asfalt emulsion

Emulsion 101Alan James AkzoNobel Surface ChemistryAkzoNobel Surface Chemistry

Emulsion 101

• Residue from the vacuum distillation of crude oilC d il t i 1 60% h lt d di th

• Asphalt• The Chemistry of Emulsions• Crude oil contains 1-60% asphalt depending on the source• Not all refineries produce asphalt• 36 million ton asphalt used in USA each year• 31 million ton used in road construction rest mostly in roofing

y• The Chemistry of Emulsifiers• The Setting process • Emulsion Formulation• 31 million ton used in road construction, rest mostly in roofing• Emulsion Formulation

Surface Chemistry 2

Asphalt

• Residue from the vacuum distillation of crude oilC d il t i 1 60% h lt d di th• Crude oil contains 1-60% asphalt depending on the source

• 36 million ton asphalt used in USA each year• 31 million ton used in road construction, rest mostly in roofing• 2 3 million ton used in emulsions rest mostly in hot mix• 2-3 million ton used in emulsions, rest mostly in hot mix• 7-10 million ton emulsion worldwide

Surface Chemistry 3

Asphalt

• Supplied in grades depending on its consistency/viscosityF l i i it i d fi d b t t lik t ti• For emulsions viscosity is defined by tests like penetration

and softening point• The choice of viscosity depends on the end use.

Surface Chemistry 4

Why Use Asphalt Emulsion

Cold processes save energy

Easier handling and storageSafe and environmentally friendlyLow cost in place and on-Low cost in place and onsite techniquesEasily mixed with latex and cementand cementWater dilutableDeferred Set

Surface Chemistry

Emulsions around the Home

• Dispersion of one liquid in another (immiscible) liquid

Surface Chemistry

• One of the liquids is usually water

Emulsion Types

O/W W/O W/O/WO/W W/O W/O/Woil-in-wateremulsion

water-in-oil (inverted emulsion)

multiple emulsion

Surface Chemistry

Asphalt Emulsion

100 micron/0.1mm

Photomicrograph of An Asphalt EmulsionDroplets are 1-20 micron in diameter

Surface Chemistry

Source :BASF

Size Distribution of Asphalt Emulsion DropletsDroplets

ume

%

medianmedian ((d50d50))volu

particle size (micron)

Surface Chemistry

Components of an Asphalt Emulsion

water 30-50%

solvent 0-10%chemicals 0.2-2.5%

polymer 0-4%

asphalt 40-70%

p y %

Surface Chemistry

Production of Bitumen Emulsions

• Asphalt dispersed in a colloid mill into micronAsphalt dispersed in a colloid mill into micron droplets in water

Emulsion

Colloid Mill AsphaltSoap

Surface Chemistry 11

Inside the Colloid Mill


Schematic of Batch Emulsion Plant

emulsifieracidstabilizer

asphalt emulsion

batch soap water inlet

140C 90C

50C

tank water inlet

colloid L t

Surface Chemistry

colloid mill Latex

Bitumen tank kitEmulsion tank kit

Bitumen loading pump

D filliDrum filling

Emulsion plant

Control room

Of loading pumpand flow meter for emulsion Batch soap tank kit

and heating

Surface Chemistry 14Water-phase mixing unit

and heating

Stabilization of Asphalt Droplets

no charge- droplets can come into contact and coalesce

Cationic em lsion electrostatic rep lsion pre ents close approach

+ + +++ +

Cationic emulsion-electrostatic repulsion prevents close approach of drops

+ + +++ +Anionic emulsion-electrostatic repulsion prevents close approach

f d

- - --- -

of drops

Surface Chemistry

Breakdown of the Emulsion

Flocculation and Coalescence

Emulsion DropletsCharge on droplets prevents close

Flocculation Close approach of droplets leads to

Coalescence Water drains between droplets

Coalescence Trapped water diffuses out.

approach adhesion between droplets. Water is squeezed out

and surfactant film breaks down, Droplets fuse, trapping some water

Setting Curing

Surface Chemistry


Settlement (Sedimentation)

•Asphalt is generally denser than waterp g y•Sedimentation may lead to irreversible flocculation and/or coalescence

Surface Chemistry


Evaporation of Water

•Evaporation of water forces droplets together d t l land eventual coalescence

Surface Chemistry


Flocculation and Coalescence

•Flocculation and Coalescence in contact with Aggregate

Surface Chemistry

Classification of Emulsion by Reactivity

rapid-setting:reactive emulsion sets quickly even with unreactivereactive emulsion sets quickly even with unreactive aggregates

medium setting:medium-setting:medium reactive emulsion which can be mixed with open graded aggregates with low fines content

slow-setting:low reactive emulsion which can be mixed with reactive aggregates with high fines contentaggregates with high fines content


