Determination of molecular weight and molecular sizes of polymers by high temperature gel permeation chromatography with a static and dynamic laser light scattering detector

Polymer ◽  
2003 ◽  
Vol 44 (23) ◽  
pp. 7209-7220 ◽  
Author(s):  
Yonggang Liu ◽  
Shuqin Bo ◽  
Yejuan Zhu ◽  
Wenhe Zhang
Keyword(s):  
Molecular Weight ◽  
High Temperature ◽  
Light Scattering ◽  
Laser Light ◽  
Gel Permeation Chromatography ◽  
Laser Light Scattering ◽  
Dynamic Laser Light Scattering ◽  
Gel Permeation ◽  
Molecular Sizes

Determination of absolute molecular weight of sodium lignosulfonates (NaLS) by laser light scattering (LLS)

Holzforschung ◽  
2013 ◽  
Vol 67 (3) ◽  
pp. 265-271 ◽  
Author(s):  
Yong Qian ◽  
Yonghong Deng ◽  
Yunqing Guo ◽  
Conghua Yi ◽  
Xueqing Qiu
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Laser Light ◽  
Gel Permeation Chromatography ◽  
Laser Light Scattering ◽  
Sodium Polystyrene Sulfonate ◽  
Sodium Lignosulfonate ◽  
The Absolute ◽  
Syringe Filter

Abstract The problems related to the determination of the absolute molecular weight (Mw) of sodium lignosulfonate (NaLS) are the focus of the present work. Four narrow-dispersed NaLS fractions were collected by filtration, ultrafiltration, and gel permeation chromatography (GPC), and their Mw measured by laser light scattering (LLSMw) was compared with that obtained by GPC (GPCMw). The LLSMw values were much larger than GPCMw, and this Mw difference increased with increasing Mw of NaLS. This finding confirms the known polyelectrolyte and aggregation effects of NaLS. The deviation is also partly due to the conformation differences between the GPC standard (sodium polystyrene sulfonate) and the NaLS molecules. The effects of polyelectrolytes and NaLS aggregates could be inhibited by adding enough NaCl salt in the NaLS solution and filtering the NaLS/NaCl solution through a syringe filter. As a result, the slow mode in dynamic LLS measurement disappeared. By this approach, the absolute LLSMw values were only slightly larger than that determined by GPC due to the conformation differences between the GPC standard and the NaLS molecules.

scholarly journals Comparative Study on Molecular Weight of Konjac Glucomannan by Gel Permeation Chromatography-Laser Light Scattering-Refractive Index and Laser Light-Scattering Methods

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Mei Xu ◽  
Dong-Sheng Li ◽  
Bin Li ◽  
Chao Wang ◽  
Yu-Peng Zhu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Refractive Index ◽  
Light Scattering ◽  
Laser Light ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Konjac Glucomannan ◽  
Laser Light Scattering ◽  
Gel Permeation ◽  
Single Method

The gel permeation chromatography, combined with laser light scattering and refractive index (GPC-LLS-RI) online method and laser light scattering (LLS) single method, researched the weight-average molecular weight (Mw) of konjac glucomannan (KGM) in this paper. The results show that the determination results of molecular weight of KGM are similar by two method, the molecular weight of KGM is2.476×105 g/mol by online method measured, and it is2.508×105 g/mol by single method measured, compared with only 1.3% difference between the two methods. At the same time, the molecular weight distributions of KGM and conformation index were analyzed by online method, while the second virial coefficient (A2) that characterizes the interaction between KGM molecules and solvent molecules was acquired by single method, which can provide reliable foundation for the molecular chain morphology research of KGM.

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