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

Thiol-Crosslinked Poly(hydroxyurethanes)

Title: METHOD FOR PRODUCING OR CURING POLYMERS USING THIOL-ENE POLYADDITION REACTIONS

Number/Link: W2017/081120

Applicant/Assignee:  Henkel

Publication Date: 18-05-2017

“Gist”: Unsaturated PHU are crosslinked using polythiols

Why it is interesting: The invention is about poly(hydroxyurethanes) (PHU) containing alkylene groups that are crosslinked using thiol-ene ‘click’ polyaddition reactions. The unsaturated PHU are first prepared by aminolysis of cyclocarbonates using unsaturated amines. In an example di-trimethylolpropane is converted to di-trimethylolpropanedicarbonate using ethylchloroformiate.  The di-TMPDC is then reacted with 3-aminopropylvinylether to prepare the PHU, which is then crosslinked using pentaerithritol-tetra(3-mecaptopropionate) in the presence of a photoinitiator and UV light.  The invention is said to be useful for isocyanate-free adhesive- and coating systems.

Di-trimethylolpropanedicarbonate

Hybrid PU-Peptide PUDs

Patent Title: AQUEOUS PEPTIDE-FUNCTIONALIZED POLYURETHANE DISPERSIONS

 Number/Link: WO2016/135162

Applicant/Assignee: Henkel; Max-Panck Ges.

Publication date: 1-09-2016

Gist”: A maleimide-capped prepolymer is reacted with the -SH groups in a peptide

Why it is interesting: Polyurethane-protein hybrids are interesting novel materials which potentially have a number of unique properties unattainable with conventional synthetic polymers. In a previous case discussed in this blog an NCO-ended polyurethane prepolymer was reacted with a peptide in water to make a PU-peptide dispersion.  This type of grafting, however, is not very specific because the isocyanate will react mostly with the free amino groups of lysine, which is usually  ‘abundant’ in a typical peptide. According to this invention the grafting can be made very specific by first end-capping the NCO prepolymer with maleimide groups and dispersing in water. The dispersion is then reacted with a peptide solution at pH7. In these circumstances the maleimide will react selectively with the free thiol group of cysteine, of which usually very few are present in a typical peptide because most thiol groups are engaged in S-S disulfide bridges.  Preferably a peptide consisting of 10-200 amino acids is used, with preferably only one free thiol group. By selective grafting the properties of the peptide can be conserved.  The PU-peptide dispersions are claimed to be especially useful for metal adhesives.

L-cysteine

L-cysteine