TPUs from Block Polyester Polyols

Patent Title: THERMOPLASTIC POLYURETHANE HAVING HIGH TEAR PROPAGATION STRENGTH  & PROCESS FOR PRODUCING TRANSPARENT HARD THERMOPLASTIC POLYURETHANES

 Number/Link: WO2018/115460  WO2018/115468

Applicant/Assignee:  BASF

Publication date: 28 June 2018

Gist”:  Polyester polyols containing a “hard block” of polyethyleneterephthalate are used in the preparation of TPU 

Why it is interesting: According to this invention thermoplastic polyurethanes with a high hardness at a relatively low hardblock level (<75%), or a high tear strength at relatively low Tg (<5°C) can be prepared from a polyester polyol that is a block copolymer containing 10-50% of an aromatic polyester block, the rest being aliphatic polyester. In the examples diols are prepared from PET together with adipic acid and BDO or DEG. The diols are reacted with MDI or HDI and a chain extender like BDO or HDO.

PET

Poly(ethyeleneterephthalate)

Fiber Reinforced TPU Composites

Patent Title: THERMOPLASTIC POLYURETHANE MATRIX RESIN

 Number/Link: WO 2018/104145

Applicant/Assignee:  Henkel

Publication date: 14 June 2018

Gist”: TPU based on a vicinal alkane diol together with an alkoxylated aromatic diol can be used as matrix material in a fiber composite

Why it is interesting: According to this invention a thermoplastic polyurethane with a high Tg (pref. >80°C) and a high stiffness (>1GPa) can be prepared from a short chain, sterically hindered, vicinal diol (e.g. 1,2-propanediol or 2,3-butanediol), an alkoxylated aromatic diol (e.g. alkoxylated bisphenol A or F) and an aromatic diisocyanate (e.g. 4,4’MDI) pref. mixed with some high functionality isocyanate (e.g. polymeric MDI) to control branching an molecular weight. The TPU composition can be used to make a fiber reinforced composite in an RTM-type process. The cured thermoplastic matrix has high mechanical properties but still allows for post-cure modification of the moulded part.

EtoxBisF

Ethoxylated Bisphenol F

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

Breathable TPU Membranes

Patent Title: POROUS THERMOPLASTIC MEMBRANES

 Number/Link: WO2017/178482

Applicant/Assignee:  BASF

Publication date: 19-october-2017

Gist”: Semi-permeable membranes are made by phase inversion of all-hardblock TPU solutions

Why it is interesting: ‘Breathable” membranes show a high resistance to liquid water permeation (LEP) combined with a high water vapour permeability (WDD). According to this invention breathable polyurethane membranes can be prepared by dissolving an all-hardblock thermoplastic polyurethane in a polar, aprotic solvent (like N-methyl pyrrolidone) together with a water soluble compound, casting a film and coagulating the film with water. In the examples diisocyanates (MDI, TDI and HDI) are stoichiometrically reacted with chain extenders (MEG, BDO and HDO).  The resulting materials were schredded and dissolved in NMP together with some glycerol. 150 μm thick films were cast on glass and coagulated in water, resulting in membranes with an average pore size ranging between 4 and 500 nm.  The membranes are said to be useful to make breathable fabrics for outdoor wear e.g. (“Gore Tex” (TM) – type materials)

N-methyl-2-pyrrolidone

 

 

 

 

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