Method for depolymerising oxygenated polymer materials

Patent metadata

Field	Value
Publication number	US-10189868-B2
Application number	US-201515535533-A
Country	US
Kind code	B2
Filing date	Dec 16, 2015
Priority date	Dec 17, 2014
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

The present invention concerns a method for depolymerizing oxygenated polymer materials and the use of said method in the recycling of plastic materials and the preparation of aromatic compounds that can be used as fuel, synthesis intermediates and raw materials in the construction sectors and in the petrochemical, electrical, electronic, textile, aeronautical, pharmaceutical, cosmetics and agrochemical industries. The present invention also concerns the use of aromatic compounds obtained by the method for depolymerizing oxygenated polymer materials according to the invention, in the production of fuels, electronic components, plastic polymers, rubber, drugs, vitamins, cosmetic products, perfumes, food products, synthetic threads and fibers, synthetic leathers, glues, pesticides and fertilizers.

First claim

The invention claimed is:

1. A process for depolymerizing oxygenated polymer materials by selective cleavage of the oxygen-carbonyl bonds of the ester functions and of the carbonate functions, comprising a step of placing said oxygenated polymer materials in contact with a silane compound of formula (I)

in which
R 1 , R 2 and R 3 represent, independently of each other, 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 as defined above and R 2 and R 3 , taken together with the silicon atom to which they are linked, form an optionally substituted silyl heterocycle;

in the presence of a catalyst which is:
an organic catalyst selected from the group consisting of
the carbocations of formula (X 1 ) 3 C + with X 1 representing a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, a silyl group, a siloxy group and a halogen atom;
oxoniums chosen from (CH 3 ) 3 O + BF 4 − and (CH 3 CH 2 ) 3 O +BF 4 − ;
a silylium ion (R 5 ) 3 Si + with R 5 representing, independently of each other, a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a heterocycle, a silyl group, a siloxy group;
disilyl cations;

with the anionic counterion of said silylium ion, of said carbocations and of said disilyl cations being
a halide selected from the group consisting of F − , Cl − , Br − and I − ; or
an anion selected from the group consisting of BF 4 − , SbF 6 − , B(C 6 F 5 ) 4 − , B(C 6 H 5 ) 4 − , CF 3 SO 3 − , PF 6 −; or

an organometallic catalyst comprising ruthenium or iridium selected from the group consisting of:
the iridium complexes of formula (II):

in which
R 6 represents an alkyl or aryl group;
R 7 represents a hydrogen atom or an alkyl group;
X 2 represents a —CH 2 − group or an oxygen atom;
Y − represents a counterion selected from the group consisting of B(C 6 F 5 ) 4 − and B(C 6 H 5 ) 4 ; and
S represents a solvent molecule, coordinated to the complex, selected from the group consisting of dimethyl sulfoxide (DMSO), acetonitrile (CH 3 CN) and acetone (CH 3 COCH 3 ); and

the ruthenium complexes of formula (III):

in which
R 8 represents a hydrogen atom or an alkyl group;
R 9 represents an aryl or an alkyl group, said aryl and alkyl groups being optionally substituted;
Z represents a —CH 2 − group, an oxygen atom or a sulfur atom; and
A − represents a counterion chosen from B(C 6 F 5 ) 4 − and [CHB 11 H 5 Cl 6 ] − ; or

a catalyst of Lewis acid type selected from the group consisting of:
the boron compound selected from the group consisting of BF 3 , BF 3 (Et 2 O), BCl 3 , BBr 3 , triphenylhydroborane, tricyclohexylhydroborane, B(C 6 F 5 ) 3 , B-methoxy-9borabicyclo[3.3.1]nonane (B-methoxy-9-BBN), B-benzyl-9-borabicyclo[3.3.1]nonane (B-benzyl-9-BBN);
the borenium compound Me-TBD-BBN 30 , the borenium ferrocene derivatives corresponding to the formula

