
CO . CO

CH2ocH2c~(cH3 )2 Xl-- --X2 Using the ge~eral procedure of Example l, RfC~2CH2SH, N-(isobutoxymethyl)acrylamide,acrylamide (both are hydrophilic monomers), acetone solvent and 0.15 g (0.0006 mole) of azo catalyst as in Example 1 were reacted at 58C for 5.5 hours. Sufficient acetone was used to give 25% solids solutions. 'rhe solid products were isolated i~ essentially quantitative yield.

On Table lO are given the experimental data for preparing these oligomeric materials.

~ ~Z9;3~

Table 10 Exam~le 32 33 34 35 __ - ___ RfC~2CH2SH grams 5.8 4.7 3.5 2.8 moles 0.0125 0.01 0.0075 0.006 N-(isobutoxymethyl) grams 9.8 7.9 5.9 4.7 acrylamide moles 0.0625 0.05 0.0375 0-03 Acrylamide grams -- 3.6 5.3 6.4 moles -- 0.05 0-075 0 09 ~ce~one grams 47 4~ 4~ 42 x~tapproximate) 5 S 5 5 x2(approximate) o 5 10 15 3~

Examples 36-40 Rf~12CH2S~I2 I~l~H
L CONH2~

The following exa~ples were prepared from RfCH2CH2SH
and acrylamide using a catalyst as in Example 1. The reaction were run in isopropanol at 60C~ for 16 hours at 20~ solids and then diluted with water to 7% solids for analysis.

~ T~ble ll Example 36 37 38 39 40 -a RfC~2CX2S~ moles 0.01 0.01 0.01 0.01 0.01 Acrylamide moles 0.05 0.10 0.15 0.25 0.25 x value 5 lO lS 25 50 Sur~ace Tension, 0.01~ 19.4 22.8 26.5 34.~ 44~5 dynes~cm Rf-distrlbutin, %; C6; C8; ClO; C12; 33~ 3~ 23~ 5 Cloudy - ~4 -Examples 41-42 In order to show the effect of the Rf chain length of the oligomers on the foam expansion ratio the following oligomers were synthesized:

RfCH~CH2;~CH~-CH~ 11 CONH
1 s In one pint bottles were charged 10.8 9 C6FI3CH2CH2SH(or 13.55 gms CaF17CH2CH25H), 3U g of acrylamide, 132.4 gms isopropyl alcohol(IPA) and 0.03 9, of ca~alyst as in Example 1.The bottles were purged thoroughly with nitrogen and placed in a 75C bath overnight. The resulting m~xtures were isolated as 20% solids, 25~ IPA, S5% water by evaporating ~PA and charging water.

The products were analyz~d by HPLC to show a distrlb-ution of components under an envelope. The C8FI7 der1vative dlstrlbutlon envelope centered at longer retention time than did the C6f 13 distrlbutlon envelope.

a Example 41: Rf ~ C6F1s Example 42: Rf = CaF~7 33~

Examples 43~45 R~CH2CH25~cH2cH~H
L CONH2~

The following examples were prepared from R~CH~CH~SH
~. ..
and acrylamide, using 2,2'-azobis-(2,~-dime~hylvaleronltrile) as catalyst The reactions were run in acetone at 60C fO~ 16 hours at ~S~ sol ids and obtained as powders qua~tita~ively by evaporating the solve~t at 45C in a forced-air oven.
Table 12 X 2~11D 1 e 4 3 4 4 4 5 RfCH2CH2Saag, moles 4.38, 0.01 4.38, 0.01 4.38, 0.01 Acryla~ide g, moles . 3.55, 0.05 7.11, 0.10 10.66, 0.1;
value 5 10 15 Surface Tension @ 0.1% 15.6b 16.6 ' 16.8 dynes/cm @0.0l~ l9.2b l9.l 22.3 a Rf-distribution~ %: C6~ C8'C10~ C12i 46~ 42~ 10~ l b Cloudy ~ 9 E~amples 46-51 H2c~2s~cHzcH 1 ¦ CH2C~H
L cO~H~xl l C02H~X2 The following materials were added, in this order, to the reaction vessel: acrylamide, acrylic acid (both are hydrophilic mono-mers~ RfGH2CH2SH, sufficient isopropyl alcohol to give 20% solids solu-tion and azo catalyst as in Example 1. The reaction vessel was then purged with nitrogen and placed in a 70C bath for 20 hours. The re~
sulting products were placed in a 60C draft-oven to remove the solvent and then in a vacuum-oven to remove any unreacted monomers.

