SURFACTANTS

INTRODUCTION

Are surfactants of natural or synthetic

origin ?

• They can be either.

• Surfactants from natural origin (vegetable or animal) are known as oleo-chemicals and are derived from sources such as palm oil or tallow.

• Surfactants from synthetic origin are known as petro-chemicals and are derived from petroleum.

What does surfactant do ?

Water & Oil are mortal enemies

Surfactants acts as clamp

binding Water & Oil are together

Surface Tension –

Force between

two liquids

How does surfactant work?

Cleaning/DetergencyHow does cleaning take place ?

Real Soil Composition

Required Effects when Cleaning

How Surfactants Work

Surfactant : Definition

Substance which reduces surface/interfacial tension between two phases

Compounds having tendency to gather around the interface between two different materials by altering the properties of interface remarkably

Serves as good mediator to settle dispute between two phases which are not friends

Surfactants reduce the surface tension of water by adsorbing at the liquid-gas interface.

They also reduce the interfacial tension between oil and water by adsorbing at the liquid-liquid interface.

• Surfactants are molecules that preferentially adsorb at an interface, i.e.

• Solid/liquid (froth flotation)• Liquid/gas (foams)• Liquid/liquid (emulsions)

• Water: surface tension = 72 dynes/cm• Water + 1.0% Surfactant: Surface tension = 20 –

40 dynes/cm

• Significantly alter interfacial free energy (work needed to create or expand interface/unit area).

• Surface free energy of interface minimized by reducing interfacial area.

TYPES

INTRODUCTION

• Anionic (-ve)• Cationic (+ve)• Zwitterionic

(Charge depends on pH)• Nonionic (No charge)

N+

Br-

SO-Na+

O

OSodium dodecylsulfate (SDS)

Cetylpyridinium bromide

O

OP

O

OO

OCH2CH2N(CH3)3+

O-

Dipalmitoylphosphatidylcholine (lecithin)

O O O O OH

Polyoxyethylene(4) lauryl ether (Brij 30)

Anionic Surfactants

Carboxylates

Alkyl benzene Sulphonates

Soaps

LABS

FAS

Sulfosuccinate

Diester

Sulfosuccinate

Monoester

Uses : Anionic Surfactants

• Cleansing Formulation– Shampoo– Hand wash– Bath gels– Tooth Paste– Soaps & Detergents

Cationic Surfactants

Important Property Substantivity

Cationic Surfactants

Amphoteric Surfactants

N+

CH3

CH3

CH2COO-

CONH(CH2)3 N+

CH3

CH3

CH2COO-

Cocobetaine (CB)

Cocoamidopropylbetaine ( CAPB)

Uses : Amphoteric Surfactants

• Betaines are used in personal care products e.g. hair shampoos, liquid soaps, and cleansing lotions.

• All-purpose cleaning agents, hand dishwashing agents, and special textile detergents..

Nonionic Surfactants

Nonionic Surfactants

Water Solubility of NonionicsReason

Cloud Point

Effect of moles of EO on Cloud Points of Nonionic

Influence of Cloud Point on Soil Removal

HLB –Hydrophilic Lipophilic Balance

HLB is a means of expressing the hydrophilic property of surfactants in figures

HLB ValueSignificance

HLB Value 1 2 3 4 5 6 7 8 9 1011 12

13

14 15 16 17

18

Use

Water in oil emulsifier

Oil in water Emulsifiers

 

Wetting AgentsDetergent

s

 

 

Solubilizer

HLB According to Griffin (only for PEG types)

substantive to skin and hair

HLB = 20 ( 1 – SV / AV ) Where S V = Sap value of ester of polyhydric alcohol AV = Acid value of fatty acid used

Calculation of HLB value of PEG-7-glyceryl-cocoate

AV of cocofatty acid = 265 mg KOH/g SV of PEG-7-glyceryl-cocoate = 95

HLB = 20 ( 1 – 95 / 265 ) = 12.8

HLB According to Griffin (only for polyhydric alcohol types)

HLB = 7 + m * Hh + n * Hl where

• m - number of hydrophilic groups in the molecule• Hh - Value of the hydrophilic groups• n - Number of lipophilic groups in the molecule• Hl - Value of the lipophilic groups

• Ex : Calculation of HLB of SLES

• Formula of SLES : CH3(CH2)11O (CH2CH2O)2SO3Na

• HLB = 7 + (1 x 1.3 + 2 x 0.33 + 38.7)+(12 x - 0.475)• = 42

HLB According to Davis

Nonionic SurfactantsProperties

MOST COMMONLY USED ANIONICS

1. Alcohol Sulfates.

2. Ethoxylated Alcohol Sulfates.

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 fatty alcohol (C8-C18) with sulfur trioxide.

