Non-Isocyanate Polyurethane Flexible Foams

Title: NON ISOCYANATE POLYURETHANE FOAMS

Number/LinkUS2017/0218124

Applicant/Assignee: Faurecia

Publication Date: 3 august 2017

“Gist”: Flex foams from a blend of two polyfunctional cyclocarbonates, a polyamine and HFC blowing agent.

Why it is interesting: While non-isocyanate polyurethanes are well known by now, examples of NIPU foams, especially flexible foams are rare. According to this case NIPU foams ‘having good resilience and low density’ can be prepared by reacting two polyfunctional carbonates A and B with a polyamine in the presence of a blowing agent and a catalyst. Cyclocarbonate A is (pref) trimethylolpropaneglycidylether carbonate and B is a polyetherpolyol with the OH groups replaced by glycidylcarbonate groups, for example an alkoxyalated trimethylolpropaneglycidylether carbonate. The polyamine is e.g. 1,6 diaminohexane.  The ratio A:B is preferably about 60:40.  In the examples no value for the resilience is given (but my guess based on the Tg is that it is probably not very high) and the lowest moulded density achieved is 140 kg/m³. So still a long way to go..

Glycidylether carbonate of alkoxylkated trimethylolpropane

Non-Isocyanate Poly(Amide-Hydroxyurethanes)

Patent Title: NON-ISOCYANATE POLYURETHANES AND METHODS OF MAKING AND USING THE SAME

 Number/Link: WO 2017/ 030880

Applicant/Assignee: ELEVANCE RENEWABLE SCIENCES

Publication date: 23-feb-2017

Gist”: Telechelic cyclocarbonate-alkylesters are reacted with diamines in the melt

Why it is interesting: According to this invention (ω-) unsaturated alkylesters can be converted to mono-cyclocarbonate alkylesters and then reacted with diamines to prepare thermoplastic poly(amide-hydroxyurethanes) (PAHU). For example methyl-9-decenoate was first epoxidized and then reacted with CO2 to produce 9,10-cyclic carbonate-methyl decanoate. After separation and washing the cyclocarbonate was reacted – in the melt- with a mixture of dodecane diamine and a PTMO diamine (Jeffamine THF-100). It is said that the unsaturated alkylesters can be prepared from natural oils using (cross- or self-) metathesis followed (or preceded) by transesterifaction with alkanols.

PAHU preparation scheme

PAHU preparation scheme

Non-Isocyanate Polyurethanes from Sucrose-Fatty Acid Esters

Patent Title: BIOBASED CYCLIC CARBONATE FUNCTIONAL RESINS AND POLYURETHANE THERMOSETS THEREFROM

 Number/Link: US2016/0312060

Applicant/Assignee: NDSU

Publication date: 27-10-2016

Gist”: Epoxidized sucrose-fatty acid esters are reacted with CO2, then with polyamines

Why it is interesting:  Esters of unsaturated fatty acids and sucrose have been known since the 1960s and are useful in e.g. coatings.  Highly subsituted sucrose esters with an average of 7.7 fatty acid chains per molecule, a molecular weight of about 2400 and a relatively low viscosity of 300-400 mPa.s are commercially available. According to this invention, epoxidized sucrose-fatty acid esters can be further reacted with carbon dioxide resulting in a resin with a ‘pluraility’ of cyclocarbonate groups. Curing with polyamines results in highly crosslinked poly(hydroxyurethanes) useful for coatings, composites and adhesives.

Epoxidized sucrose-fatty acid ester

Epoxidized sucrose-fatty acid ester

 

 

Polyurethane Prepolymer with Very Low Monomeric Isocyanate Content

Patent Title: ULTRALOW MONOMER POLYURETHANES

 Number/Link: WO 2016/142513

Applicant/Assignee: Henkel

Publication date: 15-09-2016

Gist”: An NCO-ended prepolymer is reacted with a bis(alkoxysilylalkyl)amine

Why it is interesting: This invention is about laminating adhesives with a ‘primary aromatic amine migration limit’ of less than 10ppb, in accordance with the EU regulation for food packaging laminates. The low monomeric content is achieved by first making a NCO-ended prepolymer, which is then reacted with an monofunctional ‘H-acidic’ compound, preferably a bis(alkoxysilylalkyl)amine.  In an example a mixture of diols (OHv 108 to 236) was  reacted with 2.4-TDI down to an NCO value of 3.85%. Then 4,4′ MDI, trimethylolpropane and a triiso based on TDI were added to an NCO value of 2.2%.  Finally the prepolymer was reacted with bis(3-(triethoxysilyl)proplyl)amine at an NCO/NH ratio of 7:1.  Final NCO value was 2% with 0.05% (w/w) free 2,4-TDI and less than 0.01% free 4,4′-MDI. The prepolymer is said to be useful in 1K and 2K adhesive compositions and is said to have better adhesion properties and reactivity compared to NCO-free adhesives like sile silane-terminated PU adhesives.

Bis(3-(triethoxysilyl)propyl)amine

Bis(3-(triethoxysilyl)propyl)amine

Cooperative Catalyst System for NIPU

Title: Catalyst for Non-Isocyanate Based Polyurethane

 Number/Link:US2015/247004

Applicant/Assignee: Dow; Univ. Northwestern

Publication date: 3-09-2015

Gist”: The cyclocarbonate-amine reaction is catalysed by a lewis acid/lewis base combination

Why it is interesting: It is well known that polyhydroxyurethanes can be produced from cyclic carbonates and amines.  These “nonisocyanate polyurethanes” can have advantages over conventional polyurethanes, e.g. as coatings with improved chemical resistance. The reactivity of (especially 5-ring)  cyclocarbonates is however much lower than that of isocyanates making the reaction much less practical.  According to this invention that problem can be solved by using a ‘cooperative’ catalyst system consisting of a lewis acid and an organic lewis base. In an example a difunctional cyclocarbonate-capped prepolymer is reacted with 1,3-cyclohexane-bis(methylamine) catalysed by a mixture of  lithium trifluoromethanesulfonate and triazabicyclodecene.
It has been noted before in this blog that Dow, as one of the major isocyanate producers, also appears to be interested in non-iso PU.

Triazabicyclodecene.

Triazabicyclodecene.