Experimental data for preparing these oIigomeric materials are given in Table 13. The polymers were all isolated in 90 % yields.

3~3S

Tabl~ 13 Example 46 47 48 49 50 ~1 _ _ RfCH2CH2SHa moles.013 .013 .013 .013 . .013 .013 Acrylamide moles.2ZS .247 .221 .130 .026 Aerylic acid moles.006 .013 .039 , .130 .234 ¦ 26~ ¦
IPA grams ' 124 126 1 126 ¦ 126 ¦ 126 ¦ 125 Azo catalyst grams 1 1.9 1-9 ¦ 1-9 1 1-9 j 1-9 1.9 xl 1 19.6 1 19 1 17 ` 10 ~ 2 0 X2 '~ 4 1 1 3 1 10 1 18 20 f calculated i 16.9 ¦ 16.9 _ _ 1 ' 16.7 ____ _ i . _ . .. _.__ i _ , a Rf-d;stribution, % C6, Ca, Clo~ Cl~; 33, 36, 23, 7 ~2~3~

~e~

2~CH2CH25--rCU2CH ~HZf(CH3~
CONH 1 9 . 6 CONH2 o 4 To the reaction vessel were charged - acrylamide (0.255 moles), methacrylamide (0.0052 moles), RfCH2CH2SH (0.013 moles), isopropanol (127 g), catalyst as in Example 1 (1.9 g). The reactor vessel was purged with nitrogen and placed in a 70aC bath for 20 hours. The product was stripped of solvent in a 60C drait-oven and then in a vacuum-oven to remove unreacted monomers. The product was obtained in 93% yield (~ F
calculated 16.9%).

a Rf-distribution, ~ C6, C8, C10, C12;

3~3S

ExamDles 53-57 . . .

R~C112C112S~ f~112 1 IC~13 L CONH x 1 COOH X2 The following ~aterials were added, in this order, to the reaction vessel: acrylamide, methacryIamide (both are hydrophilic monomers) RfCH2CH2SH , sufficient isopropyl alcohol to give 20% solids solution and azo catalyst as in Example 1. The reaction vessel was then purged with nitrogen and placed in a 70C bath for 20 hours. The resulting products were placed in a 60C bath for 20 hours. The resulting products were placed in a 60C draft-oven to remove the solvent and then in a vacuum-oven to remove any unreacted monomers.

E~perimental data for preparing these oligomeric materials are given in Table 14. The polymers were all isolated in 90% yields.

Copolymers with high levels of methacrylic acid did not give stable protein foam concentrates.

- so -T~ble 14 E~ample 53 54 55 56 57 RfCH2CH2SHa mol es. 013. 013. 013. 012. 01 1 Acry l ami de mo l es . 255. 247. 22 l . 120 . 022 Methacry l i c ac i dmo l es . 005 . 013 . 039 . l 20 . 198 IPA gramsl Z7 125 130 125 120 Azo catalyst grams l . 9l . 9 l . 9 l . 9 l . 9 ~1961~9 ~ l 16.9 16.8 14.8 ._ . .

a Rf-distribution, X C6, Cf" ClO, CI2; 33, 36, 23, 7 3~;

l .
Rf C~2CH2S - CH2~- - H

To the reaction vessel, was added RfCH2CH2SH
(.007 moles), vinyl acetate (.140 moles), sufficient isopropanol to give 20% solids, and azo catalyst as in Example 1 (.01~ by weight of vinyl acetate) . The solution was purged with N2 and reacted at 70~C for 20 hours. The clear yellow liquid thus obtained was hydrolyzed by adding NaOH (5.5 g) and heating at about 70C for 20 hours. The clear orange solution obtained was then dried via a vacuum pump. The % yield WdS 99.6.

43~

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Utility of the Oligomers in Protein Foam The following examples demonstrate the utilit~ of the instant oligomers for use in protein foam. The use of the oligomers in a protein foam base, in addition to reducing the flammability of fuel-foam mixtures and reducing fire extinguishing time, also allows for the adjustment of foam expansion ratio and foam drainage rate in both fresh and sea water dilutions. The first examples show the negative impact of prior art fluorochemical on foam expansion ratio, drainage rate and dilution stability. Subsequently, exdmples of the instant oligomers as additives in protein foam are presented showing the range of effects on foam expansion and drainage rate.

