Applications

Hydroxyl is an important functional group and knowledge of its content is required in many intermediate and end-use products such as polyols, resins, lacquer raw materials and fats (petroleum industry). The test method to be described determines primary and secondary hydroxyl groups. The hydroxyl number is defined as the mg of KOH equivalent to the hydroxyl content of 1 g of sample.The most frequently described method for determining the hydroxyl number is the conversion with acetic anhydride in pyridine with subsequent titration of the acetic acid released: H3C-CO-O-CO-CH3 + R-OH -> R-O-CO-CH3 + CH3COOH. However, this method suffers from the following drawbacks: - The sample must be boiled under reflux for 1 h (long reaction time and laborious, expensive sample handling) - The method cannot be automated - Small hydroxyl numbers cannot be determined exactly - Pyridine has to be used, which is both toxic and foul-smellingBoth standards, ASTM E1899-08 and DIN 53240-2, offer alternative methods that do not require manual sample preparation and therefore can be fully automated: The method suggested in ASTM E1899-08 is based on the reaction of the hydroxyl groups attached to primary and secondary carbon atoms with excess toluene-4-sulfonyl-isocyanate (TSI) to form an acidic carbamate. The latter can then be titrated in a non-aqueous medium with the strong base tetrabutyl- ammonium hydroxide (TBAOH). The method suggested in DIN 53240-2 is based on the catalyzed acetylation of the hydroxyl group. After hydrolysis of the intermediate, the remaining acetic acid is titrated in a non-aqueous medium with alcoholic KOH solution. The present work demonstrates and discusses an easy way to determine the hydroxyl number according to ASTM E1899-08 or DIN 53240-2 with a fully automated titrimetric system for a great variety of industrial oil samples.

The presence of excessive water in plastics adversely affects the performance of polymeric goods which is why water determination is of crucial importance. This article describes the accurate and straightforward determination of the water content using the Karl Fischer Oven Method in ten different plastic types that are not amenable to direct Karl Fischer titration. The experiments revealed that besides the determination of the oven temperature, sample preparation is one of the most important steps of the analysis, especially in case of hygroscopic plastic samples.

The Combustion IC system presented allows the automated determination of organic halogen and sulfur compounds in all flammable samples. Both combustion digestion, which is automatically controlled with a flame sensor, and the professional Liquid Handling guarantee highest precision and trueness. This poster describes the determination of the halogen and sulfur content in a certified polymer standard, a coal reference material as well as in latex and vinyl gloves.

Indication of the titration endpoint of the weakly alkaline or weakly acidic terminal groups in non-aqueous solution is frequently not easy. An improvement is possible by using a suitable titrant (TBAH = tetrabutylammonium hydroxide for terminal carboxyl groups; perchloric acid for terminal amino groups).An improvement in the evaluation can also be achieved by choosing benzyl alcohol as the solvent.The choice of electrode combination and the measuring setup is also important. Differential potentiometry using the three-electrode technique results in a great improvement in titrations in poorly conducting solutions. Noisy signals are eliminated.

This Application Bulletin describes a simple polarographic method to determine monomeric styrene in polymers. The limit of determination lies at 5 mg/L. Before the determination, styrene is converted to the electrochemically active pseudonitrosite using sodium nitrite.

Maleic and fumaric acid can be reduced electrochemically to succinic acid. In acidic solutions a differentiation of the two acids is not possible since both are reduced at the same potential. On the other hand, separation at pH 7.8...8.0 is easily possible since fumaric acid is now more difficult to reduce at the lower proton concentration (as a result of cis-trans isomerism) than maleic acid.

Polyurethanes are one of the most commonly used types of plastic. They are produced by the reaction of raw polyols with isocyanates. Depending on the starting material a wide variety of plastics can be obtained. The determination of the acid value, hydroxyl value, and isocyanate content plays an important part in the analysis of raw materials for plastics.The acid number of polyol raw material is usually used in quality control to ensure batch-to-batch uniformity. Additionally it is used as correction factor for calculating the true hydroxyl number. In this Application Bulletin the determination of the acid number according to ASTM D4662 and ASTM D7253 is described.One raw material for polyurethanes are polyols. Polyols contain multiple hydroxyl groups. Therefore, hydroxyl number of a raw material directly correlates to the amount of polyols present and it is thus an important quality control parameter. In this Application Bulletin the determination of the hydroxyl number according to ASTM E1899 and DIN 53240-3 is described.As polyols react stoichiometrically with isocyanates, the knowledge of the isocyanate content is an important quality parameter for the production of polyurethanes. In this document the determination according to EN ISO 14896 method A, ASTM D5155 method A and ASTM D2572 is described.

