self-healing coatings for improved corrosion resistance ... · self-healing coatings for improved...
TRANSCRIPT
Subramanyam ‘Kasi’ Kasisomayajula
Research and Development ManagerSeptember 10th, 2019
Self-Healing Coatings for Improved Corrosion
Resistance and Adhesion Maintenance
Outline
Protective Coatings for Corrosion Control
Microencapsulated Healing Agents with Various Chemistries
Zinc-Based Sacrificial Protection
Performance Testing via Salt Fog Exposure
- Evaluation of One Coat Systems
- Evaluation of Two Coat Systems
Key Takeaways
Outline
Protective Coatings for Corrosion Control
Microencapsulated Healing Agents with Various Chemistries
Zinc-Based Sacrificial Protection
Performance Testing via Salt Fog Exposure
- Evaluation of One Coat Systems
- Evaluation of Two Coat Systems
Key Takeaways
Failure in Protective Coatings
0
-81
Fre
e E
ne
rgy C
ha
nge
(Δ
G°
, k-c
al/m
ole
)
Uncoated
Steel
Protective Coating
Coated Steel
Lifetime of Protective Coating
Effective lifetime of coating is limited by
environmental factors and damage
FeOOH line
Without the coating the metal quickly oxidizes to form an oxide with inferior
mechanical properties
Protective coating lengthens lifetime of substrate and lifetime extension depends on
coatings physical and chemical properties
Damage to the coating will compromise its protective capabilities and hasten
degradation of substrate
COST: Annual global cost of corrosion estimated to be US$2.5 trillion (3.4% of
global GDP)*
Page 4
Adapted from Paint and Coatings Applications and Corrosion Resistance, Schweitzer, P.A.
*http://impact.nace.org/economic-impact.aspx
Improvement in Protective Coatings
Without the coating the metal quickly oxidizes to form an oxide with inferior
mechanical properties
Protective coating lengthens lifetime of substrate and lifetime extension depends on
coatings physical and chemical properties
Damage to the coating will compromise its protective capabilities and hasten
degradation of substrate
COST SAVINGS: Self-healing functionality minimizes impairment of protective
capabilities that occur after damage leading to cost savings
0
-81
Fre
e E
ne
rgy C
ha
nge
(Δ
G°
, k-c
al/m
ole
)
Uncoated
Steel
Protective Coating
Coated Steel
Lifetime of Protective CoatingLifetime Extension due to
Self-Healing Functionality
Protective Coating
Coated Steel
Extension achieved by maintaining more
robust protection after the coating is damaged
Effective lifetime of coating is limited by
environmental factors and damage
FeOOH line
Page 5
Adapted from Paint and Coatings Applications and Corrosion Resistance, Schweitzer, P.A.
Introduction to Self-Healing Coatings
Traditional Coatings
Used for protective and/or decorative purposes
Functional Coatings
Additional functionality (best described as functional
if functionality is static)
Superhydrophobic, antifouling, intumescent, etc.
