The ingredient that makes cakes fluffy now also works for safer and more sustainable plastics
Foamed plastics are used in everything from furniture to shoes, cars and toys. But thanks to Solvay’s research teams, a safe alternative is now available, based on the company’s historic specialty product: sodium bicarbonate. Wait, what? OK, let’s dive in further with two Solvay scientists who contributed to the development of Alve-One®: lab technician Camille Dupont and project manager Jean-Yves Seguin.
So, who came up with this idea, and why?
Jean-Yves (pictured left): “The idea for a sustainable alternative for the production of foamed plastics came from a multidisciplinary approach gathering our teams in Marketing, Business and at RIC-D, our Research & Innovation lab in the Soda Ash & Derivatives facility in Dombasle, in Eastern France. One of the purposes of RIC-D is to develop new applications for sodium bicarbonate and process improvements for its production. As part of this vast task, our team came across a simple idea: to apply the molecule’s fluffing properties to plastics.”
OK, let’s back up. What are foamed plastics?
Camille: “Foaming means creating little bubbles in the material, sort of like holes in Emmental cheese. As a result, foamed plastics, instead of being 100% pure plastic, are a combination of plastic and air. This is a chemical process, not a physical one, and it’s mainly used for weight reduction purposes, but also for sound and thermal insulation, for softness and to reduce raw material use.”
Jean-Yves: “The trick with foaming is finding the right balance between incorporating bubbles and adding the functionalities enabled by the foaming agent, while maintaining sufficient mechanical resistance. Foamed plastics are everywhere around us: in cars (where their weight reduction properties are particularly crucial), shoes, flooring, furniture, wallpaper, home insulation, sneakers, toys, and so on.”
Then, what’s the problem with foamed plastics?
Jean-Yves: “The problem lies in the ingredient used for the foaming process: azodicarbonamide, or ADCA. This substance is used in 90% of the foams produced with chemical blowing agents, yet it is polluting, the end products emit VOCs (volatile organic compounds that pollute indoor air – and contribute to that ever popular ‘new car’ smell) and its residues limit the recycling of the plastics it’s mixed in with. ADCA is classified as a substance of very high concern (SVHC) by REACH, Europe’s regulation for chemicals, so we are proud to have developed a valuable alternative.”
What’s the sustainable alternative that you helped to innovate?
Jean-Yves: “It’s called Alve-One® Solutions and was developed following a global technology push. Our goal was to identify all the domains where the properties of sodium bicarbonate could be applied, and one of the ideas that came out of that was the encapsulation of sodium bicarbonate to allow the control of the gas release, as in pharmaceutical applications, to enable plastic foaming.”
Camille: “Seeing the poor environmental profile of ADCA, our team set out to bring an alternative to market, and we did it fast, working closely with our customers right from the beginning of product development.”
Every ton of ADCA replaced by Alve-One® in foamed plastics is equivalent to 10 tons of CO2 emissions avoided.
So what is Alve-One® exactly?
Camille (pictured right): “It’s sodium bicarbonate combined with additives for functionalization (more on that below). It has an inorganic-based formulation and comes as a powder with varying particle shape and size that manufacturers can mix in with all types of resins for all the current applications of foamed plastics. Sodium bicarbonate is a common household product that is used in baking powder, animal feed and pharmaceuticals. It’s harmless health- and environment-wise.”
Jean-Yves: “When used as a baking agent, sodium bicarbonate releases a gas that makes cakes fluffy: with Alve-One®, the same principle is applied to plastics.”
Let’s talk science...what’s the chemistry behind the product?
Jean-Yves: “In order for sodium bicarbonate to be efficient in foaming plastics, we need to resort to functionalization. When it reaches a certain temperature, the molecule decomposes into gas and water: that’s what generates the bubbles. But since the sodium bicarbonate is mixed in with plastic, this decomposition has to happen at a higher temperature than usual in order for the foaming process to work.”
Camille: “The solution is to encapsulate it with additives. We screened all the products and technologies to do that, conducted tests and formed partnerships with numerous companies and universities. One of the challenges to overcome was the processing temperature, which can vary greatly according to the plastic being foamed (PVC, PP, PE, XLPO, EPDM…) and the process used (extrusion, calendering, injection molding…). Thanks to our formulation skills, the Alve-One® team developed step by step a family of foaming agents that could fit all processing conditions while exhibiting similar performance to ADCA.”
And what then makes Alve-One® more sustainable?
Camille: “In addition to being a safe product, Alve-One® also has a much smaller carbon footprint than ADCA, due to a series of factors reducing CO2 emissions at every step of the product’s lifecycle: manufacturing, transportation, recyclability (plastics containing Alve-One® can be recycled, as opposed to those containing ADCA), and end-of-life: the ultimate residue of Alve-One® is sodium carbonate.”
Jean-Yves: “Not to mention, it is estimated that every ton of ADCA replaced by Alve-One® is equivalent to 10 tons of CO2 emissions avoided. Because of all this, Alve-One® was awarded the Solar Impulse Efficient Solutions Label and identified as a clean solution by chemical vigilance NGO ChemSec.”
So why isn’t it everywhere already?
Jean-Yves: “Alve-One® has been commercially available since 2019, and certain manufacturers have started using it in their formulations. The Covid-19 pandemic slowed down its propagation, but there is another obstacle: force of habit. ADCA has been around for decades, and manufacturing processes have long been optimized for its use. There is a lot of education necessary.”
Camille: “Manufacturers want a product that will adapt to their specific manufacturing processes. We are collaborating closely with our customers for their current and future needs. The strength of Solvay is that we don’t just sell a product, we also provide expertise and know-how.”
Jean-Yves: “Alve-One® can be tailored to the needs of both thermoplastics and elastomer-based foam producers. The automotive industry, among other businesses, is particularly enthusiastic about this customizable alternative to ADCA as it enables them to pursue their efforts in eco-design in a sustainable way while ensuring better quality indoor air for passengers and being in line with the new chemicals strategy for sustainability set up by the European Union, which means the use of ADCA is only going to become more and more strictly regulated. Our work has even generated other substitution opportunities beyond Europe, such as OBSH, another less widespread organic chemical blowing agent.”
Camille: “Up to now, there was no alternative, but we’ve been seeing great results with Alve-One®, and rising consumer awareness is another push for its adoption. In the meantime, we continue to work on solutions to make it even more efficient and cost-effective.”
As consumers and companies turn to safer and more sustainable chemicals, solutions such as Alve-One® are poised to take off, for the health of people, planet and business.