Title: THERMOPLASTIC POLYURETHANES, PRODUCTION AND USE THEREOF

 Number/Link: WO2015/155084  (German)

Applicant/Assignee: Bayer

Publication date: 15-10-2015

“Gist”: Paraformaldehyde-PO polyols are used to make TPU

Why it is interesting: Polyoxymethylene (POM) is a highly crystalline ‘engineering thermoplastic’ often used in blends together with TPU. In this invention POM is not blended but used to make a POM-polyether ‘block’ diol which is then used to make TPU. The diol is prepared by using paraformaldehyde as a starter which is reacted with PO (and optionally CO2) using DMC catalysis. The POM-block acts as a ‘hard block’ and use of the diol allows for an improved control of Tg, melt viscosity, hardness, chemical resistance etc. of the TPU.  In the examples TPU is made from a 2000 MW parafomaldehyde/PO-CO2 block copolymer  together with 4,4’MDI and BDO.

Paraformaldehyde