2D Analysis of Thermoplastic Elastomers TPE
LCGC Asia Pacific
Polymer Standard Services
Introduction
Blockcopolymers such as SBS (styrene-butadiene-styrene) are an important product class and a typical example of complex polymers. In addition to the molar mass distribution, a chemical composition distribution may also be present in copolymers. While GPC/SEC is the established method for the determination of molar mass averages and distribution, gradient HPLC can be applied to separate based on chemical composition.
Gradient HPLC can be hyphenated with GPC/SEC in a fully automated setup to measure both distribution simultaneously with a high peak capacity and to detect differences in batches (cf. Figure 1).
Figure 1: Scheme of two-dimensional chromatography.
Experimental
All experiments were performed on PSS SECcurity equipment using the following conditions:
Eluent 1st dim.: n-Hexane/THF p.a. gradient
Column 1st dim.: PSS Si-60 5 μm
Flow-rate 1st dim.: 0.1 mL/min
Injection volume: 20 μL
Transfer: PSS 2D tandem transfer valve with two 100 μL loops
Eluent 2nd dim.: THF p.a.
Column 2nd dim.: PSS HighSpeed SDV 5 μm, 10000 Å
Flow-rate 2nd dim.: 6.25 mL/min
Detection: SECcurity VWD 1260 UV at 254 nm
Calibration: PSS Polystyrene ReadyCal Standards, PSS Polybutadiene standards
Data system: PSS WinGPC Unity 7.5
Results
The 2D approach is the only way to determine two property distributions independently and unambiguously. The online combination of gradient HPLC and GPC/SEC increases the peak capacity of the separations and those peaks which cannot be separated by either method alone to be examined more closely. The HPLC conditions are selected to separate according to polybutadiene content.
Figure 2: Contour plot of a thermoplastic elastomer.
Figure 2 shows the contour plot for a thermoplastic elastomer that shows one narrow main peak in GPC/SEC. However, 2D separation reveals that four different compositions are present that co-elute in the GPC/SEC experiment. The species differ in composition and polybutadiene content. The colour code indicates the concentration of each peak. Simultaneous molar mass results and composition results can be measured using the calibrated GPC/SEC and HPLC axis.
PSS Polymer Standards Service GmbH
In der Dalheimer Wiese 5, D-55120 Mainz, Germany
tel.+49 6131 96239 0 fax +49 6131 96239 11
E-mail: Pkilz@polymer.de
Website: www.pss-polymer.com
New Study Uses MSPE with GC–MS to Analyze PFCAs in Water
January 20th 2025Scientists from the China University of Sciences combined magnetic solid-phase extraction (MSPE) with gas chromatography–mass spectrometry (GC–MS) to analyze perfluoro carboxylic acids (PFCAs) in different water environments.
The Next Frontier for Mass Spectrometry: Maximizing Ion Utilization
January 20th 2025In this podcast, Daniel DeBord, CTO of MOBILion Systems, describes a new high resolution mass spectrometry approach that promises to increase speed and sensitivity in omics applications. MOBILion recently introduced the PAMAF mode of operation, which stands for parallel accumulation with mobility aligned fragmentation. It substantially increases the fraction of ion used for mass spectrometry analysis by replacing the functionality of the quadrupole with high resolution ion mobility. Listen to learn more about this exciting new development.
A Guide To Finding the Ideal Syringe and Needle
January 20th 2025Hamilton has produced a series of reference guides to assist science professionals in finding the best-suited products and configurations for their applications. The Syringe and Needle Reference Guide provides detailed information on Hamilton Company’s full portfolio of syringes and needles. Everything from cleaning and preventative maintenance to individual part numbers are available for review. It also includes selection charts to help you choose between syringe terminations like cemented needles and luer tips.
The Complexity of Oligonucleotide Separations
January 9th 2025Peter Pellegrinelli, Applications Specialist at Advanced Materials Technology (AMT) explains the complexity of oligonucleotide separations due to the unique chemical properties of these molecules. Issues such as varying length, sequence complexity, and hydrophilic-hydrophobic characteristics make efficient separations difficult. Separation scientists are addressing these challenges by modifying mobile phase compositions, using varying ion-pairing reagents, and exploring alternative separation modes like HILIC and ion-exchange chromatography. Due to these complexities, AMT has introduced the HALO® OLIGO column, which offers high-resolution, fast separations through its innovative Fused-Core® technology and high pH stability. Alongside explaining the new column, Peter looks to the future of these separations and what is next to come.
Oasis or Sand Dune? Isolation of Psychedelic Compounds
January 20th 2025Magic mushrooms, once taboo, have recently experienced a renaissance. This new awakening is partially due to new findings that indicate the effects of psilocybin, and its dephosphorylated cousin psilocin may produce long lasting results for patients who might be struggling with anxiety, depression, alcohol and drug abuse, and post-traumatic stress disorder. Hamilton Company has developed a methodology for the isolation and identification of 5 common psychedelic compounds used in the potential treatment of disease. The PRP-1 HPLC column resin remains stable in the harsh alkaline conditions ideal for better separations.
