A team at the University of Missouri is working on a new approach to polyurethane systems formulation that leans heavily on experience gained in the chemical engineering sector.
The goal is to be able to simulate virtual formulations to make the process of designing real formulations faster, cheaper and more efficient.
Putting computer simulation at the heart of formulations design has the potential to transform the polyurethane industry in the same way that process simulators have transformed engineering design.
If the process is as successful in polyurethane formulation design as it has been in engineering design, it will enable faster and better development of new formulations as well as the use of bio-based raw materials. It will also improve our understanding of fundamental processes, and as a bonus, the application of artificial intelligence will help to efficiently address aspects of safety, environment, and patentability.
The university group is several years into developing a formulation simulation system that would achieve these goals. They are beginning to realise both expected and unexpected benefits.
Why use simulation?
Simulators are used to model a large number of systems and processes which can be understood in physical chemistry terms through multiple differential equations. Improving computing power gives simulators access to dozens of reaction and thermodynamic parameters, and several degrees of freedom. These complexities are as relevant to building a complex petrochemical plant as to the smaller but equally complicated job of designing and modelling the chemical and physical processes in polyurethane foam-forming processes.
In chemical engineering, for example, once thermodynamic and kinetic parameters are obtained for pure components, the formulation simulation is able to predict the behavior of the many combinations of these pure components. The same is increasingly true of polyurethane formulations.
The Missouri team has examined the processes used in making a viable polyurethane formulation and looked at the levels of complexity in each stage. It grouped these into four sets ranging from the comparatively simple in Level 1 to complex in Level 4. This gave the team a direction of work and it has substantially completed all of the Level 2 problems.
The details of all the methods and applications use, and yet to use, exceed the space available, so the team will concentrate on three current predicted temperature profiles, tack-free times, and successful foam formation with a short look at possible applications of vapour phase emissions of foams.
Figure 1 shows representative concentration, temperature, degree of polymerisation, and height (density) profiles generated by the simulation.