Naming of Emulsions

rapid-settingcationic

CRS - 2 High viscosity (65% asphalt)

cationic slow-setting

CSS - 1h hard asphalt

Low viscosity

HFMS - 2s

high-float

with solvent

Low viscosity (57% asphalt)

medium-setting (anionic)


Emulsions are classified according to Reactivity and Particle Charge

+ve -ve

Reactivity and Particle Charge

rapid-setting CRS RSmedium setting CMS MS

chip-sealopen graded mixmedium-setting

slow-settingCMS MS

CSS SS

open-graded mix

dense-graded mix

The principle is to match the reactivity of the emulsion with the reactivity of the aggregateaggregateRapid set emulsions are used with unreactive, low surface area aggregates Slow –set emulsions are used with reactive high surface area aggregates

Surface Chemistry

Functions of the Emulsifier

determines type of Emulsion formed. i.e. O/W or W/Oreduces energy needed to emulsify asphaltdetermines charge on emulsion dropletsstabilizes emulsion droplets as they are formed in thestabilizes emulsion droplets as they are formed in thecolloid millstabilizes the droplets during storage of the emulsionprovides the right setting behaviorprovides the right setting behaviorinfluences the physical properties of the emulsioninfluences properties of cured road material.

Surface Chemistry

Typical Emulsifier Structures

counterionLipophilic/hydrophobic tail hydrophilic head group

R(tallow) --------------------------------- NH2+CH2CH2CH2NH3+

R(nonylphenyl) O CH CH OCH CH O H

R(tallow) --------------------------------- N+(CH3)3 Cl-

2Cl-

R(nonylphenyl) ------------------------ O----CH2CH2OCH2CH2O---H

R(tall oil)---------------------------------- COO-

R(li i ) SO

none

Na+

NaR(lignin)----------------------------------- SO3- Na+

R= hydrocarbon or mostly hydrocarbon with 12-22 carbonsN= nitrogen C=carbon H= hydrogen O= oxygen

Surface Chemistry

N= nitrogen, C=carbon, H= hydrogen, O= oxygenS= sulfur, Cl= chlorine, Na = sodium

Cationic emulsions tend to be acidic, anionic emulsions alkalineanionic emulsions alkaline

RNH2+CH2CH2CH2NH3+ 2Cl-RNHCH2CH2CH2NH2 + 2HCl =

insoluble neutral form + acid = soluble cationic 'soap'

RCOO Na+RCOOH + NaOH = RCOO- Na+RCOOH + NaOH =

insoluble neutral form + alkali = soluble anionic 'soap'

R= hydrocarbon or mostly hydrocarbon with 12-22 carbonsN= nitrogen, C=carbon, H= hydrogen, O= oxygenS= sulfur, Cl= chlorine, Na = sodium

Surface Chemistry

Some charged emulsifiers do not need pH adjustmentpH adjustment

RN(CH3)3+ Cl -

soluble quaternary amine

RSO3- Na+

soluble olefin sulphonate

R= hydrocarbon or mostly hydrocarbon with 12-22 carbonsN= nitrogen, C=carbon, H= hydrogen, O= oxygenS= sulfur, Cl= chlorine, Na = sodium

Surface Chemistry

Cationic emulsifier

H d b Ch i (Oil L i )

Head Group (Water Loving)

Hydrocarbon Chain (Oil Loving)

HC N+

C l-

Counterion (Water Loving)


(Water Loving)

What is Interfacial Tension?

Water molecules like to bond to Attraction Forces in Watereach other

In bulk water molecules have lots of close friends and are

Attraction Forces in Water are stronger than most other liquids -

OilOilhappy.

At the oil/water interface the water molecules have only weak ybonds and are not quite so happy

This creates tension

Tension = Energy

So surface tension is higher

WaterWater


higher

Surface Activity

OilOil Surfactants (Emulsifiers) separate oil and waterp

Surfactant Head group can bond with water

Water can make new friends!Water can make new friends!

This reduces tension and makes it easier to make new interface

WaterWater


Emulsifier Molecules concentrate at the oil-water interfacethe oil-water interface

“Tails” in the Oil and “Heads” in the Water

oil

water

Surface Chemistry

water

Emulsifiers in EmulsionManufacture

Emulsion

Manufacture

Colloid Mill BitumenWater-phase

Emulsification produces interface. 500 sq meters/liter. Emulsifier reduces the interfacial energy and also


Emulsifier reduces the interfacial energy and also provides charge

More Emulsifier Gives Smaller Particles.

