PET-Lignin Polyols

Patent Title: HIGH RECYCLE CONTENT POLYOLS FROM THERMOPLASTIC POLYESTERS AND LIGNIN OR TANNIN

 Number/Link: WO2016/118411

Applicant/Assignee: Resinate Materials Group

Publication date: 28-07-2016

Gist”: PET is glycolized and then reacted with lignin or tannin

Why it is interesting: This application is about ‘sustainable’ aromatic polyester polyols partly based on recycled materials and partly on biorenewable materials. According to the invention the polyols can be prepared by first glycolizing (waste) PET and subsequently reacting the mixture with lignin at 110-210°C while removing volatile condensation products.  The resulting polyols (pref) show a OH value between 40 and 400 mg KOH/g, a fn of 2-2.2 and a viscosity at 25°C of 500 to 3000 cP. In the examples polyols with up to 25 wt% lignin are shown. The polyols are said to be useful e.g. in 2K PU coating compositions.

Part of a lignin structure

Part of a lignin structure

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Polyurethane Rigid Foam Containing Lignin

Title: COMPOSITIONS OF PHENOLIC BIOPOLYMERS

 Number/Link:WO2015/055662

Applicant/Assignee: Solvay

Publication date: 23-04-2015

Gist”: Lignin is emulsified in a halogenated polyol and then used to prepare rigid foams.

Why it is interesting: This case is about yet another attempt to incorporate lignin into polyurethane materials. In this invention lignin is dispersed in a halogenated polyol using a suitable milling process. The polyol is preferably a brominated ‘rigid’ polyether.  The dispersed lignin (pref.) has a (d90) mean particle size of less than 100μm and is used in an amount of up to about 50% on the brominated polyether.  The lignin dispersion can then be used together with other polyols in rigid foam formulations.  The resulting foams should have improved flammability properties and the lignin is said to have no negative effect on thermal insulation properties.

Part of a typical lignin structure

Part of a typical lignin structure

 

Rigid Foams Containing Lignin

Title: PROCESS FOR THE PREPARATION OF LIGNIN BASED POLYURETHANE PRODUCTS

 Number/Link: WO2015/021541

Applicant/Assignee: Enerlab 2000

Publication date: 19-02-2015

Gist”: Dried lignin is mixed with isocyanate before being reacted with a rigid polyol and HFC blowing agent to make rigid foams

Why it is interesting: Lignin is a cheap and abundantly available hydroxy-functional biopolymer and it is no surprise that many attempts are being made to incorporate it into polyurethane materials. This case claims that lignins, dried to a moisture content of (preferably) less than 1% (0.5% in the examples), can be mixed with isocyanates to form a relatively stable mixture with a decent potlife. The mixture can then be used to make polyurethane materials.  In the examples HFC-blown rigid PU and PIR foams are shown containing about 20% of dried lignin and with densities ranging between about 30 to 40 kg/m³.  Interesting development, however claim 41, which states that elastomers and even TPUs can be made with mixtures, is clearly over the top in my opinion.

Part of a typical lignin structure

Part of a typical lignin structure