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Identification of polymers, copolymers and mixtures by gas chromatography

this paper comprehensively reviews the technology of analyzing and identifying rubber, synthetic polymers, copolymers and mixtures by gas chromatography

experience has proved that a capillary gas chromatography method can be used to determine the antioxidants topanola and O of 250PPM in 11 bromo + alkyl methacrylate and 50ppm in methyl methacrylate. This analysis was carried out using a temperature programmed capillary column hp-ye 10mx0.53mm (inner diameter)] at a carrier gas flow rate of 16.5ml/min. After ethyl acetate extraction, gas chromatography electron capture detection method is used for routine simultaneous determination of epichlorohydrin (3-chloro-1,2-propylene oxide), 3-Chloro-1,2-Propanediol and 1,3-dichloro-2-propanol in aqueous solution of polyeepichlorohydrin resin. These impurities can be determined within the detection limit of mg/Z

an overview introduces examples of gas chromatography and gas chromatography mass spectrometry (GC/MS) in the paint and coating industry. This review introduces the technologies and references related to raw material quality monitoring, solving problems in production, and identifying polymers and other components in paint

mineral water samples stored in Polyethylene Lined aluminum foil/paperboard composite packaging are incubated at constant temperature at 40ac, and then the incubated solution is injected with absorption method to analyze the volatiles in mineral water through gas chromatography column. The strength of odors such as unnatural flavor, disgusting flavor, musty flavor, metallic flavor and dry flavor in the incubated solution is tested by the official of civil aircraft materials industry development alliance in Shanghai Academy of Aeronautics and Astronautics. The components measured by inhalation method were then identified as aromatic hydrocarbons and aromatic carbonyl compounds by gas chromatography/mass spectrometry. Styrene and polystyrene (the corresponding concentration is 13mg/kg \ 43mg/kg) are the main components of 20 compounds in polystyrene milk packaging identified by GC/MS. The detection limit of styrene monomer determined by this equilibrium liquid surface space method is O, which has been given key support in the field of new materials in the scientific and technological research plan, the national high-tech industrialization project and other scientific and technological plans.29mg/kg. In a corresponding method for the determination of styrene and polystyrene in milk, acetone is used to precipitate protein, extract fat and the residue of packaging materials. The detection limits of styrene and polystyrene were 0.16mg/kg and 0.28mg/kg respectively. Sensory boards and gas chromatography have been used to identify the odor emitted by commercial polyethylene

tenax - GC collection tube is used to collect odorous volatiles at room temperature. Due to its low viscosity and good curing performance, Mannich base products are often used as curing agents for epoxy resins. A direct gas chromatography flame detection method was discussed to determine the residual phenol, formaldehyde and phenylethanol in the Mannich base composition as a curing agent. Because of toxicity, this sensitive detection method with a wide linear concentration range is needed to monitor the concentration of phenol with a legal limit. High temperature capillary gas chromatography is also used to separate phenolic varnish and epoxy phenolic oligomer. The methyl methacrylate monomer precipitated during the aging of polymethylmethacrylate at different temperatures was determined by gas chromatography and polarography. There is an exponential relationship between monomer yield and aging temperature. It was introduced that an improved liquid level space gas chromatography method was used to determine the free monomer of methyl methacrylate in contact lenses produced by any method. This method can detect the quality of contact lenses from unknown sources within 15 minutes, and it has also been used to evaluate the product testing of new polymerization initiators

epoxidized soybean oil is a common additive in polymers (such as PVC), which can be converted into fatty acid esters by tetramethylhydroxylamine, and then detected by capillary gas chromatography flame ionization method. Epoxy soybean oil in PVC can be extracted with toluene first, then derivatized and then analyzed. A short capillary column was used to separate methyl 1,2 and 3-cycloxyoctadecanoate. Many technologies, such as mid cut, low-temperature capture and backwashing, have been used to develop a technology using capillary as the main body instead of packed column to determine the residual vinyl chloride monomer in PVC. This capillary based method solves some problems related to the accuracy and reproducibility required for the ultra trace determination of this suspected carcinogen

specific element chromatography uses atomic emission detection (AED) to provide information on the types of additives in polymer extracts. The high resolution of capillary gas chromatography and the high selectivity and sensitivity of atomic emission detector make up for the shortcomings of mass spectrometry and infrared spectroscopy in the identification of additive mixtures in supercritical extracts of rubber samples