4 5

4

4.5

e m

icro

n

3.5

rticl

e si

ze large head group

3

edia

n pa

r

0.2 0.3 0.4 0.52.5

me

small head group

Surface Chemistry

Emulsifier level %

Emulsifier Molecules are very small!

If an asphalt droplet were the size of the world, then the emulsifier head group would occupy an area of 4 square

il d th t il ld t t 5 il dmiles and the tail would penetrate 5 miles deep

emulsifier length 3/1 000 000 mm

asphalt droplet

3/1 000 000 mm

Surface Chemistry

diameter 3/1000 mm

Emulsifier generates charged Asphalt DropletsDroplets

Counterions diffuse into the water phase leaving the

Surface Chemistry

asphalt surface with a net positive charge

Headgroup Charge and pH

Headgroups Acid Neutral Alkaline

Sulphonate SO3-

Ethoxylate (C2H4O)xH

---

ooo

A i NH2/NH3+

Carboxylate COOH/COO- - -

+

o

o+Amine NH2/NH3+

Quaternary Amine N(CH3)3+ +

+ o

+ +

+

Mineral

Asphalt +

o+

o -

-


o

Manufacture of Emulsifiers

Animal fatVegetable oils

Splitting Nitrilation Fatty aminesg

water hydrogen

th l hl id

ammonia

QuaternizationFatty aminesQuaternaryammoniumsalts

methylchloride

AlkoxylationNonyl phenoland Alcohols

Alkoxylates

Ethylene or propylene oxide

Olefins alkylbenzenes alkylnaphthalenes

Sulfonation Sulfonates

Sulfuric acid, sulfur trioxide


Manufacture of Emulsifiers

Tall Oil

Tall Oil

CondensationImidazolinesand amidoamines

polyaminesp y

Lignin

Lignin

Addition Ligninamines

amine


Factors Affecting Breaking and Curing

Aggregate Reactivityf f h f h i tsurface area, surface charge, surface chemistry

filler chemistry e.g. cement, lime

Emulsion ReactivityEmulsion Reactivityemulsifier chemistry, concentrationother additives

Temperature, Humidity, Wind Speed

asphalt viscosity

Mechanical Treatment e.g.compaction

Surface Chemistry

Setting Mechanisms Cationic Emulsions

pH changes due to chemistry of aggregate or filler

Heteroflocculation between emulsion droplets and oppositely charged mineral filler and aggregate

Adsorption of ‘free’ surfactant onto aggregate.

Absorption of water into porous substrates

Evaporation of water

Surface Chemistry

pH changes after mixing emulsion with Aggregate

pH

Aggregate

10

12 0.5% cement

6

8 no cement

2

4

00 60 120 180 240

Time after Mixing (seconds)


Time after Mixing (seconds)

Possible stages in cationic emulsion breakingbreaking

contact of emulsion contact of emulsion

with aggregatewith aggregate

adsorption of 'free' adsorption of 'free'

Emulsifier, pH risesEmulsifier, pH rises

Rise in pH Rise in pH

leads to leads to

coagulation/spreading coagulation/spreading

over surfaceover surface

contact of emulsion contact of emulsion

with aggregatewith aggregate

adsorption of 'free' adsorption of 'free'

Emulsifier, pH risesEmulsifier, pH rises

Rise in pH Rise in pH

leads to leads to

coagulation/spreading coagulation/spreading

over surfaceover surfacegg ggg g , p, p

flocculationflocculation

gg ggg g , pp

flocculationflocculation

Surface Chemistry


Surface Chemistry

Emulsifier Chemistry and Use Levels

level % typical emulsifiers

0.15-0.300.30-0.60

tallowdiaminetallowdiamine

CRSCMS

0.6-2.0 tallowtetramine, tall oil imidazolineMicro

CSS 0.8-2.5 tallowdiquaternary, ethoxylates

RSMS

0.2-1.0

0.6-1.5

tall oil acids

tall oil acids

SS 1.0-2.5 lignosulphonates, ethoxylates

Surface Chemistry

Other Emulsion Ingredients

• Polymer – modify binder properties• SBR, NR or PC Latex added via soap or asphalt• SBS, EVA polymer added via asphalt

• Solvents – modify binder propertiesN hth i l i it N 2 f l il fl il• Naphtha, mineral spirits, No2 fuel oil, flux oils

• added via asphalt, soap or to finished emulsion• Rheology Modifiers – modify emulsion properties

• Calcium or sodium chloride to reduce viscosity• Calcium or sodium chloride to reduce viscosity• water soluble polymers from cellulose, xanthan etc to increase viscosity and reduce settlement• Associative polymers like acrylates to increaseAssociative polymers like acrylates to increase viscosity

