UV Resistant Viscoelastic Foams

Patent Title: POLYURETHANE PRODUCT WITH SULFUR-CONTAINING POLYOL

 Number/Link: WO2018/111806

Applicant/Assignee:  Dow

Publication date: 21 June 2018

Gist”: VE foams using S-containing polyether polyols

Why it is interesting: According to this invention sulfur containing polyols improve the UV resistance of polyurethane materials.  It is believed that sulfur acts as a UV absorber incorporated into the polymer, thereby reducing the need for additives such as antioxidants.  In the examples an S-containing polyether diol is prepared by reacting 2,2′-thiodiethanol with propyleneoxide up to an OH value of  188 mg KOH/g. The diol is then used in an amount of 5 to 15% on the total polyol blend to prepare low resilience flexible foams showing an improved UV resistance.

 

TDE

2,2′-thiodiethanol

 

PCM-Containing Viscoelastic Foams

Patent Title: VISCOELASTIC POLYURETHANE FOAM WITH COATING

Number/Link: WO2017/210439

Applicant/Assignee: Dow

Publication date: 7 December 2017

“Gist”: Open-celled visco-foam is impregnated with an aqueous dispersant composition containing a phase change material

Why it is interesting: According to Dow, open-celled viscoelastic polyurethane foams can be prepared by using a acid-modified polyolefin latex cellopener, as discussed before in this blog. In the current invention these open-celled foams are impregnated with an aqueous composition comprising an ionomer (a sodium salt of a maleic anhydride copolymer) and a microencapsulated PCM. The composition is said to ‘coat’ the cell struts with PCM and increase the comfort properties of the foam.
I wonder if with this process enough PCM can be in introduced to have a noticeable effect.

bluewave

Dow’s proprietary BLUEWAVE dispersion process is used to prepare the cellopening latex

Viscoelastic Polyurethane Elastomers

Title:  IMPACT PROTECTION FOAM

Number/Link: US2017/0233519

Applicant/Assignee: Dow

Publication Date: 17 august 2017

“Gist”: Viscoelastic foams are prepared from MDI, castor oil and a hydrophilic polyether polyol.

Why it is interesting: According to this invention energy absorbing foams with relatively low density and a low hardness and resilience in the temperature range from about -10 to +40°C, can be produced by reacting a blend of hydrophilic and hydrophobic polyols containing castor oil, about 0.5 pbw water and some catalyst and chain extender with MDI.  The examples show foams of about 500 kg/m³ with hardness below shore 50A and ball rebound below 15% at both -10 and +23°C. The foams are said to be useful for impact-protective garments.

Castor oil

Castor oil component

PU Flexible Foams with Reduced Acetaldehyde Emissions

Title: METHOD FOR THE REDUCTION OF ALDEHYDE EMISSION IN POLYURETHANE FOAM

Number/Link: WO2017/134296

Applicant/Assignee: Huntsman

Publication Date: 10 August 2017

“Gist”: Cyanoacetamide is used as aldehyde scavenger

Why it is interesting: Reduction of aldehyde emissions from (especially flexible) polyurethane foams remains an important issue and has already been discussed a number of times on this blog. According to this case the use of (pref) 0.05 to 0.5 pbw of cyanoacetamide in a flexible foam formulation will reduce the emission of formaldehyde, acetaldehyde, propionaldehyde, and possibly of higher aldehydes as well.
While an interesting compound, the use of cyanoacetamide in polyurethanes is not new and the effect is hardly surprising.

Cyanoacetamide

 

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