Soft Ionomeric TPU

Patent Title: SOFTENING THERMOPLASTIC POLYURETHANES USING IONOMER TECHNOLOGY

 Number/Link: US20160347900

Applicant/Assignee: Univ. Akron; Covestro

Publication date: 1-Dec-2016

Gist”: TPU is prepared with ionomeric groups having bulky counter-ions

Why it is interesting: According to this invention a novel type of plasticized thermoplastic polyurethane can be made  by incorporating as chain extender a diol containing an ionic group with a bulky counter ion. It is said that the steric hindrance of the bulky counter ions creates additional free volume that softens the polymer and lowers the melt viscosity. In the examples N,N-bis(2-hydroxyethyl)-2-aminoethane sulfonic acid (BES) is used together with bulky alkylammonium cations. The softest TPU shown has a 37 Shore A hardness at 25% hardblock content and 7.6 mole% BES-tetrakis(decyl)ammonium. This accounts for a 35 point hardness decrease compared to an ionomer-free control sample.

N,N-bis(2-hydroxyethyl)-2-aminoethane sulfonic acid

N,N-bis(2-hydroxyethyl)-2-aminoethane sulfonic acid

Highly Tuneable Shape Memory Polyurethanes

Patent Title: PROCESSABLE, TUNABLE THIOL-ENE CROSSLINKED POLYURETHANE SHAPE MEMORY POLYMERS

 Number/Link: WO2016/126703

Applicant/Assignee: Texas A&M University

Publication date: 11-08-2016

Gist”: SMPUs are made from combinations of different diisocyanates and chain extenders and different levels of crosslinking using thiol-ene click chemistry

Why it is interesting: This invention is about shape memory polyurethanes with tuneable glass transition temperature and stiffness. In a first step a low mole weight TPU is prepared from a diisocyanate and a short chain diol including some trimethylolpropane allyether (TMPAE) and allylalcohol as chain stopper. The TPU is then blended with a polythiol and a photoinitiator to allow for UV curing. The Tg can be tuned from 30 and 105°C by combining different types of chain extenders and di-iso’s ranging from DEG-HDI to CHDM-H12MDI.  The modulus (in the rubber state) can be  varied between 0.4 to 20 MPa by controlling the level of crosslinking through the amount of TMPAE and amount and type of polythiol.  The SMPUs are said to be especially useful for biomedical applications.

Reaction scheme of the invention

Reaction scheme of the invention

Dianhydrohexitol-Based TPU

Patent Title: METHOD FOR PREPARING THERMOPLASTIC POLYURETHANE PELLET

 Number/Link:  WO2016/055731  (French)

Applicant/Assignee: Roquette Freres

Publication date: 14-04-2016

Gist”: Use of isosorbide as chain extender for TPU preparation

Why it is interesting: According to this invention the use of dianhydrohexitols as chain extender results in thermoplastic polyurethanes with improved overmoulding properties, notably improved colour, abrasion resistance and soft touch. In the examples TPUs prepared from 4,4’MDI, PTMEG 1000 and chain extended with isosorbide are compared to 1,4-butanediol extended TPUs. The isosorbide TPUs are softer with better abrasion resistance and -in my opinion surprisingly- have a somewhat brighter colour.

Isosorbide

Isosorbide

 

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