Approaching a Day When 100% of Petrochemical Raw Materials Can Be Replaced
The latest developments in bio-based coatings
There is much work still to be done to replace all petrochemical raw materials, but there are fewer barriers every day, says Nathan Noyes, sales development specialist for Smart Materials at Croda. Here he offers insight into the remaining challenges and the current focus in bio-based coatings.
What are the main hurdles in developing bio-based coatings?
Nathan Noyes: The development of a bio-based coating is not always a straightforward journey. The hurdles tend to be internal, and can be overcome with clarity, commitment, and collaboration. Clarity as to the priorities and targets for sustainable formulation, including bio-based carbon content, as well as for performance. Commitment to invest the time and energy required to assess which materials have the greatest impact on those targets, and to fully evaluate options for their replacement or improvement. And, most importantly, collaboration with academia, suppliers, partners, and customers wherever possible, to share both the burden and reward of bringing new bio-based technologies to market.
Other practical hurdles to sustainable development still exist in the coatings industry, including a lack of standardized requirements for bio-based content that would drive market demand and innovation. Consideration for the fate at end of life of even bio-based coatings is another limitation on sustainability in our industry and can be seen as either a hurdle to overcome when reformulating or an opportunity.
Which raw materials are currently the focus of research for more sustainable coatings?
Noyes: At Croda we are glad to see strong interest from formulators across nearly all segments to develop more sustainable coatings. Each market area requires a different raw material focus. In the case of architectural and DIY coatings, which today are predominantly acrylic latex systems, we see much-needed research around renewable drop-in replacements for acrylic monomers. And while those technologies are still being scaled, we see a resurgence of interest in bio-based resins such as alkyds, and a toolbox of sustainable additives to help optimize performance while formulating bio-based coatings with these resins, such as our 100% renewable ECO resin emulsifiers, wetting agents, and dispersants.
In industrial and protective coatings, there is a similar focus on reducing carbon footprint by shifting to high performing bio-based alternatives to existing materials, such as epoxy resins and their curing agents, as well as polyols used in polyurethanes; but also a continued effort to reduce, eliminate, or replace ingredients that are harmful to humans or the environment. The development of non-isocyanate polyurethanes (NIPU) is an example of this, and an area where we are proud to collaborate with organizations throughout the value chain for significant progress.
In your opinion, to what extent can petrochemical raw materials be replaced with renewable ones?
Noyes: We are rapidly approaching a day when 100% of petrochemical raw materials can be replaced. But to be clear, this will be through a combination of investment in new, more sustainable routes to existing chemistry and, where this is not practical, careful selection of bio-based alternatives that may be chemically different than incumbent materials but offer performance that is comparable or even superior.
For instance, with our portfolio of bio-based polyester polyols and other building blocks for condensation polymers, we have shown that unique properties can be brought about which are not as easy to be obtained from fossil fuel-based raw materials. At Croda we carefully weigh both approaches in all our developments, and we encourage and assist formulators to do the same.
Even today, alkyd coatings can be made to nearly 100% bio-based carbon content, and polyurethanes are already exceeding 70% in some cases. There is much work still to be done to replace all petrochemical raw materials, but there are fewer barriers every day.