Title: USE OF POLYUREA NANOPARTICLES AS PERFORMANCE MODIFIERS IN POLYURETHANE MATERIALS
Number/Link: WO2014/012769
Applicant/Assignee: Huntsman
Publication date: 23-01-2014
“Gist”: A dispersion of polyurea particles prepared from 4,4′ MDI, diamine chain extender and a high mole weight monoamine is used to improve mechanical properties of flex foam.
Why it is interesting: Dispersions of polyurea particles with an average diameter of a few hundred nanometer and a Tg>150°C (pref.) can be produced by first reacting a relatively high MW polyether monoamine and a di-isocyanate (optionally dispersed in e.g. polyol) and subsequently adding a diamine chain extender. The dispersion is then used in a flexible foam or elastomer formulation, such that the amount of particles in the material is about 1-5% (w/w). In an example a 2000MW EO/PO monoamine was used together with 4,4′-MDI and a diamine chain extender to produce a particle dispersion in polyol, which was then used in polyurethane formulations. The particles do seem to have a positive effect on mechanical properties, however, the results for flex foam are clouded because of a sharp increase in material density compared to the reference. This density increase may well be due to a cellopening effect as described in WO2007/104623 in which a similar particle dispersion is used.