Chemistry Reference
In-Depth Information
polyethylene samples to demonstrate the
resolution and comprehensive information
produced by this instrument. Other analy-
tical methods with slower crystallization
rates down to 0.01
8
C/min, sub-ambient
temperatures for less crystalline polymers,
higher elution temperatures for polypropy-
lene, or different flow rates are easily
programmed through the virtual
molecular weight and long chain branching
detection as well as the possible adaptation
to work in reverse mode as GPC fractiona-
tion followed by the TREF analysis of the
GPC fractions.
[1] W. W. Yau, J. J. Kirkland, D. D. Bly, ''Modern size
exclusion liquid chromatography'', Wiley, 1979.
[2] L. Wild, T. Ryle, D. Knobeloch, I. R. Peat,
instru-
J. Polym.
Sci., Polym. Phys. Ed. 1982, 20, 441.
[3] B. Monrabal, Polymer ChAR, in: ''Encyclopedia of
Analytical Chemistry'', R. A. Meyers, Ed., John Wiley
&Sons Ltd., 2000.
[4] B. Monrabal, in: ''New Trends in Polyolefin Science
and Technology'', S. Hosoda, Ed., Research signpost,
1996, 126.
[5] J. V. Bosch, A. Ortin, B. Monrabal, International GPC
Symposium proceedings, Arizona, 1998, 633-640
[6] P. J. DesLauriers, D. C. Rohlfing, E. T. Hsieh, Polymer
2002, 43, 159.
[7] L. G. Hazlitt, D. G. Moldovan, US Pat. 4,798,081
(1989).
[8] W. W. Yau, D. Gillespie, Polymer 2001, 42, 8947.
[9] B. Monrabal, A. Ortin, L. Romero, 12
th
mentation software user interface.
This cross-fractionation instrument also
proves to be a very powerful tool for
obtaining the SCB distribution along the
MWD for the most demanding applications
of pipe grade HDPE resins having very
little comonomer incorporated. An
approach for measuring the distribution
of comonomer along the MWD for HDPE
products based on cross-fractionation data
obtained by TREF fractionation and GPC
analysis has been studied and its feasibility
established using the instrument and ana-
lysis conditions described in this work.
Addition of other detectors online will
still increase the amount of information
generated by this cross-fractionation instru-
ment. A methyl sensitive head can be
incorporated to the IR detector in order to
measure the methyl groups concentration
and, as a result, the comonomer weight
percent directly both for polyethylene and
polypropylene copolymers. Future devel-
opments also include coupling viscometer
and light scattering detectors to this
instrument, which will provide absolute
Intern. Symp.
on Polymer Analysis and Characterization, La Rochelle
June 28 1999.
[10] B. Monrabal, A. Ortin, P. del Hierro, L. Romero,
International GPC Symposium proceedings
, Las Vegas,
2000.
[11] L. Wild, T. Ryle, D. Knobeloch,
Polym. Prepr., Am.
Chem. Soc., Polym. Chem. Div.
1982, 23, 133.
[12] S. Nakano, Y. Goto,
J. Appl. Polym. Sci.
1981, 26,
4217.
[13] C. Li Pi Shan, D. Gillespie, L. Hazlitt, Ecorep 2005
Lyon.
[14] J. Nieto, T. Oswald, F. Blanco, J. B. P. Soares, B.
Monrabal, J Polym Sci. B: Polym. Phys. 2001, 39, 1616.
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J Polym Sci. B: Polym. Chem.
1999, 37, 89.
