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VAE Emulsions - Current Status and Future Innovations

Dr. Alexander Madl – Jan 30, 2018

Evolution of VAEVinyl-acetate ethylene co-polymer emulsions (VAE) are one of the youngest children in the family of emulsion polymers.

Initial experiments to introduce ethylene as monomer into the emulsion polymerization were done in 1950s and VAE was made commercial available in the late 1960s1. This new type of co-polymer emulsions took a while to become successful outside of niche markets and on global scale.

Starting in the 1990s their growth rate got an onset and now VAE emulsions are amongst the fastest growing sub-segments in the emulsions world.

The business is currently driven by the shift to Asia and other emerging regions with an ongoing boom in construction. Adding to that is the increasing environmental awareness of the local customers.

Housing and construction is going green! Therefore waterborne systems continue to replace solventborne ones.

VAE is prone to gain increasing share when it comes to the application of low emission or even zero volatile organic component (VOC) formulations.


Have a look on the graph below showing historical and prognostic growth rates for specific sub-segments of polymer emulsions.

Growth Rates of Polymer Emulsions
Historical and prognostic growth rates for specific sub-segments of polymer emulsions based on data for polymer emulsions global demand 2000 – 2021
Source: “D. Urban and K. Takamura (Ed.), Polymer Dispersions and Their Industrial Applications, Wiley-VCH, 2002“, Grand View Research, and Freedonia, Inc.


Much different from most of the other sub-segments of emulsion technologies with a high diversification of suppliers; only about ten producers in total, supply to the VAE segment. Amongst this already very little group, only three corporations dominate the market:


 » Wacker
 » Celanese, and
 » Dairen

Together they account for about 80% of the global available capacity. All three producers are fully or partly back-integrated into Vinyl acetate monomer (VAM).


Estimated Shares of Global VAE Producers
Estimated share of VAE producers on global VAE capacity
Source: Freedonia, Inc. and corporate publications



Half a Century of VAE Emulsions


Initially many companies experimented with VAE emulsion technology. Amongst them were:

 » Air Reduction Corporation (Airco)
 » DuPont
 » Monsanto
 » Hoechst
 » Wacker, and
 » Union Oil of California

Over the years, some of them sold the technology or disinvested from it. Between 1995 and 2010 several mergers and acquisition led to the formation of the two global leaders.

In 2008 Wacker took over the emulsions business from Air Products, after already 10 years of shared responsibilities in two joint ventures. Celanese took over the Hoechst legacy VAE emulsions business from Clariant. And then, they merged it in 2005 with the emulsion business legacy from ICI.

Development in VAE Around the World


The recent development of the VAE emulsions segment was characterized by fast expansion of manufacturing capabilities in Asia.

Since 2005 the leading VAE producers built up about 700,000 metric tons annual capacity for VAE emulsions in China and South-East Asia. And another 100,000 metric tons are already announced to go on-stream in the next two years. Less than 100,000 metric ton capacity expansion were announced both in Europe and USA for the same time frame, whilst in parallel VAE manufacturing sites were closed or consolidated.



VAE Technology Challenges


There are also challenges for VAE technology. Most serious one is the stable supply with ethylene. If the VAE manufacturing site is not directly connected to ethylene supply, there are additional challenges when ethylene needs to get brought in with rail or road car, compared to liquid monomers. This adds to raw material cost.

In general, raw material cost is still the largest cost driver for VAE emulsions. There are regional differences in price for the main monomers VAM and ethylene that also impact the sales price. Also, cost for supply of the final product can have significant contribution to the total cost. This is true for all emulsion products, where up to 50% water is carried around on the way to the customer.

In the recent years VAE emulsions found its limits in growth in existing applications, such as:

 » Engineered fabrics or
 » Paper and packaging adhesives

The reasons are in general low growth rates of the applications or non-in-kind replacement.

VAE Technology Challenge

In general, VAE emulsions face strong competition in most of its markets. In all major regions there are three or more suppliers active for VAE emulsions, beside the competition from other emulsion chemistries or other technologies solving the same customer need in the application. With this comes, that there are only a few segments left, where VAE emulsions hold a real specialty position. Most of the large volume products became commodities and therefore margins are challenged.


VAE Chemistry with VAM


VAE emulsions form a special class within the space of Vinyl acetate based co-polymer emulsions. VAM and Ethylene exhibit almost ideal co-polymerization behavior. Therefore, they can form ideal random co-polymers under the right process conditions.

Ethylene adds softness, flexibility, chemical resistance, hydrophobicity and adhesion to non-polar surfaces to the VAM based emulsions space, which stands for:

 » Rigid polymers
 » Hardness, and
 » Already high adhesion on polar surfaces, such as: Cellulose fiber in paper, wood, or similar materials

The table below lists some typical monomers to synthesize polymer emulsions, with key physical data:

Monomer Boiling point / °C Tg / °C ΔpolyH / MJ
kg-1
Ethylene - 103 - 100 - 3,42
1,3-Butadiene - 4.5 - 85 - 1,28
n-Butyl acrylate 148 - 54 - 0,60
VeoVa10™ 270 - 280 - 3 - 0,48
Vinyl acetate 73 28 - 1,02
Vinyl chloride - 13.4 85 - 1,69
Styrene 145 100 - 0,65


Copolymerization parameters for selected monomer combinations used in commercial emulsion polymerization are mentioned below:

Monomer r1/r2
1,3-Butadiene / Styrene 0.75 / 0.58
Styrene / n-Butyl acrylate 0.19 / 0.80
n-Butyl acrylate / Vinyl acetate 6.40 / 0.03
Vinyl acetate / Ethylene 1.40 / 0.79


 » Continue reading to know more about VAE technology and thus, explore:

 − Major application sectors
 − Possible solutions to limitations
 − Potential materials initiating innovation
 − And more!

1 Comments on "VAE Emulsions - Current Status and Future Innovations"
Yong Hae C Feb 15, 2018
Great explained

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