In previous blogs, we have looked at coatings products in the context of their supply chains from raw materials through manufacture and on to use. We have learned that every element of the product life cycle has implications for the environmental, social and economic pillars of sustainability, and that all three elements need to be taken into account when new products are being developed. No-one will thank us in the long run for wasting valuable resources, be they materials, people or money,  particularly when those resources have a finite source of supply that could become exhausted some day!

Companies in the chemical, plastics and coatings sectors are increasingly applying this kind of thinking in the development of innovative technologies and processes. This is very much to their collective credit. Either they seek to reduce the environmental and economic impact in the coating manufacturing chain or they work to enhance the functionality of coatings to improve the overall level of sustainability for the downstream use and consumer. They may even try and impact both upstream and downstream aspects of sustainability with the same product development.

About three years ago, I visited a local DIY store in England and noted on the top of a can of architectural decorative paint the proud claim that ‘this can of paint has 30% less carbon footprint than it did three years ago’. At the time, carbon footprint was all the rage as the sole measure of sustainability and dovetailed well with concerns over carbon dioxide content in the atmosphere and future supplies of oil.

This year, I attended the European Coatings Exhibition in Nuremburg and noted a significant broadening in thinking. There was recognition that carbon footprint is not the sole measure of sustainability. Instead, plenty of promotional airtime was given to ‘renewable content’ or ‘bio-sourced’ raw material usage derived from either agricultural products or waste streams. In support of this thinking, AkzoNobel recently announced that it was committed to doubling its proportion of renewable material in its purchasing slate from its current levels by 2020.

However, the idea of using renewable materials is not new. Biopol, now more than 30 years old, is manufactured from glucose or starch using an enzyme route. It has similar mechanical properties to polypropylene and is currently used in the medical industry for internal sutures. Synthesis routes that produce biodiesel and bioethanol have been available for some time and have been increasingly exploited over the last 10 years in North America.

More recently and closer to the coatings industry, we have seen Purac’s biobased building block, Lactide, which is produced by fermentation from sugars, and can be used to build polyester resin. These co-polyester resins can be used in polyester-based coatings, PU coatings, other PU applications and unsaturated polyesters. Interestingly, Purac claims that its products enable polyester resin producers to create modified resins with an improved property profile in their final application; an important bonus from sustainable innovation.

In a bold move, Solvay announced significant investment in the manufacture of a precursor to epoxy resins using renewable sources of glycerine as a raw material replacing propylene derived from oil. Using technology that was developed in the first half of the last decade, Solvay has started up a world-scale plant to make Epichlorohydrin under the trade name (Epicerol®) in Thailand with a second unit under construction in China. A full Life Cycle Analysis has demonstrated significant net benefits offered by this route opposite existing manufacturing processes.

Following on from this announcement, AkzoNobel and Solvay have announced an unprecedented three-year deal in which AkzoNobel guarantees to buy volumes of glycerine-based epichlorohydrin indirectly via the epoxy resins its purchases from Solvay‘s customers. This is another step forward in AkzoNobel’s quest to double its renewable purchases and demonstrates how the customer can influence the upstream supply chain to focus on improving the sustainability of their part of the value chain.  

On the surface, one could assume that any replacement of finite sources of raw materials with renewable ones would be a good thing. However, a local improvement may have a negative impact elsewhere in the supply chain. This is particularly the case if these renewable raw materials have been taken out of the food supply chain or require excessive amounts of water to grow in an area where rainfall is limited.

This line of research still has a lot of mileage left in it, and the blog will be returning to this issue in future editions. When one reads that U.S. academia is working on synthetic photosynthesis, you can be sure that we will all be in for some interesting surprises and hopefully some truly sustainable benefits from technological innovation down the pike.

 If you are aware of other good examples of renewable raw materials being used either directly or indirectly in the manufacture of coatings, this blog would be pleased to hear from you. 

-Tony Mash