Solution for Advanced Polymer analysis with a single system
In order to improve the chemical and physical performance of synthetic polymer materials, various parameters must be controlled and monitored such as 1) directing the molecular weight distribution of polymers, 2) types and blend ratios of additives, and 3) types and blend ratios of polymers in a “polymer blend” consisting of more than two types of polymers are performed. When these analyses are performed on a single high quality system, throughput and quality of new material development can be accelerated, compared to analysis with conventional GPS/SEC and HPLC.
AQUITY APC p-QSM system
The ACQUITY Advanced Polymer Chromatography with the polymer-Isocratic Solvent Manager system (APC p-ISM) had been designed for high throughput and high resolution Gel Permeation/Size Exclusion Chromatography (GPC/SEC) analysis (refer to Polymer Characterization with APC).
When analyzing polymer blends and additives in polymeric materials, a gradient method is usually required for effective separation of the sample components. For analysis of these types of materials a system should also be compatible and robust enough to allow for the prolonged use of strong organic solvents such as THF and DMF.
The APC with polymer-Quaternary Solvent Manager system (APC p-QSM) has the same solvent compatibility as the existing APC p-ISM system and has been specifically designed to meet the increasing demands of advanced polymer research. This APC p-QSM system is a UPLC/SEC system with tolerance to prolonged use of the strong organic solvents commonly used for chemical materials analysis, and offers the flexibility to analyze the molecular weight distribution of complex polymer blends, their additives and general analysis of small molecules using GPC/SEC, GPEC (Gradient Polymer Elution Chromatography), and reversed-phase LC within a single system.
Molecular weight distribution with higher resolution
As the polymeric substances are mixtures of molecules with a distribution of molecular weights, it is necessary to characterize molecular weight distribution to control and improve the final materials properties and quality standards, whilst speeding up product innovation. APC technology for GPC is a low dispersion, high-resolution, size-based separation technology. The technology also benefits from rigid and high pore volume hybrid particle APC columns, which results in high-speed analysis (refer to Polymer Characterization with APC). The APC p-QSM system, has the same low dispersion as the APC p-ISM and can perform high-speed, high-resolution advanced GPC by combination with an APC column.
The figure shows a comparison of calibration curves and molecular weights collected on the APC p-ISM versus APC p-QSM system using a RI (Refractive Index) detector. There is no change in the level of data quality between both systems, R2 of the10 point calibration curves are consistent to within 4 decimal places and mean peak Mw showing 99.9% consistency between both systems.
Polymer blend analysis with Gradient Polymer Elution Chromatography (GPEC)
A polymer blend is a compatible or incompatible material that physically mixes two or more polymers, to create a new material.
By compatibilizing these polymers with a stabilizer and/or controlling phase separation in an incompatible system, these can dramatically improve the materials physical properties, compared to those of each component polymer, and so are attracting attention as one method for developing engineering plastics.
To determine the type polymer and a suitable blending ratio, the GPEC separation technique is often used. The GPEC method purposefully phase separates and precipitates a polymer blend or copolymer temporarily onto the column or column frit, the gradient ratio is then increased in favor of a good solvent until it reaches the polymer’s solubility point, releasing the polymer from the surface of the column. When GPC separation is used for these types of samples, chemically different polymers of a similar hydrodynamic volume o often co-elute, and if reversed-phase separation is used for these types of polymers, they can remain partially solubilized throughout the separation resulting in coelution and poor baseline separation. In GPEC analysis of copolymers and polymer blends gradient analysis can only be achieved with aggressive solvents. The APC p-QSM system has the gradient capability of a UPLC system and APC p-ISM’s compatibility with these aggressive and strong solvents, meaning it can provide high throughput GPEC analysis.
Polymer additives analysis with reversed-phase LC
One aspect of polymer analysis is the qualification and quantification of polymer additives, used to introduce a variety of chemical and physical properties to polymer materials. Understanding the types of additives and blending ratio in a polymeric material, is directly associated with improving material quality.
This is important in a wide variety of industries, for example in the case of extractables and leachables research, there is a tendency towards the incorporation of additives which are difficult to elute from polymer materials are used. In other words, additives with higher molecular weight and higher hydrophobicity are used, meaning that during analysis, elution from the column is difficult, even in reversed-phase analysis, unless a strong solvent such as THF is used. The figure below shows an overlay of 5 reversed-phase chromatograms of common polymer additives, including Irganox 1076 that has higher hydrophobicity than Irganox 1010 commonly used as antioxidant. Gradient analysis using water and THF can provide high quality baseline separation of these additives. Utilizing the features of UPLC technology such as, low dispersion, small particle size column separation, high throughput, and excellent reproducibility in reversed-phase analysis offers much improved separation over conventional HPLC.
The APC p-QSM system offers both GPC/SEC and gradient UPLC separation, with all-round tolerance to strong organic solvents commonly used for chemical materials analysis. The system provides flexibility for diverse and complex polymer analysis to a higher quality in a single system.