Within the last months, the smart chemolysis activities focused on providing material from pilot plant scale (COV) for foaming trials at REC. Different experiments for valorisation of the upper phase by polyurethane (PU) foaming were done by REC based on the recycled polyols obtained from COV. In total, 4 batches of polyols based on chemolysis of standard ether-TDI PU foam were produced.
The polyol purity of all batches was between 98-99% with a minimum amount of amines and other contaminants still present. The recycled polyol had similar properties like IOH, water content, viscosity when compared to a fossil fuel based conventional material. The recycled material when used up to 100% in a standard conventional Recticel comfort foam formulation had similar physical properties, satisfying the comfort foam specifications when compared to the reference PU foam having 100% virgin polyol. Lab-scale flexible TDI based polyether PU foams (cf. Figure) were successfully produced with 100% recycled polyol with a minor change in the formulation. Additionally, we can also conclude that up to 70% recycled polyol, PU foam properties satisfy the comfort foam specifications when compared to the reference without altering anything in the formulation. Also, the PU foam containing 70 or 100% recycled polyol passed the Certipur emission test.
Based on these results, a spreadsheet model estimating the PU recipe based on the different batches of recycled polyols was established. All in one results from foaming trials at REC show that we can replace 100% of the virgin polyol in standard conventional PU formulations (without fillers) by slightly adjusting the recipe and 70% replacement of the virgin material is also possible without any changes in the formulation.