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CASHEW NUTSHELL LIQUID BASED WATERBORNE AND LOW VIS COSITY SOLVENT-FREE EPOXY CURING AGENTS

Donald C. Lawson III, Jing Hu, Mengjiu Chen, Hong Xu

Cardolite Corporation Monmouth Junction, NJ, USA

Abstract: Cardolite is introducing two new classes of epoxy curing agents based on renewable cashew nutshell liquid (CNSL) technology. The first class is a waterborne curing agent that permits easy mixing with standard liquid epoxy resins without the need for co-solvents. And the second class includes light color, solvent-free, low viscosity phenalkamides that enable the formulation of true solvent-free epoxy coatings that do not contain benzyl alcohol. For the waterborne curing agent we demonstrate several, VOC-free, primer and self-leveling formulations to illustrate the wide formulation latitude available with this visible end of potlife CNSL waterborne curing agent. Cost and performance advantages are examined. Performance characteristics of the waterborne curing agent include fast cure and hardness development under low temperature and high humidity, adhesion over dry and damp concrete, along with excellent stain resistance. Performance data of CNSL based diluents used along with this CNSL waterborne curing agent are included. The low viscosity, solvent-free phenalkamides are the first of their kind, making it possible for formulators to transition to solvent-free systems without an increase in cost, the need for expensive application equipment, or a compromise in performance. With a low admixed viscosity, forgiving use levels, non-toxic labeling, and good compatibility with various epoxy resins, these products provide broad formulation latitude to coating manufacturers. Performance advantages include fast cure and hardness development with good flexibility at low temperatures with excellent film appearance under adverse conditions all while maintaining a workable pot life. With excellent corrosion protection, water and chemical resistance, coupled with good color and gloss retention after UV light exposure the solvent-free phenalkamides are suitable for primers, topcoats, and one-coat direct-to-metal systems. The overall performance properties of the solvent-free phenalkamides, compared to polyamides and polyamidoamines, are included in this paper. Introduction: Cashew Nutshell Liquid (CNSL) is a bio-renewable resource found in the honeycomb structure of the cashew nutshell as shown in Figure 1 and is considered a byproduct of the cashew industry. CNSL is a non-food chain abundant product. Cashew trees can grow abundantly in tropical conditions. The main producers of cashew nutshell liquid are Brazil, India, and Vietnam. Figure 1: Cashew fruit and nutshell

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CNSL consists of mostly anacardic acids (80-90%) and small amounts of cardol and other methyl derivatives. The highly useful chemical cardanol is produced from the decarboxylation of the anacardic acid and subsequent distillation technologies [1]. Cardanol is a pentadecadienyl phenol with an aliphatic side chain that usually consists of a mixture of one, two, and three double bonds in a linear chain as displayed in Figure 2 . Figure 2: Example of Cardanol Structure

Cashew Nut

25% Kernel

25% Cashew Liquid

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The Mannich reaction of CNSL, formaldehyde, and certain amines is called a phenalkamine (phenol-alkyl-amine). Phenalkamines exhibit unique properties due to the CNSL derived structure. The aromatic ring provides good chemical resistance while the OH group gives good reactivity for fast and low temperature cure, and strong adhesion even to damp or poorly prepared surfaces. The highly hydrophobic aliphatic side chain delivers excellent water resistance, good flexibility, low viscosity, extended pot life, and excellent corrosion protection [2]. This paper will present two different curing agent pathways to achieve zero VOC and/or high solids formulations with application friendly viscosities via CNSL based curing agents. Materials and Methods: The raw materials used in this study are all commercially available. Evaluations were performed in clear and pigmented formulations depending on the test. Curing agents were used per recommended use level. Drying times (ASTM D5895), pendulum hardness (ASTM D4366), flexibility (ASTM D522), adhesion (ASTM D3359), and appearance at low temperature and high relative humidity were measured with clear formulations. QUV (ASTM D4587), overcoat, and salt spray (ASTM-B117) were evaluated with pigmented formulations. The tack free and dry hard data were recorded according to ASTM D5895-03.

