Acrylated polyurethanes by reactive extrusion

A one-step acrylated polyurethanes prepolymers synthesis by reactive extrusion and bulk reaction is discussed.These oligomers are obtained by a simultaneous reaction of MDI, polycaprolactone and hydroxyethyl-acrylate. In order to obtain a high reaction conversion within the extruder, tin laurate catalyst was used at 90°C. In these conditions, an appropriate radical initiator can be introduced during the extrusion without double bond polymerization. Comparing bulk and reactive extrusion prepared products, oligomer Tg were respectively 18°C and +8°C for oligomers and +18°C and +27°C for the issued networks.