A modification of the periodic acid method for the determination of monoglycerides and free glycerol in fats and oils

Pohle, W. D.; Mehlenbacher, V. C.

doi:10.1007/bf02634879

Cited by 80 publications

(12 citation statements)

References 4 publications

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“…Mixed mono-and di-glycerides of stearic acid are used as antistatic agents in polypropylene, and their determination is based on the periodate oxidation of adjacent hydroxyl groups in the a-monoglyceride [14]. The ground material (10 g), or proportionately less if more than 2% of additive is expected (so that the amount in the extract does not exceed 200 mg), is extracted in a 500 ml conical flask with 50 ml of chloroform by gently refluxing on a hotplate for 2 h. To the cooled mixture are added 5 ml of I: I pyridine:glacial acetic acid and, by pipette, 50.0 ml of potassium period ate solution (prepared by dissolving 2.8 g of the reagent in 50 ml of 25% v/v sulphuric acid with gentle warming, adding 975 ml of glacial acetic acid and mixing).…”

Section: Titrimetric and Volumetric Proceduresmentioning

confidence: 99%

The separation and analysis of additives in polymers

Newton

1993

Polymer Characterisation

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This chapter describes the extraction, separation, identification and estimation of various organic and inorganic additives and polymeric materials in a range of plastic formulations such as poly(vinyl chloride), polypropylene, polyamide and polytetrafluoroethylene. It will concentrate primarily on their fractionation into, typically:(a) a solvent-soluble organic fraction (b) a solvent-insoluble inorganic or polymeric fraction (c) the solvent-soluble base polymer.The extraction techniques employed will include solvent dissolution and extraction, centrifugation, polymer precipitation, filtration and ashing. Details will be given of the identification of these fractions using IR spectroscopy, pyrolysisjGC, HPLC, mass spectrometry and NMR spectroscopy, often after further separation using either specific solvents or TLC [21]. All IR spectra are recorded over the region 4000-667 cm-1 (2.5-15.0 /lm).The estimation of individual components by gravimetric techniques, IR spectroscopy, UV -visible spectroscopy, HPLC or titrimetry will be described.The basic principles of solvent extraction, etc., for the analysis of plastics formulations are well established and docu'mented [1--4] and are still valid today. However, changes and improvements have been made, particularly in the fields of separation science and spectroscopy, to incorporate new ideas and instrumentation and to accommodate new additives. Despite such trends as robotics, the need for an experienced practical plastics analyst working at a bench using solvents, extraction flasks and beakers still exists.One theme running through this chapter will be that of method validation and the measurement of precision by way of calculated estimated standard deviations (sd) and coefficients of variance (cv) using 'check samples' of known formulation and a collection of reference polymers and additives of known provenance. This approach not only will be necessary for any laboratories seeking accreditation such as BS5750 or NAMAS, particularly as a means of demonstrating to external auditors the competence of B. J. Hunt et al. (eds.), Polymer Characterisation

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Section: Titrimetric and Volumetric Proceduresmentioning

confidence: 99%

The separation and analysis of additives in polymers

Newton

1993

Polymer Characterisation

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“…6 The acid value of the phthalic anhydride was equivalent to 99.8% purity. Linoleic acid was prepared as described previously7 from safflower oil fatty acids; analysis of the methyl esters by gas chromatography showed the product to be 98Y0 linoleic acid (cis,cis-9,12-octadecadienoic acid).…”

Section: Methodsmentioning

confidence: 99%

Molecular weight distribution in alkyd resins. Part III. Presence of microgel in alkyd resins

Solomon

Hopwood

1966

J of Applied Polymer Sci

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SynopsisAlkyd resins which have the same overall chemical composition and the same degree of polymerization have been prepared from synthetic mixtures of mono-, di-, and triglycendm of linoleic acid, glycerol, and phthalic anhydride. The properties of these resins difiered significantly. Microgel particles are present in all resins, but the quantity and size of the gel particles is a function of the glyceride composition. The concept of microgel is used to explain the solution and film forming properties of these resins. Examination of a range of commercially available alkyd resins has shown that microgel particles are present where the functionality is greater than two.

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“…,D( I + K 1 ) (2) Das Diol geht durch Addition von L Molen 1 in die Derivate M I und N1 uber. Diese Verbindungen nehmen aber gleichzeitig durch Addition von weiterem l-Chlor-2,3-epoxypropan (1) unter Bildung von M2, N 2 und B2 ab.…”

Section: Bevechnunyunclassified

Mathematisches Modell der polyaddition von 1‐chlor‐2,3‐epoxypropan an ein diol

Novák¹,

Šváb²

1975

Makromol. Chem.

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Eingangsdatum: 1 I. Juli 1974)*' ZUSAMMENFASSUNG:In dem mathematischen Modell, mit dem die Produktzusammensetzung bei der Polyaddition von I-Chlor-2,3-epoxypropan ( 1 ) (Epichlorhydrin) an ein Diol berechnet wurde, wurde die Voraussetzung gemacht, daB die Reaktivitaten der 3-Chlor-2-hydroxypropyloxy-Endgruppen gleich (d. h. von der MolekulgroRe unabhangig) sind und daB sich der Epoxidring von 1 nur unter Bildungder C,-Ather offnet. Ein Vergleich des fur verschiedene kinetische Parameter berechneten und des experimentell im Augenblick des volligen Durchreagierens von 1 bestimmten Anteiles von nicht abreagiertem I ,2-Propandiol (bei verschiedenen Ausgangsmolverhaltnissen l/Diol) erlaubte die Bestimmung der Verhaltnisse der Geschwindigkeitskonstanten von funf moglichen Reaktionen des untersuchten Systems. Fiir die Polyaddition von I an 1,2-Propandiol wurde die beste Annaherung bei den relativen Geschwindigkeitswerten K , =0,8; K2=0,6 und K 3 = K4=0,5 erzielt. SUMMARYA mathematical model for the composition of products resulting from a polyaddition of I-chloro-2,3-epoxypropane ( 1 ) (epichlorohydrin) to a general diol was constructed on the assumption that the reactivities of the 3-chloro-2-hydroxypropyloxy end groups are equal (i.e. independant from molecular size) and that the oxirane ring of I opens to give exclusively C,-ethers. By comparing the calculated and experimentally obtained percentage of unreacted 1,2-propanediol at the time of complete conversion of 1 (for various chosen kinetic parameters and for different initial mole ratios of I/diol) the relative rates of five possible types of reactions of the investigated system could be determined. For the polyaddition of I to 1.2-propanedio1, the best approximation was obtained with relative rates K , =0,8; K2=0.6. and K 3 = K4=0,5.Das vor kurzem ausgearbeitete mathematische Modell der Polyaddition stellt nur von 1 -Chlor-2,3-epoxypropan (1) (Epichlorhydrin) an ein r,o-Diol

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A modification of the periodic acid method for the determination of monoglycerides and free glycerol in fats and oils

Cited by 80 publications

References 4 publications

The separation and analysis of additives in polymers

The separation and analysis of additives in polymers

Molecular weight distribution in alkyd resins. Part III. Presence of microgel in alkyd resins

Mathematisches Modell der polyaddition von 1‐chlor‐2,3‐epoxypropan an ein diol

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