Foam expansion ratio and drainage rate measurements were carried out using a laboratory ~ranch-pipe nozzle fabr1cated from l/4" and l/8" stainless steel tubing, operating at a nitrogen pressure of 30 psi and a flow rate of 600 cc/min. lO0 cc of protein foam premix was ~oamed into a conical bottom 2 l graduated cylinder. foam expanslon ratios are calcuated from the ratio of volume of foam produced ~o volume of pre-mix used, with a precision of + 0.2. 3rainage rates are expressed as the time, in minutes, required for 25X of original pre-mix volume to accumulate in the conical bottom of the graduated cylinder with a precision of ~ 0.2 min.
This value is called quarter drain time or Q.D.T.

Presentation of foam expansion ratio and drainage rate data in the following tables is in the form of ~ ~alues which show most clearly, the magnitude and direction of the effect of theinstant oligomers on protein foam. Therefore d ~L~4~ 5 Qxpansion of ~ 1.1 means that the expanslon ratio oF proteln -~
foam with the subject additive is 1.1 units greater than the protein foam expansion ratio when no additive is present.

:

~ 3 Prior Art Flaorouhem;cals in Protein Foam Exa~ples 74-8!5 The following tabulation indicates that conventional fluorochemical surfactants known to the prior-art are deleterious to protein foam expansion and drainage rate. Each surfactant was dissolved in the protein-base ~3~) at 0.3X F and tested at 3% dilution in sea water. Table 17 Sea Water Example Rf-Surfactantb ~Expansion~Q~T
74 LODYNE 5-112 -4.3 -6.0 Zonyl FSN -7.7 76 Zonyl FSE -3.5 -2.5 77 Zonyl FSAa ~ 0.7 78 Zony1 FSB -5.5 79 Monflor 31 -3.3 -2.7 Monflor 52 -5, R
81 Fluorad FC-9S -2.8 ~2.6 8Z Fluorad fC-170 -7.6 a3 Fluorad FC-172 -4.5 84 Fluorad FC-128 -3.8 -3.6 FT 248 ~3 4 -3.2 a Concentrate stabi]ity was poor.
The commercially available surfactants used in the examples are:
FC-9S, which is an alkali metal salt of a perfluoroalkyl-sulfonic acid.
FC-128, which is a perfluoroalkanesulfonamido alkyl-enemonocarboxylic aoid salt as disclosed in U.S. Pat. ~o.
2,809,990.

~23~3S

FC-170, which is a nonionic perfluoroalkanesul-fonamido polyalkylene oxide derivative.
FC-172, ~hich is an amphoteric perfluoroalkylcarboxy-late.

Zonyl FSA an anionic derived from linear perfluoro-alkyl telomers.
Zonyl fSa, an amphoteric carboxylate deriYed ~rom linear perfluoroalkyl telomers.
Zonyl FSN, a nonionic derived from linear perfluoro-alkyl telomers.
Zonyl FSE, an anionic long chain fluorocarbon derivative.
Monflor 31, an anionic derived from branched tetra-fluoroethylene oligomers as disc10sed in GB Pat. No. 1,148,486.
Monflor 52, a nonionic derived from branched tetra-fluoroethylene oligomers as disclosed in Brit. Pat. No.
1,130,822, 1,176,492 and 1,155,607.
FT 248, C~FI7503 ~C2Hs)4 LODYNE S-112, which is an anlonic surfactant/Rf-synergist composition as described in U.S. 4,089,804.

2~3S

~ 58 -Examples 8Ç-93 The following examples illustrate the improvement which can be attained in the foam expansion of a conventional 3~O regular protein foam by the addition of various amounts of the oligomers described in Examples 37 and 38.

Table l_ Effect of Additive Oligomer on the Foam Expansion for 3% Tap and 3X Sea Water Dilution % Actives in _ Protein Foam _ ~ ExPansion Example 37 Example 38 In In Example Concentrate 3~O Dilution Tap Sea Tap Sea 86 0.00 0.00 5.3a 6 la 5 3d 6 12 87 0.02 0. 0006 0 +0 . 3 - -88 0.13 0.0033 +0.8 ~1.1 - -89 0.20 0.00~ 1.2 +1.1 0.27 0.008 +0.9 +1.7 - -91 0.50 0.015 ~1.0 +1.9 +1.5 ~1.7 92 1.00 0.03 ~1.3 ~2.1 +1.9 ~1.6 93 l.S0 ~ 0.045 - - +1.4 ~1.2 a Actual measured.expansion ratios.

