Method for depolymerising oxygenated polymer materials by nucleophilic catalysis

Patent metadata

Field	Value
Publication number	US-11820869-B2
Application number	US-201917269445-A
Country	US
Kind code	B2
Filing date	Aug 13, 2019
Priority date	Aug 23, 2018
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

The present invention relates to a method for depolymerising oxygenated polymer materials, in particular by nucleophilic catalysis and to the use of said method in the recycling of plastic materials and the preparation of aromatic and aliphatic compounds that can be used as fuel, synthesis intermediates, raw materials in the construction sector, and in the petrochemical, electrical, electronic, textile, aeronautical, pharmaceutical, cosmetic and agrochemical industry. The present invention also relates to a method for manufacturing fuels, electronic components, plastic polymers, rubber, medicines, vitamins, cosmetics, perfumes, food products, synthetic yarns and fibres, synthetic leathers, glues, pesticides, fertilisers comprising (i) a step of depolymerisation of oxygenated polymer materials according to the method of the invention and optionally (ii) a step of hydrolysis, and optionally (iii) a step of functionalisation and/or defunctionalisation.

First claim

The invention claimed is:

1. A method for depolymerising oxygenated polymers by selective cleaving of oxygen-carbon bonds of ester functions (—CO—O—) and carbonate functions (—O—CO—O—), wherein the method comprises a step of putting into contact said oxygenated polymers with a hydrosilane compound of formula (I)

wherein
R 1 , R 2 and R 3 represent, independently from one another, a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, a silyl group, a siloxy group, an aryl group, an amino group, said alkyl, alkenyl, alkynyl, alkoxy, silyl, siloxy, aryl and amino groups being optionally substituted, or
R 1 is a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, a silyl group, a siloxy group, an aryl group, an amino group, said alkyl, alkenyl, alkynyl, alkoxy, silyl, siloxy, aryl and amino groups being optionally substituted, and R 2 and R 3 , taken together with the silicon atom to which they are linked to form an optionally substituted silyl heterocycle;

in presence of a Lewis base catalyst, said Lewis base catalyst being
an alcoholate of formula (II)
(R 6 —O − ) w M w+   (II)

wherein
w is 1, 2, 3, 4, and 5;
R 6 is an alkyl comprising 1 to 6 carbon atoms, an alkenyl comprising 2 to 6 carbon atoms, an alkynyl comprising 2 to 6 carbon atoms or a monocyclic or polycyclic aryl typically bi- or tri-cyclic comprising 6 to 20 carbon atoms; and
M is a metal chosen from among Li, Na, K, Cs or Rb, Cu, Mg, Zn, Ca, Sr, Ba, Pb, Al, Sb, La, Zr, Si, Ti, Sn, Hf, Ge, V; or
a compound allowing to release a fluoride (F − ) of formula (III):
Y z+ —(F − ) z   (III)

wherein
z is 1, 2, 3, 4;
Y is an alkyl ammonium of which the alkyl comprises 1 to 6 carbon atoms, an alkenyl ammonium of which the alkenyl comprises 2 to 6 carbon atoms, an alkynyl ammonium of which the alkynyl comprises 2 to 6 carbon atoms, or an aryl comprising 6 to 10 carbon atoms; a quinine ammonium, or
Y is a metal chosen from among Li, Na, K, Cs, Rb, Cu, Zn, Ca, Ba, Al, Zr, Sn;
a fluorosilicate chosen from among:
hexafluorosilicates SiF 6 2− with an alkaline counterion chosen from among Li, Na, K and Cs; or
fluorosilicates of formula (R 7 ) 3 SiF 2 − with an alkyl ammonium counterion of formula N(R 10 ) 4 + or a sulfonium counterion of formula S(R 11 ) 3 + ; with
R 7 being an alkyl comprising 1 to 6 carbon atoms chosen from among methyl, ethyl, propyl, butyl, pentyl or hexyl and their branched isomers; or an aryl comprising 6 to 10 carbon atoms chosen from among phenyl, benzyl or naphthyl;
R 10 being a hydrogen atom; a methyl, an ethyl, a propyl, a butyl, and their branched isomers;
R 11 being a hydrogen atom; a methyl, an ethyl, a propyl, a butyl, and their branched isomers or primary, secondary or tertiary amines;

a primary or secondary amide, a guanidine derivative chosen from among
bicyclic sodium or potassium guanidinates, in particular sodium or potassium salt of the anion of 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (or Hhpp),
guanidine,
1,5,7-triazabicyclo[4.4.0]dec-5-ene (or TBD);
a carbenic heterocycle of general formula (IV):

wherein
R 8 and R 9 represent, independently from one another, an alkyl comprising 1 to 6 carbon atoms, an alkenyl comprising 2 to 6 carbon atoms, an alkynyl comprising 2 to 6 carbon atoms or a bi- or tri-cyclic aryl comprising 6 to 20 carbon atoms;
a carbonate of formula (V)
M′ 2 CO 3   (V)

wherein M′ is a metal chosen from among Li, Na, K, Cs or Rb.

