All posts tagged elastomers

Very Tough Polyurethane Elastomers Based on a Novel Type of Polyester Polyol

Title: POLYESTER POLYOL FOR USE IN POLYURETHANE

Number/Link: WO2013/156450

Applicant/Assignee: Purac Biochem

Publication date: 24-10-2013

“Gist”: Tough polyurethane elastomers can be prepared from polyester polyols based on dimer acid and lactide oligomers.

Why it is interesting: The invention claims a new type of ABA polyester polyol where A is a hydrophilic lactide oligomer and B is a hydrophobic dimer diacid initiator. The lactide ologimers can be produced by ring-opening polymerization of cyclic lactide and preferably contain between 4 and 16 lactoyl units. The dimer diacid is prepared by dimerizing unsaturated C12 to C22 fatty acids, preferably linoleic or linolenic acid. The molecular weight of the polyester polyol is preferably between 1000 and 3500 dalton. Solid polyurethane elastomers prepared from this type of polyols reportedly have much improved toughness and other mechanical properties.

Example of a Dimer Acid

Polyurethane Elastomers with High Abrasion Resistance

Title: POLYURETHANE WITH IMPROVED ABRASION RESISTANCE, THE METHOD FOR PREPARING THE SAME AND USE THEREOF

Number/Link: US2013/0274365

Applicant/Assignee: Bayer

Publication date: 17-10-2013 (priority PCT/DE)

“Gist”: Small amounts of polyisoprene improve abrasion resistance of elastomers

Why it is interesting: It is known that polyether polyols have advantages over polyester polyols for the production of polyurethane elastomers: the resulting elastomers have better low temperature properties, better hydroslysis resistance and antimicrobial properties, however the mechanical properties as well as the abrasion resistance are lower. According to this invention the abrasion resistance of polyether elastomers can be greatly improved by incorporating a small amount of polyisoprene in the formulation. In the examples 2% polyisoprene with a MW of 28,000 or 45,000 is used in a formulation of polyether polyol, butanediol, water and catalyst together with a non-disclosed isocyanate. The resulting elastomers have a density of 600 kg/m3 and show a markedly improved abrasion resistance.

Structural units present in polyisoprene

POLYURETHANE WITH IMPROVED ABRASION RESISTANCE, THE METHOD FOR PREPARING THE SAME AND USE THEREOF

2 Comments

by Gerhard Bleys on October 22, 2013 • Permalink

Posted in Elastomers

Tagged abrasion, elastomers, isoprene, plasticizer, rubber

Posted by Gerhard Bleys on October 22, 2013

https://purpatents.com/2013/10/22/polyurethane-elastomers-with-high-abrasion-resistance/

Polyurethane/Polyurea Elastomers from 2,4′-MDI and MDA

Title: MOLDED POLYURETHANE ELASTOMER PARTS MADE OF DIPHENYLMETHANE DIISOCYANATE-BASED NCO PREPOLYMERS AND METAL SALT COMPLEXES, AND A METHOD FOR PRODUCING SAME

Number/Link: US2013267655

Applicant/Assignee: Bayer

Publication date: 10-10-2013 (priority PCT/DE)

“Gist”: Molded PU/PUA elastomers are prepared from a 2,4′-MDI based prepolymer cured with blocked MDA

Why it is interesting: A prepolymer with an NCO content between 3 to 7% is prepared from MDI containing more than 97% of the 2,4′ isomer together with a diol with an OH value of about 100. (e.g a PTMEG or a polycaprolacton). The prepolymer is then cured with a salt-complexed diphenylmethanediamine (“blocked MDA”). Because of it’s relatively low viscosity and long potlife the system allows for the production of thick-walled, bubble-free molded elastomers. Probably because there is less premature polyurea phase separation (due the 2,4′-MDI) the system cures homogeneously.

4,4′-MDA

Innovation in Polyurethanes

All posts tagged elastomers

Very Tough Polyurethane Elastomers Based on a Novel Type of Polyester Polyol

Polyurethane Elastomers with High Abrasion Resistance

Polyurethane/Polyurea Elastomers from 2,4′-MDI and MDA

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