GB1590463A - Polyglycerol derivatives useful as nonionic surfactants - Google Patents

Description

(54) POLYGLYCEROL DERIVATIVES USEFUL AS NONIONIC SURFACTANTS (71) We, BASF WYANDOTTE CORPORATION, a corporation organized under the laws of the State of Michigan, United States of America, of 1609 Biddle Avenue, Wyandotte, State of Michigan, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to derivatives of polyglycerols useful as nonionic surfactants.

The preparation of various polyglycerols, by condensing glycerol in the presence of an alkaline catalyst at temperatures such as 100--300"C is disclosed in U.S. Patent No. 3,637,774. The patent goes on to teach the making of various partial esters or full esters of such polyglycerols for various purposes, such as gelling agents, lubricants, wetting and dispersing agents, etc. The reaction of partial esters with alkylene oxides to form adducts is suggested. Such esters are, however, subject to hydrolysis under alkaline conditions.

The reaction of organic hydroxyl compounds (including polyglycerol) with alkylene oxides is disclosed in U.S. Patent No. 2,253,723. The patent discloses the use.of stannic chloride as catalyst for the reaction of an alkylene oxide with virtually any organic hydroxyl-containing compound. Stannic chloride is completely unsuitable as a catalyst for the making of products in accordance with the present invention. Moreover, the patent does not mention the fatty epoxides which are used as reactants to produce the products of the present invention.

Alkali-stable nonionic surfactant compositions are known which result from the reaction of a fatty alcohol with a lower glycoside, in a manner similar to that described in U.S. Patent 3,547,828 or U.S. Patent 3,772,269. In these patents, neither the hydrophilic group nor the hydrophobic group has any similarity to those used in our composition; furthermore, such compositions differ chemically from those of the present invention, in that the hydrophobe is joined to the hydrophile through an acetal or a hemiacetal linkage, which is not stable in acid media.

GB Patent Specification No. 1,421,707 discloses the making of nonionic surfactants by reacting a-olefin epoxides (1,2-alkylene oxides) containing a C8 to C20 alkyl group directly attached to

with a particularly purified polyglycerol containing 3 or more glycerol units. Its teachings can be distinguished from those of the present invention both on the ground that the particular purification process set forth in that patent specification is not necessary and on the ground that that patent specification does not make it obvious to those skilled in the art that with a glycidyl-ether approach (using a compound in which a long-chain alkyl group is attached via an ether oxygen atom rather than directly), results substantially as good can be obtained with the use of starting materials which are more readily available and less expensive.

U.S. Patent No. 3,719,636 teaches making nonionic surfactants by reacting, for example, C,2 to C14 fatty alcohols with several moles of glycidol

When glycidol condenses, it yields (in effect) glycerol units. Working with glycidol has the drawback that the glycidol is not easy or inexpensive to make and that it is difficult to prevent the glycidol from self-polymerizing.

According to the present invention there is provided a nonionic surfactant material resulting from the reaction of a polyglycerol containing an average of three to thirty glycerol units, usually five to thirty glycerol units, with a proportion, sufficient to substitute four to twenty-five percent of the hydroxyl groups of the polyglycerol, of a reactive oxirane-containing hydrophobe compound which is a glycidyl ether or a precursor thereof reacting to form the same product.

The hydrophobe compound may be, in particular, a glycidyl ether of a C6 to C20 fatty alcohol or a mono- or di-glycidyl ether derived from a polyoxyalkylene compound prepared from propylene oxide, butylene oxide, ethylene oxide or a mixture of two or more thereof and, in the case of a monoglycidyl ether, a lower alcohol of up to 6 carbon atoms which is not itself hydrophobic.

For the best results the reactive oxirane-containing hydrophobe compound should have an average oxygen/carbon atom ratio of not greater than 0.4:1. In that event surfactant compositions result which have solubility and stability in a variety of concentrated ionic solutions, especially in basic media, and are biodegradable in many instances.

