Aluminium-27 nuclear magnetic resonance studies of the hydrolysis of aluminium(III). Part 2. Gel-permeation chromatography

1981 ◽  
pp. 1606 ◽  
Author(s):  
J. W. Akitt ◽  
Alan Farthing
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Gel Permeation Chromatography ◽  
Magnetic Resonance Studies ◽  
Gel Permeation ◽  
Hydrolysis Of ◽  
Nuclear Magnetic

scholarly journals Cleavage of the Graft Bonds in PVDF–g–St Films by Boiling Xylene Extraction and the Determination of the Molecular Weight of the Graft Chains

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1098 ◽  
Author(s):  
Chen ◽  
Seko
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Thermal Degradation ◽  
Gel Permeation Chromatography ◽  
Extraction Time ◽  
Gel Permeation ◽  
Irradiation Graft ◽  
Nuclear Magnetic

To determine the molecular weight of graft chains in grafted films, the polystyrene graft chains of PVDF–g–St films synthesized by a pre-irradiation graft method are cleaved and separated by boiling xylene extraction. The analysis of the extracted material and the residual films by FTIR, nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC) analyses indicates that most graft chains are removed from the PVDF–g–St films within 72 h of extraction time. Furthermore, the molecular weight of the residual films decreases quickly within 8 h of extraction and then remains virtually unchanged up to 72 h after extraction time. The degradation is due to the cleavage of graft bonds, which is mainly driven by the thermal degradation and the swelling of graft chains in solution. This allows determination of the molecular weight of graft chains by GPC analysis of the extracted material. The results indicate that the PVDF–g–St prepared in this study has the structure where one or two graft chains hang from each PVDF backbone.

The Synthesis of Polystyrene-B-Poly(4-Vinylpyridine) by Nitroxide-Medium Controllable Free Radical Polymerization

2012 ◽  
Vol 531 ◽  
pp. 366-369
Author(s):  
Si Kai Zhou ◽  
Ya Juan Xu ◽  
Shao Ming Fang ◽  
Zhi Jun Chen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Free Radical ◽  
Magnetic Resonance ◽  
Radical Polymerization ◽  
Diblock Copolymers ◽  
Free Radical Polymerization ◽  
Gel Permeation Chromatography ◽  
1H Nuclear Magnetic Resonance ◽  
Gel Permeation ◽  
Nuclear Magnetic

In this paper, a system polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) were synthesized by nitroxide-medium controllable free radical polymerization. PS-b-P4VP were characterized by 1H-nuclear magnetic resonance (1H-NMR), infrared spectrum (FTIR) and gel permeation chromatography (GPC). The results have indicated that diblock copolymers can be prepared and with molecular polydispersities in the range of 1.08 to 1.31. The structure of diblock was showed by 1H-nuclear magnetic resonance.

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