응용 분야 및 기법

Polymer materials that are used for building and decoration purposes need to be flame resistant. To reach the required level of resistance flame-retardants are added to the plain polymer. Flame-retardants are often haloorganic compounds. The use of such components and the respective concentration of introduced halogens can be determined by Combustion IC. The recovery over the full system is tested with acertified reference material (CRM).

Combustion Ion Chromatography combines pro-hydrolytic sample combustion and the absorption of emerging combustion gases in an oxidizing, aqueous solution that is then channeled to an ion chromatograph for the analysis of halogenides and sulfur (as sulfate). The combustion and analysis of the certified reference materials (ZRM) makes clear the reliability of Metrohm Combustion Ion Chromatography.Keyword: pyrohydrolysis

This Application Note demonstrates how NIR spectroscopy can be used to determine the content of coatings on nylon fibers, quickly and without requiring either sample preparation or the use of reagents. In order to suppress the effects arising from scattering on the surface coatings, one forms the second derivative spectra; the linear least-squares regression method is used to calculate the calibration function.

During polymerization, real-time determination of hydroxyl and acid numbers of polyols provide important information about molecular weight and the reaction end point. This Application Note sheds light on the practical aspects of process monitoring in a polyol batch process using NIRS methodology. Real-time process monitoring with NIRS is the key to lower production costs and better product quality.

This Application Note shows that near-infrared spectroscopy with its exceptionally short analysis times significantly accelerates quality monitoring of polymer granulates and raw materials. Polyethylene (PE) und polypropylene (PP) can be identified in parallel. PE density is also determined in the same measurement.

Toxic and corrosive chemicals such as p-toluenesulfonyl isocyanate (TSI) and tetrabutylammonium hydroxide are used for the Hydroxyl Number analysis of polyols by titration according to ASTM D4274-16. This application note demonstrates how the XDS RapidLiquid Analyzer operating in the visible and near-infrared spectral region (Vis-NIR) provides a cost-efficient and fast solution for the determination of the hydroxyl (OH) number of polyols. With no sample preparation or chemicals needed, Vis-NIR spectroscopy allows for the analysis of polyols in less than a minute.

Functional group and viscosity analysis (ASTM D789) of polyamides can be a lengthy and challenging process due to the sample’s limited solubility. This application note demonstrates that the DS2500 Solid Analyzer operating in the visible and near-infrared spectral region (Vis-NIR) provides a cost-efficient and fast solution for a simultaneous determination of the intrinsic viscosity as well as the amine, carboxylic, and moisture content in polyamides. With no sample preparation or chemicals needed, Vis-NIR spectroscopy allows for the analysis of polyamides in less than a minute.

Polyvinyl alcohol (PVA) is a linear polymer, used in a variety of medical products (e.g. eye drops). Here, the degree of alcoholysis is an important index for the water solubility, viscosity, and adhesion of the product. The degree of alcoholysis is defined as the percentage of hydroxyl functional groups compared to the total functional groups accessible in the molecule. Conventional alcoholysis determination can take up to six hours per sample. Compared to the primary method, analysis with near-infrared spectroscopy (NIRS) only takes one minute. The following application note describes the determination of the degree of alcoholysis by NIRS.

Determination of the density of polyethylene (PE) (ASTM D792) is normally a challenging procedure due to reproducibility difficulties. Measurement via FT-IR can be problematic when larger sample sizes must be analyzed due to sample inhomogeneity. This application note demonstrates that the DS2500 Solid Analyzer operating in the visible and near-infrared spectral region (Vis-NIR) provides a reliable and fast solution for determination of the density of PE. With no sample preparation or chemicals needed, Vis-NIR spectroscopy allows the analysis of larger, inhomogeneous sample sizes of PE in less than a minute.

To monitor the quality of PVC (polyvinyl chloride), it is important to measure the molecular weight during the production process, as this parameter has a significant influence on chemical and mechanical stability as well as fire retardant properties. The standard method to determine PVC molecular weight, defined here as the average weight of the molecules that make up the polymer, is by size exclusion chromatography (SEC). This analytical method is time-intensive and requires trained personnel to perform. Determining the molecular weight of PVC is easier with near-infrared spectroscopy (NIRS). NIRS provides results in just a few seconds and can quickly indicate when adjustments to the production process are necessary.are necessary.