Kinetics and thermodynamics of anionic polymerization of 2‐methoxy‐2‐oxo‐1,3,2‐dioxaphosphorinane

Publisher Website
Google Scholar
Abstract
Kinetic activation parameters and thermodynamic functions describing the reversible anionic polymerization of 2‐methoxy‐2‐oxo‐1,3,2‐dioxaphosphorinane (1,3‐propylene methyl phosphate) were determined. Enthalpy and entropy of the anionic propagation ⇌ depropagation equilibrium were found to be close to those found previously by the present authors for the cationic polymerization, while the activation parameters of propagation and depropagation differ substantially for both processes and reflect the differences in the involved mechanisms. Thus, data for anionic polymerization (and cationic polymerization in parentheses) are: ΔH1s° = −0.7 kcal/mole (−1.1); ΔS1s° = −2.8 cal/mole‐deg (−5.4); ΔHp‡ = 26.7 kcal/mole, and ΔSp‡ = −6.1 cal/mole‐deg. The polymers obtained have low degrees of polymerization (DPn ≤ 10) because of the extensive chain transfer, leaving cyclic end groups in macromolecules. The presence, structure and concentration of the end groups have been determined by 1H‐, 31P‐, and 13C‐NMR spectra.