This Application Bulletin describes the determination of the thermostability of PVC in accordance with ISO 182 Part 3 using the dehydrochlorination method with the 895 Professional PVC Thermomat. The instrument permits fully automatic determination of the stability time. The test is suitable for monitoring the manufacture and processing of PVC products manufactured in the injection molding process, for their final clearance, characterization and for the comparison of PVC products and for testing the effectiveness of heat stabilizers.

Generally speaking, the gas extraction or oven method can be used for all samples which release their water when they are heated up. The oven method is indispensable in cases in which the direct volumetric or coulometric Karl Fischer titration is not possible, either because the sample contains disruptive components or because the consistency of the sample makes it very difficult or even impossible to transfer it into the titration vessel.The present Application Bulletin describes automatic water content determination with the aid of the oven technique and coulometric KF titration, using samples from the food, plastic, pharmaceutical and petrochemical industry.

The presented titration system can be used for the fully automated determination of the hydroxyl number (HN) according to ASTM E1899 and EN ISO 4629-2. The method allows, the determination of polyols and oxooils without boiling under reflux or other sample preparation and is therefore a big benefit for laboratories that have to cope with a high sample throughput.The standards EN 15168 and DIN 53240-3 relay on the same analysis method as in ASTM E1899.

The present Application Bulletin elucidates several applications for the polymer industry that can be carried out with the aid of NIR instruments. This Bulletin contains analyses of a wide range of parameters in a very large array of samples. The hydroxyl number is one of the best-known of the parameters that can be determined rapidly using near-infrared spectroscopy. The determination of the hydroxyl number in different areas and in different polyol types is also a part of this Bulletin. Each application describes the sample and the instrument that was originally used for the analysis, as well as the recommended instruments and the results.

This method is applicable to all samples containing glycerin in the absence of other triols or other compounds that react with periodate to produce acidic products. Glycerin may be determined in the presence of glycols. A periodate solution reacts slowly with diols and triols in acidic aqueous media at room temperature. A quantitative amount of formic acid is generated from the reaction with glycerin (a triol). The reaction with diols produces neutral aldehydes. The amount of formic acid generated by this reaction is determined by titration against sodium hydroxide.

Determination of sodium, ammonium, and potassium in polyethers using cation chromatography with direct conductivity detection.

The determination of halogens and sulfur in waste products is important. The inline combination of the Mitsubishi Combustion Module with the Metrohm IC is a suitable method for this type of samples. The recovery rates are analyzed with a certified reference material, e.g., a low-density polyethylene (LDPE).Keyword: pyrohydrolysis

Latex gloves are used in clean room environments in order to prevent contaminations. The use of gloves that release corrosive halogenides or sulfate is forbidden in nuclear power plants. The total content of halogen and sulfur is determined by means of Combustion Ion Chromatography. An eluate test is carried out to check the elutable percentage of halogens and sulfate from gloves. Sample preparation is comprised of preconcentration and matrix elimination (MiPCT-ME), as described in AN-S-304.Keyword: pyrohydrolysis

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

Polyisobutene (PIB) is an important raw material for a large range of products. Quality control requires the determination of the fluorine content. This task is easily done by Metrohm Combustion IC applying flame sensor technology and Inline Matrix Elimination.Keyword: pyrohydrolysis

The Restriction of Hazardous Substances Directive (RoHS) requires to reduce the halogen content in several organic materials used in electrical and electronic equipment. In this context, there is a huge interest for using halogen-free polymers. To check for halogens in polymers according to standard IEC 60754, Metrohm Combustion IC applying flame sensor technology and Inline Matrix Elimination is an indispensable method. The examined polymeric material contains halogens at a level of up to 1%.

