Making a corporate commitment to sustainable development, while a major step in the right direction, has to be backed up by technological developments that not only provide environmental improvements but also ensure economic competitiveness. Not an easy combination to achieve! Such developments often come from unexpected quarters. Papers presented recently at conferences in the United States and Saudi Arabia offer tantalizing glimpses of the way forward in terms of recycling of materials and the use of renewable materials.
A High-Quality Colorant from Recycled Tire Rubber
Sun Chemical recently announced that it had developed new process technology that converts post-consumer tires into a “new, pigmentary material that offers the formulator a colorant with both high-performance and environmental benefits. The new material offers excellent hide, has low resin demand and is ideal for use in thin film coatings that have a smooth or textured finish.”
The tire industry has been looking for new uses for post-consumer tires for many years, and currently the key outlets are fuel, ground rubber and civil engineering applications. When tires are pyrolysed to extract their fuel value, a char remains that can be sold as a carbon black. However, the quality of the resultant product is not acceptable as a colorant for the coatings industry.
The Sun Chemical technology, which provides this elastomeric material in a controlled range of particle sizes and morphologies, is new and proprietary at this stage. However, the degree of control over median particle size despite a variable raw material source offers opportunities for a range of applications as a colorant in spray applications and in thin films. As with many such developments, it is not a direct drop-in replacement for other materials but has some interesting benefits such as improved salt spray resistance, greater lap sheer strength and enhanced tactile properties.
This new technology may very well provide the way forward towards creating a regenerative economic cycle for tire rubber for which the coatings industry and its customers are the prime beneficiaries in terms of sustainability.
What could be seen as simply carbon black made from recycled rubber is much more than that. Its property balance, to quote Sun Chemical, is “unique”; another example of the serendipitous nature of R&D in the world of renewable and recycled materials.
Rust Inhibition Using Naturally Occurring Ginger
I recently attended a coatings conference in Saudi Arabia organised by Al-Jazeera Paints. I was struck by the commitment of both speakers and attendees to new technology, the very different issues and requirements of the marketplace in that part of the world, and also the very positive attitude to sustainability.
When flying into Saudi Arabia, one realises the impact of the climate on building design and materials of choice. Temperatures of 40 °C (100 °F) plus are sustained on a regular basis and are often accompanied by high winds that stir up the desert sand and impair the surfaces of buildings even in towns and cities. A speaker from Jotun took the opportunity at the conference to promote products that had been designed specifically for this region and formulated to offer weather fastness and dirt/sand/alkali resistance.
Another speaker at the conference was Abdulaziz Gomaa from Al-Azhar Universty in Cairo, Egypt. It is well known that the inhibitive action of organic compounds containing sulphur, nitrogen and oxygen is due to the formation of a bond between the metal and the lone pair of electrons present in the additive. He announced that gingerol, a key ingredient in ginger root, has the kind of chemical structure that supports the formation of bonds with metals, and thereby has the potential to inhibit corrosion in combination with suitable paints. Gingerol has an oxygen atom in exactly the right location on the molecule to support bonding to metals, and hence, provide corrosion prevention.
Experimentation with steel coated with an epoxy primer followed by an alkyd topcoat (both paints contained 5% ginger extract) delivered impressive corrosion resistance results in 3.5% salt solutions. The speaker explained that the presence of gingerol leads to the formation of a complex film over the steel surface, which acts as a good barrier between the steel surface and any aggressive environment.
Here we have a naturally occurring molecule that enhances the sustainability of the substrates it protects and is manufactured from raw materials sourced from renewable sources of supply.
Whatever next?? You never know what is around the next corner, and as with recent developments in bio-sourced surfactants and resins, we are not only seeing the potential for lower environmental footprints and reduced variable costs of production, but also the potential for improved properties that can be of significant value downstream.
We do live in interesting times!