STUDIES ON A NEW RAPID AND SIMPLE DETERMINATION METHOD OF CHAIN-LENGTH DISTRIBUTION OF A CROSSLINKED POLYMER BY CHEMORHEOLOGY
1988 Volume 61 Issue 11 Pages 772-778
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1988 Volume 61 Issue 11 Pages 772-778
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.
Nx(t)=Nx(0)•e-xkt (1), qm, x(t)=x•Nx(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>Nx(t)=∑<∞><x=1>Nx(0)•e-xkt (3)
