TOSOH
CUSTOMER MAGAZINE
Engineering and commodity plastics such as polyamides, nylon,
polyphenylene sulfides, polypropylene, and polyethylene excel other
materialsby their mechanical strength and their resistance to che-
mical and physical degradation. However, these advantages turn
into hurdles when it comes to their characterization. They are semi-
crystalline and need elevated temperatures or special solvents for
complete dissolution. This requires specialized instruments and co-
lumns to ensure that the sample remains in solution and avoids re-
crystallization.
The first step in high temperature GPC analysis is an efficient dissolu-
tion and filtration of samples prior to analysis. As the polymer chain
is stressed by heat and shaking sample preparation needs to be very
gentle. The optional sample processing unit DF-8321 can process up
to 24 samples by moving the sample carefully and applying a tem-
perature program ranging from 40 to 220 °C until full dissolution has
occurred. Samples can be filtered automatically to avoid clogging of
the GPC column.
EcoSEC HT has a unique dual flow design which includes the use
of two pumps under stable temperature atmosphere. The sam-
ple pump delivers solvent from the reservoir through the fol-
lowing system components in sequence: autosampler, analyti-
cal column and sample side of refractive index (RI) detector cell.
At the reference side the solvent flows via the reference pump
through a reference column (used to ensure equal pressure condi-
tions) and the reference side of the RI detector. This results in an
extremely stable baseline shown in Figure 1 for three different mobile
phases.
The RI detector and the temperature controlled pumps of the EcoSEC
HT system deliver precise flow rates at all temperatures, even when
changes in environmental conditions occur, thus producing repro-
ducible results sample after sample, day after day. For optimum
performance the GPC column should be carefully selected to fit the
temperature and solvent conditions. The TSKgel family offers a wide
range of GPC/SEC columns with individual pore sizes but also mixed-
bed and multi-pore columns exhibiting linear mass calibrations. The
intraday and day to day reproducibility of EcoSEC HT GPC analysis
with RI detection at 140°C are shown in Figure 2.
With the installation of the high temperature instrument in our large
and modern application lab in Griesheim, we now have two instru-
ments, an ambient system up to 60 °C and an HT system up to 220 °C
available to demonstrate the power of EcoSEC for polymer characteri-
zation. Interested scientists and researchers are kindly invited to have
a look at the systems and get some polymer samples analyzed.
HIGH TEMPERATURE GEL PERMEATION
CHROMATOGRAPHY
THE COMPACT HIGH TEMPERATURE SYSTEM EcoSEC HT FOR GEL PERMEATION CHROMATOGRAPHY (GPC) ANALYSIS, THE LATEST
ADDITION TO TOSOH’S POLYMER ANALYSIS PLATFORM, IS NOW INSTALLED AND READY FOR MEASUREMENTS IN OUR LAB IN GRIES-
HEIM. THIS ALL IN ONE GPC/SEC SYSTEM FOR THE ANALYSIS OF ENGINEERING AND COMMODITY PLASTICS, PROVIDES STABLE
THERMOSTATIZATION UP TO 220 °C.
06
GPC
EcoSEC HT
FIGURE 1:
BASELINE DRIFT OF THE DUAL FLOW RI DETECTOR OF THE EcoSEC
HT GPC SYSTEM FOR ODCB (A, 145 °C), TCB (B, 145 °C), AND 1-CN (C, 220°C) AT 1 ML
/MIN WITH 2 X TSKgel GMH
HR
-H (S) HT2
FIGURE 2:
GPC ELUTION PROFILE OF INTRADAY REPRODUCIBILITY OF THE
EcoSEC HT GPC SYSTEM
FOR POLYMER SAMPLE ANALYSES, INSTRUMENT / SOFTWARE DE-
MONSTRATIONS, AND ANY OTHER RELATED QUESTIONS PLEASE CONTACT
OR
40
20
0
60
Retention time [min]
50
45
0
Detector response (mV)
A: ODCB
B: TCB
C: 1-CN
[mV]
10
0
20
30
0
5
10
15
Detector response (mV)
Retention time (minutes)
Injection #1
Injection #2
Injection #3
Injection #4
Injection #5
Injection #6
Column:
TSKgel GMHHR-H(S)HT2
Solvent:
ODCB, 1.0 mL/min, 145 ˚C
Flow Rate:
1.0 mL/min
Temperature:
145 ˚C
Sample:
Polystyrene (F-20), 0.02 %, 300 µL
