TPU for RTM

Patent Title: THERMOPLASTIC PUR WITH HIGH TG FOR REACTION TRANSFER MOLDING (RTM)

 Number/Link: WO2018/050433

Applicant/Assignee:  Henkel

Publication date: 22 march 2018

Gist”:  High Tg TPU from polycyclic diols

Why it is interesting: The invention is about thermoplastic polyurethanes with high Tg and high stiffness that are useful for fiber-reinforced composites made by (reactive) resin transfer moulding.  The TPU is prepared from an isocyanate, a conventional diol chain extender and at least 25% (w/w) of a bridged- fused- or spiro- polycyclic diol. In the examples MDI is reacted with 1,2-propanediol or 2,3-butandiol and 4,8-bis(hydroxymethyl)tricyclo[5.2.1.02,6]decane. The resulting TPUs show a Tg of more than 135°C.

tricylodecane

4,8-bis(hydroxymethyl)tricyclo[5.2.1.02,6]decane

Rigid Thermoplastic Polyurethanes

Patent Title: ISOCYANATE-MODIFIED RIGID THERMOPLASTIC POLYMER COMPOSITIONS

 Number/Link: WO2017/146948  WO2017/146949

Applicant/Assignee: Eastman Chemical

Publication date: 31 august 2017

Gist”: A “rigid”, high Tg polyester diol is extended with 4,4′ MDI

Why it is interesting: Rigid, high modulus TPUs have been known for a long time – see e.g. Upjohn’s classic patent on ‘Isoplast’ from 1981. These materials are high hardblock TPUs made from diisocyanates, chain extenders with only a small amount of high molecular weight diol as an impact modifier. According to the current invention however, rigid TPUs can be made using less than 40% (w/w) of diisocyanate, a high Tg polyester diol and optionally some chain extender.  The polyester is prepared from ‘rigid’ diols like isosorbide or 1,4-cyclohexanedimethanol together with a ‘rigid’ diacid like terephthalic acid, such that the diol has a MW of more than 400 Dalton and a Tg of more than 40°C. The diisocyanate is pref. 4,4-MDI. The rigid TPUs have a Tg of more than 145°C and a tensile modulus of 1 GPa or higher. They are said to be less moisture sensitive than conventional rigid TPUs.

1,4-cyclohexanedimethanol