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~ .

"33~i 60. -Example 100 - 104 The results listed in Table 20 show the effects of Rf chain length on the foam expansion ratio of protein foam and a~so the effects of the change in tha value of x on the foam expansion ratio of protein foam. The measurements were made on 3~ fresh w~ter dilutions of AER-O-FOAM 3% REGULAR
(~ational Foam).

Table 20 Effect of R Length and Value of x on_ Protein Foam Expansion ------ f Example Additive Rf x ~ Expansion 100 Example 41 C6F13 lS -2.Z
101 ~ 42 C8FI7 15 +l.9 102 36 33.3~3.23 5 -1.7 103 " 37 C6CaCI~cl2 lO -0.4 33:38:23:5 104 " 38 C6C,3clocl~ 15 +0.7 ~4~ 5 Examp1es 105 - 123 Table 21 below further demonstrates the utility of the subject oligom~rs to allow the adjustment of the foam expansion ratio and the Q~T values of protein foam compositions.

rable 21 ffect of Example Oli~omers on Sea Water Foam Ex,oansion Patio and QOT Value of Protein Foam Exampl.e Addi.tivea Expansion a QOT

Example 105 ll -0.7 -3.9 106 46 0 -l.8 107 47 -l.4 -1.8 108 48 ^0.7 -l.5 109 50 0 +0.7 111 53 +l.l -3,5 1.12 5~ +0.9 -2.2 113 55 +l.l -1.6 11~ 56 +0.7 -0.2 115 57 +0.8 0 116 60 0 o 117 61 +0.5 -0.4 ~18 62 +2.7 . -2.0 119 63 +0.5 +0.2 .1~0 64 tO . 4 -l.7 121 65 +l.5 -0.4 .122 68 +1.0 ~ 0.3 123 70 0 - 0.3 ~Z~335 The following examples sho~t th~ use~ulness o~ ~he oligomers due to ~heir surface activity 1n applications other than prote;n foam.

Examples 124 ~

A watex based coa~ing formulation (40.9% solids) was mixed together, consisting of 28.6 parts of water soluble, crosslinkable resin, containing polyethylene oxide se~ments as water solubilizing units and being derived from diepoxides, 15.4 parts (80% solids in isopropanol) of a cxosslinking mela-mine resin and 56 parts water. This aqueous resin was applied with a No. 7 wound wire rod to electrolytic tin plate, which has a re-maining layer of a hydrocarbon-type oily impurity from processing and is especially difficult to wet. The samples were cured in a cir-culating air oven at.200C or 10 minutes.

Surface active compounds were incorporated into the formulation to improve wetting, which was judged visually and expressed in percent co~rered surface area. The results axe tabulated below.

Table 22 -Additive Cover~ge Ex Additive % of % after Chemical T~rDe Solids* Cure Remarks 1~4 Control, none -- 25 beaded up 125 Example 32 o 55 85 rough crlnkled 126 . Example 33 0.70 95 slightly crinkled 127 Example 34 0.86 100 smooth 128 Example 35 1.03 100 smooth 129 nonionic hydro- l.O 50 carbon(Pluronic L-72) 130 silicone (BYK-301) -1.0 75 131 nonionic fluori- 1.0 60 nated (FC-430) * 10% solution or emulsion of additive added to formulation to give s~ated % additive on solids.

Only the novel oligomers of this invention (Examples 125 to 128), especially :Examples 127-128, essentially prevent a reduction of covered suriace area during cure.

~Z9~3~

Examples 132 - 140 Usin~ the procedure of Exanlples 124 - 131,other oligomeric additives of the invention were used to i~prove wettiny of c~red epoxy coatings as seen on Table 22.

T~ble 23 AdditiveCoverage Ex Additive % of % after _ Chemical Ty~e Solids* Cure Remarks 132 Control, none -- 10 Very poor 133 Example 25 0.36 lO0 smooth 134 Example 26 0,34 lO0 good, few rough spots 135 Ex~nple 27 0.31 lO0 some wrinkles 136 Example 28 0.29 lO0 wrinkles 137 Example 29 0.19 80 many voids 138 Example 30 0.31 85 many voids 139 Ex~nple 31 0.42 90 many .voids 140 Example 31 plus 0.21 60 poor a~photeric 0 03 ~luori~ated surfactant (Lodyne S-100) * 10% solution or emulsion of additives added to formulation to give stated % additives on solids.

