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

PU Elastomers from SGO Polymerized Acrylic Polyols

Patent Title: PHYSICAL PROPERTY IMPROVEMENT OF POLYURETHANES

 Number/Link: WO2018/132648

Applicant/Assignee:  BASF

Publication date: 19 July 2018

Gist”: Solvent-free acrylate polyols are reacted together with polyether polyols and diisocyanates

Why it is interesting: In this invention a solvent-free (“100% solids” in the patent’s terminology) acrylic polyol is blended with a conventional polyether polyol and reacted with an aliphatic or aromatic diisocyanate.  The acrylic polyol is prepared by co-polymerizing (e.g.)  ethyl- or butyl (meth)acrylates, styrene and a hydroxyl functional acrylate like 2-hydroxyethyl acrylate or 4-hydroxybutyl acrylate, using BASF’s “solid grade oligomer” (SGO) polymerization process. The SGO process is a high temperature and high pressure continuous process allowing for the production of low-solvent acrylic resins. The polyurethanes are said to have increased physical properties, esp. tear- and tensile strength properties.

HBA

Hydroxybutylacrylate

Flexible Foams with Improved Humid-Aged Properties

Title: POLYURETHANE FOAM PRODUCTION PROCESS, PRE-MIX, FORMULATION, AND PRODUCT

 Number/Link: WO2013/143129

Applicant/Assignee: Air Products

Publication date: 3-10-2013

Gist”: Use of halohydrins as an additive in flexible foam formulations improves humid aged properties.

Why it is interesting: Properties of flexible polyurethane foams after humid-ageing appear to greatly improve when about 0.5 to 1 pphp of a halohydrin is added to the formulation.  “Halohydrin” is in this case used as a synonym for halo-alcohol. Mentioned are 2-(2-chloroethoxy)ethanol, 2,2-dichloroethanol and 1-chhloro-6-hexanol e.g. According to the examples the effect appears to be real and most pronounced for mechanical properties after humid ageing viz. tensile and elongation properties. It is not immediately clear to me what the underlying mechanism could be.

Chloroethoxyethanol

Chloroethoxyethanol