Theoretical Consideration of Phase Behavior of the Products of Free‐Radical Copolymerization Described by the Penultimate Model

Abstract

The penultimate model of copolymerization taking into account the dependence of the reactivity of a macroradical on the type of the unit preceding the ultimate one is well-known in polymer chemistry. All types of chemical structure of multiblock copolymers capable to form during copolymerization processes described by such a model are revealed in the present work. Phase diagrams of copolymers of all these types specifying the regions of thermodynamic stability of spatially periodic mesophases differing in morphology are constructed in the framework of the weak segregation theory. Besides, the periods and amplitudes of the variation of different type densities of units in mesophases as well as volume fractions of these latter within the regions of their coexistence are calculated.

Modeling of the Penultimate Unit Effect in Chain-Growth Copolymerizations

“…The penultimate model is generally employed when the terminal model (first-order Markovian model) is not able to satisfactorily describe polymerization rates. Two types of the penultimate model have been proposed: (i) the first one is named the explicit penultimate model which assumes that both the terminal and penultimate units of the radical can affect both the reactivity and selectivity; (ii) the second one denominated the implicit penultimate model which considers that despite the terminal and penultimate units of the polymeric radical affect the reactivity, only the terminal unit affects the selectivity [5][6][7][8][9][10][11][12][13].…”