static-mixing laboratory techniques for aliphatic polyurea
TRANSCRIPT
Static-Mixing Laboratory TechniquesFor Aliphatic Polyurea Coatings
David W. House, Dejan Ilijevski, Ray Scott, and John Leon
Presented at the Polyurea Development Association
December 1, 2000
A Typical Formulation for a Sprayed,Aliphatic Polyurea Coating
A-Side: Isophorone diisocyanate
JEFFAMINE D-2000
JEFFAMINE D-2000
JEFFAMINE T-5000
Curative(s)
B-Side:
NCO
NCO
H2N R1 NH2
NH2
R2
R2 R2
NH2H2N
R1
R1 NH2R1H2N
Low molecular weightpolyamine(s)
Benefits of Polyurea Coatings
* Improved physical properties* Very fast cure time - fast turnaround time* Fast physical property development (24h)* Virtually unaffected by moisture* Essentially unaffected by ambient temperature* Do not require catalyst* Better thermal stability
Challenges
* Very short pot life* High formulation viscosity
- Effective mixing- Application and adhesion to substrate- Surface uniformity
Solution
* Specialized equipment* Formulation development
High-Pressure, Impingement Mixing
* Handles pot lives of 2+ seconds* Heated components (160-170 oF)* High pressures (2000-3000 psi)* Uses spray gun to continuously deliver the
atomized formulation* Component volumes in gallons* Excellent in field use (large-scale)
High-PressureImpingement Mixing
Iso Resin
Challenge
* Lab-scale formulation development
Solution Requirements
* Screen large number of formulations in a short time* Mimic field equipment (impingement mixing)* Handle the very fast reaction kinetics
- Equipment size- Component volumes- Change-over time
Static Mix Gun Assembly
Static (Motionless) Mixing
* Uses extrusion to static mix the componentsand a draw down knife to spread the coating
* Low pressures (about 80 psi)* Room temperature and higher* Component volumes in grams* Fast, simple clean-up (disposable cartridges)* Quick screening of many different formulations
* Inexpensive (equipment and chemicals)* Small, uses minimal lab space* Uses same basic formulation parameters as
those used in impingement mixing* Technique is easy to learn* Handles pot lives of 10+ seconds
Coatings Made Using Impingement Mixingversus Static Mixing
Clearlink 1000
• Clear, colorless liquid• Equivalent Weight 161• Specific Gravity 0.90 at 68oF (20oC)
• Ames Test Nonmutagenic• LD50 (acute oral, rat) 482 mg/kg
Cycloaliphatic Secondary Diamine
• Viscosity 36 cSt at 100oF (38oC)• Pour Point -44oF (-42oC)• Flash Point (PMCC) 325oF (163oC) min• Vapor Pressure < 1 mm Hg at 68oF (20oC)
Comparison of Static Mixing to Impingement Mixing
Impt Static StaticFormulation Mixing Mixing Mixing
A-SideDesmodur I (%) 45 44.6 39.2JEFFAMINE D-2000 (%) 55 55.4 60.8
% NCO 14.8 14.5 12.2Index 105 105 105
B-SideJEFFAMINE D-2000 (%) 32.2 35.0 49.3JEFFAMINE T-5000 (%) 8.6 15.2 12.7Clearlink 1000 (%) 46.8 49.8 38.0TiO2 (%) 12.4 0.0 0.0
Comparison of Static Mixing to Impingement Mixing
Impt Static StaticProcessing Mixing Mixing Mixing
Volume Ratio (A/B) 1.00 1.00 1.00Weight Ratio (A/B) 0.96 1.08 1.08
Spray/Cartridge Temp. (oF) 140 73 73Coating Thickness (mil) 41 31 34
Pot Life (sec) 9 ~ 15 < 20Tack-Free Time (min) --- 3.5 15
Comparison of Static Mixing to Impingement Mixing
Impt Static StaticPhysical Properties Mixing Mixing Mixing
Hardness, inst. (Shore D) 43 60 48
Tensile Strength (psi) 2820 4060 4170100% Modulus (psi) 1350 1560 1040Elongation (%) 500 530 600
Tear Resistance (pli) 500 630 490Tear Prop. Resist. (pli) 525 550 400
Resilience (%) 40 41 40
Comparison of Static Mixing to Impingement Mixing
Impt StaticFormulation Mixing Mixing
A-SideDesmodur I (%) 45 39.6JEFFAMINE D-2000 (%) 55 60.4
% NCO 14.8 12.4Index 105 105
B-SideJEFFAMINE D-2000 (%) 40.7 50.7JEFFAMINE T-5000 (%) 9.9 12.8VESTAMIN IPD 7.7 2.0 Clearlink 1000 (%) 30.8 34.5
Comparison of Static Mixing to Impingement Mixing
Impt StaticPhysical Properties Mixing Mixing
Hardness, inst. (Shore D) 42 48