The samples for QUV-A exposure were prepared on QD-36 cold rolled steel panels. Pigmented systems were applied via a 375 micron wet application bar. After a three-day room temperature cure, the panels were exposed in the QUV Accelerated Weathering Tester (Q-Lab Products). The exposure cycle was 8 hours QUV-A light at 60°C / 4 hours condensation at 50°C. Q-panel QD surface 3”x6”x0.020” was used for drying times, flexibility, pendulum hardness, and QUV tests. Concrete pavers and grit blasted Sa 2.5 steel were utilized for adhesion. The grit blasted steel was also used for salt spray, and overcoat tests. Films were cured for 7 days at room temperature unless specified otherwise. The waterborne curing agents were applied within 5 minutes of mixing (exception end-of-pot-life). The remaining curing agent formulations were given a 20 minute induction time. The panels for impact tests were prepared with a 125 micron wet application bar over QD-36 panels. Samples were cured at room temperature for seven days before the test. Impact properties were tested with a Gardner impact tester (BYK Gardner) according to ASTM D522. The adhesion tape test was performed on rusted S-36 panels (Q-panel, 3”x6”x0.020”). To obtain the uniform rusted surface, clean S-36 panels were immersed in a 60°C water bath (Precision circulating water bath, Model 260) for 24 hours followed by a warm tap water rinsing to remove any loose rust. The panels were lightly dried with a paper towel and stored at room temperature for seven days before use. Pigmented systems were applied over the rusted panels via a 250 micron wet application bar. After a seven-day room temperature cure, the cross-hatch adhesion test was performed. Early water resistance was evaluated on a clear coating prepared via a BYK 200µ gap wet application bar over a QD-36 panel. The panel was immediately placed in a 25°C incubator for cure. Every one or half-hour, one water droplet was dropped on the coating surface. The time point when the water droplet no longer gave any visual marking on the surface was recorded.

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The pull off adhesion properties over dry and wet concrete blocks were tested according to ASTM D4541 using an automatic adhesion tester (PosiTest AT-A, DeFelsko). Part 1: CNSL Waterborne Curing Agent - Zero Volatil e Organic Compounds (VOCs) We have developed a waterborne CNSL curing agent for epoxy coatings. It is designed for cost effective water-based concrete primers and self-leveling formulations that require quick return to service, excellent adhesion to concrete, top coat compatibility, and durability. The following data is a comparison of properties and performance against a competitive non- CNSL based waterborne curing agent. Table 1. Typical Properties

Properties 8100 Series Competitive WBCA

Viscosity @ 25°C (cPs) 20000-50000 40000

Amine value (mg KOH/g) 120-140 150-190

Solids 50 50

AHEW 270 275

Color (Gardner) 7 4

Recommended, (phr, EEW 190)

125-160 140-180

Table 2. Admixed Viscosity with Liquid Epoxy Resin

Curing Agent Effort Required to Reduce Admix Viscosity With Water 8100 Series Very easy to reduce with water

Competitive WBCA Initial resistance for water acceptance The 8100 series is compatible with standard liquid epoxies (standard Bis-A and Bis-F epoxies) No additional emulsifiers or solvents are required. A unique feature of the 8100 series is the presence of the highly hydrophobic cardanol side-chain, resulting in excellent water resistance. The cure speed and hardness development of the CNSL waterborne curing agent is able to take advantage of the phenalkamine structure Figure 3 – Figure 7 with a visible end of pot life Figure 8 .

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Figure 3. Cure Properties (linear dry times)

Stoichiometric (1:1) with liquid epoxy at (std.) 50-55% relative humidity Figure 4. Clear Primer Hardness Development 25 °C / 55% R.H.

Clear Floor Primer #1 / DFT = 200µ

The CNSL waterborne curing agent exhibits excellent low temperature high humidity cure, with an early walk-on time of <24 hours in a non-pigmented formulation (Figure 5 ).

Figure 5. Clear Primer Hardness Development 10 °C / 80% R.H.

Clear Floor Primer #1 / DFT = 200µ

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For the higher film thickness (3mm) self-leveling formulation, humidity will play a role in hardness development. Air flow across the surface during the cure cycle is required for early walk-on hardness to help remove the water at humidity levels above 55% R.H. With very mild air flow excellent hardness development is observed at 10°C / 80% R.H. (Figure 6 and Figure 7, Self-Leveling Formula #1 ). Figure 6. Self-Leveling Hardness Development 25 °C / 55% R.H.

Figure 7. Clear Primer Hardness Development 10 °C / 80% R.H.