Ghosh, 2006 (Editor: Functional Coatings, Wiley)
Smart Coatings
Additional dynamic functionality
Noticeable/predictable response to trigger
mechanism
Challener, 2006 (JPCL/Coatings Tech)
Self-Healing Coatings
Damage triggers protective and/or aesthetic recovery
Non-Autonomic: Healing requires energy from
external source
Autonomic: healing activated by damage, external
intervention not required
Page 6
TRADITIONAL COATING
FUNCTIONAL COATING
SMART COATING
Healing agent released
to site of damage
Healing agent polymerizes
and heals damageMicrocapsules ruptured
by damage
Self-Healing Microcapsules
Superhydrophobic Surfaces
Corrosion Protection
Cho et al., Adv. Mater. 2009, 21, 645–649
-5
0
5
10
15
20
0 5 10 15 20 25 30
Self-Healing Coatings: Maintenance of Adhesion after Damage
Page 7
Ad
he
sio
n L
oss (
mm
)
Systems and Chemistries Evaluated
Average Control
Performance
(9.1 mm, rating 3)
Average Self-Healing
Performance
(2.1 mm, rating 7)
130%
Rating
Improvement
Multi-Coat Epoxy Powder
Primer-Based Systems
Multi-Coat Epoxy Zinc
Primer-Based Systems
Single Coat Zinc
Primers
Epoxy Primer-
Based Systems
Polyurethane
DTM
Alkyd Maintenance
Coating
Textured Polyester
Powder Coating
Standard Commercially
Available CoatingStandard Commercially
Available Coating with Self-Healing Additive
Data Mark Size is Proportional to Exposure
Time (Largest Represents 2,500 h)
Outline
Protective Coatings for Corrosion Control
Microencapsulated Healing Agents with Various Chemistries
Zinc-Based Sacrificial Protection
Performance Testing via Salt Fog Exposure
- Evaluation of One Coat Systems
- Evaluation of Two Coat Systems
Key Takeaways
Page 8
Microencapsulated Healing Agents
CAPSULE CORE TECHNOLOGY EXAMPLES OF END-USE APPLICATIONS
Dual Capsule System
Reactive Silicone Polymers with Ability to
Cure Under Water
- Heavy Industrial Protective Coatings
- Maintenance and New Construction
- Fatigue Resistant Adhesives
Single Capsule System
Solvent-Promoted Cure of Epoxy Resin
- Light to Heavy Duty Protective Coatings
- Powder Coatings
- Adhesives and Structural Composites
Single Capsule System
Oxygen-Initiated Cross-Linking of
Functionalized Alkyd Resins
- Industrial Maintenance Coatings
- Protective Wood and Concrete Coatings
- Automotive Undercoatings
Page 9
Outline
Protective Coatings for Corrosion Control
Commercialized Microencapsulated Healing Agents
Zinc-Based Sacrificial Protection
Performance Testing via Salt Fog Exposure
- Evaluation of One Coat Systems
- Evaluation of Two Coat Systems
Key Takeaways
Page 10
Zinc-Based Sacrificial Protection
High content of metallic zinc particles form interconnected network
throughout the coating Pigment Volume Concentration (PVC) > Critical Pigment Volume Concentration
(CPVC)
Usually above 60% by volume in solvent-based organic zinc-rich coatings
Page 11
Reference
ElectrodeCounter
Electrode
Working
Electrode
Electrochemical Test Set-up
0
1
2
3
4
5
6
7
8
9
10
0 50 100 150 200 250
Imp
ed
an
ce (
log
|Z|@
0.1
Hz)
Time of Exposure (Hours)
Control
Unscribed Coating
Salt Fog Exposure (Hours)
1.5
2
2.5
3
3.5
4
4.5
0 50 100 150 200 250
Imp
ed
an
ce (
log
|Z|@
0.1
Hz)
Time of Exposure (Hours)
Control
Scribed Coating
Salt Fog Exposure (Hours)
Impedance drop after exposure to salt spray for both
unscribed and scribed coatings indicates salt solution
penetration into pores causing decrease in impedance
Formation of zinc
corrosion products
increases impedance
Exposure started after
coating was scribed
Improving Zinc-Based Protection
Page 12
Corresponding Electrochemical Data
Systems Evaluated
Control System
Substrate: Cold Rolled Steel (CRS)
Matrix: Epoxy-Based Zinc-Rich Primer
System Incorporating Self-Healing Additive
Substrate: Cold Rolled Steel