The manufacture of ultrapure water for the pharmaceuticals industry or the semiconductor industry requires high-quality ion exchangers. Metrohm Combustion Ion Chromatography is an indispensable tool in this connection for testing the purity of anion exchange material. The output sample was wet and had to be dried at 105 °C in a special oven with waste air evacuation.Keyword: pyrohydrolysis

The EU directive for limiting the use of certain hazardous substances in electrical and electronic devices and IEC 61249-2-21 define limit values for halogen contents in materials that are used in electronics. Metrohm Combustion IC with ion chromatography determination permits precise, rapid and automated halogen determination in raw materials that are used in printed circuit boards according to IEC 61189-2.Keyword: pyrohydrolysis

Halobutyl rubber is frequently used in the production of pharmaceutical stoppers. It is ideal for this application due to its low permeability to gases and its chemical resistance. Chlorinated and brominated butyl rubber stoppers are analyzed for their halogen and sulfur content. Halogen and sulfur compounds are released by pyrohydrolysis and analyzed by subsequent ion chromatography (IC).

Polystyrol is brominated to increase flame retardation. The brominated polystyrene finally consists of 25 to 35% of bromine. The determination of bromine by combustion ion chromatography (CIC) requires a specially optimized absorption solution to trap all bromide. This work shows the optimization of the absorption solution for high-bromine samples.

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).

Organic halides must be monitored in the environment. Combustion ion chromatography (CIC) is used for accurate halogen analysis in solids following EN 17813:2023.

The International Standard ISO 17463 describes the determination of the anticorrosive properties of high impedance organic protective coatings on metals. This technique uses cycles composed of electrochemical impedance spectroscopy (EIS) measurements, cathodic polarizations and potential relaxation. This application note shows the compliance of the Metrohm Autolab PGSTAT M204 and flat cell with the standard ISO 17463.

The water content of plastic chips is determined according to Karl Fischer. Because of the low water content of the sample, the oven method (200 °C) and coulometric titration have to be used.

The presence of water in expandable polystyrene (EPS) can have a negative impact on the thermal insulation properties, as it increases thermal conductivity. If EPS is exposed to a high moisture environment, additional water may be absorbed, which can further affect thermal insulation.Direct analysis of the moisture content by Karl Fischer titration requires the water to be extracted from the EPS, which involves several time-consuming steps. Therefore, determination of the water content with an oven system is preferred. As EPS expands when heated, the use of sample boats, as required by ASTM D6869, is not possible, as the EPS will contaminate the oven system. This Application Note describes the determination of water content in EPS using an oven system with closed sample vials. A determination takes about 7 to 14 min depending on the water content of the sample and the sample size.

The water content, also called moisture content, of plastics is an important quality parameter, as it affects the properties and processability of some plastics. A high water content can lead to degradation of the plastic by hydrolysis or cause surface imperfections. Additionally, it can affect the physical properties of some plastics.For this analysis, the oven technique is used, as volatile compounds present in plastics will interfere, if the water content is directly determined by coulometric Karl Fischer titration. The water content determination in polycarbonate pellets, performed with the 885 Compact Oven Sample Changer and 899 Coulometer, is described in this Application Note.

This Application Note describes the determination of copolymer levels in polyethylene (PE) and polyvinylacetate (PVA) pellets using NIRS. The determination of the composition of the polymer blends takes less than 30 seconds and requires no sample preparation. The second derivative spectra are analyzed by means of the linear least-squares regression method.

This Application Note shows that NIR spectroscopy is an excellent tool for determining low concentrations of additives in finished polypropylene pellets. This is demonstrated by monitoring the UV stabilizer Tinuvin 770 and the antioxidant Irganox 225. The application of multiple linear regression (MLR) models minimizes interferences that originate from different coating thicknesses and interferences in the polymer pellets.

The determination of the water content of soft contact lenses using NIR spectroscopy is described in this Application. A liquid sample kit with gold diffuse reflector was used for measuring the lenses in transflexion mode. A PLS model was developed for predicting the water content.

Determination of the diethylene glycol content, isophthalic acid content, intrinsic viscosity (ASTM D4603), and the acid number (AN) of polyethylene terephthalate (PET) is a lengthy and challenging process due to the sample’s limited solubility and the need to use different analytical methods. 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 these parameters in PET. Vis-NIR spectroscopy allows for the analysis of PET in less than one minute without sample preparation or using any chemical reagents.

