Applications of Higher Alcohols in Household Surfactants - ACS

8 Applications of Higher Alcohols in Household Surfactants

Downloaded by MONASH UNIV on May 4, 2015 | http://pubs.acs.org Publication Date: June 15, 1981 | doi: 10.1021/bk-1981-0159.ch008

TED P. MATSON Conoco Inc., Chemicals Research Division, P.O. Box 1267, Ponca City, OK 74601

The major d e r i v a t i v e s o f normal primary higher a l c o h o l s used i n the detergent i n d u s t r y i n c l u d e : 1. 2. 3. 4.

Alcohol ethoxylates (nonionics). A l c o h o l ether s u l f a t e s . Alkyl sulfates. M i s c e l l a n e o u s — I n c l u d i n g two other comparatively minor p r o d u c t s — a m i n e oxides and a l k y l g l y c e r y l ether s u l f o n a t e s .

S m i t h Q ) gives an e x c e l l e n t review o f commercial s u r f a c tants and others have reviewed the f o r m u l a t i o n o f household products(20. Chemistry Nonionics. The a l c o h o l nonionics are processed according to the f o l l o w i n g : 0

/\

ROH + n CH - CH • R0(CH -CH 0) H z z z z n The amount o f ethylene oxide w i l l g e n e r a l l y be at l e a s t 60 percent o f the t o t a l weight o f the f i n i s h e d e t h o x y l a t e to give the best p r o p e r t i e s . This would be about 7 moles on a l a u r y l ( 0 ^ ) range a l c o h o l and 9 to 10 moles o f ethylene oxide on a s t e a r y l (C^g) range a l c o h o l . These r e s u l t i n g n o n i o n i c s can be used i n heavy-duty powders, heavy-duty l i q u i d s , and hard-surface c l e a n e r s . 0

o

o

A l c o h o l Ether S u l f a t e s . The ether s u l f a t e s are prepared by the s u l f a t i o n o f a l c o h o l e t h o x y l a t e s as shown i n the steps below: 1. SO RO(CH -CH 0) H _ ^ - i ^ R O ( C H - C H 0 ) S 0 3 N a + ^ 0 2

2

3

2

r

2

2

3

0097-615 6/ 81 /0159-0101 $05.00/0 ©

1981 American Chemical Society

In Monohydric Alcohols; Wickson, E.; ACS Symposium Series; American Chemical Society: Washington, DC, 1981.

102

MONOHYDRIC

ALCOHOLS

The s t a r t i n g e t h o x y l a t e i s g e n e r a l l y the 3-mole adduct but can be as low as a 1-mole e t h o x y l a t e . S u l f a t i n g agents can be S0~, c h l o r o s u l f o n i c a c i d , or sulfamic a c i d . A v a r i e t y of n e u t r a l i z i n g agents can be u s e d — i n c l u d i n g NaOH, ammonia, triethanolamine, and MgCOH)^. The ether s u l f a t e s are used i n l i g h t - d u t y l i q u i d s , heavy-duty powders, and shampoos. A l k y l S u l f a t e s . The a l k y l s u l f a t e s or a l c o h o l s u l f a t e s are prepared very s i m i l a r l y to the ether s u l f a t e s shown above. 1. SO Downloaded by MONASH UNIV on May 4, 2015 | http://pubs.acs.org Publication Date: June 15, 1981 | doi: 10.1021/bk-1981-0159.ch008

R 0 H

and

2. NaOH '

R 0 S 0

3

N a

+

H

2°

The a l c o h o l s u l f a t e s are used i n heavy-duty powders shampoos.