The CNSL waterborne curing agent displays a clear end-of pot-life. Figure 8. Visible End of Pot-life

Admixed with standard liquid epoxy reduced with water – total weight solids 52%

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The CNSL waterborne curing agent exhibits good overall flexibility. Formulations incorporating CNSL reactive diluent display additional flexibility when compared to C12-C14 aliphatic glycidyl ether (Self-Leveling Formula #1 vs Self-Leveling Formula # 2, Table 4 ). Table 3. Flexibility (Pigmented Formulation #1)

8100 Series Competitive WBCA

Direct Impact 20 in-lbs 15 in-lbs

Reverse Impact 4 in-lbs < 4 in-lbs

DFT of 100µ (over CRS) Table 4. Resistance to Damage from Impact [DFT 3mm] Propert y Self -Leveling Formula #1 Self -Leveling Formula #2 Hammer strike over concrete Slight indentation with a few very

small cracks at point of impact Slight indentation with no cracks at point of impact

Adhesion to Dry Concrete :

• Used 100 micron drawdown applicator to apply primer on concrete paver and cured for 7 days before adhesion test.

• Adhesion to Damp Concrete : o Concrete pavers fully immersed in water. After 72 hrs

freestanding water on the top removed by blotting with paper towels.

o Pavers were ½ immersed in water and primer was applied with a 100µ drawdown applicator

o Coated pavers were cured for 7 days before adhesion test. Table 5. Adhesion Pull-off Values

Curing Agent Dry Concrete (psi/MPa)* Wet Concrete (psi/MPa)*

Direct to concrete Direct to concrete NX-8101 650 / 4.48 620 / 4.27 Competitive WBCA 625 / 4.30 523 / 3.56

*Mode of failure: in the concrete The CNSL waterborne curing agent exhibits good chemical with excellent stain resistance. Table 6. MEK Resistance* 7 day cure @ 25°C

Marring Break-through Softening

NX-8101 Yes No Slight Competitive WBCA Yes No More

*(200 double rubs) Table 7. 24 hour Spot Test @ 25°C

NX-8101 Competitive WBCA Mustard Slight stain Slight stain Ketchup No Effect Slight stain

3% Acetic Acid No Effect No Effect Bleach No Effect No Effect Coffee No Effect No Effect Ethanol No Effect No Effect Xylene No Effect No Effect

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The marginal cost of water, combined with the ability to increase the filler loading (using water to adjust the viscosity) results in a lower relative cost for the self-leveling formulation. Formulation Cost in Self-leveling Formulation

• Diluent demand is less • Relative filler loading is more than 2 times greater • Water content used for viscosity reduction is a minimal cost • Results in lower relative applied cost

Formulation Guidelines

• Standard liquid epoxies can be used (based on Bisphenol A or F) • No additional emulsifiers are required • Reactive diluents (mono or di-functional) can be used without additional emulsifiers • Preliminary evaluations show enhanced flexibility and higher filler loadings with

Ultra LITE 513 versus standard C12-C14 reactive diluents • Dispersants like Disperbyk 192 help with pigment wetting

(The dispersant can be used in either the epoxy (PART A) or the curing agent (PART B) to aid in pigment dispersion)

• Defoamers like BYK 045 and BYK 054 help with air release and surface appearance • Temperature of NX-8101 should remain below 40°C during the pigment dispersion phase

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CNSL Waterborne Curing Agent Formulations Clear Floor Primer Formulation #1

PART A Wt.

EPON 828 86.93

Heloxy 8 11.84

BYK 348 0.62

BYK 054 0.62

Subtotal 100.00

PART B Wt.

NX-8101 130.00

Subtotal

PART C Wt.

D.I.Water 42.00

Subtotal 42.00

Total Wt A + B + C 272.00

Mix Part A + B together first Then reduce with half the Part C water Adjust final mix with remaining water

Self-Leveling Formula #1 Self-Leveling Formula #2

PART A Wt.

EPON 828 19.27

Heloxy 8 2.13

Disperbyk 192 0.51

Rhodopol 23 (xanthan gum) 0.05

Cimbar 325 (barium sulfate) 20.50

TIPURE R-706 6.30

BYK 054 1.23

Subtotal 50.00

PART B Wt.

NX-8101 27.00

Subtotal 27.00

PART C Wt.

D.I.Water 24.00

Subtotal 24.00

PART D Wt.

Sil-Co-Sil 106 (quartz powder) 81.29

US Silica NJ #70 (quartz sand) 98.71

Subtotal 180.00

Total A + B + C + D 281.00

PART A Wt.

