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Characterization of polyvinyl chloride. Part III. An alternative GPC method for measuring the radii of gyration, and the degree of long‐chain branching of polydispersed polymers
Author(s) -
Chan Richard K. S.,
Worman Charles
Publication year - 1972
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760120609
Subject(s) - branching (polymer chemistry) , radius of gyration , dispersity , polymer , polyvinyl chloride , polyvinyl acetate , polymer chemistry , materials science , degree (music) , gyration , analytical chemistry (journal) , physics , polymer science , chemistry , mathematics , chromatography , geometry , composite material , acoustics
A method for measuring the unperturbed radius of gyration and the degree of long‐chain branching in Gaussian‐distribution polymers is proposed. Polyvinyl chloride (PVC) and polyvinyl acetate (PVAc) were selected to illustrate the method. It was observed that PVC samples prepared by homogeneous and heterogeneous polymerizations exhibit the same degree of long‐chain branching. This conclusion is supported by viscometric data. The polydispersity ratios ( M w / M n ) indicate that both types of polymerizations would yield a very small amount of total branching (long chain and short chain.) The calculated unperturbed radius of gyration of linear PVC samples was found to be 0.185 \documentclass{article}\pagestyle{empty}\begin{document}$ \left( {\frac{{{\rm \dot A}^{\rm 2} {\rm mole}}}{{{\rm gm}}}} \right) $\end{document} , and that of PVAc was determined to be 0.107 \documentclass{article}\pagestyle{empty}\begin{document}$ \left( {\frac{{{\rm \dot A}^{\rm 2} {\rm mole}}}{{{\rm gm}}}} \right) $\end{document} . The value obtained for PVC is shown to be in agreement with the value determined from the viscometric method as described in our previous work.