Concentrol, a leading company in chemical solutions, has always kept in mind that it is necessary to leave the least possible impact on the planet. Therefore, more and more, they take special care in the development of their new solutions and in the effect that these can have on the environment.
As has been demonstrated throughout a life span dedicated to the industry, polyurethane has many uses. It can both be used for the manufacture of coatings and paints, for food preservation or for insulation and construction, among others. PU is a material that is being used more and more due to its effectiveness, safety, lightness and great insulation qualities. Originally, CFC gases were used for the manufacture of polyurethane foam, then HCFCs and, years later, HFCs were used. The problem with all these fluorine-based agents is that, despite the advances that each one of them made for the sector, they continued to be harmful to the environment.
By constantly studying the market, Concentrol has detected the need for new silicone surfactants necessary for the manufacture of foams from these new blowing agents – HFO (hydrofluoroolefins), the “ecofriendly” blowing agent. For this reason, after intensive R&D work, a new range of surfactants is currently being manufactured and marketed. These products help producers of polyurethane systems to manufacture more environmentally sensitive solutions.
HFO: what is it and what are its benefits?
HFO is a blowing agent that is used as a blowing agent to form polyurethane foam. It is part of the fourth generation of refrigerants and is an element of easy conversion, safe and of low total cost. Unlike the rest of blowing agents with these characteristics, they are not persistent, bioaccumulative or toxic, they do not have any impact on the ozone layer and their use implies a very small Global Warming Potential (GWP). In addition, it should be noted that the degradation of HFO can lead to trifluoroacetic acid (TFA), which at current concentrations does not affect marine life, humans or the environment. As explained in a Honeywell sustainability article, “to date, the use of HFO refrigerants and blowing agents has helped avoid the release of 170 million metric tons of CO2e into the atmosphere so far, equivalent to emissions from more than 35 million cars, almost all licensed cars in the UK”.
All these characteristics make it the most viable alternative in terms of sustainability and energy efficiency. Many scholars agree that HFO could be, in the not too distant future, the substitute for HFC, which is why Concentrol will continue to bet on having suitable solutions for its use.
The implications of silicone surfactants
One of the most important drawbacks to take into account when working with HFO has to do with the degradations derived from its use. In the ozone layer, these blowing agents can lead to the following two chemical reactions:
CH2= CFCF3 + OH —> CF3COF + HCHO + H₂O + O2
CH2= CFCF3 + + Cl —> CF3COF + HC(O)Cl + O2 + CO
In the specific case of PU systems, the most common is that HFO triggers the first of these reactions, since they carry bases (OH groups).
The first chemical reaction gives rise to reaction number three, which is the following:
CF3COF + H₂O —> CF3COOH + CO₂ + HF
The resulting reaction, formed by CF3COOH and HF, is what could lead to the degradation of surfactants, since they can give rise to an acidic and corrosive environment with much more aggressive conditions than those they usually have. If you want to investigate more about this topic, you can consult the “Study on environmental and health effects of HFO refrigerants”, by the Norwegian Environment Agency.
In the following table, you can see very visually all the HFOs that exist at this time, and those that end up emerging after their decomposition.
Contrary to what some people think, all these degradation problems mentioned above occur when the surfactant is formulated with HFO for several days and in closed systems, not at the time of foaming in situ, a process that does not usually cause problems.
Besides, it is also common to carry out aging studies to see how this blowing agent behaves over time. To analyze the aging process, several experiments are carried out that can last up to two weeks. These tests use high temperatures (50-60 °C), which serve to simulate a longer period of time. With these processes, it is analyzed if the surfactants support the degradation generated by the HFO blowing agent.
Concentrol’s current solutions
Concentrol’s research team continues to focus on investigating surfactants for all types of applications that carry HFO. Currently, in their product range they already have several consolidated references with good results for different applications, such as:
- CONCENTROL STB PU-2248 for integral or spray PU foam.
- CONCENTROL STB PU-2272 for discontinuous insulation panels (PUR and PIR) and appliances.
- CONCENTROL STB PU-2285 for discontinuous insulation panels (PUR and PIR) and block foam.
The company also has others that are under development. In addition, it should be noted that some of these references are without SVHC, that is, cyclic components.
Concentrol works with the objective of responding to the specific needs of each client, and therefore offers the possibility of adapting solutions based on their preferences. Contact us and we will be happy to advise you.
