Carbamate Blown Rigid Foams

Patent Title: A METHOD FOR PRODUCING AN OPEN CELL RIGID POLYURETHANE FOAM

 Number/Link: WO2018096101  WO2018096102

Applicant/Assignee:  Covestro

Publication date: 31 may 2018

Gist”: An open cell rigid foam is prepared using an amine-CO2 adduct and water as blowing agents

Why it is interesting: According to this invention an open cell rigid spray foam can be prepared from a conventional rigid foam formulation and a blowing agent consisting of 4-12 parts (pref.) on 100 parts of polyol of an adduct of a primary or secondary amine and carbon dioxide, together with 15 to 50 parts of water.  The properties of the resulting open cell, low density foam are said to be largely independent of ambient conditions and spray thickness. The foams are useful for thermal insulation applications in construction.

carbamate

Carbamate of N,N-dimethylaminopropylamine

 

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Coated Fracking Proppants

Patent Title: AMIDE BASED COATING

 Number/Link: WO2017/213855

Applicant/Assignee:  Dow

Publication date: 14 December 2017

Gist”: Proppant particles are coated with polyamide based on isocyanate and carboxylic acids

Why it is interesting: Proppant particles are used in the hydraulic fracturing process to force open rock fissures to extract gas and oil – as discussed before in this blog. According to this invention the proppant particles are coated with a reacting mixture of a polyisocyanate (e.g. polymeric MDI) and polycarboxilic acids (e.g. a blend of citric acid and an acid-terminated polyether triol). Under the high pressure and temperature of the fracture, the coating will bond the proppant particles together, thus preventing flow-back of the proppant and the blocking of the well. The coating can contain additives to capture heavy metals like radium and sulfides like hydrogensulfide to reduce contamination of the fracture fluid.

citricacid

Citric acid

Solid-Solid PU PCM

Patent Title: PHASE-CHANGE MATERIAL FOR STORING THERMAL ENERGY, MANUFACTURING METHOD AND USES OF SUCH A MATERIAL

 Number/Link:  WO2017/198933 (French)

Applicant/Assignee:  UNIV CERGY-PONTOIS

Publication date: 23 november 2017

Gist”: A crosslinked PEG-HMDI elastomer can be used as phase change material.

Why it is interesting: Phase change materials, used to dampen temperature cycles in buildings, are well known. Most organic phase change materials (e.g. paraffines) show solid-liquid phase transitions and therefore need to be macro- or micro-encapsulated. This invention is about polyurethane PCMs with a solid to solid phase transition, and therefore need not be encapsulated. The PU PCM is prepared by reacting a polyethylene glycol with a diisocyanate like HMDI together with a crosslinker like glycerol. The solid elastomer is then ground into powder which can be used in construction materials like plaster or cement. The transition temperature and the latent heat of the PCM is controlled through the mole weight of the PEG (e.g. 1000 to 2000 Da) and the degree of crosslinking.
Solid-solid PU PCMs are not new, see WO2011/089061 (Huntsman), which (in my opinion) presents a more elegant and flexible solution to the problem.

Phase_Change_Materials

Temperature damping by PCM (Wikimedia Commons)

 

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