Chemistry Reference
In-Depth Information
Figure 13.
Trivariate
di
stribution of chain length, chemical composition and long chain branching. Model parameters:
t ¼
0.002,
F
¼
0
:
5,
r
1
r
2
¼
1.
tion for chains with different number of
LCBs per chain, as defined by Equation (1).
As the number of LCBs per chain increases,
the CLD move towards higher averages
and the CCD becomes narrower. This
equation quantifies the intuitive notion
that more branched chain will have higher
average lengths and that longer chains will
have compositions that are closer to the
average copolymer composition. This is,
of course, the same prediction given by
Stockmayer distribution for linear chains.
Each of the distributions shown in
Figure 13 are normalized but, in reality,
their fractions in the whole polymer will vary
depending on the polymerization condi-
tions.
[1,2,12]
Regardless of these conditions,
the less branched chains always have higher
molar fractions (but not necessarily higher
mass fractions) than more branched chains.
Figure 14.
CLD and average LCB/chain distributions for a model branched polymer. Model parameters:
a¼
0.1 and
t ¼
0.001.