EPON 828 18.95

Ultra LITE 513 2.46

Disperbyk 192 0.47

Rhodopol 23 (xanthan gum) 0.06

Cimbar 325 (barium sulfate) 23.00

TIPURE R-706 5.00

BYK 054 0.03

Subtotal 50.00

PART B Wt.

NX-8101 27.00

Subtotal 27.00

PART C Wt.

D.I.Water 24.00

Subtotal 24.00

PART D Wt.

Sil-Co-Sil 106 (quartz powder) 90.32

US Silica NJ #70 (quartz sand) 109.68

Subtotal 200.00

Total A + B + C + D 301.00

Mix Part A + B together first Then reduce with half the Part C water

Next stir in the Part D silica sand mixture Adjust final mix with remaining water

Mix Part A + B together first Then reduce with half the Part C water

Next stir in the Part D silica sand mixture Adjust final mix with remaining water

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Pigmented Formula #1 Pigmented Formula #3

PART A Wt.

EPON 828 52.16

Heloxy 8 3.13

Disperbyk 192 1.59

Cimbar 325 (barium sulfate) 11.70

TIPURE R-706 31.30

BYK 054 0.13

Subtotal 100.00

PART B Wt.

NX-8101 74.00

Subtotal 74.00

PART C Wt.

D.I.Water 25.00

Subtotal 25.00

Total A + B + C 199.00

PART A Wt.

EPON 828 53.00

Heloxy 8 5.50

Disperbyk 192 1.59

Cimbar 325 (barium sulfate) 23.00

TIPURE R-706 16.78

BYK 054 0.07

Subtotal 100.00

PART B Wt.

NX-8101 77.50

Subtotal 77.50

PART C Wt.

D.I.Water 22.50

Subtotal 22.50

Total A + B + C 200.00

Mix Part A + B together first Then reduce with half the Part C water

Mix Part A + B together first Then reduce with half the Part C water

*Pigmented Formula #2

PART A Wt.

EPON 828 30.00

Ultra LITE 513 3.00

Subtotal 33.00

PART B Wt.

NX-8101 43.59

D.I. Water 18.54

Disperbyk 192 2.32

Imsil A25 Silica 8.05

Cimbar EX (barium sulfate) 8.41

TIPURE R-706 12.50

Surfynol DF-62 0.54

BYK 054 0.62

D.I. Water 5.43

Subtotal 100.00

Total A + B 133.00

Mix Part A + B together well before application

*Temperature of NX-8101 should remain below 40°C during the pigment dispersion phase

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Solvent-free Phenalkamides

Two new CNSL based, solvent-free phenalkamides, #3040 and #3060, are introduced. The data that follows is a comparison of properties and performance against competitive non- CNSL based polyamides and polyamidoamines. Cure speed, flexibility, color stability, gloss retention, recoat properties, and anti-corrosion properties are compared. Part 2: #3040 Performance #3040 is a 100% solids phenalkamide curing agent. The typical properties of #3040 are listed in Table 8 . A widely used commercial solvent-free polyamide (referred to as PolyA ) was chosen for the performance comparison. The viscosity of #3040 (around 5000 cps) is less than half of PolyA (around 12,000 cps), which makes #3040 suitable for a high solid formulation. Table 8. Typical properties of #3040 and PolyA

Properties #3040 PolyA Color (Gardner) ≤ 11 ≤ 11

Viscosity, cps 4,000 - 6,000 11,560

Amine value (mg KOH/g) 370 - 410 370 - 410

AHEW

(theoretical) 118 97

Recommended use level (phr) 50 – 70

(55 recommended) 50 - 70

Gel time @ 55phr (min) 110 158 One of the unique advantages of phenalkamides is the faster cure property at low temperature in comparison to polyamide type curing agents. Figure 9 shows the Persoz hardness development of #3040 and PolyA as a function of cure time at 10°C and 92%R.H. condition. Figure 9. Persoz hardness development at 10°C and 9 2%R.H.

The #3040 system reached a Persoz hardness of 38 seconds on the 2nd day but the commercial PolyA system only reached 15 seconds. With the additional cure up to the 10th day, the #3040 system achieved a Persoz hardness of 100 seconds but the PolyA system only managed a hardness of 21 seconds. It suggests that #3040 not only had faster hardness development than PolyA at low temperature but is also less influenced by the high humidity. The lower sensitivity to high humidity of #3040 was also observed in the lower hazy appearance of #3040 versus PolyA as shown in Figure 10 .

