Title: POLYISOBUTYLENE-BASED POLYURETHANES CONTAINING ORGANICALLY MODIFIED MONTMORILLONITE

 Number/Link: WO/2014/018509

Applicant/Assignee: UNIVERSITY OF AKRON

Publication date: 30-01-2014

“Gist”: A small amount of montmorillonite, modified with a quaternary ammonium compound containing an amine group, is incorporated in a polyisobutylene-based TPU.

Why it is interesting: Montmorillonite-type clay is “exfoliated” using a quat. ammonium compound which has an alkyl subsituent containing a primary amine group. The salt group will electrostatically interact with the clay while the amine group will react with isocyanate when used in a polyurethane formulation, thus incorporating the clay into the polymer structure. In an example a (T)PU is made from HMDI, 1,6-hexanediol and a mixture of a 4000MW polyisobutylene diol and a 1000MW PTMO diol. A montmorillonite was exfoliated using trimethyl-1-propylamine ammonium iodide (I¯N+(CH3)3CH2CH2CH2-NH2)  and incorporated in the PU to make the nanocomposite. In an amount of 0.5% (w/w) the clay increases stiffness, mechanical- and creep properties of the PU.  However at higher amounts (2%,5%..) these properties actually deteriorate.

Polymer morphology model according to the invention. (omMMT = organically modified montmorillonite)