Non-Isocyanate Polyurethanes from Thiocarbonates

Patent Title: PROCESS FOR THE MANUFACTURING OF A POLYMER WITH URETHANE GROUPS

Number/Link: WO2019/034470 and WO2019/034473

Applicant/Assignee: BASF

Publication Date: 21 February 2019

“Gist”:  A cyclic thiocarbonate is reacted with a diamine and then with a diacrylate

Why it is interesting: NIPU is prepared by reacting a five-ring monothiocarbonate with di- (or poly-) amine and then with a compound having at least two thiol-reactive functional groups like e.g. ethylenically unsaturated groups. The reaction has advantages over conventional PU chemistry like being isocyanate-free, less moisture sensitive and running at moderate temperatures. In an example methyl monothiocarbonate is reacted with 1,5-pentanediamine and 1,4-butandioldimethacrylate, resulting in a colourless, transparent polymer with a high thermal stability.
An interesting take on hybrid non-isocyanate polyurethanes.

scheme1

Reaction scheme according to the invention

Novel Chain Extenders

Patent Title: METHOD OF PRODUCING FIVE-CARBON RING-CONTAINING COMPOUND AND FIVE-CARBON RING DERIVATIVE-CONTAINING POLYURETHANE, AND FIVE-CARBON RING DERIVATIVE-CONTAINING POLYURETHANE

Number/Link: US2019/0048123

Applicant/Assignee: CHUNG SHAN INSTITUTE OF SCIENCE AND TECHNOLOGY

Publication Date: 14-February 2019

Gist”: Novel chain extenders are derived from dicyclopentadiene (DCPD)

Why it is interesting: DCPD is a by-product of ethylene production by steam cracking of naphta.  It is produced in large quantities and it makes sense to search for new applications.  According to this invention, the compound shown below can be prepared by first ‘degrading’ DCPD to cyclopentadiene, followed by reaction with phenol to produce 4-(cyclopent-2-enyl)phenol which is then converted to 4-cyclopentenylphenol (translocation of the double bond).  The cyclopentenylphenol is then reacted with phenol followed by reaction with ethylene carbonate to produce the chain extender. In an example the chain extender is reacted with a 4,4′-MDI prepolymer in solvent.
Clever chemistry and an interesting compound, but its usefulness remains to be shown.

extender

Chain extender according to the invention

Polyurethane for Oil Well Refracking

Patent Title: METHODS AND MATERIALS FOR REFRACTURING A PARTIALLY DEPLETED OIL AND GAS WELL

Number/Link: US2018/0346786

Applicant/Assignee:  Covestro

Publication Date: 6 December 2018

“Gist”: Use of low-reactive, low-viscosity PU systems for oil well sealing

Why it is interesting: It is known that partially depleted fracking wells can be “re-fractured” to increase production. Prior to this operation former perforations in the well casing need to be sealed to prevent furthering of existing fractures, by using a chemical “diverting agent”.  According to this invention, the diverting agent can be a polyurethane system with a long potlife and relatively low viscosity, which is prepared from an unblocked hexamethylene diisocyanate and a polypropyleneoxide triol which is miscible with the isocyanate. In the examples an allophanate-modified HDI is used together with a 450-molecular weight PO triol and a delayed-action tert amine catalyst. The system does not de-mix and has a gel time ranging from 30 to more than 1000 minutes.

refracking

Sealing of fracking well