Transcript
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
Surface Chemistry 12
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
Breakdown of the Emulsion
Settlement (Sedimentation)
•Asphalt is generally denser than waterp g y•Sedimentation may lead to irreversible flocculation and/or coalescence
Surface Chemistry
Breakdown of the Emulsion
Evaporation of Water
•Evaporation of water forces droplets together d t l land eventual coalescence
Surface Chemistry
Breakdown of the Emulsion
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
Surface Chemistry 20
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)
Surface Chemistry 21
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)
Surface Chemistry 27
(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
Surface Chemistry 28
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
Surface Chemistry 29
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
Surface Chemistry 31
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 -
-
Surface Chemistry 35
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
Surface Chemistry 36
Manufacture of Emulsifiers
Tall Oil
Tall Oil
CondensationImidazolinesand amidoamines
polyaminesp y
Lignin
Lignin
Addition Ligninamines
amine
Surface Chemistry 37
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)
Surface Chemistry 40
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
Breakdown of the Emulsion
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
Typical Cationic Emulsion Recipes
Asphalt 150pen 67Polymer modifier
Cationic typeCationic 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
Typical Cationic Emulsion Recipes
Asphalt 150pen 67Low concentration cationic emulsifier
Cationic 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
Typical Cationic Emulsion Recipes
Asphalt 150pen 67Acid needed to activate
emulsifierCationic 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
Typical Cationic Emulsion Recipes
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
Calcium chloride 0.1Soap pH 2Water to 100
Asphalt 62Tallowdiquaternaryamine a 1.2
CSS-1
Soap pH 6Water to 100
Surface Chemistry
Typical Cationic Emulsion Recipes
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
Asphalt 62Tallowdiquaternaryamine a 1.2
CSS-1
Soap pH 6Water to 100
Surface Chemistry
Typical Cationic Emulsion Recipes
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
N id d dAsphalt 62Tallowdiquaternaryamine a 1.2
CSS-1
No acid needed
Soap pH 6Water to 100
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
Typical Anionic Emulsion Recipes
Asphalt PG64-22 65Anionic latex grade
Anionic latex 2Tall Oil 1.2Potassium hydroxide 0.4
hth 7
HFMS-2HP
naphtha 7Soap pH 11.5Water to 100
Asphalt 62Lignin based product 2.0Soap pH 10.5
SS-1p p
Water to 100
Surface Chemistry
Typical Anionic Emulsion Recipes
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
naphtha 7Soap pH 11.5Water to 100
Asphalt 62Lignin based product 2.0Soap pH 10.5
SS-1p p
Water to 100
Surface Chemistry
Typical Anionic Emulsion Recipes
Asphalt PG 64-22 65 To activate emulsifierAnionic latex 2Tall Oil 1.2Sodium hydroxide 0.4
hth 7
HFMS-2HP
To activate emulsifier
naphtha 7Soap pH 11.5Water to 100
Asphalt 62Lignin based product 2.0Soap pH 10.5
SS-1p p
Water to 100
Surface Chemistry
Typical Anionic Emulsion Recipes
Asphalt PG64-22 65To provide workability in the mix application
Anionic latex 2Tall Oil 1.2sodium hydroxide 0.4
hth 7
HFMS-2H
pp
naphtha 7Soap pH 11.5Water to 100
Asphalt 62Lignin based product 2.0Soap pH 10.5
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 alan.james@akzonobel.com
Surface Chemistry
top related