3~ii The olisomers of xamoles 25-3l also gave improved coverage of cured epoxy coatings. The cured coatinq of Example 25 was partlcularly good.

Examples 141 - _ Usi~g the pxocedure of Example 124 - 131, still o~her oligomers were evaluated as additives to improve the coverage of epoxy coatings as seen on Table Table 24 Additive Covera~e Ex Additive % of ~ after Chemical Type Solids* Cure Re~ar~s .

141 Control, none -- lO Very poor 142 Example l8 0.30 10 beaded up 143 Example lg 0.46 50 poor 144 Example 20 0.61 ~0 many small voids 145 Example 20 plus 0.31 85 some voids amphoteric 0.30 , and streaks fluorinated surfactant (L.dyne S-}o~) * 10% solution or emulsion of additives added to formulation to give stated ~ additives on solids.

Examples 145-148 Using an experimental hard-surface cleaner ~i.e, floor polish) the oligomers o~ the instant invention were added to the floor polish ~ormulation in order to improve spreading and leveling characteristics.

The oligomer additives were mixed with the cleaner to give a. 05%F in solution. A 25 ml sample of formulation was placed on a 5 mil aluminum foil sheet using a syringe. The drop ~as allowed to stand for 5 minutes after which time the diameter of the drop was measured and the area covered was calculated.
High ~umbers for area indicate improved spreadlng and leveling characteristics. The results are given on Table 25.

Z~335 - ~7.-- Table 2s Ex Additlve %F in Calculated Leveling _ Chemical TYpe Formulation Drop area mm2 Ratinq *

145 Control, none -- 70.9 8 146 Example 19 0.05100.3 147 Example 37 0 05 loa.3 4 148 Amphoteric 0.05 95 0 2 fluorinated sur~actant (Lodyne S-100) * Leveling rating = subjective visual observatlon of dried drop ~here 1 = best (s~oothest, most level); 8 = worst ~high ridge around drop, uncoated center area).

Claims (20)

CLAIMS:

1. An oligomer of the formula wherein Rf is a straight or branched chain perfluoroalkyl of 4 to 18 carbon atoms, perfluoroalkyloxyalkylene of 5 to 19 carbon atoms, or mixtures thereof, E is a straight or branched chain alkylene of 1 to 12 carbon atoms, -CON(R')-E'-, -SO2N(RI)-E'-, -E"-CON(R')-E'-, -E"-S-E'-, -E"-N(R')-E;
or -E"-SO2N(R')-E'-, where R' is hydrogen or alkyl of 1 to 6 carbon atoms, E' is alkylene of 2 to 8 carbon atoms and E" is alkylene of 1 to 4 carbon atoms; represents a hydrophilic monomer unit derived from a hydro-philic vinyl monomer and represents a hydrophobic monomer unit derived from hydrophobic vinyl monomer, x is an integer of 4 to about 500, y is zero or an integer of up to 250, the sum of x and y is between 4 and about 500; and is between 1 and 0.5 ,

2. An oligomer according to claim 1, wherein the sum of x and y is between 10 and about 200.

3. An oligomer according to claim 1 or 2, wherein y is 0.

4. An oligomer according to claim 1 of the formula wherein Rf is a straight or branched chain perfluoroalkyl of 6 to 14 carbon atoms, E is ethylene is , or wherein T1 is -COOMe; -CONH2; -CONHR2;-CONR2R3; -CONH-E1-NR2R3;
-CONH-E1-NR2R3R4X ; -CONHCH2OH; -CONHCH2OR2; -CONHE2OH;
-CO(OE1)nOR1;-COOCH2CHOHCH2OH; -CONH-E2-SO3MP; -CON(E1OH)2 T2 is -OH; -OE2OR1; -(OE1)nOR1; -SO3Me; -C6H4SO3Me;
, pyridinium halide, -NHCOR1, -NH2 T3 & T4 are independently -COOMe; -CONH2; -CO(OE1)nOR1;
-CONH-E1-OH; -CON(E1-OH)2 R1 is hydrogen or methyl , R2,R3,R4 are independently alkyl with 1 to 6 carbon atoms, E1 is alkylene with 2 or 3 carbon atoms, E2 is alkylene with 2 to 6 carbon atoms, Me is hydrogen or alkali metal, X is halide, n is 1 tu 20 is , or wherein G1 is -COOR5; -OCOR2; -CN; -OR5; -C6H5; -C6H4X
G2 is hydrogen, R2 or halide G3 and G4 are independently -COOR5 or combined can be -CO -O-CO-R1, R2, X are as previously defined R5 is alkyl with 1 to 18 carbon atoms, or cycloalkyl, aryl or alkenyl with 6 to 18 carbon atoms the sum of x and y is between 4 and about 500, and is between 0.5 and 1.

