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

Hybrid Polyisocyanurates for Composites and Coatings

Patent Title: DUAL-CURING ISOCYANURATE POLYMERS

 Number/Link:WO2018/087395 WO2018/087396  WO2018/087399 (German)

Applicant/Assignee:  Covestro

Publication date: 17 May 2018

Gist”:  Di-isocyanate trimer is reacted with hydroxymethacrylates and polyacrylates in the presence of a trimerization catalyst. 

Why it is interesting: According to these inventions a reaction system with two curing modes can be prepared by mixing high functionality oligomeric isocyanate, ethylenically unsaturated compounds, unsaturated compounds containing isocyanate-reactive groups, timerization catalyst and a free-radical initiator at an NCO index of 100 to 200. The system shows a relatively low viscosity and can e.g. be used in fiber-reinforced composites and in coatings. In the examples HDI trimer is reacted with hexanedioldimethacrylate and hydroxypropylmethacrylate in the presence of potassium acetate and a peroxybenzoic acid.

HDI isocyanurate

HDI-trimer


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

Aliphatic Polyisocyanurate Composites

Patent Title: METHOD FOR PRODUCING A POLYISOCYANURATE COMPOSITE MATERIAL

 Number/Link: WO 2017/191216  (German)

Applicant/Assignee:  Covestro

Publication date: 9 November 2017

Gist”: Partially trimerized aliphatic diisocyanates are mixed with glass fiber and reacted using a trimerization catalyst

Why it is interesting: Conventional fiber-reinforced composites based on unsaturated polyesters, epoxies, polyurethane and the like are not weather-stable and need to be coated for outdoor use. Weather stable polyisocyanurate composites are known (WO2007/096216 – Huntsman) but are based on aromatic diisocyanates and show high reactivity and short ‘pot life’. According to this invention, PIR composites with improved reaction profile and weatherability can be prepared from partially trimerized aliphatic diisocyanates with a diisocyanate monomer content of less than 20% (w/w). In the examples commercially available HDI and IPDI trimer is used together with short glass fiber and a potassium acetate/PEG 400 blend as catalyst cured at a temperature of 160 to 180°C.

Isophorone diisocyanate (IPDI)

 

SiC-PU Nanocomposites

Patent Title: POLYURETHANE/UREA SILICON CARBIDE NANOCOMPOSITE

 Number/Link: WO2017/027231

Applicant/Assignee: 3M

Publication date: 16-feb-2017

Gist”: Surface modified SiC particles are dispersed in and covalently bound to a polyurethane matrix

Why it is interesting: Silicon carbide (carborundum) particles with an average particle size of about 500 nm are NCO-functionalized by reacting with a surface modfifying agent, e.g 2-triethoxysilylpropylisocyanate. The modified particles are then dispersed and covalently reacted into a polyurethane/polyurea matrix in an amount of 50-55% (w/w) on the composition. The composites can be made into highly erosion resistant films, for use on the outer surface of aircraft.

3-triethoxysilylpropylisocyanate

3-triethoxysilylpropylisocyanate