(CRS)
Microencapsulated
Epoxy-Based Healing Agent
Matrix: Epoxy-Based Zinc-Rich Primer
Release of healing agent
restricts salt solution
uptake at damage site
Scribed Coating
2
2.5
3
3.5
4
4.5
0 100 200
Imp
ed
an
ce
(lo
g|Z
| 0.1
Hz)
Control Self-healing
Salt Fog Exposure (Hours)
0
2
4
6
8
10
0 100 200
Imp
ed
an
ce
(lo
g|Z
| 0.1
Hz)
Control Self-healing
Unscribed Coating
Similar impedance indicating
minimal effect of microcapsules
when coating is NOT damaged
Salt Fog Exposure (Hours)
Lower cathodic current
(lowering of electrolyte
penetration)
Lower anodic current
corresponds to slower
oxidation of zinc
Scribed Coating
(CR = 2.2 μA/cm2)
(CR = 0.55 μA/cm2)
-1.05
-1
-0.95
-0.9
-0.85
-0.8
-0.75
-4.2 -3.2 -2.2 -1.2 -0.2
Po
ten
tia
l (E
we
/V)
Current (log(|<I>/mA|))
Control
Self-healing
Outline
Protective Coatings for Corrosion Control
Commercialized Microencapsulated Healing Agents
Zinc-Based Sacrificial Protection
Performance Testing via Salt Fog Exposure
- Evaluation of One Coat Systems
- Evaluation of Two Coat Systems
Key Takeaways
Page 13
Performance TestingStatic (Standard) Exposure
Used for standard benchmarking studies (most common approach)
Panels are scribed using a 500 micron scribe tool, followed by exposure to ASTM B117 conditions
for a specified duration.
Panels are scraped to remove loose/disbonded material around the scribe and the width of the
disbonded area measured and recorded.
Dynamic Exposure
Simulates more aggressive conditions such as repeated assault to a damaged area during
transportation, installation, or service.
Panels are scribed using a 500 micron scribe tool, followed by exposure to ASTM B117 conditions
for a specified total duration.
Panels are scraped every 250 h to remove loose/disbonded material around the scribe and the
width of the disbonded area measured and recorded.
Page 14
Scribe
Panels
End Exposure
Scrape Test
Start Salt Fog
Exposure
24 h
1000 h Static Exposure Example
Scribe
Panels
End Exposure
Scrape Test
Start Salt Fog
Exposure
24 h
1000 h Dynamic Exposure Example
1. Stop Exposure
Scrape Test
2. Continue
Exposure
1. Stop Exposure
Scrape Test
2. Continue
Exposure
1. Stop Exposure
Scrape Test
2. Continue
Exposure
250 h 250 h 250 h 250 h
Outline
Protective Coatings for Corrosion Control
Commercialized Microencapsulated Healing Agents
Zinc-Based Sacrificial Protection
Performance Testing via Salt Fog Exposure
- Evaluation of One Coat Systems
- Evaluation of Two Coat Systems
Key Takeaways
Page 15
Performance Testing on Cold Rolled Steel (CRS)
Page 16
150 μm Scribe
150 μm Scribe
500 μm Scribe500 μm Scribe
Self-healingControl
Coating: Zinc-rich primer (>85 wt% zinc)
(SSPC Paint 20 Level 1)
DFT: 3 mils
Substrate: 3”x5” lightly abraded CRS
Capsule Size: 10μm
Application Method: Conventional Spray
Exposure Time: 250 h
Test: ASTM B117 exposure, Scrape 250 h
Note: Coatings were applied via
manufacturer’s specifications.
Control System
System Incorporating Self-Healing Additive
Substrate: Cold Rolled Steel (CRS)
Matrix: Epoxy-Based Zinc-Rich Primer
Substrate: Cold Rolled Steel
(CRS)
Microencapsulated
Epoxy-Based Healing Agent
Matrix: Epoxy-Based Zinc-Rich Primer
0
2
4
6
8
10
12
14
150 500
Ad
hes
ion
Lo
ss
fro
m S
cri
be
(m
m)
Scribe Width (microns)
Control
Control + 4wt% AMPARMOR™ 2000Self-healing
Control
Performance Testing on Cold Rolled Steel (CRS)
Page 17
150 μm Scribe
150 μm Scribe
500 μm Scribe500 μm Scribe
Control
Coating: Zinc-rich primer (>85 wt% zinc)
(SSPC Paint 20 Level 1)
DFT: 3 mils
Substrate: 3”x5” lightly abraded CRS
Capsule Size: 10μm
Application Method: Conventional Spray
Exposure Time: 500 h
Test: ASTM B117 exposure, Scrape 500 h
Note: Coatings were applied via
manufacturer’s specifications.