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.

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.

This Application Note demonstrates the feasibility of Vis-NIRS for the simultaneous determination of multiple chemical and physical parameters in epoxy resins. Vis-NIRS is a fast alternative to conventional lab methods: it accelerates raw material inspection, process monitoring, and final product control.

Determination of isocyanates (ASTM D7252) is a challenging procedure due to the reactivity of these organic species with atmospheric moisture, as well as their toxicity. Furthermore, HPLC analysis typically used for this kind of analysis involves sample preparation steps and chemicals, with each measurement taking up to 20 minutes to complete. This application note demonstrates that the XDS RapidLiquid Analyzer operating in the visible and near infrared spectral region (Vis-NIR) provides a chemical-free and fast solution (under one minute) for determination of isocyanate content.

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.

Polypropylene (PP) is a general purpose resin widely used in industries such as electronic manufacturing and construction, as well as in packaging materials. PP resins must be melted first in order to be formed into the intended shape, and therefore flow properties are important characteristics which affect the production process. The standard procedure to analyze melt flow rate (MFR) requires a significant amount of work with packing the sample, preheating, and cleaning. With no sample preparation or chemicals needed, Vis-NIR spectroscopy allows the analysis of MFR in less than a minute.

Identification of individual polymers with FT-IR spectroscopy can be a challenge due to sample inhomogeneity especially when larger sample sizes need to be analyzed. 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 the identification of high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polypropylene (PP). With no sample preparation or chemicals needed, Vis-NIR spectroscopy allows the identification of larger inhomogeneous sample amounts in less than a minute.

Determination of the vinyl content of silicone rubber is a lengthy and challenging process. First, the vinyl groups must be converted to ethylene by reacting with an acid, followed by the determination of the produced ethylene with gas chromatography (GC).This application note demonstrates that Vis-NIR (visible near-infrared) spectroscopy provides a cost-efficient and fast solution for the determination of vinyl content in silicone rubbers. With the DS2500 Solid Analyzer it is possible to obtain results in less than a minute without sample preparation or any chemical reagents.

PVC (polyvinyl chloride) foils with a PVDC (polyvinylidene chloride) coating are often used for high performance packaging films like pharmaceutical blister packs or in food packaging. In multi-layer blister films, the PVC serves as the thermoformable backbone structure, whereas the PVDC coating acts as a barrier against moisture and oxygen. The Water Vapor Transmission Rate (WVTR) and Oxygen Transmission Rate (OTR) are influenced by the composition and the thickness of the coating. A fast way to monitor PVDC coating thickness is with near-infrared spectroscopy. Results are provided in a few seconds, indicating when adjustments in the polymer production process are necessary.

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.

The standard test method for ash content analysis is thermogravimetric analysis (TGA). Although TGA is easy to perform, it is time-intensive and requires the use of nitrogen gas. In contrast to the primary method, near-infrared spectroscopy (NIRS) is a fast analytical technique which can measure multiple parameters including ash content in polymers within one minute.

This Application Note shows the feasibility of NIR spectroscopy for the analysis of density in polyethylene granulates. Compared to the standard method, NIRS analysis shows a lower prediction error when air bubbles are present in PE pellets.

The synthetic rubber known as Bromobutyl (BIIR) has many of the attributes of butyl rubber, but has better adhesion to other rubbers and metals, resulting in substantially faster cure rates. The simultaneous quantification of the bromine content, Mooney viscosity, volatile content, calcium stearate content, and functional bromide in BIIR can be easily performed with near-infrared spectroscopy (NIRS) without the use of chemicals.

Near-infrared (NIR) spectroscopy is able to determine the intrinsic viscosity of rPET in less than one minute without any sample preparation. This Application Note demonstrates that the Metrohm DS2500 Solid Analyzer operating in the visible and near-infrared spectral region (Vis-NIR) offers users an easier way to perform this analysis without the use of toxic chemicals.

Near-infrared spectroscopy streamlines ethylene tetrafluoroethylene production by offering rapid, chemical-free analysis of melt flow rate and moisture content.

Polypropylene and polyethylene can pose recycling challenges. With near-infrared spectroscopy (NIRS), users receive polyolefin composition results in seconds.