M i s c e l l a n e o u s . The amine oxides used i n household products are g e n e r a l l y a l k y l dimethyl amine oxides and are prepared from a l c o h o l s as shown below: R 0 H

2. ?CH )NH ' " < 3 > 2 CH

3

CH. / RN(CH )\ + H 0 3

2

2

3

2

-I RN—0 C H

3

These a l k y l dimethyl amine oxides are used as foam s t a b i l i z e r s p r i m a r i l y i n l i g h t - d u t y l i q u i d s and shampoos where the major a c t i v e i n g r e d i e n t i s e i t h e r an a l c o h o l ether s u l f a t e or an a l c o h o l s u l f a t e . The a l k y l group i s usually C to C.. which gives the best o v e r a l l foam s t a b i l ity(3). The a l k y l g l y c e r y l ether sulfonates are prepared as follows: 1 0

1 2

1 4

CI ROH

+

CH CHCH 2

1

Linear Alcohol

CI 2

Epichlorohydrin

• R-0-CH CHCH 2

2

OH A l k y l Ether Chlorohydrin


8.

MATSON

Higher Alcohols in Household Surfactants

SO~Na

CI R-0-CH CHCH o

103

(

2

+

Na SO 2

R-0-CH CHCH 2

2

OH A l k y l Ether Chlorofeydrin

Sodium Sulfite

Alkyl Glyceryl Ether Sulfonate

These products can be found i n l i g h t - d u t y l i q u i d s and i n some shampoos and detergent bars and are p r i m a r i l y used to enhance s k i n emolliency and " c l e a n i n g a b i l i t y . "


Nonionics Heavy-Duty Powders. Nonionics f i n d use i n the major volume household product, heavy-duty powders. The words heavy duty are synonymous w i t h laundry a p p l i c a t i o n s . Products of t h i s type f o l l o w the general f o r m u l a t i o n as shown below: 10 percent n o n i o n i c . 25 to 35 percent sodium t r i p o l y p h o s p h a t e ( o r sodium carbonate). 5 t o 10 percent m e t a - s i l i c a t e . q.s. sodium s u l f a t e and other minor c o n s t i t u e n t a d d i t i v e s ( b l e a c h , perfume, a n t i r e d e p o s i t i o n agents, c o l o r , etc.). The optimum a l c o h o l and amount o f ethylene oxide i s dependent upon the type o f s o i l and the type o f foam d e s i r e d f o r for the f i n i s h e d product. Figure 1(4) shows the optimum ethylene oxide content i n a heavy-duty powder f o r m u l a t i o n s i m i l a r to that shown i n the f o r e g o i n g . L i n e s are " i s o d e t s " — l i n e s of equal detergency ranging from a lower detergency r a t i n g of 1 to a high o f 4. Figure 1 shows that the optimum detergency i s e x h i b i t e d i n the 62 percent ethylene oxide range. On an a l c o h o l of C j to C ^ , t h i s would amount to about 7 moles o f ethylene oxide. A higher a l c o h o l molecular weight could r e s u l t i n an ethylene oxide content approaching 10 moles. This detergency was that e x h i b i t e d on a combination o f three types o f standard s o i l e d c l o t h s . The optimum a l c o h o l e t h o x y l a t e on o i l y s o i l s can be d i f f e r e n t . Nonionics have the advantage o f performing e x c e p t i o n a l l y w e l l i n comparison to other types o f a c t i v e i n g r e d i e n t s w i t h o i l y s o i l s . The choice of product can 2



104

MONOHYDRIC ALCOHOLS

140 160 180 200 220 240 260 Alcohol Molecular Weight Figure

1.

Heavy-duty

detergency

alcohol, nonionic

hardness;

_j

i

Cio

C|2

i C14

(0.2% concentration;

120°F)

i C|6

i C|8

50 ppm

i C 2 0 C22

Alcohol Base Figure 2.

Heavy-duty

detergency

nonionic

isodets (0.4% concentration;

hardness; 190° F)

300 ppm


8.