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Figure 10. Film appearance after 24 hrs cure at 10° C and 92%R.H. condition

Polyamide systems are known for outstanding flexibility; however, phenalkamine systems are usually brittle. As the chemical combination of polyamide and phenalkamine, phenalkamide #3040 exhibited good mandrel bend property and impact resistance favorably to PolyA. Table 9. Flexibility data of PolyA and #3040 system s

Systems Mandrel Bend Direct impact (lbs)

Reverse impact (lbs)

PolyA 1/8”, good 150 80

LITE 3040 1/8”, good 90 60

Figure 11 shows the test results of early water resistance. A clear coating film with wet film thickness of 200µ was applied over QD-36 panels. The panel was immediately put into a 25°C incubator to cure. Every hour a water droplet was dropped on the coating surface. The earlier water droplets gave more pronounced marks. Once the coating had developed enough crosslinking, the drop of water no longer left any circle mark on the coating surface. Figure 11 shows that point #12, which corresponds to 12 hours cure, is free of marking for #3040, but there was an observed mark for PolyA. This indicates that #3040 is inherently more hydrophobic than PolyA.

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Figure 11. PolyA and #3040 after early water resist ance test

The mechanical properties of #3040 are listed in Table 10 . Liquid epoxy was mixed with #3040 at 55 phr. The mixture was poured into the standard stainless dies and cured at room temperature for three days. Then the samples were de-molded and further cured at 40°C for 16 hours before conducting mechanical property tests. The flexural strength and compressive strength of #3040 are suitable for adhesive applications. Table 10: Mechanical properties and water absorptio n data of #3040 Tensile strength (MPa) 44.2 Flexural strength (MPa) 97 Compression strength (MPa) 77 Elongation (%) at break 10.8 Water absorption (%)Total 0.79

Many epoxy systems are used as primers in multi-layer coating structures. Excellent adhesion with the topcoat, which is usually a polyurethane (PU) system, is a critical property. Figure 12 shows the results of an early recoat test method. The three panels in the upper row were based on PolyA system; the other three panels in the bottom row were from the #3040 system. First a non-tinted white primer of the two systems was applied over blasted steel panels. Then the coated panels were put into a 5°C chamber for cure. After various cure times in the 5°C chamber, e.g. 1 day, 7days or 14 days, the panels were taken out to be topcoated with a commercial black 2K PU system, then returned to the 5°C chamber for another 24 hour cure before conducting the cross-hatch adhesion tests. We can see that the three panels based on PolyA system have very poor adhesion between the PolyA primer and the black PU topcoat; compared to #3040 which exhibited excellent adhesion to PU topcoat at low temperatures regardless of the cure time.

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Figure 12. 5 °C Early Recoat Evaluation

Part 3: #3060 performance #3060 is a very low viscosity solvent-free phenalkamide curing agent in which no benzyl alcohol is present. This part of the paper evaluates the performance of #3060 compared to two widely used commercial polyamidoamine adducts, which are referred to as PolyB and PolyC. The typical properties of these three curing agents are listed in Table 11. We can see that the two polyamidoamine adduct curing agents contain benzyl alcohol (BA) to lower the viscosities while the latest phenalkamide #3060 has very low viscosity without BA. The low viscosity and zero BA content of #3060 can help the formulation of true solvent-free paint systems. Table 11. Typical properties of #3060, PolyB and P olyC

Properties #3060 Polyamidoamine adduct

PolyB PolyC Color (Gardner) ≤ 10 ≤ 10 ≤ 10

Viscosity, cps 500 - 1,000 700 - 2,000 450 - 1,300

Amine value (mg KOH/g) 450-490 250 - 290 280 - 320

AHEW (theoretical) 104 115 115

Recommended use level (phr) 55 ~60 ~60

Gel time @ 55phr (mins) 35-55 78 50 Solvent None Benzyl alcohol Benzyl alcohol

Another unique property of #3060 is its fast cure even at low temperature condition. In Figure 13, it can be seen that #3060 had much shorter dry time in comparison to Poly B and C, especially at low temperature of 10°C. It indicates that #3060 can overcome the drawback of slow cure observed in many polyaminoamine adducts.