Reliable monitoring of TBC in styrene according to ASTM D4590 requires an explosion-proof solution like the 2060 TI Ex Proof Analyzer.

Polyurethanes are a class of synthetic polymers formed by reacting liquid di/polyisocyanates and polyols with a catalyst and various additives in a reactor. Polymer properties are modified with stepwise additions of these chemicals at different points in time depending on whether the process has reached an equilibrium. NCO functional groups from unreacted isocyanates must be quenched at the end for a finished product, and this parameter must be known to determine the proper chemical mixing ratio. A fast, non-destructive real-time measurement of %NCO can be obtained by using NIR spectroscopy with a probe seated directly in the reactor.

This Process Application Note presents a way to closely monitor multiple parameters simultaneously during the dioctyl terephthalate production process with near-infrared spectroscopy.

The thermostability of polyvinyl chloride (PVC) was determined using the dehydrochlorination procedure at 180 °C. Comparison of the thermostability of pure PVC polymer, blended PVC (blended with stabilizer, plasticizer, filler) and blended PVC after processing.

Determination of the thermostability of polyvinyl chloride (PVC) using the dehydrochlorination procedure at 200 °C.

The thermal stability of raw or processed PVC provides information about the quality of the plastic. Higher stability times can be correlated with longer lifespans. With the 895 Thermomat, the dehydrochlorination rate at elevated temperatures can be determined within a short time. Additionally, quality deviations in the purchased raw material as well as in the end products can be detected. The 895 Thermomat has been optimized for this application regarding three important points: safety, handling, and time-savings. The measurement is based on the standard EN ISO 182-3.

This application highlights Metrohm’s XTR® technology to identify colored polymers by extracting the Raman signal from spectra with strong background fluorescence.

Handheld Raman spectroscopy enables rapid polymer masterbatch analysis, while Metrohm’s XTR® algorithm mitigates fluorescence interference for accurate additive identification.

Raman spectroscopy can easily monitor polymerization by tracking monomer consumption and polymer formation, providing a valuable tool for polymer manufacturers.

Acid throwing, a historical method for retribution against women, has become a modern threat of a different nature. Concentrated acids and other corrosive substances have emerged as modern tools of social violence. Aggressors use common plastic containers with openings that create a powerful directional spray, such as lemon juice squeeze bottles. Sulfuric and phosphoric acids were chosen for analysis here due to their highly corrosive nature- acid attacks in London most commonly use sulfuric, phosphoric, and nitric acids.2017 saw a remarkable number of acid attacks in the UK, with reported incidences averaging 2x a day. Detection and regulation of acids may contribute to prevention of this social scourge.

This application note presents the Orbital Raster Scan (ORS) technology from Metrohm Raman to overcome low resolution, poor sensitivity, and sample degradation while still interrogating a large sample area.

Compared to potentiometric titration, Raman spectroscopy is a rapid, accurate, and reliable secondary method for estimating the amine value (AV) of epoxy hardeners.

Determination of fluoride, glycolate, chloride, and oxalate in a latex dispersion using anion chromatography with conductivity detection after chemical suppression and dialysis for sample preparation.

Determination of fluoride, chloride, nitrite, nitrate, benzoate, and sulfate in PVC film using anion chromatography with conductivity detection after chemical suppression.

Determination of chloride, sulfite, sulfate, oxalate, and thiosulfate in lignin using anion chromatography with conductivity detection after chemical suppression.

Determination of phosphate and sulfate in a liquid polymer sample using anion chromatography with conductivity detection after chemical suppression.

Aromatic dicarboxylic acids, e.g., terephthalate, isophthalate and 5-sulfoisophthalate, are important monomers in the manufacture of polyesters and alkyd resins. The monomer ratio of the dicarboxylic acids has an enormous influence on polymerization. The separation of the late-eluting components is completed within 15 minutes if a short Metrosep A Supp 15 - 50/4.0 type column is used together with high eluent concentrations and flow rates.

The carboxyl end groups (CEG) in polymers, such as polyethylene terephthalate (PET), are a measure of the number of unreacted carboxylic acid groups at each end of a polymer chain. The number of CEGs may influence the hydrolysis resistance of geosynthetics, such as geogrids and geotextiles. The lower the CEG value the higher is the hydrolysis resistance of geosynthetics, which in turn increases their stability.This Application Note describes the photometric titration of carboxyl end groups in PET pellets using the Metrohm Optrode. The acidic end groups of the polymer are titrated with an ethanolic KOH solution using bromophenol blue as indicator.

