End-Group Analysis and Number-Average Molecular Weight Determination of Some Polyalkylene Glycols and Glycol Polyesters Using Nuclear Magnetic Resonance Spectroscopy.

1964 ◽  
Vol 36 (10) ◽  
pp. 1981-1985 ◽  
Author(s):  
T. F. Page ◽  
W. E. Bresler
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Average Molecular Weight ◽  
Group Analysis ◽  
Resonance Spectroscopy ◽  
Molecular Weight Determination ◽  
Number Average Molecular Weight ◽  
End Group

End-Group Method for Molecular Weight Determination of PET Depolymerization under Microwave Irradiation

2012 ◽  
Vol 554-556 ◽  
pp. 1933-1937 ◽  
Author(s):  
Qing Hua Feng ◽  
Qing Hua Tang ◽  
Wei Lu Zhang ◽  
Yan Hua Jia ◽  
Dong Zhang
Keyword(s):  
Molecular Weight ◽  
Microwave Irradiation ◽  
Average Molecular Weight ◽  
Relative Number ◽  
Group Method ◽  
Molecular Weight Determination ◽  
Stannous Oxide ◽  
Hydrolytic Depolymerization ◽  
End Group

A series of catalysis hydrolytic depolymerization of PET catalyzed by zinc acetate, zinc sulfate, stannous oxide respectively under microwave irradiation at different temperature with time was studied, in which the microwave power was 260W, the ratio of water to PET was 10:1 and the dosage of the catalysts was 0.5% of PET. The relative number average molecular weight of the undepolymerized PET was determined by end-group method. The results show that the molecular weight of the undepolymerized PET decreases with the reaction time increasing, and tends to be stable at the end of the depolymerization reaction. Under the same time, the temperature is higher, the molecular weight is smaller. The molecular weight of the undepolymerized PET reduces most quickly with stannous oxide among the three catalysts.

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