Patent Title: CYCLIC DYNAMIC POLYUREAS FOR POLYMERIC UREA PROCESSING
Applicant/Assignee: University of Illinois
Publication date: 11-08-2016
“Gist”: 1K polyurea coatings from thermoreversible cyclic urea oligomers
Why it is interesting: This application is related to W02016/069582 of the same applicant, discussed before on this blog. In this case the sterically hindered ureas are prepared in solvent and at a relatively low concentration. Under these conditions cyclic oligomers will be formed which can be separated and used as powder coatings, or, together with (e.g.) catalysts, polyols and crosslinkers, as liquid coatings. When heated the rings will open and the coating composition will cure. In an example 1,3-bis(isocyanatomethyl)cyclohexane is reacted with N,N’-di-t-butyl ethylenediamine, in DMF, which forms cyclic oligomers at low-, and linear polymers at high concentrations.
Thermoreversible polyurea according to the invention
Posted by Gerhard Bleys on August 22, 2016
Patent Title: PROCESSABLE, TUNABLE THIOL-ENE CROSSLINKED POLYURETHANE SHAPE MEMORY POLYMERS
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
Posted by Gerhard Bleys on August 12, 2016
Patent Title: POLYURETHANE-BASED BINDER DISPERSION
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.
Posted by Gerhard Bleys on August 8, 2016
Patent Title: HIGH RECYCLE CONTENT POLYOLS FROM THERMOPLASTIC POLYESTERS AND LIGNIN OR TANNIN
Applicant/Assignee: Resinate Materials Group
Publication date: 28-07-2016
“Gist”: PET is glycolized and then reacted with lignin or tannin
Why it is interesting: This application is about ‘sustainable’ aromatic polyester polyols partly based on recycled materials and partly on biorenewable materials. According to the invention the polyols can be prepared by first glycolizing (waste) PET and subsequently reacting the mixture with lignin at 110-210°C while removing volatile condensation products. The resulting polyols (pref) show a OH value between 40 and 400 mg KOH/g, a fn of 2-2.2 and a viscosity at 25°C of 500 to 3000 cP. In the examples polyols with up to 25 wt% lignin are shown. The polyols are said to be useful e.g. in 2K PU coating compositions.
Part of a lignin structure
Posted by Gerhard Bleys on July 29, 2016