The epoxy content of epoxy resins has a strong influence on the reactivity of the resins as well as on the properties of the coating obtained from the resin curing process. The epoxy content is thus an important quality control parameter for manufacturers as well as consumers. This analysis is based on the reaction of hydrogen bromide with the epoxy groups of the sample. Hydrogen bromide in turn is produced by the reaction of tetraethylammonium bromide (TEABr) with standardized perchloric acid. The standards EN ISO 3001 and ASTM D1652 describe the determination of the epoxy content expressed as epoxy equivalent weight (EEW) by titration. The use of a Titrando and Solvotrode easyClean instead of manual titration greatly increases the reproducibility and repeatability of the determination.

The partial acid number (also partial acid value) describes the quantity of potassium hydroxide that is required for neutralizing all carboxyl-terminated groups and free acids plus half the anhydride groups in an unsaturated polyesterresin (UPR). This Application Note describes the determination of the partial acid value by automatic, potentiometric titration according to EN ISO 2114 using KOH in ethanol as titrant.

The total acid number (TAN) indicates the amount of potassium hydroxide required for neutralizing all carboxyl-terminated groups and free acids plus the free anhydride groups in an unsaturated polyester resin (UPR). In this Application Note the TAN determination using automated, potentiometric titration according to EN ISO 2114 using KOH in ethanol as titrant is described.

The hydroxyl number indicates the amount of potassium hydroxide in milligrams required to neutralize the acetic acid taken up on acetylation of 1 g of an unsaturated polyester resin (UPR) containing free hydroxyl groups. In this Application Note the determination of the hydroxyl number by automated, potentiometric titration according to EN ISO 2554 using KOH in methanol as titrant is described.

Polyurethane (PU) is a class of very important polymers due to its flexibility and insulating properties. It is used in various industries such as the automobile industry, in building construction, as well as in the production of synthetic fibers. PU is mostly produced via a chemical reaction between polyisocyanates and polyols.The isocyanate (NCO) content in the raw material is crucial to control its properties. This Application Note shows an easy and straightforward way to determine the NCO content in polyurethane raw materials using a fully automated titration system from Metrohm.

The quantity of hydrolyzable chloride in epoxy resins has an influence on their reactivity and on the properties of the epoxy coating obtained.Rapid and accurate determination is possible with an OMNIS system using potentiometric titration with the dAg ring electrode and silver nitrate as the titrant.

The hydroxyl number is an important sum parameter for quantifying the presence of hydroxyl groups in a chemical substance. As a key quality parameter, it is regularly determined in various polymers like resins, paints, polyesterols, fats, and solvents. Unlike other standards, EN 4629-2 works pyridine-free and without refluxing at elevated temperatures for a longer time. The determination is based on the catalytic acetylation of the hydroxyl group. It is performed at room temperature, requires only a small sample volumen, and can be fully automated.This Application Note describes the potentiometric determination of the hydroxyl number in 1-octanol and polyethylene glycol according to EN 4629-2. Using the OMNIS DIS-Cover technique, all sample preparation steps can be fully automated. Furthermore, the use of an OMNIS Sample Robot allows parallel analysis of multiple samples. The average time per analysis for one sample is thus reduced from approximately 49 min to 25 min., considerably increasing productivity in the laboratory.

The hydroxyl number is an important sum parameter for quantifying the presence of hydroxyl groups in a chemical substance. As a key quality parameter, it is regularly determined in various polymers like resins, paints, polyesterols, fats and solvents. Unlinke other standards, ASTM E1899 works pyridine-free and without refluxing at elevated temperatures for a longer time. It is performed at room temperature, requires only a small sample size, is applicable to extremely low hydroxyl numbers (<1 mg KOH/g sample) and can be performed fully automatically. This Application Note describes the potentiometric determination of the hydroxyl number in 1-octanol and polyethylene glycol according to ASTM E1899, EN 15168 and DIN 53240-3. Using the OMNIS DIS-Cover technique all sample preparation steps can be fully automated. Moreover, the use of an OMNIS Sample Robot allows parallel analysis of multiple samples. The average time per analysis for one sample is thus reduced from approximately 24 min to 12 min., increasing productivity in the laboratory considerably.

