scholarly journals Determination of diethyleneglycol content and number of carboxylic end groups in poly(ethylene terephthalate) fibers using imaging and conventional near infrared spectroscopy

2016 ◽  
Vol 49 ◽  
pp. 15-21 ◽  
Author(s):  
Viviane Fonseca Caetano ◽  
Lívia Rodrigues e Brito ◽  
Jarbas José Rodrigues Rohwedder ◽  
Celio Pasquini ◽  
Maria Fernanda Pimentel ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Ethylene Terephthalate ◽  
Near Infrared ◽  
Poly Ethylene Terephthalate ◽  
End Groups ◽  
Poly Ethylene

Study of PET depolymerization during recycling

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Ljerka Kratofil Krehula ◽  
Zlata Hrnjak-Murgić ◽  
Branka Andričić ◽  
Jasenka Jelenčić
Keyword(s):  
Chemical Structure ◽  
Ethylene Terephthalate ◽  
Recycling Process ◽  
Mechanical Recycling ◽  
Scanning Calorimetry ◽  
Degraded Samples ◽  
Poly Ethylene Terephthalate ◽  
End Groups ◽  
Poly Ethylene

AbstractDepolymerization of poly(ethylene-terephthalate) (PET) in PET/HDPE blends, obtained from virgin polymers during mechanical recycling was studied. Extrusion of PET/HDPE blends was simulation of the first cycle of recycling and extrusion of the blends with EPDM/HDPE (E-M) masterbatch and HDPE/EPDM (PEM) masterbatch the second cycle. After that the samples were additionally treated to examine their thermooxidative stability. Blends were characterized by determination of the concentration of carboxyl groups by Pohl titration, by FTIR spectroscopy and differential scanning calorimetry (DSC) to determine crystallization (Tc) and melting (Tm) temperatures. The concentration of determinated carboxyl end groups in blends indicate presence of formed polymer radicals with hydroxyl-carboxyl end groups as the result of depolymerization of PET. Presence of characteristic groups was also confirmed by FTIR. DSC results indicate the influence of HDPE on crystallization temperature of PET and points to the fact that even degraded samples maintain the chemical structure of PET. From the results it can be seen that addition of the particular modifier can reduce and even prevent the depolymerization during the recycling process.

Near Infrared Spectroscopy Used in Purification and Determination of Pharmaceutical Cocrystal

2013 ◽  
Vol 41 (12) ◽  
pp. 1928
Author(s):  
Zong-Liang CHI ◽  
Miao-Miao WANG ◽  
Xiao-Dong CONG ◽  
Shao-Guang LIU ◽  
Bao-Chang CAI
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Pharmaceutical Cocrystal
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