in which R 10 =phenyl and R 11 =3,5-dimethylpyridyl;
aluminum compounds selected from the group consisting of AlCl 3 , AlBr 3 , aluminum isopropoxide (Al(O-i-Pr) 3 ), aluminum ethoxide (Al(C 2 H 3 O 2 )), Krossing's salt [Aq(CH 2 Cl 2 )]{Al [OC(CF 3 ) 3 ] 4 }, the Li{Al[OC(CF 3 ) 3 ] 4 }, Et 2 Al + ;
indium compounds chosen from InCl 3 , In(OTf) 3 ;
iron compounds chosen from FeCl 3 , Fe(OTf) 3
tin compounds chosen from SnCl 4 , Sn(OTf) 2 ,
phosphorus compounds chosen from PCl 3 , PCl 5 , POCl 3
trifluoromethanesulfonate or triflate compounds (CF 3 SO 3 − ) of transition metals and of lanthanides chosen from scandium triflate, ytterbium triflate, yttrium triflate, cerium triflate, samarium triflate and neodymium triflate.

2. The process as claimed in claim 1 , wherein the oxygenated polymers are selected from the group consisting of:
saturated or unsaturated polyesters selected from the group consisting of polyglycolic acid (PGA), polylactic acid (PLA), polycaprolactone (PCL), polyhydroxyalkanoate (PHA), polyhydroxybutyrate (P3HB), 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),
polycarbonates selected from the group consisting of PC-BPA, polypropylene carbonate (PPC), polyethylene carbonate (PEC), poly(hexamethylene carbonate), allyl diglycol carbonate (ADC) or CR 39, and
hydrolyzable tannins, especially gallotannins and ellagitannins, and suberin.

3. The process as claimed in claim 1 , wherein the oxygenated polymers are selected from the group consisting of:
PET and PLA;
PC-BPA;
gallotannins and ellagitannins, and suberin.

4. The process as claimed in claim 1 , wherein the catalyst is an organic catalyst selected from the group consisting of:
carbocations selected from the group consisting of the trityl cation ((C 6 H 5 ) 3 C + ), tropilium (C 7 H 7 ) + , the benzilic cation (C 6 H 5 CH 2 + ), the allylic cation (CH 3 —CH + —CH═CH 2 ), methylium (CH 3 + ), cyclopropylium (C 3 H 5 + ), the cyclopropyl carbocation selected from the group consisting of the dimethylcyclopropyl carbocation and the dicyclopropyl carbocation, the triazabicyclodecene (TBD) cation, acylium (R 1 —C═O) + with R 1 as defined above and selected from the group consisting of methyl, propyl and benzyl, benzenium (C 6 H 5 ) + , and the norbornyl cation (C 7 H 11 ) + ;
oxoniums selected from the group consisting of (CH 3 ) 3 O + BF 4 − and (CH 3 CH 2 ) 3 O + BF 4 − ;
a silylium ion selected from the group consisting of Et 3 Si + and Me 3 Si + ;
disilyl cations bearing a bridging hydride selected from the group consisting of the formulae indicated below

with the anionic counterion of said silylium ion, of said carbocations and of said disilyl cations being
a halide selected from the group consisting of F − , Cl − , Br − and I − ; or
an anion selected from the group consisting of BF 4 − , SbF 6 − , B(C 6 F 5 ) 4 − , B(C 6 H 5 ) 4 − , CF 3 SO 3 − , PF 6 − .

5. The process as claimed in claim 4 , wherein the organic catalyst is selected from the group consisting of triphenylcarbenium tetrakis(perfluorophenyl)borate [(Ph) 3 C + B(C 6 F 5 ) 4 ] − .

6. The process as claimed in claim 1 , wherein the catalyst is an organometallic catalyst selected from the group consisting of:
the iridium complexes of formula (II):

in which
R 6 represents an alkyl or aryl group;
R 7 represents a hydrogen atom or an alkyl group;
X 2 represents a —CH 2 31 group or an oxygen atom;
Y − represents a counterion selected from the group consisting of B(C

Assignees

• Commissariat Energie Atomique

Inventors

• Cantat Thibault
• Feghali Elias

Classifications

• C07C2531/14

  of aluminium or boron · CPC title

• C07C29/09

  by hydrolysis · CPC title

• C08J2397/00

  Characterised by the use of lignin-containing materials · CPC title

• C07C1/22

  by reduction · CPC title

• C08J11/18

  by treatment with organic material · CPC title