The determination of PBBE (tetrabromobisphenol A - TBBPA, octabromodiphenyl ether - OCTA and decabromodiphenyl ether - DECA) in a polymer sample was carried out with the Nucleosil EC - 250 mm column; for this purpose a methanol and phosphate buffer was used as an eluent and subjected to UV detection in accordance with the IEC 62321 method for RoHS testing.

The determination of chromium(VI) polymers using anion exchange chromatography with UV/VIS detection after post-column reaction with diphenylcarbazide as per IEC 62321 method for RoHS testing.

Determination of styrene monomers in polystyrene. Free styrene is converted to a polarographically active pseudonitrosite.

Ti is determined in polyethylene terephthalate (PET) after digestion in sulfuric acid and hydrogen peroxide. Adsorptive stripping voltammetry (AdSV) with mandelic acid as complexing agent is used for this application.

Co is determined in polyethylene terephthalate (PET) after digestion in sulfuric acid and hydrogen peroxide. The application is carried out with adsorptive stripping voltammetry (AdSV) in ammonia buffer with dimethylglyoxime (DMG) as complexing agent.

Sb is determined in polyethylene terephthalate (PET) after digestion in sulfuric acid and hydrogen peroxide. The application is carried out with anodic stripping voltammetry (ASV) in hydrochloric acid.

The EU directive on «Restriction of Hazardous Substances» (RoHS) requires the testing of four regulated heavy metals (Pb, Hg, Cd, Cr(VI)) in electrotechnical products. After sample preparation according to IEC 62321 the determination of lead and cadmium in polymer materials can be carried out by anodic stripping voltammetry (ASV) using ammonium oxalate buffer pH 2.

The EU directive on «Restriction of Hazardous Substances» (RoHS) requires the testing of four regulated heavy metals (Pb, Hg, Cd, Cr(VI)) in electrotechnical products. After sample preparation according to IEC 62321 the determination of chromium(VI) in polymer materials can be carried out by polarography in ammonia buffer pH 9.6.

The EU directive on «Restriction of Hazardous Substances» (RoHS) requires the testing of four regulatedheavy metals (Pb, Hg, Cd, Cr(VI)) in electrotechnical products. After sample preparation according to IEC62321 the determination of mercury in polymer materials can be carried out by anodic stripping voltammetry (ASV)at a gold rotating disk electrode (Au-RDE).

Raman spectroscopy is a quick nondestructive method for the direct identification of plastics. It can also be used for the analysis of flame retardants, lubricants and other additives. Coupled with chemometric software, quantitative and advanced qualitative analyses can be performed.

The NanoRam is a state-of-the-art, handheld Raman spectrometer for the rapid identification of chemicals used in the pharmaceutical manufacturing process. It has been specifically designed for these applications and is fully compliant with all the major global regulatory, safety, and commercial testing agencies applicable to the pharmaceutical industry.

Small, fast high-performance Raman spectrometers are now readily available. Three real-life Raman quantitative and semi-quantitative analysis applications are discussed. These applications showcase the versatility of Raman spectroscopy and the potential impact that it can make in various industries such as security, pharmaceutical, and plastics and polymers.

This e-book explains how Raman and near-infrared (NIR) spectroscopy enable rapid, nondestructive polymer analysis, ensuring high quality while reducing costs and waste.

The coupling of ion chromatography and inductively coupled plasma mass spectrometry (ICP/MS) leads to a high-performance measurement system that masters several particularly challenging analyses. It enables for example reliable determination of element compositions, oxidation states and chemical bonds. This information is used, for example, for assessing the toxicity of medications, environmental and water samples as well as foods and beverages.

Underestimation of quality control (QC) processes is one of the major factors leading to internal and external product failure, which have been reported to cause a loss of turnover between 10–30%. As a result, many different norms are put in place to support manufacturers with their QC process. However, time to result and the associated costs for chemicals can be quite excessive, leading many companies to implement near-infrared spectroscopy (NIRS) in their QC process. This paper illustrates the potential of NIRS and displays cost saving potentials up to 90%.