SURFACTANTS

SURFACTANTS ³IN A NUT SHELL´

By Tom Schoenberg SCHOENBERG CONSULTING

SURFACTANT CLASSES ANIONICS AMPHOTERICS/BETAINES CATIONICS NONIONICS

SURFACTANT CLASSES ANIONICS AMPHOTERICS/BETAINES CATIONICS NONIONICS

ANIONICS Definition: Th The e anion portion of  of tthe molecule is li lip poph philic. ilic. Example: Examp le: Sodiu odium m Lauryl Lauryl Sulf ate: Cation: Ca tion: Sodiu odium m (hydro (hydroph philic) ilic) Anion: La Laurylsulf  urylsulf ate (li lip poph philic) ilic)

SODIUM LAURYL SUFATE

Lipophilic

Hydrophilic

MOST COMMONLY USED ANIONICS 1. Alcohol Sulf ates. 2. Ethoxylated Alcohol Sulf ates. 3. Sulfosuccinates. 4. Linear Alkylbenzene Sulfonates. 5. Alpha Olefin Sulfonates.

ALCOHOL SULFATES History: Commercial usage began in the mid 1940¶s. Made by the reaction of a f atty alcohol (C8--C18) with sulfur trioxide. (C8 The alcohol sulfuric acid is neutr alized with sodium or ammonium hydroxide, or  an amine.

CHARACTERISTICS OF ALCOHOL SULFATES 1. 2. 3.

4. 5. 6. 7.

C12 (Lauryl) provides the highest foam. Hydrolyzes at pH < 4.5. Can be readily thickened when combined with alkanolamides, betaines, amine oxides etc. Thickening can be greatly enhanced by the addition of electrolytes (NaCl, KCl etc.). Light color. Bland odor.

MAJOR APPLICATIONS Shampoos Body Wash Liquid Hand Soap Bath Products Facial Cleansers Syndet Bars

ETHOXYLATED ALCOHOL SULFATES History: Commercial usage began in the early 1950¶s. Made by the sulf ation of an ethoxylated f atty alcohol. Typically, the alcohol is lauryl (C12) and ethylene oxide is in the r ange of 2of 2-3 moles. The salts are typically sodium or  ammonium.

SODIUM LAURETH SUFATE

Lipophilic

Hydrophilic

PROPERTIES OF ETHER SULFATES More soluble than alcohol sulf ates. Hydrolyze at pH < 4.5. Enhance foam stability of LAS (Linear  Alkylbenzene Sulfonates). More mild than alcohol sulf ates. Mildness is significantly improved when blended with a sulfosuccinate.

MEAN SCORE

EFFECT OF BLENDS ON IRRITATION 15% ACTIVE

6.0

SLS 4.0

AOS

2.0

SLES 0 0

25

50

75

PERCENT DISODIUM OLEAMIDO MEA SULFOSUCCINATE

100

LINEAR ALKYLBENZENE SULFONATE (LAS) Prepared by the sulfonation of alkyl (typically C12) benzene with sulfur  trioxide. Salts are typically sodium, ammonium or amines.

SODIUM DODECYLBENZENE SUFONATE

Lipophilic

Hydrophilic

APPLICATIONS OF LAS Primary surf actant used in household and industrial products: liquid dish wash, car  wash, laundry, etc. Rarely used in personal care. Stable in acidic products.

Sulf ates Hydrolyze More Readily Than Sulfonates Due to the Weaker R--O-S Bond Weaker R Sulfonate: Sulf ate:

ALPHA OLEFIN SULFONATES Made by the sulfonation of C14of C14-16 alpha olefin. Product is actually a mixture of  Na 2,3 alkenylsulfonate and Na 33hydroxy--alkanesulfonate. hydroxy

ALPHA OLEFIN SULFONATES

Sodium 2,3 alkenylsulfonate

Sodium 33-hydroxy hydroxy--alkanesulfonate

PROPERTIES Excellent foamer. Difficult to thicken. Stable in acid. Used in both personal care and house hold cleansers. More mild than LAS.

APPLICATIONS Liquid dish wash. Acid cleaners. Car wash. Liquid hand soap. Sulf ate free cleansers.

SULFOSUCCINATES Monoesters are primarily used in personal care cleansers. Diester  (sodium dioctylsulfosuccinate) is the most cost effective wetting agent available.

TWO TYPES MONOESTER

DIESTER

(GOOD FOAMER, MILD)

(POOR FOAMER, LOW SOLUBILITY)

MONOESTERS ARE FROM TWO SOURCES

MONOALKANOL AMID AMIDES

FATTY ALCOHOLS, ALCOHOLS, OR ETHOXYLATED ETHOXYLATED ALCOHOLS

GENERAL DIFFERENCES BETWEEN SULFOSUCCINATE TYPES AMID AMI DE Mild to skin and eyes. Thicken Th icken and condition.

FATTY ALCOHOL Mild to skin. Foam ams s better. Water  Wa ter wh white ite color.

PROPERTIES Will hydrolyze in acid or  or a alk lka aline conditions. Should be for mul Should ula ated in a pH r ange of  of 5.0 5.0-7.0. 5.0Are mild to skin and eyes. The most cost The cost//effective mild surf act cta ants avail ila able.

EFFECT OF BLENDS ON SKIN IRRITATION 5.0

4.0

3.0

2.0

4.7

4.0

1.0

1.5 0.9

0.9

25/75

0/100

0 100/0

75/25

50/50

SLES/DSLSS* *SLES: Sodium Laureth Sulf ate DSLSS: Disodium Laureth Sulfosuccinate

EFFECT OF BLENDS ON FOAM 500

400 FOAM HT.

300

(ml.)

450 200

420

350

100

0 100/0

25/75

0/100

SLES/DSLSS* *SLES: Sodium Laureth Sulf ate DSLSS: Disodium Laureth Sulfosuccinate

AMPHOTERICS/BETAINES

AMPHOTERICS ARE DERIVITIVES OF FATTY IMIDAZONES

AMPHOTERICS

Zwitter Ion (Isolectric For m)

Cationic (Acid For m)

Anionic (Alkaline For m)

PROPERTIES OF AMPHOTERICS FOR HI&I APPLICATIONS Stable in alkaline and acid conditions. The propionate and dipropionate type are excellent for HI&I cleaners. Low and high foaming is dependant on the molecular weight of the f atty moiety. A C8 will be a low foamer, whereas, a C12 is a high foamer.

EXAMPLES OF CAUSTIC SOLUBILITY Compound

%NaOH

Coco Dipropionate

41

Caprylic (C8) Dipropionate

38

Caprylic (C8) Propionate

30

Caprylic (C8) Diacetate

28

Coco Propionate

25

Octyl Betaine

23

Sodium Xylene Sulfonate

22