Test Methods and Identification of Recycled Polyester
75
might be reduced with increased monomer yield by adopting to the following process
detailed in the below section. Whereas the reaction takes place at mild conditions
[7].
2.1.3 Glycolysis
PET recycling is plausible through glycolysis that taken place in a wide scope of
temperatures from 180 to 250 °C. The different catalyst is used to achieve a certain
degree of glycolysis. The process of conversion begins in 4–5 h and tailor-made
finish is possible in 9 h. The ideal yield of reaction can be obtained in a few seconds
with the use of a catalyst. PET glycolysis engages with the use of metal salts, ionic
liquids, and hydrotalcite. These catalysts have distinctive properties and executed
at assorted environmental condition such as temperature and pressure. There is a
breakthrough that enzyme has a degradative biocatalytic activity for PET witnessed
by researchers [8]. Therefore, PET degradation by enzymatic catalyst is welcome
and given in brief.
Advantages
• Temperature condition
• Depolymerization is faster in lower time
• Highest quality and efficiency are possible with appropriate catalyst.
2.1.4 Metal Salt as Catalyst
Active salts or eco-friendly metal salts are used for the reaction of PET glycolysis. The
following salts such as zinc acetate, sodium carbonate and bicarbonate, sodium and
potassium sulfate has been explored. The PET glycolysis results in the preliminary
color change as such as silver and white; amber (yellow and orange); green and blue
for the different substances. On the whole, temperature, ethylene glycol (EG) and
PET molar ratio on the reaction prevalently affect the reaction yield. Despite, an
increased temperature from 165 to 180 °C has emulated the higher yield. Hence, the
optimum temperature can be set as 180 °C. Similarly, increasing EG: PET molar
ratio (from 4 to 6) has also improved the reaction [9]. Overall, the reaction is stable
and remarkable with respect to the appropriate change in temperature, pressure, and
EG: PET ratio (Table 1).
In the note, zinc acetate as a catalyst has been showing the maximum yield as
compared with others. The best efficiency was observed within 180–195 °C. The ideal
condition of the reaction and the end product can be assessed through toxicity and
nonbiodegradability studies. The end product of polymer containing monomer, dimer
and trimmer molecules have experienced with the conventional approaches used
75
might be reduced with increased monomer yield by adopting to the following process
detailed in the below section. Whereas the reaction takes place at mild conditions
[7].
2.1.3 Glycolysis
PET recycling is plausible through glycolysis that taken place in a wide scope of
temperatures from 180 to 250 °C. The different catalyst is used to achieve a certain
degree of glycolysis. The process of conversion begins in 4–5 h and tailor-made
finish is possible in 9 h. The ideal yield of reaction can be obtained in a few seconds
with the use of a catalyst. PET glycolysis engages with the use of metal salts, ionic
liquids, and hydrotalcite. These catalysts have distinctive properties and executed
at assorted environmental condition such as temperature and pressure. There is a
breakthrough that enzyme has a degradative biocatalytic activity for PET witnessed
by researchers [8]. Therefore, PET degradation by enzymatic catalyst is welcome
and given in brief.
Advantages
• Temperature condition
• Depolymerization is faster in lower time
• Highest quality and efficiency are possible with appropriate catalyst.
2.1.4 Metal Salt as Catalyst
Active salts or eco-friendly metal salts are used for the reaction of PET glycolysis. The
following salts such as zinc acetate, sodium carbonate and bicarbonate, sodium and
potassium sulfate has been explored. The PET glycolysis results in the preliminary
color change as such as silver and white; amber (yellow and orange); green and blue
for the different substances. On the whole, temperature, ethylene glycol (EG) and
PET molar ratio on the reaction prevalently affect the reaction yield. Despite, an
increased temperature from 165 to 180 °C has emulated the higher yield. Hence, the
optimum temperature can be set as 180 °C. Similarly, increasing EG: PET molar
ratio (from 4 to 6) has also improved the reaction [9]. Overall, the reaction is stable
and remarkable with respect to the appropriate change in temperature, pressure, and
EG: PET ratio (Table 1).
In the note, zinc acetate as a catalyst has been showing the maximum yield as
compared with others. The best efficiency was observed within 180–195 °C. The ideal
condition of the reaction and the end product can be assessed through toxicity and
nonbiodegradability studies. The end product of polymer containing monomer, dimer
and trimmer molecules have experienced with the conventional approaches used