The use of the glycidyl-ether approach according to the invention makes it unnecessary to use fatty expoxides, which are sometimes expensive or not readily available.

The polyglycerol containing a desired average number of glycerol units may be obtained in any manner known to those skilled in the art. One satisfactory procedure, involving dehydration of glycerol in the presence of an alkaline catalyst at 100 to 3000C is adequately disclosed in U.S. Patent No. 3,636,774.

The glycidyl ether may be prepared by the reaction of epichlorohydrin with an appropriate alcohol ROH according to the equation:

Such preparation is well known to those skilled in the art-see, for example, U.S.

Patent No. 2,314,039. In the foregoing, R may be, for example, an alkyl radical of 6 to 20 carbon atoms. This implies that the surfactants of the invention are made from the corresponding fatty alcohols, rather than from fatty 1,2-epoxides.

Those skilled in the art will also appreciate that it will not always be necessary or desirable to isolate the glycidyl ether

the intermediate monohalohydrin ether R-O-CH2-CHOH-CH2-Cl will itself in many cases react under basic conditions with the material containing glycerol units to yield an equivalent product.

The glycidyl-ether approach is not limited to the use of a C6-C20 fatty alcohol as the alcohol ROH; it is also possible to start with a lower alcohol of up to 6 carbon atoms, such as n-butanol and n-propanol, plus butylene oxide or propylene oxide, alone or in admixture with one another or with a minor proportion of ethylene oxide, and make an alkoxylated hydrophobic alcohol, usually having 3 to 20 oxyalkylene units, which is then susceptible of being converted by reaction with epichlorohydrin as described above to a corresponding glycidyl ether. In making such materials using ethylene oxide, an average ratio of oxygen to carbon of 0.4:1 or lower in the oxyalkylene units is usually employed in order to ensure that the product is hydrophobic.

The reaction of the hydrophobe compound (glycidyl ether or its precursor) with the polyglycerol is preferably carried out under basic conditions. It is essential that the hydrophobe material be used in proper proportion in relation to the polyglycerol, such that 4 to 25 percent of the hydroxyl groups of the polyglycerol are substituted by a reaction with the oxirane-containing hydrophobe. If less than 4 percent of the hydroxyl groups of the polyglycerol are substituted, a sufficiently powerful surfactant effect is not usually obtained because the composition remains too hydrophilic. On the other hand, the substitution of more than 25 percent of the hydroxyl groups of the polyglycerol is to be avoided because this makes the composition more hydrophobic than is ordinarily desirable and results in lower solubility of the product composition in water and in alkaline media.

Surfactant compositions of the invention as prepared in their anhydrous form range from viscous liquids to glassy, thermoplastic solids. For handling purposes, they are conveniently diluted with water to form solutions containing 50 to 80 weight percent of solids.

Appropriate conditions of temperature and pressure, as well as the use of proper catalysts, solvents, etc., for the reaction of polyglycerol with the oxiranecontaining hydrophobe are important to the success of this invention, as will be recognized by those skilled in the art. In general the reaction may be practiced at temperatures ranging from 100 to 2000C and at atmospheric pressure.

These surfactant materials have several possible uses. They include use as a surfactant in alkaline bottle-washing compositions, baths for the kier boiling of cotton, alkaline paper-pulp deinking compositions, electrolytic baths for the cleaning of metal parts or for the electro-deposition of metal, foam-type or other industrial alkali cleaning media, and textile-treating formulations. They may be used as a component of shampoos, cosmetics, heavy-duty detergents and other cleaning products. They may be used, moreover, as intermediates for the production of other valuable chemical products; for example, they may be sulfonated to yield anionic surfactants, or polyoxyalkylated to yield other surfactants of a desired hydrophobic-hydrophilic balance and/or molecular weight.

In many circumstances, nonionic surfactants according to the invention are incorporated, in amounts sufficient to impart substantial surface-active properties, in aqueous solutions containing 0.1 to 50 weight percent of an alkali-metal hydroxide, such as sodium hydroxide or potassium hydroxide.