Tensile Strength (psi) 2510 4340100% Modulus (psi) 1200 1075Elongation (%) 470 600
Tear Resistance (pli) 415 500Tear Prop. Resist. (pli) 345 390
Resilience (%) 39 45
Volume Ratio (A/B)Weight Ratio (A/B)Coating Thickness (mil)
1.001.0334
1.001.0533
1.001.0633
1.001.0836
1.001.0928
A-SideDesmodur I (%)
JEFFAMINE D-2000 (%)
% NCOIndex
26.773.3
7.0105
33.166.9
9.7105
38.161.9
11.8105
42.157.9
13.4105
45.055.0
14.8105
B-SideJEFFAMINE D-2000 (%)JEFFAMINE T-5000 (%)
Clearlink 1000 (%)
36.147.916.0
29.142.628.4
23.438.338.3
18.834.846.4
15.031.953.1
Effect of Clearlink 1000 Level on Polyurea Coatings
Pot Life (sec)Tack-free Time (min)
< 302.5
< 304.0
< 306.0
< 309.0
< 30> 10
Hardness, instant (Shore D) After 10 sec (Shore D)
17 (56A)9 (41A)
31 (79A)20 (68A)
4636
5445
6050
0
10
20
30
40
50
60
70
10 20 30 40 50 60
Clearlink 1000 Level, %
Har
dn
ess,
Sh
ore
DEffect of Clearlink 1000 Level on Hardness
56A
79A
95A
41A
68A
88AInstantAfter 10 sec
0
500
1000
1500
2000
2500
3000
3500
10 20 30 40 50 60
Clearlink 1000 Level, %
Ten
sile
Str
., p
si
0
100
200
300
400
500
600
700
800
900
1000
Elo
ng
atio
n, %
Effect of Clearlink 1000 Level on Tensile Strengthand Elongation
0
100
200
300
400
500
600
10 20 30 40 50 60
Clearlink 1000 Level, %
Tea
r S
tren
gth
, pli
Resistance
Propagation
Effect of Clearlink 1000 Level on Tear Strength
Formulations for the Chain Extender Level Study
Isocyanate Component
VESTANAT IPDIJEFFAMINE D-2000
%NCO
A
4555
14.8
B
4555
14.8
C
4555
14.8
D
4555
14.8
E
4555
14.8
Resin Blend
JEFFAMINE D-2000JEFFAMINE T-5000VESTAMIN IPDAClearlink 1000Ti02
48.1714.9622.830.0
10.64
48.6212.1516.5711.6011.05
45.6110.0111.9621.0211.12
40.669.897.6930.7710.00
32.188.600.00
46.7812.38
Index = 105, Iso/Resin Ratio = 1.00:1.00
Effect of Clearlink 1000 Levelon Physical Properties
0
10
20
30
40
50
60
Har
dn
ess,
Sh
ore
D
0 sec 10 sec
12 pbw 21 pbw 31 pbw 47 pbw
0
500
1000
1500
2000
2500
3000
Tensile Str.
Ten
sile
Str
., ps
iEffect of Clearlink 1000 Level
on Physical Properties
0
100
200
300
400
500
Elong. Tear R.
Elo
ng, %
/Tea
r, p
li
Pbw Clearlink 1000: 12, 21, 31, 47.
Effect of Isocyanate Index on Physical Properties
Isocyanate Index 0.95 1.00 1.05 1.10 1.15 1.20
Isocyanate Component
VESTANAT IPDIJEFFAMINE D-2000
%NCO
4555
14.8
4555
14.8
4555
14.8
4555
14.8
4555
14.8
4555
14.8
Resin Blend
JEFFAMINE D-2000JEFFAMINE T-5000VESTAMIN IPDAClearlink 1000
43.2115.4315.4325.93
44.7015.5913.5126.20
45.8316.6712.5025.00
46.6717.7811.1124.44
47.2518.689.89
24.18
48.6519.469.73
22.16
Iso/Resin Ratio = 1.00:1.00
0
500
1000
1500
2000
2500
3000
Tensile Str.
Ten
sile
Str
., ps
iEffect of Isocyanate Index on Physical
Properties: ~25 pbw CL1000, 41 Shore D
0
100
200
300
400
500
600
700
800
Elong. Tear R.
Elo
ng, %
/Tea
r, p
li
Index: 95, 100, 105, 110, 115, 120
QUV Weatherometer Study2000 Hours Exposure to a UV B-313 Bulb
0
500
1000
1500
2000
2500
Un
its
Tensilepsi
Elong. % Mod100%
Mod300%
Tear pli
Unexposed 2000 hr QUV
Elcometer Adhesion Strengthof a Clearlink 1000-Based Polyurea Coating
0
200
400
600
800
1000
1200
1400
Ad
hes
ive
Str
., p
si
Concrete Smooth Steel Blasted Steel 2 mil Blasted
100%CF
100%AF
85%CF
Conclusions
* A new laboratory technique has been developed for screeningpolyurea and polyurethane impingement-mixed formulations
* The static mixing method is fast, easy to learn, inexpensive,requires no specialized equipment or lab preparation, andneeds minimal space.
* The technique mimics the physical properties of coatingsmade using impingement mixing and is useful forestablishing trends
Summary
The use of Clearlink 1000 in polyurea coatings...
* Produces light-stable coatings* Increases working time* Improves adhesion to substrate
Significantly increases:* Hardness* Tensile strength* Elongation* Tear Strength
Acknowledgement
Aureliano Perez, Jr. and Kenneth M. Hillmanof Huntsman Corporation, USA
“It just sprays better”