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Figure 13. Dry hard Data

#3060 also exhibited much better hardness development at low temperature as shown in Figure 14 . The 5°C Persoz hardness development of #3060 confirms the distinctive low temperature cure performance of phenalkamide chemistry. Figure 14. Persoz Hardness at 5°C

In general, when curing agents are used in a pigmented system that contains diluents, or hydrocarbon resins, the hardness development can be hindered. However, the test results obtained from the systems based on Base #1 and Base #2 show that #3060 gave much faster hardness development in comparison to the two polyaminoamines. In general, phenalkamine systems have poor color stability due to the presence of phenolic structures. However, phenalkamides exhibited significant improvement of color stability in comparison to phenalkamine systems. Figures 15 and 16 show color stability and gloss retention after QUV A exposure, respectively. We can see that the delta E changes of the #3060 system were lower than that of the PolyC system, which indicated better color stability. The PolyB system also showed low delta E changes with longer QUV A exposure as observed in Figure 15 . However, the dark blue line in Figure 16 revealed that Poly B system showed poor gloss retention. A visual check at the 168 hour QUV A mark revealed that the PolyB and PolyC systems had chalking issues, which were reflected in the significant loss of gloss.

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Figure 15. QUV A Delta E

Figure 16. QUV A Gloss Retention

One of the unique properties of #3060 is the excellent adhesion over different type substrates. In this study with Base #2 , the adhesion properties over three different type substrates, rusted S-36 panels, non-pretreated CRS Q-36 panels and AA 2024 T3 panels, were investigated. The non-pretreated CRS Q-36 panels were not solvent cleaned before coating. AA2024 T3 aluminum alloy panels were sanded with 220 grit sand paper to remove the oxidation layer then cleaned by acetone. Best results are with #3060 as indicated in Table 12 .

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Table 12. Various Substrates Adhesion [Base #2]

The excellent adhesion of #3060 continues over dry and wet concrete. Both of the pull-off adhesions over dry and wet concrete surfaces were greater than 500 psi and the failures were due to the cohesion breakdown in the concrete, as shown in Figure 17 . The superb adhesion to wet concrete surfaces illustrates that #3060 has good tolerances over non-prepared substrates. Figure 17. Concrete Adhesion

Dry Wet

Due to the outstanding adhesion properties, #3060 is expected to attain excellent corrosion protection. In this study, the anti-corrosion properties of #3060 were assessed via salt spray (B117). The coating systems, based on Base #1, were applied to blasted panels (SA2.5) followed by 7 days room temperature cure, the final dry film thickness for the three systems were about 9 mils. The photo images of testing panels after 2000 hours salt spray exposure are shown in Figure 18. The surface rusts were removed by using aircraft remover paint stripper (Rust-Oleum). It can be seen that, similar to the PolyC system, the #3060 system had no blisters field blisters, which was much better than the PolyB system. Figure 18. 2000 Hour Salt Spray [DFT 9µ over Sa 2.5 steel panels]

PolyB PolyC #3060

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#3060 is found to be suitable for construction and structural adhesive applications due to its superb mechanical properties and fast bond strength development. In Table 13 , the tensile strength, flexural strength and compressive strength of the #3060 system under a 16 hours 40°C cure are listed. Table 13. Mechanical properties [after 16 hours 40°C cure]

#3060 also exhibited good elongation performance due to the presence of the long aliphatic side chain derived from cardanol. As shown in Table 14, the high reactivity of #3060 results in quick bond strength development, as only 8 hours was required to reach 85% of the bond strength established after 7 days. Table 14. Lap shear strength development at 25°C

Conclusions: Cardolite has a new waterborne class curing agent based on renewable cashew nutshell liquid (CNSL) technology for use with standard liquid epoxy resins without the need for co-solvents. VOC-free, primer and self-leveling formulations with a wide formulation latitude and visible end of potlife are now available. An additional new class of light color, solvent-free phenalkamide epoxy curing agents based on renewable cashew nutshell liquid (CNSL) technology has been introduced as excellent replacements to commercial polyamides and polyamidoamines. These new phenalkamides are non-toxic labeling and true solvent-free (no benzyl alcohol). The low viscosity, great wetting properties with good compatibility with various epoxy resins enable these two new phenalkamides many opportunities for high solids formulations without increase in cost. References:

1. Risfaheri et al., Indonesian Journal of Agriculture (2009), 2(1): 11-20 2. Z. Dai, et al., SPI-ERF Conference(1994)