Omniphobic Polyurea

Patent Title: MOISTURE-CURABLE OMNIPHOBIC COATINGS

Number/Link: US2019/0031909

Applicant/Assignee: US Navy

Publication Date: 31 January 2019

“Gist”: Polyurea topcoat containing both silane and perfluoro groups

Why it is interesting: According to this invention, a coating having both hydrophobic and oleophobic properties can be prepared by reacting an alkoxysilane-terminated polyurea with a perfluoromaterial having at least one alkoxy- or hydroxyl group. In an example a coating is prepared by reacting a polyurea based on HDI trimer and N-butyl-3-aminoppropyltrimethoxysilane with triethoxy(perfluoro-octyl)silane. The coating showed contact angles of more than 140 degrees vs water and more than 90 degrees vs hexadecane.

omniphobicpolyurea

Reaction system according to the invention

Thermoplastic PU-PDMS Copolymer

Patent Title: THERMOPLASTIC POLYURETHANE

Number/Link: WO2019/016313 (German)

Applicant/Assignee: BASF

Publication Date: 24 January 2019

“Gist”:  Thermoplastic polyurethane comprising OH-ended poly(dimethylsiloxane).

Why it is interesting: The invention relates to thermoplastic polyurethanes prepared from diisocyanate, polyether or polyester diol and a difunctional isocyanate-reactive polysiloxane.  The materials are said to have improved “haptic”-, hydrophobicity- and tensile properties while retaining the processibility of TPU and are useful for ‘on-body’ applications like wristbands. In the examples both 4,4′-MDI and HDI are used together with chain extenders, polyTHF, BDO-HDO adipate and EO capped PDMS to prepare TPUs ranging from 55 to 95 Shore A.

pdms-eo

EO-capped PDMS

Phosgene-Free Polyisocyanate with PDMS Backbone

Patent Title: MULTI-FUNCTIONAL CARBAMATE HAVING SOFT-SEGMENTS, POLYISOCYANATE OBTAINED VIA SUBSEQUENT NON-PHOSGENE SYNTHESIS METHODS, URETHANE PREPOLYMER AND ELASTOMERIC URETHANE HAVING SOFT-SEGMENTS DERIVED THEREFROM, AND PREPARATION METHOD THEREOF

 Number/Link: US20180186918

Applicant/Assignee:  Great Eastern Resins Industrial

Publication date: 5 July 2018

Gist”: Biscarbamate with PDMS softblock backbone is heat-cracked into diisocyanates

Why it is interesting: The invention relates to isocyanate-capped “softblock” siloxanyl prepared without using phosgene and polyurethanes derived therefrom. The invention is accomplished by reacting relatively high MW polydimethylsiloxanediamines with diphenylcarbonate.  The resulting biscarbamate is heated under reduced pressure to produce the diisocyanate and to remove the phenol by-product.  The isocyanates can be reacted with polyols and/or chain extenders to produce highly hydrophobic polyurethanes with low surface tension and good chemical resistance.

biscarbamate

Biscarbamate with PDMS backbone