Nonionic surfactant materials according to the invention in the generally preferred embodiment have the formula ZCH2CHZCH2[OH2CIIZCH2iZ where n is an integer from 2 to 29 and each Z independently is OH or R, provided that from 4 to 25 percent of them are R, R being selected from (1) monovalent radicals having the structure -OCH2-CHOH-CH2-OR1, where each R' independently is either (a) a long-chain alkyl radical containing 6 to 20 carbon atoms, or (b) a polyoxyalkylene glycol ether radical --(CH,CH R2~OR3, where each R2 independently is hydrogen, methyl or ethyl, p is an integer from 3 to 20, and each R3 independently is an alkyl radical containing 1 to 6 carbon atoms, the average oxygen/carbon atom ratio of the radical (CH2CHR2O)p being not greater than 0.4:1, and (2) divalent radicals having the structure -O-(-CH2-CH R2-O-)0-CH2-CHOH-CH2O- in which q is an integer from 6 to 40 and R2 has the above meaning, the average oxygen/carbon atom ratio of the radical (--CH,,-CHRR2-O), being not greater than 0.4:1, each monovalent radical constituting one R and each divalent radical constituting two Rs in the same or different units of the formula ZCH2CHZCH2(OCH2CHZCl12lnZ In the above formula the radicals ( I ) (b) are derived from a monoglycidyl ether of a lower alcohol and the radicals (2) from a diglycidyl ether.

The invention is illustrated by the following specific examples, in which the parts are by weight unless otherwise specified.

Example 1 A mixture of 2-hydroxy-3-chloropropyl ethers of straight-chain C,0C,2 alcohols is prepared and reacted with polyglycerol having an average of five glycerol units in a weight ratio of three parts of polyglycerol per part of the mixture of glycidyl ethers.

To a flask, there are charged 495 grams (3 mols) of a mixture of C,0 to C,2 straight-chain alcohols, 1.5 gram of boron trifluoride etherate as catalyst, and 335 grams (3.6 moles) of epichlorohydrin. The material in the flask is provided with a nitrogen blanket and heated over a period of about 2 hours at a temperature of about 56 to 600C with the alcohols and catalyst being present in the flask initially and with the epichlorohydrin being charged to the flask during the 2-hour period mentioned above. Materials in the flask are stirred during the two hours and thereafter for an additional two hours, while the material in the flask is permitted to cool to about 33"C. Sodium bicarbonate (3 grams) is charged to the flask, which is then subjected to an absolute pressure of 2 millimeters of mercury and heated over a period of one hour to approximately 1030C, and then permitted to cool. There is thus prepared a product comprising approximately 830 grams of a mixture of 2hydroxy-3-chloro-propyl ethers of C,O to C12 alcohols.

The glycidyl-ether precursor product mentioned above is reacted with polyglycerol to obtain a surfactant. To a reaction flask, there are charged 300 grams of a polyglycerol having an average of 5.4 glycerol units, and 43.4 grams of an aqueous solution containing 50 weight percent of sodium hydroxide. Water is removed from the charge by heating it to between 100 and 150"C while subjecting it to a vacuum (200 to 3 millimeters of mercury absolute pressure) over a period of about 2 hours. The reaction flask is then repressurized with nitrogen to atmospheric pressure and, with constant stirring, there are added over a period of about 30 minutes 100 grams of the mixed chlorohydrin-ether product prepared above, while maintaining a temperature on the order of 130 to 1650C.

Tests on the product were conducted as in Table 1. A one weight percent aqueous solution has a pH of 11.10 and remains substantially clear at temperatures of up to 50CC. A Draves sink time of 246 seconds is observed for a 0.1 weight percent aqueous solution, and a surface tension of 28.9 dynes per centimeter.

The Draves sink test (DS), originally described by C. Z. Draves and R. G.

