Synthesis, Dilute Solution Properties, and Chain Flexibility of Poly(Difluorobenzyl Methacrylates)

Abstract

The synthesis and dilute solution behavior of poly(2,5-difluorobenzyl methacrylate) (P2,5-DFBM) and poly(2,6-difluorobenzyl methacrylate) (P2,6-DFBM) are described. The polymers were characterized by viscosity and classical light-scattering and size exclusion chromatography (SEC) measurements. The Kuhn-Mark-Houwink-Sakurada (KMHS) relationships were established. Unperturbed dimensions <r ₀ ²>^1/2, the rigidity factor σ, the characteristic ratio C _∞, and the thermodynamic parameters were determined using the Stockmayer-Fixman treatment. The double substitution in the 2,5 and 2,6 positions by fluorine atoms increases the conformational parameters. The presence of substituents such as ─CH₃─ or fluorine atoms close to the main chain (2,6 position) affects the internal rotation potential in the same way.

ACKNOWLEDGMENTS

We express our thanks to Fondo Nacional de Desarrollo Científico y Tecnologico (Fondecyt) project 8970011 for financial support. D. R. expresses thanks to Cátedra Presidencial en Ciencias' 95.