4.4
ANIONIC POLYMERISATION
A ralised scheme for the anionic polymerisation may
generalised
be written as:
IA (ion-pair formation) (4.41)
AM I (initiation) (4.42)
AMM AMMi propagation) (4.43)
(termination) (4.44)
AM,M I+HA AM,MH+
where
when
protonating agent and k k, k, and , are the dissociation, initiation,
1A is the initiator, HA is a
termination rate constants, respectively.
propagation and
as per the foregoing scheme, will be given by
The propagation rate,
R kk,[A] M (4.45)
R,K, HA]
The degree of polymerisation
is governed by the following equation:
[M (4.46a)
D,-HA involving termination, as shown in
is applicable for anionic polymerisation systems of 'living
Equation (4.46a) no termination is involved, as in the case
in which
the generalised scheme. For systems can be found on
the basis of the following
polymerisation
an expression
for the degree of
polymers,
assumptions at the same time;
initiator dissociates and
()the entire quantity of the chain growth essentially simultaneously;
dissociation initiate
formed by the consumed more or less
m o n o m e r is
7) all the anions m o n o m e r and
the
anions compete equally for the
) all the
whether the initiating species
equally by all the anions. of polymerisation
depends on
If it is a
Further, the expression for the degree sodium complex of naphthalene).expression
or a
dianion (e.g., in Fig. 4.3), the
butyl lithium) as shown
amonoanion (e.g., end only
growth takes
place at one
anion (where the chain
for D, takes the form (4.46b)
IA]
ANIONIC POLYMERISATION
A ralised scheme for the anionic polymerisation may
generalised
be written as:
IA (ion-pair formation) (4.41)
AM I (initiation) (4.42)
AMM AMMi propagation) (4.43)
(termination) (4.44)
AM,M I+HA AM,MH+
where
when
protonating agent and k k, k, and , are the dissociation, initiation,
1A is the initiator, HA is a
termination rate constants, respectively.
propagation and
as per the foregoing scheme, will be given by
The propagation rate,
R kk,[A] M (4.45)
R,K, HA]
The degree of polymerisation
is governed by the following equation:
[M (4.46a)
D,-HA involving termination, as shown in
is applicable for anionic polymerisation systems of 'living
Equation (4.46a) no termination is involved, as in the case
in which
the generalised scheme. For systems can be found on
the basis of the following
polymerisation
an expression
for the degree of
polymers,
assumptions at the same time;
initiator dissociates and
()the entire quantity of the chain growth essentially simultaneously;
dissociation initiate
formed by the consumed more or less
m o n o m e r is
7) all the anions m o n o m e r and
the
anions compete equally for the
) all the
whether the initiating species
equally by all the anions. of polymerisation
depends on
If it is a
Further, the expression for the degree sodium complex of naphthalene).expression
or a
dianion (e.g., in Fig. 4.3), the
butyl lithium) as shown
amonoanion (e.g., end only
growth takes
place at one
anion (where the chain
for D, takes the form (4.46b)
IA]
