High-Performance UV-Curable PUDs With High Renewable Carbon Content

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UV-Curable Polyurethane Dispersions

!  UV-PUD – What is it?

!  Acrylated polyurethane dispersed in water

!  Self stabilized by built in dispersive groups

!  Apply, dry, cure application process

!  Short, low temperature flash dry to remove water – not lengthy high temperature bake

!  Fast growing segment of UV-curable materials market

!  Active area of research, development and publication

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UV-Curable Polyurethane Dispersions

!  Why UV PUDs?

!  Vs. 100% Solids UV •  Dispersion viscosity independent of polyurethane MW – Low viscosity at high MW •  Avoid lower MW volatile monomers or solvents

•  Although reactive diluents can still be beneficial •  Differential properties

•  Low shrinkage on cure •  Balance of hardness/flexibility •  Enhanced adhesion •  Natural “close to grain” appearance on wood

•  Can be dry to touch before UV cure

!  Vs. Non-UV Coatings •  Instant development of properties •  Improved properties

•  Hardness, scratch/abrasion and chemical resistance •  No pot life concerns (vs. 2K systems) •  Low/no VOC

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UV-PUDs for Sustainable Coatings

!  Waterborne coatings ●  Low/No VOC

!  UV-Curing •  Low energy usage •  Reduced CO2 emissions •  High productivity

Renewable raw materials •  Reduced use of fossil fuels •  Smaller carbon footprint

Inherently sustainable products combining benefits of waterborne and UV-curing technologies

!  Use of renewable (bio-

sourced) raw materials can add another level of sustainability

!  Examples with vegetable oil polyols are well known •  Contributions of Prof. Mannari and

co-workers

!  Our approach – Use bio-sourced monomer building blocks to design polyester polyols with custom tailored properties.

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The “Biorefinery” for Chemical Building Blocks

!  Biorefinery – “A facility that integrates biomass conversion processes and equipment to produce fuels, power and chemicals from biomass.”

!  Some advantages of chemically refined building blocks ●  More consistent product ●  Higher purity ●  Some are drop-ins for petro-sourced products ●  Many unique structures only possible from natural products

!  Expanded range of biomass feedstocks including non-food sources ●  Cellulosics vs. vegetable oils ●  Agricultural or forestry waste materials

Biological or Chemical

Processes BIOMASS Purify

Chemical Building Blocks

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Examples of Bio-Monomer Building Blocks

!  Recent reviews ●  “The Highway Towards Bio-Polymers: The Breakthrough of Bio-Based Monomers & Building Blocks”, Michel Biron, Oct

9th, 2013. http://www.specialchem4bio.com/articles/2013/10/bio-the-highway-towards-bio-polymers ●  Harmsen, P. F. H., Hackmann, M. M. and Bos, H. L. (2014), Green building blocks for bio-based plastics. Biofuels,

Bioprod. Bioref.. doi: 10.1002/bbb.1468

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Project Approach

!  Biopolyester polyols were designed so that UV-PUDs made from them would have properties suitable for high performance wood coatings. ●  Good coating application properties – flow, leveling ●  Hardness plus high stain, water, chemical and abrasion resistance and good appearance

!  Several polyester biopolyols made by typical polyester polyol synthesis methods for screening ●  Focus on monomers with no petrochemical analogues

!  Two were selected for further study based on their ease of synthesis, ready monomer availability and expected properties in UV-PUDs.

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Polyester BioPolyols

!  100% renewable carbon content

Physical Form at 25oC

OH# (mg KOH/

gm)

Molecular Weight (GPC,

Mn/Mw)

Color (APHA)

Viscosity (cPs)

BioPolyol 1 Semi-solid 200 610/1290 100 4800 @ 75oC

BioPolyol 2 Semi-solid 211 540/770 10 8700 @ 60oC

BioPolyol 3 (DuPont

Cerenol 1000) Liquid 117 959 (calculated) 40 400 @ 25oC

!  Bio-polyether polyol used to tailor flexibility vs. hardness of UV-PUD ●  DuPont CerenolTM 1000: Poly(1,3-propanediol)

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Bio-Based UV-PUD Synthesis

!  Normal UV-PUD concepts can be applied

!  Made by unique, solvent free process (patent pending)

!  Free of surfactant and tin catalyst

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Liquid Properties: UV-PUDs with BioPolyols

UV-PUD Reactive Diluent Viscosity, 25oC Particle Size (nm)

1 3EOTMPTA 6 cPs 114





6 1,10-DDDA 21 cPs 120

7 1,10-DDDA 13 cPs 160

Control 1 3EOTMPTA 10 cPs 120

Control 2 3EOTMPTA 10 cPs 120

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!  Control 1: Commercial, all petrochemical sourced UV-PUD for high-end wood coatings

