It is still impossible to find out a molecular-weight distribution of a crosslinked polymer, becasue of its insolubility into solvents and its infusibility to high temperatures. This paper deals with a simple determination method of such a distribution of a crosslinked polymer by a new means of chemorheology.
For the network chains having
x-degree, the following relations are established.
N
x(t)=N
x(0)•e
-xkt (1), q
m, x(t)=x•N
x(0)•k•t (2)
Here,
N(0): the number of moles of network chains per unit volume before degradation,
N(
t): those after t of degradation,
qm(
t): the number or moles of scissions along mainchains per unit volume,
x: the polymerization degree between two crosslinks,
k: the proportionality constant for the scission along mainchains.
The total number of elastically effective chains,
N(
t) is the sum over all chain-lengths as follows. N(t)=∑<∞><x=1>N
x(t)=∑<∞><x=1>N
x(0)•e
-xkt (3)
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