Method and device for purifying polybutylene terephthalate
AssigneesNational Tsing Hua University, Chang Chun Plastics Co., Ltd., Chang Chun Petrochemical Co., Ltd.
InventorChung-Sung Tan
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Abstract
A method for purifying polybutylene terephthalate (PBT) includes: providing or receiving initial PBT, in which oligomers and tetrahydrofuran are present; dissolving the initial PBT in hexafluoroisopropanol (HFIP) to form a solution, in which the oligomers are also dissolved in the HFIP; and contacting the solution with compressed CO2 at a temperature and a pressure, thereby precipitating the purified PBT, resulting from a large portion of the oligomers are still dissolved in the HFIP, in the operation the temperature is in a range of 20° C. to 35° C., and the pressure is in a range of 900 psi to 1400 psi. A device for purifying PBT is also provided.
Claims8
A method for purifying polybutylene terephthalate (PBT), comprising:
- providing or receiving initial PBT, wherein the initial PBT comprises oligomers;
- dissolving the initial PBT in hexafluoroisopropanol (HFIP) to form a PBT/HFIP solution, wherein the oligomers are dissolved in the HFIP, wherein a weight percent of the initial PBT in the PBT/HFIP solution is in a range of about 1 wt % to about 8 wt %;
- and
- contacting the PBT/HFIP solution with compressed carbon dioxide (CO2) at a temperature of 20° C. to 35° C. and a pressure of 900 psi to 1400 psi, thereby precipitating purified PBT at the temperature and the pressure, wherein at least a portion of the oligomers are still dissolved in the HFIP.
Dependencies are inferred from the claim text.