Reactivity Ratios for Some Common Monomer Pairs

the terminal model allows the copolymer composition for a given monomer feed to be predicted from just two parameters the reactivity ratios rAB and rBA- Some values of terminal model reactivity ratios for common monomer pairs are given in Table 7.1. Values for other monomers can be found in data [Pg.339]

Substitution into the copolymer composition equation (eq. 8) shows that this condition is satisfied when [Pg.341]

The existence of an azeotropic composition has some practical significance. By conducting a polymerization with the monomer feed ratio equal to the azeotropic composition, a high conversion batch copolymer can be prepared that has no compositional heterogeneity caused by drift in copolymer composition with conversion. Thus, the complex incremental addition protocols that arc otherwise required to achieve this end, are unnecessary. Composition equations and conditions for azeotropic compositions in ternary and quaternary eopolymerizations have also been defined.211,21 [Pg.341]

An expression (eq. 11) for the overall rate constant for propagation in copolymerization (A ) can now be formulated. [Pg.341]

Note that value of kp is usually not constant with conversion since it depends on the monomer feed composition. [Pg.342]

Grccnlcy s compilation. All values rounded to two significant figures. [Pg.339]

Big Chemical Encyclopedia