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)

 

Viscoelastic Polyurethane Elastomers

Title:  IMPACT PROTECTION FOAM

Number/Link: US2017/0233519

Applicant/Assignee: Dow

Publication Date: 17 august 2017

“Gist”: Viscoelastic foams are prepared from MDI, castor oil and a hydrophilic polyether polyol.

Why it is interesting: According to this invention energy absorbing foams with relatively low density and a low hardness and resilience in the temperature range from about -10 to +40°C, can be produced by reacting a blend of hydrophilic and hydrophobic polyols containing castor oil, about 0.5 pbw water and some catalyst and chain extender with MDI.  The examples show foams of about 500 kg/m³ with hardness below shore 50A and ball rebound below 15% at both -10 and +23°C. The foams are said to be useful for impact-protective garments.

Castor oil

Castor oil component

Aerogels from Isocyanates and Epoxies

Patent Title: ORGANIC AEROGELS BASED ON ISOCYANATE AND CYCLIC ETHER POLYMER NETWORKS

 Number/Link: WO2017016755

Applicant/Assignee: Henkel

Publication date: 2-feb-2017

Gist”: Isocyanate and epoxy are reacted in solvent and supercritically dried

Why it is interesting: While most ‘conventional’ aerogels are based on silica, organic aerogels, especially isocyanate-based aerogels, are also well known: polyurethane-, polyurea-, polyamide-, polyimide-, polycarbodiimide- and polyisocyanurate aerogels have all been reported. This invention adds another type of aerogel based on the reaction of isocyanates and cyclic ethers, esp. oxetanes and oxiranes. The isocyanate with a functionality of (pref.) 2 to 3, (e.g. 4,4′-MDI or methylidynetri-p-phenyletriisocyanate) is reacted with a cyclic ether  of (pref.) functionality of 2 to 3, (e.g. N,N-diglycidyl-4-glycidyloxianiline) in a suitable solvent (e.g. DMAc). After washing, the gel is dried with supercritical carbon dioxide. The materials are useful for thermal insulation and are said to have better mechanical properties compared to other organic aerogels.

N,N-Diglycidyl-4-glycidyloxyaniline

N,N-Diglycidyl-4-glycidyloxyaniline

 

 

Insulating Wood-Aerogel Composites

Title: REINFORCED ORGANIC NATURAL FIBER COMPOSITES

 Number/Link: WO2015/144267

Applicant/Assignee: Huntsman

Publication date: 1-10-2015

Gist”: Aerogel particles are incorporated in composite wood boards

Why it is interesting: Composite wood products (OSB, MDF..) are  well known and popular construction materials which are produced by compressing wood fibers (or flakes and the like) together with a binder like e.g. a polymeric MDI. Typically these materials show thermal conductivity values of about 50 mW/m.K at densities of around 200 kg/m³.  According to this invention these insulation values can be significantly improved by incorporating (a large amount of) hydrophobic nanoporous particles and binding the composite with an in-water emulsified isocyanate. In the examples silica aerogel particles and wood fibers are mixed an bonded with an emulsifiable MDI. The amount of particles ranges from about 25 to 50% (w/w) resulting in composites with densities below 200 kg/m³ and insulation values of about 20 to 30 mW/mK.

Medium density fibreboard (MDF).

Medium density fibreboard (MDF).