Clarkson in volume 20, American DyestuffReporter, pages 201-208(1931), has been adopted as Standard Test Method 17-1952, reported in the Technical Manual of the American Association of Textile Chemists and Colorists (1964).

Examples 2-9 A polyglycerol is prepared by dehydrating glycerol in the presence of sodium hydroxide as catalyst, obtaining a polyglycerol having an average number of glycerol units per molecule as indicated below in Table 1, and thereafter, the polyglycerol so produced is reacted, in the proportions indicated in Table 1, with a material providing a suitable hydrophobic moiety, to produce a surfactant material having the indicated properties. For the sake of completeness, the results of Example 1 are also included in Table 1.

TABLE 1 Results of Tests of Various Polyglycerol+ Hydrophobe Surfactant Ex. GU Hydrophobe Ratio ST DS CP S 5 5 B 3 28.9 246 50 Sol.

2 10 A 3.2 28.8 65 > 100 Sol.

3 10 A 2.3 29.7 110 > 57 Sol.

4 20 B 3 28.5 126 94 Sol.

5 17 B 2 28.1 78 63 > 10 6 17 B 3 29.5 110 98 > 10 7 17 B 3 28.8 189 100 > 10 8 17 C 2 26.3 62 30 > 10 9 17 D 2 27.3 75 51 > 10 GU=average number of glycerol units in polyglycerol A=glycidyl ether of C,0 alkanol B=glycidyl ether of mixture of C,0C,2 alkanols C=glycidyl ether of straight-chain C5 alkanol D=glycidyl ether of mixture of straight-chain C8-C10 alkanols Ratio=parts by weight of polyglycerol per part of hydrophobe ST=Surface tension, dynes per centimeter, 0.l0Xo (wt.) solution CP=cloud point, OC S=solubility in 25 wt. percent solution of NaOH Sol.=soluble, percentage not measured.

The foregoing results demonstrate that various surfactant materials having substantial solubility in alkali may be made, starting with a polyglycerol having an average of 5 to 20 glycerol units per molecule and reacting said polyglycerol with different glycidyl ethers.

Example 10 A polyglycerol having an average of 17 units of glycerol per molecule is prepared by dehydrating glycerol. A C,8 alkanol is reacted first with epichlorohydrin and then with a base, to obtain a glycidyl ether. Then three parts of said polyglycerol are reacted with one part of said glycidyl ether, to obtain a non ionic material having surfactant properties.

Example 11 A polyglycerol having an average of 20 glycerol units per molecule is prepared by dehydrating glycerol. A C,6 alkanol is reacted with propylene oxide in a mole ratio of 1:3 to produce a propoxylated C,6 alkanol, and then the propoxylated alkanol is reacted, first with epichlorohydrin and then with a base, to obtain a glycidyl ether. Two parts of the polyglycerol are reacted with one part of the glycidyl ether, to obtain a nonionic material having surfactant properties.

Example 12 Glycerol is dehydrated to obtain a polyglycerol having an average of 18 glycerol units per molecule. Decyl alcohol is reacted with ethylene oxide in a mole ratio of 1:5, to produce an ethoxylated decanol, and then the ethoxylated decanol is reacted, first with epichlorohydrin and then with a base, to obtain a corresponding glycidyl ether. Then three parts of the polyglycerol are reacted with one part of the glycidyl ether to obtain a nonionic material having surfactant properties.

Example 13 Glycerol is dehydrated to obtain a polyglycerol having an average of ten glycerol units per molecule. A C20 alkanol is reacted with propylene oxide in a mole ratio of 1:5, to obtain a propoxylated C20 alkanol, and then the propoxylated C20 alkanol is reacted first with epichlorohydrin and then with a base, to obtain a glycidyl ether. Two parts of the polyglycerol are reacted with one part of the glycidyl ether, to obtain a non ionic material having surfactant properties.