space sampling on liquid surface and gas chromatography have been used to quantitatively measure and control the thermal oxidation of a low molecular weight hydroxyl terminated polybutadiene. When using this simple and effective technique to study the reaction rate, it was found that there was an induction period before the start of autocatalytic oxidation reaction. The reaction rate of the latter step is quickly controlled by the diffusion of oxygen into the polymer

gas chromatography has been used to study the kinetics of volatile matter precipitation from polypropylene at 70 C. Use correlation chromatography, temax adsorbent or activated carbon to enrich volatiles to improve the detector signal. A series of direct injection followed by gas chromatography analysis methods in the space above the polymer liquid level have been used to make a comparative study of the kinetics of gas evolution. The data obtained by adsorption enrichment method are different from those obtained by direct injection method and related chromatographic studies, and the latter two are in good agreement

a polymer that is difficult to identify by other methods due to the interference of additives has been identified by a direct dynamic liquid surface space method device designed for GC/MS. This device is designed to identify compounds whose boiling points are too low to be analyzed by traditional gas chromatography

reverse phase chromatography IGC is still a useful technique for determining the physical and chemical properties of pure polymers, polymer solutions and polymer mixtures. Thermal migration, polymer solubility parameters, polymer solvent and polymer polymer interaction parameters have been measured with the solution of polybisphenol a hydroxyether and the mixture with other polymers

two equations were derived to analyze the data obtained from capillary IGC experiments in order to determine the solubility and diffusion coefficient of polymer solvent system. Someone once used reverse phase gas chromatography to draw the adsorption isotherms of n-hexane, n-octane and n-nonane on polystyrene at 30 ℃, and also draw the isotherms of n-heptane at 40, 50 and 60 ℃. The calculated partition coefficients of these alkanes increase with the increase of the chain length of the tested compounds and decrease with the increase of temperature. Reversed phase chromatography has also been used in the same solvents to determine the weight fraction activity coefficient and Flory Huggins parameter of polystyrene. Other authors have used reverse phase gas chromatography to draw the phase diagram of the system containing polystyrene and high carbon alkanes (up to n-triacontane) at 190 ~ 250 ℃. Assuming that Flory Huggins parameter is independent of composition, Gibbs free mixed fo of polystyrene alkane system is calculated as the combined energy of sample cross-sectional area. The same collaborator reported the determination of the diffusion coefficient of caprolactam in nylon-6 by capillary reverse phase gas chromatography at 250 ~ 280 ℃. The activity coefficient at infinite dilution has been determined and compared with the data obtained with packed columns. One of the authors reported the determination of the activity and diffusion coefficients of several solvents in polystyrene by capillary column at 110 ~ 170 ℃. A low critical solution temperature can be seen from the retention diagram of poly (p-chlorophenylethylene) obtained by using IGC p-butyl acetate, indicating that the solubility of the polymer in this solvent decreases with the decrease of temperature. This experiment can also calculate the activity coefficient of weight fraction, Flory Huggins interaction parameter at infinite olefin release and the interaction parameter of effective exchange of polymer solvent system (A24). Some of the same group of collaborators measured some thermodynamic interactions between poly (p-chlorophenylethylene) and n-pentane, n-hexane, n-heptane, benzene, toluene, propylbenzene and cumene at 150 ~ 170 ° C, and also measured the molar adsorption enthalpy, partial molar mixing heat and solubility parameters of this polymer at infinite olefin release

the thermodynamic interaction parameters of polystyrene and polybutadiene were determined with 15 probes of different polarity at 155 ~ 185 ℃, and the interaction parameters between polymers were also determined by five polystyrene polybutadiene mixtures with different compositions

reverse phase chromatography has been used to study the surface and internal interaction properties of styrene-4-vinyl pyridine diblock copolymer. When the copolymer is adsorbed on the acid chromatographic adsorbent, the vinyl pyridine block with strong alkalinity is preferentially oriented to the stationary phase, and polystyrene is enriched on the air interface. The specific retention volume of some probe compounds in the mixture of poly-4-hydroxy-styrene, polyvinyl acetate and four homopolymers has been used to determine the thermodynamic interaction between polymers. An obvious correlation to the probe seems to be related to the interaction strength between the probe and individual homopolymers

methacrylic acid styrene diblock copolymers adsorbed on various particles with different acid/base interaction potential energy were studied by IGC. The acid-base interaction between the adsorption matrix and the polymer leads to the selective adsorption of half of the copolymer. The acid-base interaction was also determined by exposing the polystyrene surface to acid-base vapor and calculating its interaction parameters

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