The condensation polymer formed by para-formaldehyde reaction with di-amines has the property of forming engineering plastics with extremely high stiffness and also there are other di-amines which form self-healing organogels. Two such polymers discovered by scientist from IBM and KACST (King Abdulaziz City for Science and Technology) are as below:
The product thus formed are called hemiaminal dynamic covalent networks (HDCNs). Electron rich N-methylpyrrolidone (NMP) is used as solvent. HDCNs formed by polycondensation between para-formaldehyde and 4,4'-oxydianiline (ODA) and cyclized at high temperatures (50-200 ˚C), produce poly(hexahydrotriazine)s (PHTs) or PHT-HDCN (Modulus: 14 GPa) whereas at temperatures lower than 50 ˚C form ODA-HDCN (Modulus: 6 GPa).
One advantage of the high stiffness thermosets formed above is that unlike other thermosets, it can be dissolved at low pH to give back original monomers.
The figure above is a brief overview of the polymers formed by para-formaldehyde reactions with di-amine as explained earlier. The ODA-PHT and ODA-HDCN are engineering plastics and have application in the field of aviation and automotive industries. This has become even more important as more and more plastics are being used in the these two sectors to reduce weight and hence enjoy benefits of fuel savings and high speed. The self-healing organogels have more significant application in electrical and electronic applications.
As an employee of the Product Application Department at NATPET, this was one of the various research on which I was assigned to gather literature survey and present to higher management. The report included feasibility study of the project, expected cost of building production plant, market size, and market value for these polymers.