Table 3.
Summary of selected metal‐based and organocatalysts reported for PLA glycolysis.
|
Cataylst |
EG/ester unit (w/w) |
Cat. [wt %] |
T [°C] |
t [h] |
PET conv. [%] |
Y BHET [a] [%] |
Ref. |
|---|---|---|---|---|---|---|---|
|
Organocatalysts |
|
|
|
|
|
|
|
|
Urea |
4 : 1 |
10 |
180 |
3 |
100 |
80 |
[230] |
|
TBD |
5.2 : 1 |
0.7 |
190 |
3.5 |
100 |
78 |
[231] |
|
DMAP |
5.2 : 1 |
16 |
190 |
1.67 |
100 |
94[b] |
[235] |
|
DBU |
5.2 : 1 |
13 |
190 |
0.11 |
100 |
99[b] |
[235] |
|
DBN |
5.2 : 1 |
15 |
190 |
0.12 |
100 |
99[b] |
[235] |
|
TBD/MSA (1 : 1) |
20 : 1[c] |
0.5 : 1[d] |
180 |
2 |
100 |
91 |
[237] |
|
ILs |
|
|
|
|
|
|
|
|
[Bmim][Cl] |
4 : 1 |
20 |
180 |
8 |
45 |
– |
[238,239] |
|
[Bmim][Br] |
4 : 1 |
20 |
180 |
8 |
99 |
– |
[238,239] |
|
[Bmim][OH] |
10 : 1 |
5 |
190 |
2 |
100 |
71 |
[240] |
|
[Bmim]2[CoCl4] |
11.7 : 1 |
16.7 |
175 |
1.5 |
100 |
81 |
[241] |
|
[Ch]3[PO4] |
4 : 1 |
20 |
180 |
4 |
100 |
61 |
[243] |
|
DESs |
|
|
|
|
|
|
|
|
4(urea) ⋅ (ZnCl2) |
4 : 1 |
5 |
170 |
0.5 |
100 |
83 |
[244] |
|
Metal‐based |
|
|
|
|
|
|
|
|
ZnCl2 |
10 : 1[c] |
0.5 |
197 |
8 |
– |
73 |
[247] |
|
NaHCO3 |
6 : 1[c] |
5 |
–[e] |
0.58 |
– |
65 |
[248] |
|
Zn(OAc)2 |
7.6 : 1[c] |
1 : 100[d] |
196 |
1 |
– |
≈70 |
[249] |
|
Na2CO3 |
7.6 : 1[c] |
1 : 100[d] |
196 |
1 |
– |
≈70 |
[249] |
|
SO4 2−/ZnO‐TiO2‐200–300 °C |
5.6 : 1 |
0.3 |
180 |
3 |
100 |
72 |
[250] |
|
β‐zeolite |
6 : 1 |
1 |
196 |
8 |
100 |
66 |
[251] |
|
γ‐zeolite |
6 : 1 |
1 |
196 |
8 |
100 |
65 |
[251] |
|
Ti(IV)‐phosphate catalyst |
2.8 : 1[c] |
0.3 |
190–200 |
2.5 |
100 |
98[b] |
[258] |
|
Ti(OCH2CH2O)3Na2 |
12 : 1[c] |
1 : 100[d] |
190 |
3 |
– |
85 |
[262] |
|
[Co(dcype)]Cl2 |
11.1 : 1 |
1.5 : 100[d] |
190 |
3 |
– |
75 |
[263] |
|
[Ni(COD)2]/dppe (1 : 2) |
11.1 : 1 |
1 : 100[d] |
190 |
3 |
100 |
67 |
[263] |
|
Nanocatalysts |
|
|
|
|
|
|
|
|
γ‐Fe2O3 |
3.3 : 1 |
0.05 |
300[f] |
1 |
– |
>90 |
[252] |
|
Mn3O4/SNPs |
11 : 1[c] |
1 |
300[f] |
1.33 |
– |
>90 |
[253,254] |
|
ZnMn2O4 |
11.5 : 1[c] |
1 |
260[g] |
1 |
– |
92 |
[255] |
|
Fe3O4‐boosted MWCNT |
10 : 1 |
5 |
190 |
2 |
100 |
100 |
[256] |
[a] Y BHET refers to isolated yield of BHET unless otherwise stated. [b] Yield reported as a mass fraction of the products as determined by GPC. [c] Molar ratios are listed. [d] Molar ratio of [catalyst]/[PET]. [e] No temperature reported. Microwave irradiation used, power=800 W. [f] Reaction performed at approximately 1.1 MPa. [g] Reaction performed at 5 atm.