0
2
4
6
8
10
12
14
16
150 500
Ad
hes
ion
Lo
ss
fro
m S
cri
be
(m
m)
Scribe Width (microns)
Control
Control + 4wt% AMPARMOR™ 2000
Control System
System Incorporating Self-Healing Additive
Substrate: Cold Rolled Steel (CRS)
Matrix: Epoxy-Based Zinc-Rich Primer
Substrate: Cold Rolled Steel
(CRS)
Microencapsulated
Epoxy-Based Healing Agent
Matrix: Epoxy-Based Zinc-Rich Primer
Self-healing
Self-healing
Control
Performance Testing on Cold Rolled Steel (CRS)
Page 18
150 μm Scribe
150 μm Scribe
500 μm Scribe500 μm Scribe
Control
Coating: Zinc-rich primer (77-85 wt% zinc)
(SSPC Paint 20 Level 2)
DFT: 3 mils
Substrate: 3”x5” lightly abraded CRS
Capsule Size: 10μm
Application Method: Conventional Spray
Exposure Time: 250 h
Test: ASTM B117 exposure, Scrape 250 h
Note: Coatings were applied via
manufacturer’s specifications.
0
2
4
6
8
10
12
14
16
150 500
Ad
hes
ion
Lo
ss
fro
m S
cri
be
(m
m)
Scribe Width (Microns)
Control
Control + 4wt% AMPARMOR™ 2000
Control System
System Incorporating Self-Healing Additive
Substrate: Cold Rolled Steel (CRS)
Matrix: Epoxy-Based Zinc-Rich Primer
Substrate: Cold Rolled Steel
(CRS)
Microencapsulated
Epoxy-Based Healing Agent
Matrix: Epoxy-Based Zinc-Rich Primer
Self-healing
Self-healing
Control
Performance Testing on Cold Rolled Steel (CRS)
Page 19
150 μm Scribe
150 μm Scribe
500 μm Scribe500 μm Scribe
Control
Coating: Zinc-rich primer (77-85 wt% zinc)
(SSPC Paint 20 Level 2)
DFT: 3 mils
Substrate: 3”x5” lightly abraded CRS
Capsule Size: 10μm
Application Method: Conventional Spray
Exposure Time: 500 h
Test: ASTM B117 exposure, Scrape 500 h
Note: Coatings were applied via
manufacturer’s specifications.
0
2
4
6
8
10
12
14
16
18
20
150 500
Ad
hes
ion
Lo
ss
fro
m S
cri
be
(m
m)
Scribe Width (Microns)
Control
Control + 4wt% AMPARMOR™ 2000
Control System
System Incorporating Self-Healing Additive
Substrate: Cold Rolled Steel (CRS)
Matrix: Epoxy-Based Zinc-Rich Primer
Substrate: Cold Rolled Steel
(CRS)
Microencapsulated
Epoxy-Based Healing Agent
Matrix: Epoxy-Based Zinc-Rich Primer
Self-healing
Self-healing
Control
Performance Testing on Blasted Steel
Page 20
Coating: Zinc-rich primer (70-80 wt% zinc) (SSPC Paint 20 Level 2) DFT: 3 mils
Substrate: Blasted Steel Capsule Size: 10μm
Application Method: Conventional Spray
Test: ASTM B117 exposure followed by adhesion loss evaluation
Note: Coatings were applied via manufacturer’s specifications.
