High Resiliency Polyurethane Foams

Title: HIGH RESILIENCY POLYURETHANE FOAMS MADE WITH HIGH FUNCTIONALITY, HIGH EQUIVALENT WEIGHT POLYOLS WITH MAINLY SECONDARY HYDROXYL GROUPS

Number/Link: WO2017/062150

Applicant/Assignee: Dow

Publication Date: 13 April 2017

“Gist”: Use of high functionality polyols increases the resilience of flex foams

Why it is interesting:  According to this invention the resilience of flexible PU foams can be increased by using, as part of the polyol composition, a random EO/PO polyether polyol which has an equivalent weight of at least 1500, a functionality of  at least 5, a secondary hydroxyl group content of at least 70%, an unsaturation value of at most 0.01 meq/g and an EO content between 5 and 30%.  In the examples, sorbitol initiated polyols are used in both MDI and TDI-based systems, resulting in ball rebound values of up to 60% at densities of about 30 kg/m³.  As I have shown in the past (US5521226) the same (or arguably an even stronger) effect on resilience can be obtained with other high functionality polyols, indicating that the unsaturation value, primary OH content, EO content and equivalent weight are probably not relevant to the resilience increase.

Sorbitol

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Polyether-Polyacetal Polyols

Patent Title: POLYETHER-ACETAL POLYOL COMPOSITIONS

 Number/Link:  WO2016/112274

Applicant/Assignee: Dow

Publication date: 14-07-2016

Gist”: Lewis-acid catalysis for polyactal-modified polyethers

Why it is interesting: According to this application, acetal-modified polyether polyols can be prepared by first reacting a (pref.) di- or trifunctional initiator with PO until about 500 eq. wt. using DMC catalysis. This ‘starter’ polyol is then further reacted (at a lower temperature) with PO using a (pref.) Boron-based lewis acid as catalyst, e.g. tris(pentafluorophenyl)borane. Under these conditions part of the epoxy will isomerize to the corresponding aldehyde.  The aldehyde can then co-polymerize such that part of the polyol will be functionalized with polyacetal. Polyurethanes prepared with these polyols are said to show improved modulus and other mechanical properties.

tris(pentafluorophenyl)borane

tris(pentafluorophenyl)borane