PCM Containing PU Gels

Title: Temperature Regulating Polyurethane Gels

Number/Link: US2017/0210961

Applicant/Assignee: Technogel

Publication Date: 27 july 2017

“Gist”: Fatty acid ester PCMs are incorporated into Technogel-type gels without encapsulation

Why it is interesting: Polyurethane gels have been discussed before in this blog. The current invention is about “Technogel-type”  gels, made at low NCO-index and high functionality, that contain phase change materials (PCMs). The PCMs are esters of fatty acids that can be blended in molten state with the low EO polyol to form a clear solution, which is then reacted with isocyanate to form the gel. Despite not being encapsulated or forming a separate phase, the PCMs can reversibly melt and crsytallize while in the fluid phase of the gel. In the examples blends of lauryl laurate (C12-C12) and myristyl myristate (C14-C14) are used as PCM such that the phase change temperature is about 22-38°C.  The gels are said to be useful for ‘close to body’ comfort applications especially for use in matresses to improve sleeping comfort.

Lauryl laurate

 

TPU Aerosol

Title: POLYURETHANE AEROSOL COMPOSITIONS, ARTICLES, AND RELATED METHODS

Number/Link: US20170198150

Applicant/Assignee: 3M

Publication Date: 13-july-2017  (priority PCT)

“Gist”: Aqueous dispersion of a hydrazide-extended  TPU can be sprayed as aerosol to make protective films

Why it is interesting: An aqueous thermoplastic polyurethane dispersion is prepared from a non-yellowing diisocyanate, e.g. bis(4-isocyanatocyclohexyl), a diol (e.g. PPG2000), a difunctional hydrazine or hydrazide chain extender (e.g. 1,3-diaminourea) and a water solubilizing compound (e.g. dimethylolpropionic acid).  Together with a propellant the, composition is shelf-stable and can be aerosol-sprayed to form clear, non-yellowing protective films.

3M’s aerosol-sprayed protective film.

TPU Foams

Title: POLYURETHANE FOAMS AND METHOD FOR PRODUCING SAME

Number/Link: US2017/0174818

Applicant/Assignee: Lubrizol

Publication Date: 22-june-2016 (PCT oct. 2015)

“Gist”: TPUs with specific MW and polydispersity are injection moulded together with cellopener and gas in supercritical state

Why it is interesting: The invention relates to injection moulded “flexible foams”, especially useful for footwear applications. Thermoplastic polyurethanes with a Mw of 120,000 to 500,000 and a dispersity index of 1.85 to 2.51 are foamed using a gaseous blowing agent (CO2 or C1 to C6 hydrocarbons etc. ) together with a cellopener (silicone or EO/PO surfactant), such that at least 50% of cells are open.  In the examples the blowing agent is added in supercritical state to the melt before injection moulding. The type of gas used, nor the densities of the foams are mentioned.  Foaming TPU with gas in supercitical has also been file by Nike as discussed before in this blog.

Nike shoe with foamed thermoplastic midsole

 

TPU from Oleic Acid

Title: RENEWABLY DERIVED THERMOPLASTIC POLYESTER-BASED URETHANES AND METHODS OF MAKING AND USING THE SAME

Number/Link: US2017/0145145

Applicant/Assignee: Trent University

Publication Date: 25-may-2017

“Gist”: Thermoplastic polyurethane made entirely from C9 monomers derived from oleic acid.

Why it is interesting: Azaleic acid can be prepared by oxidative cleavage of the oleic acid double bond.  Azaleic acid in turn can be converted to 1,9-nonanediol and to 1,7-heptamethyldiisocyanate via azides and Curtius rearrangment (see previous blog post). In this invention a polyester diol is prepared from azaleic acid and nonanediol and is then reacted with 1,7-heptamethylenediisocyanate together with nonanediol as chain extender, resulting in a phase-separated TPU. Best properties are obtained when the nonanediol is first prepolymerized with the diisocyanate. The TPU is said to degrade without cytotoxic degradation products, and is therefore useful for medical applications such as resorbable implants and scaffolds.
Related case: US2017/0145146.

Oleic Acid

 

TPU with Moisture-Controlled Flexibility

Title: THERMOPLASTIC POLYURETHANE MATERIALS FOR FORMING MEDICAL DEVICES

Number/Link: Wo2017/066381

Applicant/Assignee: Becton Dickinson

Publication Date: 20 april 2017

“Gist”: High hardblock TPU, based on side-chain branched chain extenders, softens in water

Why it is interesting: The invention is related to thermoplastic polyurethanes for medical applications especially for intravenous catheters. These catheters need to have a high stiffness when inserted but need to become flexible once in place to prevent injuries. This is accomplished with TPUs based on MDI, PTMEG and either 2,2-dimethyl-1,3-propanediol (neopentylglycol) or 2-methyl-1,3-propanediol (MPdiol) and having a hardblock content of 50 to 75%. The examples show indeed an increased stiffness at ambient conditions and a larger softening when soaked in saline solution compared to TPU produced with a linear chain extender. It is however not mentioned which linear chain extender was used.

Neopentylglycol