All posts in category Thermoplastics

TPU from POM-Polyether Polyols

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

TPU for 3D Printing

Title: METHODS OF USING THERMOPLASTIC POLYURETHANES IN FUSED DEPOSITION MODELING AND SYSTEMS AND ARTICLES THEREOF .

Number/Link: WO2015/109141

Applicant/Assignee: Lubrizol

Publication date: 23-07-2015

“Gist”: TPU with specific crystallization temperature and modulus retention can be used for fused deposition modeling

Why it is interesting: Additive manufacturing in all its forms has been a steadily growing trend over the last few years. Many different materials have been used in these processes, but the use of thermoplastic polyurethane has proven to be difficult because of its low crystallization rate, broad melting range and challenging melt-viscosity control. According to this application TPU can be used for fused deposition modeling (“3D printing” by extruding molten thermoplastics) when it has a crystallization temperature of about 115°C and retains its shear modulus well with temperature. Examples of such TPUs have a high harblock content (about 50%) and a molar ratio of chain extender to polyol of 2 to about 4, and are prepared from 4,4′-MDI, butandiol and 2000 MW PTMEG polyether or butylene-adipate polyester diols.

Fused Deposition Modeling

Polyurethane-Polyamides from Dimer Diacids

Title: A POLYOL BASED ON DIMER FATTY ACID RESIDUES AND THE CORRESPONDING POLYURETHANES

Number/Link:WO2015/097433

Applicant/Assignee: Croda

Publication date: 2-07-2015

“Gist”: Polyurethane/polyamide elastomers based on dimer diacids and long chain dicarboxylic acids

Why it is interesting: Polyurethane elastomers (and thermoplastic elastomers) based on dimer diacids or dimer diols are very hydrophobic and hydrolysis resistant but are relatively soft with lowish mechanical properties. According to this invention, using a blend of a dimer diacid (or -diol) and a (semi-) crystalline C17 to C32 dicarboxilic acid (or -diol) results in elastomers with greatly improved hardness and tensile strength while retaining flexibility and hydrolysis resistance. The C17 to C32 dicarboxylic acids can be prepared by a self-metathesis reaction of unsaturated fatty acid esters. In the examples a C36 dimer diacid is used together with 1,18-octadodecanoic acid (prepared by metathesis from methyl oleate). This is reacted ‘one shot’ with 4,4′ MDI and hexanediol or DEG, resulting in 85 shore A elastomers with high elongation and hydrolysis resistance.

A C36 dimer diacid

Innovation in Polyurethanes

All posts in category Thermoplastics

TPU from POM-Polyether Polyols

TPU for 3D Printing

Polyurethane-Polyamides from Dimer Diacids

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