Example 14 A surfactant is made by reacting a 17-unit polyglycerol with a monochlorohydrin ether of an oxypropylated n-butanol having a molecular weight of approximately 464 (n-butanol plus about 7 oxypropylene units). The product thus corresponds to the case, within the general formula indicated hereinabove, where Z=-OCH2-CHOH-CH2-O-R3, and R3 is a polyoxyalkylene glycol ether radical +(CHCHR5O)pR6, where R5 is methyl, p=7, and R6 is nbutyl, and the percentage of the Z's that are R is 5.5 percent.

To a 500-milliliter flask there are charged 200 grams of 17-unit polyglycerol, and after warming to 900C at atmospheric pressure under a blanket of nitrogen, there are added 30 grams of a 50 weight percent aqueous solution of sodium hydroxide. Then the materials in the flask are subjected to stripping conditions (temperature 110 to 1550C) and absolute pressure of 400 to 10 millimeters of mercury) for 25 minutes to remove water. The reactor is repressurized with nitrogen to atmospheric pressure, and then there are added dropwise over a period of 1 hour and 25 minutes 100 grams of a glycerol a-monochlorohydrin ether of a 7unit-oxypropylated n-butanol, the temperature being maintained during the addition at approximately 1400 C. The reaction is permitted to continue for two hours, after which the reactor is permitted to cool, yielding 309.5 grams of a tan paste product.

The product gives, in an aqueous solution containing 0.1 weight percent, a Draves sink time (3-gram hook) of 102.6 seconds and a surface tension of 29.7 dynes per centimeter. A 1 weight percent aqueous solution is milky at temperatures greater than 25"C, and has a pH of 11.45. In dynamic foam height tests, no foaming is observed, either at 490C or at 250C. The dynamic foam height test is disclosed in an article by H. E. Reich et al. in the April 1961 issue of Soap and Chemical Specialties, volumes 37, page 55.

Example 15 Example 14 is repeated, except that there is used a different monochlorohydrin ether of somewhat greater molecular weight, namely one based upon n-butanol oxypropylated to an average molecular weight of 673 (approximately 10 oxypropyl units). There is obtained a tan paste product weighing 310 grams.

The product gives, in aqueous solution containing 0.1 weight percent, a Draves sink time (3-gram hook) of 197.1 seconds and a surface tension of 30.8 dynes per centimeter. A 1 weight percent aqueous solution is milky at temperatures greater than 25"C, and has a pH of 11.68.

Example 16 Distilled n-octyl glycidyl ether is reacted with a 9.4-unit polyglycerol on a 1:1 weight ratio, yielding a nonionic surfactant.

To a four-necked flask of 500-ml. capacity there are charged 100 grams of a 9.4-unit polyglycerol and 1 gram of a 50 weight percent aqueous solution of sodium hydroxide, and the contents of the flask are then stripped for 10 minutes at 120- 1300C and 2510 mm. of mercury absolute pressure. The vacuum is then released to atmospheric pressure by the admission of nitrogen, and then, with the material in the reaction flask at about 140"C, there are gradually added over 12 minutes 100 grams of a purified glycidyl ether of n-octanol. At the conclusion of the addition of the glycidyl ether, the cloudiness of the reaction mixture suddenly disappears, leaving a clear light-amber liquid, with an accompanying rise in pot temperature up to 1700C owing to heat of reaction. The reaction is continued for one hour at 153 to 146"C under a blanket of atmospheric-pressure nitrogen, and thereafter 50 grams of distilled water are added to obtain a clear, medium-amber product in the form of an 80 weight percent solution. Further dilution yields a 0.1 weight percent solution having a Draves sink time (3-gram hook) of 38.2 seconds and a surface tension of 28.0 dynes per centimeter.

Example 17 Example 16 is repeated, except that in place of distilled n-octyl glycidyl ether, there is used a glycidyl ether based upon a mixture of C6 to C10 alkanols. Again there is obtained a medium-amber solution containing 80 weight percent of solids.

