All posts in category Elastomers

Polyols from Epoxies and Cardanol

Title: CARDANOL MODIFIED EPOXY POLYOL

Number/Link: WO2015/077944 WO2015/077945 WO2015/078178

Applicant/Assignee: Dow

Publication date: 4-06-2015

“Gist”: Polyols are prepared by reacting an epoxy resin with cashew nutshell liquid.

Why it is interesting: Cardanol is the main component of cashew nutshell liquid which is a by-product of cashew nut processing. It is a “surfactant-like” phenolic compound which, when reacted with a polyepoxide, will result in a polyol with sec-OH groups. When used in polyurethane formulations these polyols will (unsurprisingly) be slow-reacting, highly hydrophobic and show compatibilizing properties vs apolar compounds. Dow have therefore filed three patent applications on PU systems containing these polyols: one on slowly-reacting PU systems for filament winding, one on highly hydrophobic PU elastomers and one on asphalt-PU compositions.
These are interesting polyols but they could be hard to process in my opinion.

Cardanol is reacted with bisphenol-A diglycidylether resulting in a diol according to the invention

Syntactic Polyurethane Elastomers

Title: SYNTACTIC POLYURETHANE ELASTOMERS FOR USE IN SUBSEA PIPELINE INSULATION

Number/Link: WO2015065769 WO2015065770 WO2015065771 WO2015065772

Applicant/Assignee: Dow

Publication date: 7-05-2015

“Gist”: Zn/Zr catalyzed syntactic elastomers for subsea pipeline insulation

Why it is interesting: Conventional polyurethane rigid foams cannot be used for the insulation of subsea pipelines because the foams would collapse under the pressure and they are too brittle to be bent. For these reasons syntactic elastomers can be a better choice for this application. Syntactic polyurethane elastomers consist of a solid PU matrix containing up to 50% (wt/wt) of hollow glass microspheres. The catalyst of choice to produce these materials is phenylmercury neodecanoate. However because of regulatory pressure other catalyst systems are now being used. The gist of these four patent applications appears to be the use of a mixture of a zinc carboxylate with a small amount of zirconium carboxylate as a replacement for the organomercury catalyst, but this is not the main claim (probably because of non-patentability). Instead the WO..69 case is about the use of polymer polyols in these systems, the WO..70 case is about the use of low unsat polyols, WO..71 is about a special type of morphology and WO..72 about the use of prepolymers.

Phenylmercury neodecanoate

Soft, High Resilience Polyurethane Elastomers

Title: URETHANE FOAM RUBBER AND COMPOSITION FOR FORMING URETHANE FOAM RUBBER

Number/Link: US20150105485

Applicant/Assignee: Yamaha

Publication date: 16-04-2015

“Gist”: Use of carbodiimide-MDI to make soft high resilience elastomers

Why it is interesting: According to this patent application, soft, high-resilient PU elastomers with a density higher than 300 kg/m³ can be prepared from a diisocyanate, a polyether polyol with a molecular weight of about 1000 to 4000 together with some polymeric MDI. The invention being, that the diisocyanate needs to have an “atom number minimum bond path” between the two NCO groups of at least 11. Examples of such diisocyanates would be α,ω-undecane- (or dodecane- or tridecane- etc.) diisocyanates, propylene-1,3-di(1,4-cyclohexylene diisocyanate) but also carbodiimide modified MDI which is preferred. Examples are given of 440 kg/m³ elastomers with a ball rebound of 81 and an Asker C hardness of 44 at temperatures ranging from -20°C to 50°C, based on a polyTHF diol with a MW of 2000 and a carbodiimide modified MDI. No other isocyanates are used in the examples, so it appears to me that the “atom number minimum bond path” is just an attempt to make this case new and patentable. Not very convincing. I would like to see an example with tridecanediisocyanate.

Carbodiimide modified MDI species

Innovation in Polyurethanes

All posts in category Elastomers

Polyols from Epoxies and Cardanol

Syntactic Polyurethane Elastomers

Soft, High Resilience Polyurethane Elastomers

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