Лако-красочные материалы — производство

In the steady state the rate of formation of radicals by initiation, is equal to the rate of removal of radicals by termination.

That is:

Ri = Rt

кгі [~Мг][Мі] = k-|2 [~Мі][Мг] equation A The rate of consumption of monomer M! is given by

= ki, i [- МІ] [Mi] + кг, і [~ М2] [Mi] equation В

The rate of consumption of monomer M2 is given by

From equation A

Substituting for [~Mi] in equations В and C

-d [Mi] = ki, i кг,1 [~Мг] [Mi]2 dt Ki,2 [М2]

and

Ki,2 Ка,1 [-M2] [Mi] [M2] + K2,2 [~M2] [М2]
Kl,2 [М2]

™jjT^ = [~M2](k2,l[Ml] + k2,2[M2])

then

d [Mi] d[M2]

By replacing t-^1 with r, к,2

and ~ with r2 *2,1

the following equation is obtained

d [Mi] = [Mr] ( n [Mi] + [M2]) d [M2] [M2] ([Mi] + r2 [M2])

where: r, represents the reactivity of Mi with respect to Mi and М2

r2 represents the reactivity of М2 with respect to М2 and Mi.

The equation is known as the copolymer composition equation.

The copolymer equation is normally used in this form to predict, by calculation, the composition of a polymer resulting from the polymerisation of two monomers.