• The alcohol sulfuric acid is neutralized with sodium or ammonium hydroxide, or an amine.

CHARACTERISTICS OF ALCOHOL SULFATES

1. C12 (Lauryl) provides the highest foam.2. Hydrolyzes at pH < 4.5.3. Can be readily thickened when combined with

alkanolamides, betaines, amine oxides etc.4. Thickening can be greatly enhanced by the addition of

electrolytes 5. (NaCl, KCl etc.).6. Light color.7. Bland odor.

• Shampoos• Body Wash• Liquid Hand

Soap• Bath Products• Facial Cleansers• Syndet Bars

MAJOR APPLICATIONS

ETHOXYLATED ALCOHOL SULFATES

• History: Commercial usage began in the early 1950’s.

• Made by the sulfation of an ethoxylated fatty alcohol.

• Typically, the alcohol is lauryl (C12) and ethylene oxide is in the range of 2-3 moles.

• The salts are typically sodium or ammonium.

Lipophilic Hydrophilic

SODIUM LAURETH SUFATE

• More soluble than alcohol sulfates.

• Hydrolyze at pH < 4.5.• Enhance foam stability of LAS

(Linear Alkylbenzene Sulfonates).• More mild than alcohol sulfates.

Mildness is significantly improved when blended with a sulfosuccinate.

PROPERTIES OF ETHER SULFATES

EFFECT OF BLENDS ON IRRITATION15% ACTIVE

MEANSCORE

6.0

4.0

2.0

0

0 25 50 75 100

SLES

AOS

SLS

PERCENT DISODIUM OLEAMIDO MEA SULFOSUCCINATE

LINEAR ALKYLBENZENE SULFONATE (LAS)

• Prepared by the sulfonation of alkyl (typically C12) benzene with sulfur trioxide.

• Salts are typically sodium, ammonium or amines.

Lipophilic Hydrophilic

SODIUM DODECYLBENZENE SUFONATE

APPLICATIONS OF LAS

• Primary surfactant used in household and industrial products: liquid dish wash, car wash, laundry, etc.

• Rarely used in personal care.

• Stable in acidic products.

Sulfates Hydrolyze More Readily Than Sulfonates Due to the Weaker R-O-S Bond

Sulfonate:

Sulfate:

ALPHA OLEFIN SULFONATES

• Made by the sulfonation of C14-16 alpha olefin.

• Product is actually a mixture of Na 2,3 alkenylsulfonate and Na 3-hydroxy-alkanesulfonate.

ALPHA OLEFIN SULFONATES

Sodium 2,3 alkenylsulfonate

Sodium 3-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.• Sulfate 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(GOOD FOAMER, MILD)

DIESTER(POOR FOAMER, LOW SOLUBILITY)

MONOESTERS ARE FROM TWO SOURCES

• MONOALKANOL AMIDES

• FATTY ALCOHOLS, OR ETHOXYLATED ALCOHOLS

GENERAL DIFFERENCES BETWEEN SULFOSUCCINATE TYPES

AMIDE• Mild to skin and eyes.• Thicken and condition.

FATTY ALCOHOL• Mild to skin.• Foams better.• Water white color.

PROPERTIES

• Will hydrolyze in acid or alkaline conditions.

• Should be formulated in a pH range of 5.0-7.0.

• Are mild to skin and eyes.• The most cost/effective

mild surfactants available.

EFFECT OF BLENDS ON SKIN IRRITATION

SLES/DSLSS**SLES: Sodium Laureth Sulfate

DSLSS: Disodium Laureth Sulfosuccinate

5.0

4.0

3.0

2.0

1.0

0

4.74.0

1.50.9 0.9

100/0 75/25 50/50 25/75 0/100

EFFECT OF BLENDS ON FOAM

350420450

FOAM HT. (ml.)

500

400

300

200

100

0100/0 25/75 0/100

SLES/DSLSS**SLES: Sodium Laureth Sulfate

DSLSS: Disodium Laureth Sulfosuccinate

AMPHOTERICS/BETAINES

AMPHOTERICS ARE DERIVITIVES OF FATTY IMIDAZONES

AMPHOTERICS

Zwitter Ion (Isolectric Form)

Cationic (Acid Form) Anionic (Alkaline Form)

PROPERTIES OF AMPHOTERICSFOR 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 fatty moiety.

