Chemistry Reference
In-Depth Information
Figure 5.
High-precision LCB index gpcBR by 3D-GPC.
often encountered in thin films of high-
density polyethylene (HDPE). The results
of one of these studies are shown in the
m
peak. The presence of LCB would increase the
viscometer peak to a lesser extent than the LS
peak. The 3D-TREF side of the plot shows
the structure being mainly of the high
melting type, just like the HDPE film base,
with no indication of significant branching
structure. These results are indicative of the
problem being more of a high molecular
weight ''un-melt'' rather than that of a
''gel'' or cross-linking branching problem in
the usual sense. Because a very limited
amount of the ''gel'' particles can be extra-
cted from a film sample, the very small
-structure plot in Figure 9, where the
results of the ''gel'' particle are being com-
pared with the results of the clear HDPE
film base that contains no ''gel.'' Here,
the 3D-GPC side of the plot shows the
structure being mainly of a linear high
molecular weight material with no signifi-
cant LCB. This observation is derived from
the fact that the size of viscosity peak also
increases along with the increase in the LS
Figure 6.
High-precision LCB index trefBR by 3D-TREF.
