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

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Dispersions of Comb-Structured Polyurethanes

Patent Title: POLYURETHANE-BASED BINDER DISPERSION

 Number/Link: WO2016122569

Applicant/Assignee: Hewlett-Packard

Publication date: 4-08-2016

Gist”:  Aqueous dispersions of “1,2”-dihydroxypolyacrylate -based polyurethanes

Why it is interesting: According to this invention aqueous dispersions can be made of “comb -structured” polyurethanes which are based on polyols having two hydroxyl groups at one end of the chain.  The “1,2”-diols are made by copolymerizing (e.g.) methylmethacrylate and n-butylmethacrylate together with thioglycerol up to a Mw of about 2000. The polyols can then be reacted with isocyanate and dimethylolpropionic acid for dispersion in water. The dispersions are said to have a small average particle size (10-100 nm) and be especially useful as binders for inkjet-ink.

Thioglycerol

Thioglycerol

Urethane-Acrylate Hybrids From Thiol-Ene Chemistry

Title: POLYURETHANE (METH) ACRYLATES USING MODIFIED HYDROXYTHIOLS

 Number/Link: US2015/0232422

Applicant/Assignee: Dymax Oligomers and Coatings

Publication date: 20-08-2015

Gist”: A dihydroxythiol is reacted with an acrylate and then with diisocyanate and hydroxyacrylate

Why it is interesting: This invention relates to radically polymerizable urethane oligomers which are useful as adhesives or coatings. The oligomers are prepared in two stages:  first a dihydroxy thiol is reacted with an acrylate resulting in a diol which is then reacted with an excess diisocyanate and then with hydroxyacrylates.  For example: thioglycerol is reacted with phenyltioethylacrylate.  The resulting diol is then further reacted with TDI and subsequently with polycaprolactonacrylate and hydroxyethylacrylate resulting in the structure below. The urethane oligomers can be used for coatings or adhesives which are said to have improved properties over the existing art, like improved thermal resistance.

A urethane-acrylate oligomer according to the invention

A urethane-acrylate oligomer according to the invention

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