Title: Highly elastic polyurethane foams containing castor oil

 Number/Link: EP2527381

Applicant/Assignee: BASF

Publication date: 28-11-2012

“Gist”: Flexible foam with more than 50% ball rebound based on MDI, partly prepolymerized conventional EO/PO polyol and about 15% castor oil.

Why it is interesting: Castor oil was one of the first renewable raw materials used in PU because it contains hydroxyl groups and can therefore be used ‘as such’.  Use of (unmodified) castor oil in PU will however result in an increased glass transition temperature and therefore in low resilient materials. It has therefore been patented before in low resilient “memory foam” compositions.  BASF now claim foams with >50% resilience but only 15% castor oil is used in the examples. The actual ‘trick’ is prepolymerizing part of conventional polyol which does indeed seem to increase resilience with a few percent,  probably due to some subtle phase effect.

Major Component of Castor Oil (Wikipedia)