MATSON



a l s o depend upon the temperature of use(_5) as w e l l as the type o f foam d e s i r e d . Figure 2 shows i s o d e t s at high temperature, high hardness, and high c o n c e n t r a t i o n g i v i n g a d i f f e r e n t optimum than at the lower c o n d i t i o n s of F i g u r e 1. Foam and d e t e r gency p r o f i l e s on d i f f e r e n t s o i l types w i t h d i f f e r e n t wash temperatures can be found i n the l i t e r a t u r e ( 4 - 1 0 ) . Heavy-Duty L i q u i d s . Heavy-duty laundry l i q u i d s have gained much importance and much i n t e r e s t i n the l i t e r a t u r e over the l a s t few years. Products i n the i n d u s t r y today include both b u i l t and n o n b u i l t heavy-duty l i q u i d s . B u i l t heavy-duty l i q u i d s are those which c o n t a i n a b u i l d e r such as tetrapotassium pyrophosphate (TKPP) or sodium c i t r a t e i n order to sequester calcium and magnesium hardness i o n s . Nonbuilt heavy-duty l i q u i d s c o n t a i n no b u i l d e r s and make up f o r that shortage by c o n s i d e r a b l y increased a c t i v e contents i n order to m a i n t a i n performance(8-14). B u i l t heavyduty l i q u i d s can have e i t h e r o f the f o l l o w i n g types o f formulations: 10% Nonionic 10-20% TKPP or c i t r a t e 5-10% Hydrotrope q.s. H O

10% Alkylbenzene s u l f o n a t e 0-15% Nonionic 10-20% TKPP or c i t r a t e 5-10% Hydrotrope q.s. H 0 2

Nonbuilt heavy-duty l i q u i d s can c o n t a i n e i t h e r a high r a t i o of nonionic to l i n e a r alkylbenzene s u l f o n a t e (LAS) or, more r e c e n t l y , a reverse type r a t i o . T y p i c a l formulat i o n s o f these types of products are given below: 30-35% Nonionic 10% LAS 5-10% S o l u b i l i z e r 45-55% H O

or

25-35% LAS 10-15% Nonionic 5-10% S o l u b i l i z e r 40-60% H 0 2

Again, the optimum nonionic o f choice f o r t h i s a p p l i c a t i o n w i l l depend upon the type o f s o i l to be removed i n the laundry process. For example, F i g u r e 3 shows the optimum nonionic f o r removing t y p i c a l sebum s o i l (body o i l ) i n a n o n b u i l t heavy duty l i q u i d . This f i g u r e shows that the optimum l i e s i n the c i r c l e between C « * C j , a l c o h o l at an ethylene oxide l e v e l of 60 to 80 percent. The peak of t h i s optimum would be i n the v i c i n i t y of a alcohol w i t h 70 percent EO. This i s c o n s i d e r a b l y higher i n EO content than the ethylene oxide optimum found f o r powdered laundry detergents. At the same time, as p r e v i o u s l y mentioned, d i f f e r e n t types o f s o i l can give d i f f e r e n t optimums. For example, anc

2



106

MONOHYDRIC ALCOHOLS

10

12

14

16

18

Alcohol Carbon Number Figure

3.

Formulation

50% nonionic q.s. water (test conditions: ppm; 0.10% sebum soil)

10

12 14 16 Alcohol Carbon Number

Figure 4.

Motor

120°F;

18

oil (300 ppm)


150

8.