2000
Outline
Protective Coatings for Corrosion Control
Commercialized Microencapsulated Healing Agents
Zinc-Based Sacrificial Protection
Performance Testing via Salt Fog Exposure
- Evaluation of One Coat Systems
- Evaluation of Two Coat Systems
Key Takeaways
Page 21
Performance Testing on Cold Rolled Steel (CRS)
Page 22
Control System
System Incorporating Self-Healing Additive
Substrate: Cold Rolled Steel (CRS)
Matrix: Epoxy-Based Zinc-Rich Primer
Substrate: Cold Rolled Steel
(CRS)
Microencapsulated
Epoxy-Based Healing Agent
Matrix: Epoxy-Based Zinc-Rich Primer
Build Coat Coat: 2K Solvent-Borne Epoxy
Build Coat Coat: 2K Solvent-Borne Epoxy
Coating: Zinc-rich primer (> 80 wt% zinc), epoxy
polyamide (topcoat)
DFT: Zinc Coat - 3 mils, Epoxy Coat - 8 mils, (11
mils total)
Substrate: 3”x5” lightly abraded CRS
Capsule Size: 10μm
Application Method: Conventional Spray
Exposure Time: 1000 h
Test: ASTM B117 exposure, Scrape 1000 h
Note: Coatings were applied via manufacturer’s
specifications.
Control Zinc +
Epoxy Second Coat
156 μm Scribe150 μm Scribe
500 μm Scribe500 μm Scribe
Self-healing Zinc +
Epoxy Second Coat
0
2
4
6
8
10
12
14
16
18
156μm 500μm
Ad
hesio
n L
oss f
rom
Scri
be
(mm
)
Scribe Width
9100 Control
9100 4wt%Control + 4 wt%
AMPARMORTM 2000
Control
Self-healing
Control
Performance Testing on Blasted Steel
Page 23
Coating: Zinc-rich primer (> 80 wt% zinc), epoxy
polyamide topcoat)
DFT: Zinc Coat - 3 mils, Epoxy Coat - 8 mils, (11
mils total)
Substrate: 4”x6” 16ga SSPC SP10 Blasted Steel
Capsule Size: 10μm
Application Method: Conventional Spray
Exposure Time: 2000 h
Test: ASTM B117 exposure, Scrape 2000 h
Notes: Coatings were applied via manufacturer’s
specifications.
Control + 4 wt%
AMPARMORTM 2000
Control Zinc +
Epoxy Second Coat
Self-healing Zinc +
Epoxy Second Coat
150 μm Scribe 150 μm Scribe
500 μm Scribe500 μm Scribe
Control
Control System
System Incorporating Self-Healing Additive
Substrate: Blasted Steel
Matrix: Epoxy-Based Zinc-Rich Primer
Substrate: Blasted SteelMicroencapsulated
Epoxy-Based Healing Agent
Matrix: Epoxy-Based Zinc-Rich Primer
Build Coat Coat: 2K Solvent-Borne Epoxy
Build Coat Coat: 2K Solvent-Borne Epoxy
0
5
10
15
20
25
156μm 500μm
Ad
hesio
n L
oss F
rom
Scri
be (
mm
)
Scribe Width
9100 Control
9100 4wt%Self-healing
Control
Outline
Protective Coatings for Corrosion Control
Commercialized Microencapsulated Healing Agents
Zinc-Based Sacrificial Protection
Performance Testing via Salt Fog Exposure
- Evaluation of One Coat Systems
- Evaluation of Two Coat Systems
Key Takeaways
Page 24
Key Takeaways
Performance
Only true self-healing system for protective and high-performance coatings
No external intervention required for effective healing response
Versatility
Microencapsulation approach facilitates application in a variety of existing coating
formulations without the need for any synthetic modification to resin
Multiple chemistries increase chemical compatibility
Page 25
Transportation Oil & Gas Industrial MaintenanceMachinery/Equipment
MilitaryInfrastructureAlternative Energy Consumer