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)

 

1K Dual Cure Polyurethane Adhesive

Patent Title: DUAL CURE 1K PU ADHESIVE FORMULATIONS USING MATRIX ENCAPSULATED POLYAMINES

 Number/Link: W02016022346

Applicant/Assignee: Dow

Publication date: 11-02-2016

Gist”: Encapsulated polyamines are added to a moisture curing adhesive

Why it is interesting: One component (1K) PU adhesives are either NCO-ended prepolymers cured by atmospheric moisture, or OH-ended prepolymers containing encapuslated or blocked isocyanates and which are cured by heat.  According to this invention a 1K adhesive curable by both moisture and heat can be made by incorporating an encapuslated polyamine into a 1K mositure curing prepolymer. The amine is solid at room temperature (e.g. 1,12-dodecanediamine) and is mixed with a (semi-)crystalline termoplastic with a well defined melting point, e.g. a polyacrylate or polyolefine before being added to the adhesive. Dual cure 1K adhesives allow for heat-curing the adhesive at critical spots to providing stability to an assembly.  The adhesives are said to be especially useful for the automotive industry.

1,12-dodecanediamine

1,12-dodecanediamine

 

Thermal Engine Encapsulation with Polyurethane Foam

Title: THERMAL INSULATION OF AN INTERNAL COMBUSTION ENGINE

 Number/Link: WO2014/195153 (German)

Applicant/Assignee: BASF

Publication date: 11-12-2014

Gist”:  Engine parts are encapsulated in PU foam using moulds.

Why it is interesting: Encapsulating (part of) motor car engines with heat-insulating rigid PU foam is useful because it can reduce fuel consumption and exhaust. When the mass of the foam is increased (e.g. by filling with BaSO4) the encapsulation can also reduce noise levels. BASF has been working on this concept for more than 15 years now (see e.g. DE19935335) and the current application only relates to a process improvement:  an engine part is brought into a closed mould leaving a gap between part and mould which is then filled with PU foam. This is an interesting concept but I wonder if it is actually used in current motor cars.  And if not, why not?

Car with thermally encapsulated engine.

Car with thermally encapsulated engine.