PU Elastomers with Extremely High Elongation

Patent Title:  Polyurethane Elastomer with High Ultimate Elongation

 Number/Link: US2018/0312623

Applicant/Assignee:  UNIV PENNSYLVANIA

Publication date: 1 November 2018

Gist”: Low hardblock polyurethane-polyurea elastomers are prepared from low unsat diols, HDI and a bulky diamine chain extender

Why it is interesting: The current invention relates to PU  elastomers which are said “to  have the highest reported elongation-at-break among known polyurethane elastomers“. The materials are prepared from an NCO-ended prepolymer consisting of a low unsaturated, low dispersity diol and a symmetric diisocyanate (i.e. no 4,4′-MDI), which is reacted with a “bulky” diamine chain extender. In the examples Acclaim 4200 (polyether diol with OHv 28) is used together with HDI and 2-methyl-1,5-pentanediamine. The elastomer showed an elongation at break of more than 2000%.
Because these materials have a low- and non-aromatic hardblock content, it is my opinion that they show creep rather than elasticity.

methylpentandiamine

2-methyl-1,5-pentanediamine

Aliphatic TPU with Reduced Effloresence

Patent Title: ALIPHATIC THERMOPLASTIC POLYURETHANES, PRODUCTION AND USE THEREOF

 Number/Link:   WO2018/192936 (German)

Applicant/Assignee:  Covestro

Publication date: 25 October 2018

Gist”: TPU based on 1,10-decanediisocyanate shows reduced blooming

Why it is interesting: Aliphatic thermoplastic polyurethanes, based on hexanediisocyanate (HDI) can show “blooming” i.e. the formation of a white precipitate on the surface of the material.  It is believed that this is caused by the formation of cyclic oligourethanes migrating to- and forming crystals on the surface. According to this invention, this blooming behaviour can be prevented by using long-chain aliphatic diisocyanates like 1,10-diisocyanatodecane or 1,12-diisocyanatododecane instead of HDI.

DDI

1,10-diisocyanatohexane (DDI)

 

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