!  Control 2: Flexible biobased UV-PUD made with CerenolTM polyether polyol

!  Typical properties: •  pH = 7.2 – 7.8 •  Wt% solids 38.5 – 41.3% •  MFFT < 5 C

!  Good dispersion stability

!  Tack free after physical drying

Liquid Properties: UV-PUDs with BioPolyols

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Cured Physical Properties

UV-PUD Polyols Mole Ratio Tensile

Strength Elongation 1% Modulus

1 100% BioPolyol 1 Too Brittle to Test

2 1:1 BioPolyol 1+3 4400 4.5 135,000

3 2:1 BioPolyol 1+3 Too Brittle to Test

4 1:1 BioPolyol 2+3 3900 6.3 96,000

5 2:1 BioPolyol 2+3 Too Brittle to Test

Control 1 Petrochemical Polyols 4900 3.7 180,000

Control 2 100% BioPolyol 3 4200 9.7 112,000

All with 3EOTMPTA diluent

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Cured Physical Properties

!  Properties strongly dependent on polyester biopolyol structures

!  Products made from only polyester biopolyols are very brittle, hard, high Tg

!  Polyether biopolyol used to toughen and flexibilize

!  Test Formulation (% on solids):

●  1% HEUR thickener ●  0.5% wetting agent ●  5% photoinitiator ●  Dilute to 35% solids

!  Apply at 6 mils wet

!  Air then oven dry

!  Cure at 50 fpm, 2 Hg lamps

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Coating Properties

Koenig Hardness (sec)

0

50

100

150

200

UV-PUD 1 UV-PUD 2 UV-PUD 3 UV-PUD 4 UV-PUD 5 Control 1 Control 2

0 1 2 3 4 5

Control 2

Control 1

UV-PUD 5

UV-PUD 4

UV-PUD 3

UV-PUD 2

UV-PUD 1

Rating 1=Worst 5=Best

FlexibilityTaber AbrasionStain

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!  UV-PUDs 1, 3 and 5 with high levels of polyester biopolyols have highest hardness – exceed control

!  Hardness and flexibility easily tailored with polyether biopolyol 3

!  UV-PUDs 2 and 4 with 1:1 ratio of hard:soft biopolyol have the best balance of properties

•  Improved abrasion resistance

!  All pass 200+ MEK double rubs

!  Stain resistance of biobased UV-PUDs less than Control 1

•  Lower mustard resistance

Coating Properties

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Effects of Reactive Diluents

!  In 100% solids UV ●  Reduce viscosity for application ●  Help with adhesion ●  Contribute to cured properties

!  In UV-PUD ●  Contribute to cured properties ●  Help with film formation

Reactive Coalescent

!  Reactive diluents commonly used in UV-PUDs not renewable ●  3EOTMPTA

!  DDDA one of the few renewable multifunctional acrylates available ●  1,10-Decanediol Diacrylate; derived from castor oil

62% Renewable Carbon

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Reactive Diluent Effect on Coating Properties

UV-PUD Reactive Diluent

1 3EOTMPTA

7 1,10-DDDA

2 3EOTMPTA

6 1,10-DDDA

Pairs 1 & 7 and 2 & 6 have the same polyurethane compositions •  Differ only in reactive diluent

0 1 2 3 4 5

UV-PUD 6

UV-PUD 2

UV-PUD 7

UV-PUD 1

Rating 1=Worst 5=Best

HardnessFlexibilityTaber AbrasionStain

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Reactive Diluent Effect on Coating Properties

!  Replacement of 3EOTMPTA with 1,10-DDDA…

!  Very brittle UV-PUD 1 is flexibilized and toughened

!  Little effect on properties of inherently more flexible UV-PUD 2

!  Small decrease in stain resistance; pass 200+ MEK double rubs

!  Overall increase in renewable content of cured coating

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Conclusions

!  UV-PUDs made from 100% renewable biopolyols can match the performance of commercial petroleum based products in wood coatings. ●  Products are solvent, surfactant and tin free ●  Testing on other substrates and in other applications is in progress

!  The diversity of bio-monomer building blocks now available allows wide latitude in design and properties of renewable UV-PUDs. ●  Unique structures only available from renewable sources can provide differential

properties

!  Reactive diluents – including renewable versions – can be used to tailor properties and performance and add to sustainability.

!  Patents have been filed on these unique new materials.

For more information:

www.sartomer.com

[email protected]

(800) SARTOMER

(610) 363-4100

@SartomerGlobal on Twitter

Thank you

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High-Performance UV-Curable PUDs With High Renewable Carbon Content

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