5. An oligomer according to claim 1 of the formula wherein Rf is a straight or branched chain perfluoroalkyl of 6 to 14 carbon atoms, E is -CH2CH2-R? and R? are independently hydrogen or methyl, T and G are each independently -CONH2, -COOH, , , -COO-E1-OH, -CONH-E?-SO3H, -CONHCH2OR7, and where R is methyl or ethyl; X is chloride or bromide; E? is straight or branched chain alkylene of 1 to 3 carbon atoms; R?, R? and R? are independently alkyl of 1 to 4 carbon atoms R7 is hydrogen or alkyl of 1 to 4 carbon atoms, and x+y = 5 to 500.

6. An oligomer according to claim 4 of the formula , wherein Rf is a straight or branched chain perfluoroalkyl of 6 to 14 caLbon atoms, E is ethylene is , , , , , and/or , and x is 5 to 250.

7. An oligomer according to claim 6 wherein Rf is perfluoro-alkylene of 6 to 12 carbon atoms.

8. An oligomer according to claim 4, wherein x plus y are between 10 and about 200.

9. An oligomer according to claim 6, wherein x plus y are between 10 and about 200.

10. An oligomer according to claim 9, wherein x plus y are between 15 and about 50.

11. An oligomer according to claim 6, wherein Rf is a straight chain perfluoroalkyl of 6 to 12 carbon atoms, E is ethylene, is , x is 5 to 100.

12. Process for the manufacture of an oligomer according to claim 1, which comprises polymerizing a hydrophilic monomer or monomers of of the type M1 optionally with a monomer or monomers of the type M2 in the presence of an Rf-mercaptan of formula Rf-E-SH, wherein Rf and E
are as defined in claim 1.

13. Process according to claim .12 which comprises carrying out the polymerisation in a essentially water free reaction medium at tem-peratures between 20 and 100°C.

14. Process according to any one of claims 12 and 13 which comprises carrying out the polymerisation in the presence of 0.01 to 0.5 % by weight of the monomers of a free-radical initiator.

15. Method of depressing the surface tension of an aqueous system which comprises adding thereto an oligomer according to claim l.

16. Method of improving a protein foam type fire fighting composition which comprises adding thereto an oligomer according to claim l.

17. Protein foam fire extinguishing concentrates for 3% (6%) proportioning which comprise 0.1 to 10% (0.2 to 20%) by weight of an oligomer according to claim l.

18. A protein hydrolyzate aqueous foam-forming concentrate composition for making a fire-fighting foam after dilution with from about 15 to about 35 times its volume of water which comprises a water solution of a protein hydrolyzate containing sufficient pro-tein hydrolyzate to essentially completely stabilize the foam produced after dilution, and in dissolved or dispersed condition an oligomer of claim l in a con-centration to give from about 0.003 to about 0.3% by weight of said oligomer after solution.

19. A process for extinguishing a burning hydrophobic liquid in a storage tank or containing vessel which comprises introducing beneath the surface of the burning liquid an aqueous foam, which foam then rises to the surface of said liq-uid, said foam being prepared from an aqueous solution of a protein hydrolyzate in a concentration sufficient to essentially completely stabilize the foam, said aqueous solution also containing from about 0.003 to 0.3% by weight of an oli-gomer according to claim 1.

20. A process according to claim 19 which comprises applying a dry powder extinguishing material to a combustible material to extinguish the fire and then applying an aqueous foam being prepared from an aqueous solution of a protein hydrolyzate in a concentration sufficient to essentially completely stabilize the foam, said aqueous solution also containing from about 0.003 to 0.3% by weight of an oligomer according to claim 1 to the surface of the combustible material to present reignition of said material by hot surfaces.