MATSON



i n Figure 4, we f i n d that w i t h motor o i l s o i l , the optimum detergency(46) i s c o n s i d e r a b l y narrower and i s about a a l c o h o l w i t h 60 percent ethylene oxide. Most manufacturers are very i n t e r e s t e d i n u t i l i z i n g optimum performances to make a d v e r t i s i n g claims and, t h e r e f o r e , w i l l evaluate a large number o f s o i l s . The choice of high nonionic/alkylbenzene s u l f o n a t e r a t i o as compared to a reverse high alkylbenzene s u l f o n a t e / n o n i o n i c r a t i o again depends upon the choice o f foaming a b i l i t y and the choice o f s o i l s to be removed. The high nonionic f o r m u l a t i o n gives b e t t e r performance w i t h sebum s o i l s , whereas e x c e l l e n t performance on c e r t a i n o i l y s o i l s can be obtained through the use o f alkylbenzene s u l f o n a t e s a t the high s u l f o n a t e to nonionic r a t i o . General-Purpose Cleaners. These are products which can be used f o r a v a r i e t y o f household a p p l i c a t i o n s i n c l u d i n g spray or bucket cleaners to be used to wash w a l l s , woodwork, p o r c e l a i n , l i n o l e u m , e t c . These products g e n e r a l l y c o n t a i n much smaller amounts o f a c t i v e , as they are to be used i n a more concentrated form f o r eventual d i l u t i o n w i t h water i n a c t u a l a p p l i c a t i o n . These products can c o n t a i n 5 t o 10 percent nonionic i n the t o t a l l i q u i d and may a l s o c o n t a i n TKPP as w e l l as c e r t a i n s o l v e n t s such as ethylene g l y c o l mono n - b u t y l ether. The general choice o f products for t h i s a p p l i c a t i o n would be the standard C ^ to C ^ a l c o h o l s w i t h 60 to 70 percent ethylene oxide. However, a alcohol ethoxylate o f f e r s e x c e l l e n t grease c u t t i n g and hard surface cleaning properties. Ether S u l f a t e s Heavy-Duty Powders. Although the number o f products i n which one f i n d s a l c o h o l ether s u l f a t e s i n laundry products i s e x c e p t i o n a l l y s m a l l , the volume i s f a i r l y high due to the volume o f those s p e c i f i c products. The ether s u l f a t e which i s g e n e r a l l y used i n laundry powders i s based on a C.g t o C.^ average a l c o h o l w i t h 1 t o 3 moles o f ethylene oxide on the average. Figure 5 shows t h i s to be the h i g h e s t detergency. Due to the need f o r s p r a y - d r y i n g , these w i l l always be the sodium a l c o h o l ether s u l f a t e . The ether s u l f a t e i s normally found i n these formulations a t a 4 to 5 percent l e v e l and i s used i n c o n j u n c t i o n w i t h a l k y l benzene s u l f o n a t e and/or a l c o h o l s u l f a t e s i n the f o r m u l a t i o n . The s p e c i f i c use i n t h i s type o f product was discussed at the AOCS World Conference 02 ). Light-Duty L i q u i d s . L i g h t - d u t y l i q u i d s r e f e r to the l i q u i d products s o l d today p r i m a r i l y f o r the end a p p l i c a t i o n of dishwashing. They can a l s o be used f o r the washing


107

MONOHYDRIC ALCOHOLS


108

Figure 6.

Optimum ether sulfate for ABS/ES light-duty liquids (24/6 AES—50 ppm hardness)


LAS/


8.


MATSON

of f i n e f a b r i c s . L i g h t - d u t y l i q u i d s g e n e r a l l y f a l l i n t o two major c a t e g o r i e s . One o f these i n c l u d e s the a l c o h o l ether s u l f a t e as the t o t a l major a c t i v e i n g r e d i e n t . I n the other type o f f o r m u l a t i o n , one f i n d s alkylbenzene s u l f o nate (LAS) and ether s u l f a t e . LAS and ether s u l f a t e s work i n c o n j u n c t i o n w i t h one another to develop a s y n e r g i s t i c e f f e c t upon foam s t a b i l i t y and, as a r e s u l t , are widely found i n the commercial l i q u i d formulations today. The t y p i c a l ether s u l f a t e product used i n e i t h e r o f these types of l i q u i d s i s a l a u r y l - r a n g e a l c o h o l w i t h about a 3-mole ethylene oxide content (some products may have a mixture of a l c o h o l s u l f a t e and ether s u l f a t e , but i n general the o v e r a l l average EO content i s s t i l l i n the 2- t o 3-mole range). Figure 6 shows the optimum carbon chain length for an ether s u l f a t e and s u b s t a n t i a t e s the use today o f the to range. Going above that l e v e l , one does not have too much drop o f f i n performance, but t h i s would r e s u l t i n c o n s i d e r a b l y l e s s s o l u b i l i t y o f the t o t a l formulat i o n . Going below the optimum w i l l cause a drop i n foam s t a b i l i t y performance(15). The f o l l o w i n g t a b l e shows the e f f e c t o f ethylene oxide upon the s o l u b i l i t y o f the f o r m u l a t i o n . From these r e s u l t s , i t can be r e a d i l y understood why the 40 percent e t h o x y l a t e (3 mole) i s u s u a l l y used f o r t h i s a p p l i c a t i o n . EFFECT OF EO CONTENT ON SOLUBILITY OF LP LAS/ES LIQUIDS ES P o r t i o n o f A c t i v e

