Oxidation-Proof TPU

Patent Title: POLYURETHANE, METHOD OF PREPARATION, AND ARTICLE COMPRISING THE POLYURETHANE

 Number/Link:  WO2018/057488

Applicant/Assignee:  THE UNIVERSITY OF MASSACHUSETTS

Publication date:  29 March 2018

Gist”:  TPU based on hydrogenated diene diols

Why it is interesting: TPUs based on polyether- or polydiene-diols are prone to oxidative degradation and therefore less useful for e.g. medical applications.  According to this invention, oxidation-stable TPUs can be prepared from hydrogenated polydiene diols with an Mn of 500 to 2000, combined with 5-25% (w/w) polyether diols, chain extender and diisocyanate.  In an example a hydogenated polybutadienediol with Mn of 2000 Da was reacted with 4,4′-MDI together with PTMEG 1000 and BDO in toluene.  At a hardblock content of 35% the TPU showed a Shore hardness of 80A, 250MPa tensile strength and an elongation at break of 520%.

PIB

Hydrogenated (1,2) polybutadiene

 

Enzymatic Recycling of Polyurethanes

Title: PROCESS FOR THE MATERIAL UTILIZATION OF POLYURETHANES

 Number/Link: WO2013/134801 (German)

Applicant/Assignee: Eurofoam

Publication date: 19-09-2013

Gist”: Use of specific enzymes to break down polyurethane into polyamines and its original (polyether)polyols

Why it is interesting: Chemical recycling of polyurethane by hydrolysis, glycolysis etc. is known but requires high temperatures and sometimes (when supercritical water is used) high pressures.  This can lead to side reactions and the contamination of the recycled raw materials. Enzymatic recycling of polyurethanes is known as well but is mostly limited to polyester polyurethanes and esterase enzymes which break down the ester bonds.  The current invention claims that the use of certain hydrolases of the EC3 class, especially arylacylamidase  EC3.5.1.13 selectively breaks the urethane bond. (EC=enzyme comission number). The reaction can be carried out between 30 and 50°C and at a pH of 9.5 to 11. The resulting polyols and amines can be extracted using a polar solvent. While interesting the proposed process may not be very practical as the example shows that 5 days were needed to recycle a 5 gram sample of a model foam.

Schematic representation of the enzyme catalysed reaction.

Schematic representation of the enzyme catalysed reaction.