• A C8 will be a low foamer, whereas, a C12 is a high foamer.

EXAMPLES OF CAUSTIC SOLUBILITY

CompoundCoco Dipropionate Caprylic (C8) Dipropionate Caprylic (C8) Propionate Caprylic (C8) Diacetate Coco Propionate Octyl Betaine Sodium Xylene Sulfonate

%NaOH41383028252322

COMPARATIVE FOAM HEIGHTS

Foam Ht. 210155145503010

Compound Cocamidopropyl BetaineCoco PropionateCoco DipropionateOctyl (C8) Betaine Capryl (C8) amidopropyl Betaine Caprylic (C8) Diacetate

PROPERTIES OF AMPHOTERICS FOR PERSONAL CLEANSING

• Stable over a wide pH range.

• Mild to skin and eye.

• Reduce irritation of ether sulfates.

EFFECT OF BETAINE AMPHOTERIC WITH SODIUM LAURETH SULFATE ON EYE IRRITATION

DRAIZESCORE

40

30

20

10

0

1000

7525

5050

2575

0100

SLES

AMPHO/BETAINE

COCAMIDOPROPYLBETAINE

DISODIUMCOCOAMPHODIACETATE

BETAINES

TWO TYPES

1. Alkyl2. Alkylamido

REASONS FOR BETAINE GROWTH

1. Formulators Became Familiar With the Advantages.

2. Recently Used In Household and Institutional Cleaners.

3. Favored Replacement for Diethanolamides

BETAINES

Cationic (Acid Form)

Zwitter Ion (Isoelectric Form)

BETAINES ARE BETTER VISCOSITY BUIDERS THAN

AMPHOTERICS

MODEL FORMULA

Sodium Lauryl SulfateAmphoteric or BetaineWater

pH=7.0

Wt.% 8.0 2.090.0

COCAMIDOPROPYL BETAINE

COMPARATIVE VISCOSITY BUILDING

DISODIUMCOCOAMPHODIACETATE

CPS(0000)

6.0

5.0

4.0

3.0

2.0

1.0

2.0 3.0 4.0 5.0 6.0

PERCENT NaCl

AMPHOTERICS ARE MORE MILD THAN BETAINES

EFFECT OF FREE AMINE ON EYE IRRITATION:BETAINE VS. AMPHOTERICDRAIZE

SCORE

40

30

20

10

0

1.0 2.0 3.0 4.0 5.0

PERCENT FREE AMINE

COCAMIDOPROPYLBETAINE

DISODIUMCOCOAMPHODIACETATE

50 ACTIVES: 15.0%

pH: 7.0

EFFECT OF BLENDING BETAINE WITH AMPHOTERIC ON EYE IRRITATION:

DRAIZESCORE

40

30

20

10

0

1000

2575

0100

PERCENT

COCAMIDOPROPYL BETAINE

DISODIUM COCOAMPHODIACETATE

ACTIVES: 15.0%

pH: 7.0

7525

5050

GENERAL DIFFERENCES

Mild to Skin

Mild to Eyes

Foam Boosting

Viscosity Building

Betaines Amphoterics

CATIONIC SURFACTANTS

Definition: The cation is the lipophilic portion of the molecule.

Types:• Quaternary Ammonium Compounds • Amine Salts

CATIONICS

Amine Salt:

LipophilicHydrophilic

Quaternary:

LipophilicHydrophilic

PROPERTIES OF QUATERNARY AMMONIUM COMPOUNDS

• Lower molecular weight are typically used as biocides.

• Higher molecular weight (C18) are excellent hair conditioners.

• Most are incompatible with anionic surfactants.

• Low foaming.• Extremely sensitive to hard water

and usually require a chelant.

MAJOR USES OF “QUATS”

• Biocides.• Fabric Softeners.• Hair Conditioners.• Antistatic Agents.• “Cheater” Wax.• Corrosion Inhibitors.• Leather Softening.• Pigment Dispersants.• Sewage Flocculants.

BIOCIDES

The most commonly used for household and industrial applications:

Lauryl Dimethyl Benzyl Ammonium Chloride

BIOCIDAL “QUATS”

MODE OF ACTION1. Reduce surface tension at

interface.2. Attracted to negatively charged

surfaces, including microorganisms.