• Adhesion promoters, biocides, pigments

Surface Chemistry

Typical Emulsifiers

Tallowdiamine hydrochloridesEfficientSubstantivepH sensitiveCRS and CMS

R NH NH2 2HCl

Tallowdiquaternary dichloride

R N+

N+

C H3 C H

3

C H

Cl2

Tallowdiquaternary dichlorideEfficientSubstantiveLess pH sensitive

C H3

C H3

C H3

Less pH sensitiveCSS

Surface Chemistry

R = C16/18

Typical Cationic Emulsion Recipes

Asphalt 150pen 67Soft asphalt for

chipseal applicationCationic latex 2.5Tallowdiamine 0.2Hydrochloric acid 0.1C l i hl id 0 1

CRS-2P

Calcium chloride 0.1Soap pH 2Water to 100

Asphalt 62Tallowdiquaternaryamine a 1.2

CSS-1

Soap pH 6Water to 100

Surface Chemistry


Asphalt 150pen 67Polymer modifier

Cationic typeCationic latex 2.5Tallowdiamine 0.2Hydrochloric acid 0.1C l i hl id 0 1

CRS-2P



CSS-1


Surface Chemistry


Asphalt 150pen 67Low concentration cationic emulsifier

Cationic latex 2.5Tallowdiamine 0.2Hydrochloric acid 0.1C l i hl id 0 1

CRS-2P



CSS-1


Surface Chemistry


Asphalt 150pen 67Acid needed to activate

emulsifierCationic latex 2.5Tallowdiamine 0.2Hydrochloric acid 0.1C l i hl id 0 1

CRS-2P



CSS-1


Surface Chemistry


Asphalt 150pen 67To control viscosityCationic latex 2.5

Tallowdiamine 0.2Hydrochloric acid 0.1C l i hl id 0 1

CRS-2P

To control viscosity



CSS-1


Surface Chemistry


Asphalt 150pen 67Cationic latex 2.5Tallowdiamine 0.2Hydrochloric acid 0.1C l i hl id 0 1

CRS-2P

Calcium chloride 0.1Soap pH 2Water to 100 High Dosage


CSS-1


Surface Chemistry


Asphalt 150pen 67Cationic latex 2.5Tallowdiamine 0.2Hydrochloric acid 0.1C l i hl id 0 1

CRS-2P


N id d dAsphalt 62Tallowdiquaternaryamine a 1.2

CSS-1

No acid needed


Surface Chemistry

Typical Anionic Emulsion Recipes

Asphalt PG64-22 65For “H” grade

Anionic latex 2Tall Oil 1.2Potassium hydroxide 0.4

hth 7

HFMS-2H

naphtha 7Soap pH 11.5Water to 100

Asphalt 62Lignin based product 2.0Soap pH 10.5

SS-1p p

Water to 100

Surface Chemistry


Asphalt PG64-22 65Anionic latex grade

Anionic latex 2Tall Oil 1.2Potassium hydroxide 0.4

hth 7

HFMS-2HP



SS-1p p

Water to 100

Surface Chemistry


Asphalt PG 64-22 65 High dosage for High Float propertiesAnionic latex 2

Tall Oil 1.2sodium hydroxide 0.4

hth 7

HFMS-2HP

Float properties



SS-1p p

Water to 100

Surface Chemistry


Asphalt PG 64-22 65 To activate emulsifierAnionic latex 2Tall Oil 1.2Sodium hydroxide 0.4

hth 7

HFMS-2HP

To activate emulsifier



SS-1p p

Water to 100

Surface Chemistry


Asphalt PG64-22 65To provide workability in the mix application

Anionic latex 2Tall Oil 1.2sodium hydroxide 0.4

hth 7

HFMS-2H

pp



SS-1p p

Water to 100

Surface Chemistry

Testing and Specification of Emulsions

• Composition•Water asphalt solvent polymer•Water, asphalt, solvent, polymer

• Handling and Storage• viscosity, storage stability (settlement), sieve

• ReactivityReactivity• demulsibility, cement mix test, hand mix tests

• Residue properties• penetration, softening point, float, ductility, torsional p , g p , , y,recovery, elastic recovery, PG grading(?)

•Performance tests• adhesion, mix designs, application specific tests

Surface Chemistry

Alan JamesAkzoNobel Surface Chemistry LLCCroton River CenterCroton River Center281 Fields LaneBrewster NY 10509Desk: 845 276 8298Cell: 914 525 5307Cell: 914 525 5307E-mail [email protected]

Surface Chemistry

asfalt emulsion

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