Further dilution yields a 0.1 weight percent solution having a Draves sink time (3gram hook) of 56.4 seconds and a surface tension of 29.3 dynes per centimeter. A 1 weight percent aqueous solution is milky and has a pH of 10.0.

WHAT WE CLAIM IS: 1. A nonionic surfactant material resulting from the reaction of a polyglycerol having an average of 3 to 30 glycerol units per molecule with a proportion of a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (11)

**WARNING** start of CLMS field may overlap end of DESC **. of approximately 464 (n-butanol plus about 7 oxypropylene units). The product thus corresponds to the case, within the general formula indicated hereinabove, where Z=-OCH2-CHOH-CH2-O-R3, and R3 is a polyoxyalkylene glycol ether radical +(CHCHR5O)pR6, where R5 is methyl, p=7, and R6 is nbutyl, and the percentage of the Z's that are R is 5.5 percent. To a 500-milliliter flask there are charged 200 grams of 17-unit polyglycerol, and after warming to 900C at atmospheric pressure under a blanket of nitrogen, there are added 30 grams of a 50 weight percent aqueous solution of sodium hydroxide. Then the materials in the flask are subjected to stripping conditions (temperature 110 to 1550C) and absolute pressure of 400 to 10 millimeters of mercury) for 25 minutes to remove water. The reactor is repressurized with nitrogen to atmospheric pressure, and then there are added dropwise over a period of 1 hour and 25 minutes 100 grams of a glycerol a-monochlorohydrin ether of a 7unit-oxypropylated n-butanol, the temperature being maintained during the addition at approximately 1400 C. The reaction is permitted to continue for two hours, after which the reactor is permitted to cool, yielding 309.5 grams of a tan paste product. The product gives, in an aqueous solution containing 0.1 weight percent, a Draves sink time (3-gram hook) of 102.6 seconds and a surface tension of 29.7 dynes per centimeter. A 1 weight percent aqueous solution is milky at temperatures greater than 25"C, and has a pH of 11.45. In dynamic foam height tests, no foaming is observed, either at 490C or at 250C. The dynamic foam height test is disclosed in an article by H. E. Reich et al. in the April 1961 issue of Soap and Chemical Specialties, volumes 37, page 55. Example 15 Example 14 is repeated, except that there is used a different monochlorohydrin ether of somewhat greater molecular weight, namely one based upon n-butanol oxypropylated to an average molecular weight of 673 (approximately 10 oxypropyl units). There is obtained a tan paste product weighing 310 grams. The product gives, in aqueous solution containing 0.1 weight percent, a Draves sink time (3-gram hook) of 197.1 seconds and a surface tension of 30.8 dynes per centimeter. A 1 weight percent aqueous solution is milky at temperatures greater than 25"C, and has a pH of 11.68. Example 16 Distilled n-octyl glycidyl ether is reacted with a 9.4-unit polyglycerol on a 1:1 weight ratio, yielding a nonionic surfactant. To a four-necked flask of 500-ml. capacity there are charged 100 grams of a 9.4-unit polyglycerol and 1 gram of a 50 weight percent aqueous solution of sodium hydroxide, and the contents of the flask are then stripped for 10 minutes at 120- 1300C and 2510 mm. of mercury absolute pressure. The vacuum is then released to atmospheric pressure by the admission of nitrogen, and then, with the material in the reaction flask at about 140"C, there are gradually added over 12 minutes 100 grams of a purified glycidyl ether of n-octanol. At the conclusion of the addition of the glycidyl ether, the cloudiness of the reaction mixture suddenly disappears, leaving a clear light-amber liquid, with an accompanying rise in pot temperature up to 1700C owing to heat of reaction. The reaction is continued for one hour at 153 to 146"C under a blanket of atmospheric-pressure nitrogen, and thereafter 50 grams of distilled water are added to obtain a clear, medium-amber product in the form of an 80 weight percent solution. Further dilution yields a 0.1 weight percent solution having a Draves sink time (3-gram hook) of 38.2 seconds and a surface tension of 28.0 dynes per centimeter. Example 17 Example 16 is repeated, except that in place of distilled n-octyl glycidyl ether, there is used a glycidyl ether based upon a mixture of C6 to C10 alkanols. Again there is obtained a medium-amber solution containing 80 weight percent of solids. Further dilution yields a 0.1 weight percent solution having a Draves sink time (3gram hook) of 56.4 seconds and a surface tension of 29.3 dynes per centimeter. A 1 weight percent aqueous solution is milky and has a pH of 10.0. WHAT WE CLAIM IS:

1. A nonionic surfactant material resulting from the reaction of a polyglycerol having an average of 3 to 30 glycerol units per molecule with a proportion of a

reactive oxirane-containing hydrophobe compound sufficient to substitute 4 to 25 percent of the hydroxyl groups present in the polyglycerol, the hydrophobe compound being a glycidyl ether or a precursor thereof reacting to form the same product.

2. A nonionic surfactant material according to claim 1, wherein the hydrophobe compound is a glycidyl ether of a fatty alcohol containing 6 to 20 carbon atoms.

3. A nonionic surfactant material according to claim 1, wherein the hydrophobe compound is a material of the formula

where each R2 independently is methyl or ethyl, p is an integer of from 3 to 20, and R3 is an alkyl radical containing 1 to 6 carbon atoms.

4. A nonionic surfactant material of the formula Z-CH2-CHZ-CH2-(-OCH2-CHZ-CH2)n-Z where n is an integer from 2 to 29 and each Z independently is OH or R provided that from 4 to 25 percent of them are R, R being selected from (1) monovalent radicals having the structure -OCH2-CHOH-CH2-OR1, where each R' independently is either (a) a long-chain alkyl radical containing 6 to 20 carbon atoms, or (b) a polyoxyalkylene glycol ether radical of the formula CH2-CHR2- O)pR3, where each R2 independently is hydrogen, methyl or ethyl, p is an integer of from 3 to 20, and each R3 independently is an alkyl radical containing 1 to 6 carbon atoms, the average oxygen/carbon atom ratio of the radical (CH2CHR2O)p being not greater than 0.4:1, and (2) divalent radicals having the structure -O-(-CH2-CH2-CHR-O-)qCH2-CHOH-CH2-O- in which q is an integer from 6 to 40 and R2 has the above meaning, the average oxygen/carbon atom ratio of the radical (CH2CHR2O)q being not greater than 0.4:1, each monovalent radical constituting one R and each divalent radical constituting two Rs in the same or different units of the formula Z-CH2-CHZ-CH2-[OCH2-CHZ-CH2] ,--Z

5. A nonionic surfactant material according to claim 4, wherein R2 is a polyoxyalkylene glycol ether radical of the formula WCH2-CHR2-O-)0-R3.

6. A method of making a nonionic surfactant material comprising reacting a polyglycerol having an average of 3 to 30 glyceryl units with a proportion of a reactive oxirane-containing hydrophobe compound sufficient to substitute 4 to 25 percent of the hydroxyl groups present in said polyglycerol, the hydrophobe compound being a glycidyl ether of an alkanol containing 6 to 20 carbon atoms or a material of the formula

where R2, p and R3 have the meanings given in claim 3, or a precursor of such a glycidyl ether reacting to form the same product.

7. A method of making a nonionic surfactant material substantially as described in any of the foregoing Examples 1 to 17.

8. A nonionic surfactant material when made by the method of claim 6 or 7.

9. An aqueous alkaline cleansing solution containing as surfactant a nonionic surfactant material as claimed in any of claims 1 to 5 or 8.

10. A sulfonated and/or polyoxyalkylated derivative of a nonionic surfactant material as claimed in any of claims 1 to 5 or 8.

11. A cleansing product containing a nonionic surfactant material as claimed in any of claims 1 to 5 or 8.