3. Denature protein of bacterial or fungi cells.

4. Affect the metabolic reactions of the cell.

5. Vital substances leak out.6. Causes death.

FABRIC SOFTENERS

Most widely used

• Distearyl dimethyl ammonium chloride.

• Dialkyl imidazolinium methyl methoslfate.

MOST WIDELY USED “QUATS” USED IN HAIR CONDITIONERS

• Cetrimonium Chloride

• Stearalkonium Chloride

• Distearyldimonium Chloride

FATTY AMINE SALTS

• Compatible with anionic surfactants.

• Do not depress foam.• Excellent thickeners.• Insoluble in alkaline media.• Some are very mild to skin

and eyes.

MOST COMMONLY USED

• Alkyamidopropyl Dimethylamine

• Alkyamidopropyl Morpholine

COMPARATIVE EYE IRRITATION

Isostearamidopropyl Morpholine Lactate

Distearyldimethylammonium Chloride

Stearalkonium Chloride

Cetrimonium Chloride

4

4058

75

0

20

40

60

80

100

NONIONICS

• Alkanol Amides.

• Amine Oxides.

• Ethoxylated Nonyl Phenol or Alcohols.

PREPARATION OF ALKANOL AMIDES

Made by the reaction of a mono or diethanol amine with a fatty acid, methylester or fatty glyceride, (e.g., coconut oil).

REACTION(DEA Amide)

Diethanolamine + Fatty Acid Fatty Diethanolamide + Water

ALKANOL AMIDES

• Most cost/effective thickener and foam stablizer available.

• History: Commercially available in the mid 1940’s.

• Diethanolamides are being phased out of formulas due to reported “cancer link”.

• They are being replaced by: Betaines, Amine Oxides, Monoethanolamides and Monoisopropanolamides.

MONOETHANOL AND MONOISOPROPANOL AMIDES

• Both are solid at room temperature.• Both are used as replacements for

diethanol amides.• For clear products the level should be low,

or the product can haze due to the low solubility of the amides.

• The monoethanol amides have trace amounts of DEA which is not accepted by some customers. The MIPA is a better choice since DEA does not exist in MIPA.

AMINE OXIDES

• Prepared by the oxidation of a fatty tertiary amine with hydrogen peroxide.

• They are weakly cationic on the acid side.• The alkyl amine oxides are stable in the

presence of sodium hypochlorite and are excellent surfactants for bleach cleaners.

• Not widely used in personal care.

REACTION(Amine Oxide)

Fatty Tertiary +Amine

HydrogenPeroxide

Fatty Amine +Oxide

Water

ETHOXYLATED ALCOHOLS AND NONYL PHENOLS

CHARACTERISTICS

• Fatty end of molecule is lipophilic and ethoxylatated end is hydrophilic.

• Excellent detergent and wetting properties.

• Poor foamers.

• Can not be thickened with other surfactants.

MANUFACTURED BY:

• Ethoxylation of a natural derived straight chain fatty alcohol.

• Ethoxylation of synthetic branched chain alcohol.

• Ethoxylation of nonyl phenol.

REACTION(Ethoxylated Alcohol)

Ethoxylated AlcoholFatty Alcohol

Ethylene Oxide

+

REGULATORY STATUS OF ETHOXYLATED NONYL PHENOLS

• Banned in Europe.

• Banned in some states.

• Will eventually be banned in the U.S. and Canada.

H I & I APPLICATIONS OF NONIONICS

• Commercial Dishwash.

• Home Floor Carpet Care.

• Dairy and Food.

• Hard Surface Cleaning.

OTHER INDUSTRIES

• Paints and Coatings.• Agrochemicals.• Electroplating.• Textiles.• Pulp and Paper.• Oil Field.• Metal Working.

SOME NEW GUYS ON THE BLOCK “NATURAL SURFACTANTS”

• Decylglucoside: Derived from sugar and coconut oil.

• Cocoyl Glutamate: Derived from glutamic acid (amino acid) and coconut oil.

• Cocosulfate: Derived from coconut oil.

CURRENT TRENDS AND LIMITATIONS

• Natural.• Certified Organic.• Animal friendly.• DEA Free.• Formaldehyde Free.• Nitrosamine Free.• Sulfate Free.• Low Dioxane.

THAT’S IT “IN A NUTSHELL”