2. The method according to claim 1 , wherein the oxygenated polymers are chosen from among
saturated or unsaturated polyesters chosen from among polylactic acid (PLA), polycaprolactone (PCL), polyhydroxyalkanoate (PHA), polyhydroxyvalerate (PHV), polyethylene adipate (PEA), polybutylene succinate (PBS), poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), polydioxanone (PDO);
polycarbonates chosen from among PC-BPA, polypropylene carbonate (PPC), polyethylene carbonate (PEC), poly(hexamethylene carbonate), allyl diglycol carbonate (ADC) or CR-39; or
hydrolysable tannins chosen from among gallotannins, ellagitannins, or suberin.

3. The method according to claim 1 , wherein the oxygenated polymers are chosen from among
polyesters chosen from among PET, PCL, PDO or PLA;
polycarbonates chosen from among PC-BPA or PPC;
hydrolysable tannins chosen from among gallotannins, ellagitannins, or suberin.

4. The method according to claim 1 , wherein the Lewis base catalyst is an alcoholate of formula (II), wherein R 6 is a linear or branched alkyl comprising 1 to 6 carbon atoms, chosen from among methyl, ethyl, propyl, butyl, pentyl or hexyl and their branched isomers and M is Li, Na, K or Rb.

5. The method according to claim 1 , wherein the Lewis base catalyst is an alcoholate of formula (II) chosen from among CH 3 —OLi, CH 3 —ONa, CH 3 —OK, CH 3 —ORb, CH 3 CH 2 —OK, (CH 3 —O) 3 Al, (PhO) 3 Al, (iPrO) 3 Al or tBu-OK.

6. The method according to claim 1 , wherein the Lewis base catalyst is a compound of formula (III), wherein Y is an alkyl ammonium of which the alkyl comprises 1 to 6 carbon atoms, chosen from among methyl, ethyl, propyl, butyl, pentyl or hexyl and their branched isomers.

7. The method according to claim 1 , wherein the Lewis base catalyst is a compound of formula (III), chosen from among CsF, TMAF (tetramethylammonium fluoride) or TBAF (tetrabutylammonium fluoride).

8. The method according to claim 1 , wherein the Lewis base catalyst is a fluorosilicate chosen from among fluorosilicate ammonium (K 2 SiF 6 ) or difluorotriphenylsilicate tetrabutylammonium [(n-Bu) 4 N + (Ph) 3 SiF 2 − ] also called TBAT.

9. The method according to claim 1 , wherein the Lewis base catalyst is a carbenic heterocycle of formula (IV) chosen from among 2,6-di(1,3-diisopropyl)imidazolium carbene, 1,3-bis(1-adamantanyl)imidazolium carbene or 1,3-bis(2,6-diisopropylphenyl)imidazolinium carbene.

10. The method according to claim 1 , wherein the hydrosilane compound implemented is a hydrosilane compound of formula (I) wherein R 1 , R 2 and R 3 represent, independently from one another, a hydrogen atom; a hydroxyl group, an alkyl group chosen from among methyl, ethyl, propyl, butyl, and their branched isomers; an alkoxy group of which the alkyl radical is chosen from among methyl, ethyl, propyl, butyl and their branched isomers; an alkoxy group of which the alkyl radical is chosen from among methyl, ethyl, propyl, butyl and their branched isomers; an aryl group chosen from among phenyl and benzyl; an aryloxy group of which the aryl radical is chosen from among phenyl and benzyl; a siloxy group (—O—Si(X′) 3 ) of which each X, independently from one another, is chosen from among a hydrogen atom, an alkyl group chosen from among methyl, ethyl, propyl, an aryl group chosen from among phenyl and benzyl, a polymeric organosilane of general formulas

wherein X′ is independently from one another, is chosen from among a hydrogen atom, an alkyl group chosen from among methyl, ethyl, propyl, an aryl group chosen from among phenyl and benzyl, and n is an integer comprised between 1 and 2

Assignees

• Commissariat Energie Atomique

Inventors

• Monsigny Louis
• Cantat Thibault

Classifications

• C08J11/18 Primary

  by treatment with organic material · CPC title

• C08J2367/02

  Polyesters derived from dicarboxylic acids and dihydroxy compounds; (C08J2367/06 takes precedence) · CPC title

• C08J2367/04

  Polyesters derived from hydroxy carboxylic acids, e.g. lactones (C08J2367/06 takes precedence) · CPC title

• C08J2369/00

  Characterised by the use of polycarbonates; Derivatives of polycarbonates · CPC title

• C08J2367/00

  Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers · CPC title