Influence of Chemical Heterogeneity of Copolymers on the Separation Process in Size-Exclusion Chromatography

1996 ◽  
Vol 29 (18) ◽  
pp. 6023-6030 ◽  
Author(s):  
M. Netopilík ◽  
M. Bohdanecký ◽  
P. Kratochvíl
2015 ◽  
Vol 6 (27) ◽  
pp. 4864-4874 ◽  
Author(s):  
Leena Pitkänen ◽  
Aaron A. Urbas ◽  
André M. Striegel

Examined here is the feasibility of employing Raman spectroscopy as a detection method in size-exclusion chromatography (SEC) and related macromolecular separations, for the purposes of determining the chemical heterogeneity of copolymers.


e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Sven M. Graef ◽  
Robert Brüll ◽  
Harald Pasch ◽  
Udo M. Wahner

Abstract Copolymers of ethylene with 1-decene, 1-tetradecene and 1-octadecene were prepared using the catalyst system racEt[Ind]2ZrCl2/MAO and were analysed with regard to chemical heterogeneity using crystallisation analysis fractionation (CRYSTAF), differential scanning calorimetry (DSC) and size exclusion chromatography coupled to FTIR (SEC-FTIR). The melting and crystallisation temperatures from DSC decrease linearly with increasing amount of comonomer, independently of the nature thereof. The decrease in crystallisation temperature from CRYSTAF of copolymers with higher 1-olefin content indicates a small dependence on the length of the side chain. The chemical heterogeneity of the copolymers as analysed by DSC and CRYSTAF broadens with increasing comonomer concentration.


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