Percent EO

Cloud P o i n t (°F)

C -C

1 4

17.1

48

C -C

1 4

33.5

34

C -C

1 4

39.8

30

1 2

1 2

1 2

The optimum r a t i o o f LAS t o ether s u l f a t e f o r foam s t a b i l i t y alone i s g e n e r a l l y i n the range o f 4:1 LAS/ether s u l f a t e . This can be seen i n Figure 7 where the average number o f p l a t e s washed i s p l o t t e d against d i f f e r e n t LAS/ES ratios. Shampoos. Ether s u l f a t e s are e x t e n s i v e l y used i n shampoo formulations i n the range o f 15 t o 25 percent a c t i v e . The general product o f choice i s the l a u r y l - r a n g e a l c o h o l w i t h 1 to 3 moles o f ethylene oxide. I n shampoos, e i t h e r sodium, ammonium, or triethanolamine s a l t s o f the ether s u l f a t e can be used. The choice o f these products w i l l be p r i m a r i l y r e l a t e d to the s o l u b i l i t y and the f i n i s h e d form o f the shampoo. Triethanolamine s a l t s are c o n s i d e r a b l y more s o l u b l e and, thus, w i l l be found i n a l a r g e number


MONOHYDRIC ALCOHOLS


110

Figure 7. Foam stability—LAS/ES (0.05% concentration; 50 ppm hardness; 115°F, 46°C)

r™

i

i

0 5 10 15 20 25 30 % LAS 30 25 20 15 10 5 0 % ES

i

100

i

i

i

Alcohol .••** Sulfate y'"

80 60

-

40

-

^

—'

_

AOS

20 s

0

Figure 8.

A

i

2.0

i

i

4.0 % Active

i

i

6.0

I

8.0

Drainage time at 50 ppm hardness sodium alcohol sulfate vs. AOS


8.

MATSON


111


of l i q u i d products ( e s p e c i a l l y c l e a r l i q u i d s ) . As one moves towards a l o t i o n , cream, or even paste shampoo, products move towards the sodium s a l t . These shampoos w i l l g e n e r a l l y i n c l u d e foam s t a b i l i z e r s to f u r t h e r enhance the foam c a p a c i t y . These foam s t a b i l i z e r s are normally a l k a nolamides or amine oxides. The use of the ether s u l f a t e along with these foam s t a b i l i z e r s gives t h i c k copious foam, and t h i s foam i s the general property d e s i r e d f o r shampoos. There has been over the l a s t few years c o n s i d e r a b l e use of ether s u l f a t e s made from 1 to 1 1/2 moles of ethylene oxide on the a l c o h o l . The philosophy behind t h i s use i s that one can o b t a i n the t h i c k e r , more copious foam of an a l c o h o l s u l f a t e with l e s s e r EO on the a l c o h o l and yet s t i l l maintain c o n s i d e r a b l e s o l u b i l i t y (more l i k e the ether s u l f a t e ) . Alcohol Sulfates A major a p p l i c a t i o n f o r a l c o h o l s u l f a t e s i s i t s use i n c o n j u n c t i o n with other a c t i v e i n g r e d i e n t s i n heavy-duty laundry powders. In these products, as mentioned before under ether s u l f a t e s , one w i l l u s u a l l y f i n d LAS as w e l l as ether s u l f a t e s . Ten to f i f t e e n years ago, a c o n s i d e r a b l e amount of a l c o h o l s u l f a t e was used i n c o n j u n c t i o n with LAS. These products had a very high content o f sodium tripolyphosphate which sequestered the hardness and, as a r e s u l t , allowed the a l c o h o l s u l f a t e to do i t s e x c e p t i o n a l job of detergency(16). As phosphate contents have been l i m i t e d , the use of the a l c o h o l s u l f a t e has been reduced due to i t s s e n s i t i v i t y to harder waters. Another f a c t o r which has somewhat slowed down the use of a l c o h o l s u l f a t e s i s the gradual lowering of wash temperatures from an average of 140 F many years ago (and even b o i l i n g temperatures before that time) down to an average of 100°F or l e s s today. The a l c o h o l s u l f a t e of choice today ranges between a carbon chain average of to C j - . T h i s a l c o h o l s u l f a t e can be found i n some laundry products at 3 to 5 percent of the t o t a l f o r m u l a t i o n . Shampoos. L i k e ether s u l f a t e s , a l c o h o l s u l f a t e s used i n shampoos are g e n e r a l l y i n the range of (the l a u r y l a l c o h o l range). The a l c o h o l s u l f a t e gives an except i o n a l l y t h i c k foam and gives that foam over a wide range of s o i l c o n c e n t r a t i o n s . The a l c o h o l s u l f a t e s are the choice product over o l e f i n s u l f o n a t e s due to the e x c e p t i o n a l foama b i l i t y at the a c t u a l higher use concentrations found i n washing the h a i r at h i g h - s o i l loads (Figure 8 ) . F i g u r e 8 shows t h i s foam s t a b i l i t y advantage as a f u n c t i o n of f i l m drainage at d i f f e r e n t shampoo c o n c e n t r a t i o n s . t

o


112

MONOHYDRIC ALCOHOLS

Miscellaneous As mentioned e a r l i e r , the amine oxides are used i n dishwashing l i q u i d s and i n shampoos where the major s u r f a c tant i s e i t h e r an a l c o h o l ether s u l f a t e or an a l c o h o l s u l f a t e . A l k y l g l y c e r y l ether s u l f o n a t e s are found i n some dishwashing l i q u i d s , shampoos, and detergent bars and are p r i m a r i l y used to enhance s k i n emolliency though some claims are made f o r " c l e a n i n g a b i l i t y .


1 1

Abstract The major derivatives of normal primary higher alcohols used in the detergent industry were discussed. These included alcohol ethoxylates, alcohol ether sulfates, and alkyl sulfates. The chemical reactions for preparation of each were also given. The applications of each of these derivatives were discussed with typical formulations and optimum carbon chain lengths presented. Usage of alcohol derivatives in laundry products, dishwashing liquids, and shampoos were highlighted. Literature Cited 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.

Smith, G. D. "Solution Chemistry of Surfactants," 1, K. L. Mittal, editor. Plenum Publishing Corp., 1979. Matson, T. P. J. Am. Oil Chemists Soc., 1978, 55, 66. Matson, T. P. J. Am. Oil Chemists Soc., 1963, 40, 640. Matson, T. P. Soap Chem. Specialties, November 1963, 39, 52. Matson, T. P. Specialities, 1966, 2, 17. Schick, M. J., Editor "Nonionic Surfactants," Marcel Dekker, Inc., New York, NY, 1966. Schonfeldt, N., "Surface Active Ethylene Oxide Adducts," Pergamon Press, Oxford and London, 1969. McKenzie, D. A. J . Am. Oil Chemists Soc., 1978, 55, 93. McGuire S. E.; Matson, T. P. J. Am. Oil Chemists Soc., 1975, 52, 11. Dillan, K. W.; Goodard, E. D.; McKenzie, D. A. J . Am. Oil Chemists Soc., 1979, 56, 59. Matson, T. P.; Berretz, M. Soap Chem. Specialities, November 1979, 55, 33. Matson, T. P.; Berretz, M. Soap Chem. Specialties, December 1979, 55, 41. Matson, T. P.; Berretz, M. Soap Chem. Specialties, January 1980, 56, 36. Matson, T. P.; Berretz, M. Soap Chem. Specialties, February 1980, 56, 41. Stanberry, C. J.; Matson, T. P.; Langford, J. J. Soap Chem. Specialties, 1964, 40, 43. Matson, T.P. J . Am. Oil Chemists Soc., 1963, 40, 636.

RECEIVED

December

2 9 , 1980.


Applications of Higher Alcohols in Household Surfactants - ACS

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