Über hochpolymere Verbindungen. Über die Konstitution der Polyoxymethylene

Staudinger, H.; Singer, Rudolf; Johner, H.; Lüthy, M.; Russidis, W. Kern D.; Schweitzer, O.

doi:10.1002/jlac.19294740105

Cited by 132 publications

(14 citation statements)

References 49 publications

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“…Methylacetate and methylformate are then formed by the esterification of acetic acid and formic acid with methanol. We have also confirmed the formation of large amounts of methanol and formic acid by the Cannizzaro reaction, in the reaction of paraformaldehyde + sulfuric acid [29]. Table VIII with the results given in Table XI1 (where the composition of equilibrated aqueous trioxane solutions is shown as a function of the DC1 concentration) it is evident that the degree of polymerisation increases slightly with increasing acid concentration.…”

Section: Sidesupporting

confidence: 79%

“…Methanol and formic acid can be formed via an acid catalyzed Cannizzaro reaction of formaldehyde. This reaction, although usually favoured under alkaline conditions [26], has been reported by Prins [27], Dunlo+ [28] and Staudinger [29] to occur also in acid solutions. According to our results (methoxyl group yo in Table VIII and IX), the amount of products of this reaction increases with the acidity of the media.…”

Section: Sidementioning

confidence: 82%

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NMR.‐Investigation of the Formaldehyde Addition and Oligomerisation Equilibria in the System Formaldehyde/Water/Acetic Acid/Hydrochloric Acid

Gorrie

Raman

Rouette

et al. 1973

Helvetica Chimica Acta

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Summary. -An NMR. investigation of the state of formaldehyde in acidic solutions has been carried out. Solutions of DCl/D,O/CD,COOD containing two sources of formaldehyde, i. e. paraformaldehyde (I) and trioxane (TI), were used for this purpose. In systems I and I1 the effect of various D,O/CD,COOD ratios, at a constant DC1 concentration, was studied, while for I1 the effect of changing DC1 concentration was also investigated. The results show that in aqueous solution, formaldehyde exists primarily as the monomeric and linear oligomeric forms of methylene glycol. Reducing the amount of D,O (at constant DC1 concentration), while increasing the CD,COOD content, results in an increase in the polymeric species and in trioxane. I n addition, substitution of water by acetic acid results in systems that are catalytically more active than aqueous solutions of the same hydrochloric acid concentration. Along with the usual polymer-monomer equilibria which exist in such solutions, side reactions of methylene glycol with the hydrochloric acid present also occur to a small extent, e.g. acetylation, substitution of OH by C1 and the Cannizzaro reaction. It is suggested that these findings will result in a better understanding of the formaldehyde crosslinking reactions in cotton cellulose.

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Section: Sidesupporting

confidence: 79%

Section: Sidementioning

confidence: 82%

NMR.‐Investigation of the Formaldehyde Addition and Oligomerisation Equilibria in the System Formaldehyde/Water/Acetic Acid/Hydrochloric Acid

Gorrie

Raman

Rouette

et al. 1973

Helvetica Chimica Acta

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“…[62] Poly(methylene) Mp a) Method of crystallization b) n LAM n total /n LAM Chain conformation ene) diacetates with DP ranging from 1 to 26 by Staudinger and his co-workers. [22][23][24] The starting poly(oxymethylene) was prepared by the reaction of paraformaldehyde and acetic anhydride in an autoclave at 180 8C and fractionation was performed using diethyl ether or ethyl acetate at different temperatures. Each fraction was subjected to chemical analysis and molecular weight measurements.…”

Section: Uniform Oligomers With Successive Dps For Understanding Reacmentioning

confidence: 99%

“…[21] Another Staudinger's attempt to obtain such a relationship between physical properties and molecular weights was the isolation and characterization of uniform poly(oxymethylene) diacetates with DP ranging from 1 to 22. [22][23][24] This challenging work demonstrates that a polymer comprises a mixture of homologous molecules with high molecular weights. To convince the chemists who were against him, Staudinger probably needed uniform polymer samples which could be used as pure substances on the same scientific basis that the most of chemists at that time were familiar with in the chemistry of low-molecular-weight compounds.…”

Section: Introduction and Definition Of Uniform Polymermentioning

confidence: 99%

Synthetic Uniform Polymers and Their Use for Understanding Fundamental Problems in Polymer Chemistry

Hatäda

Kitayama

Ute

et al. 2004

Macromol. Rapid Commun.

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Summary: A uniform polymer is a polymer composed of molecules that are uniform with respect to molecular weight and constitution. Besides natural uniform polymers such as nucleic acids and polypeptide, synthetic uniform polymers have been obtained by a variety of approaches. In particular, a combination of living polymerization and supercritical fluid chromatography (SFC) separation is one of the promising ways for the preparation of uniform polymers. End‐functionalized uniform polymers enabled us to prepare uniform polymer architectures such as block, graft, comb, and star polymers. Their use for understanding the fundamental problems in polymer chemistry is discussed; topics include crystallization of polymers, chain conformation in solution, and association of stereoregular polymers in solution.

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“…ince the first description by Butlerow 1 in 1859 and intensive investigations on its properties by H. Staudinger and co-workers in the twenties of the last century, [2][3][4][5][6][7][8] polyoxymethylene (POM) has been developed as a technical thermoplastic material with a great variety of applications. POM is a semicrystalline thermoplastic material and is opaque white by nature.…”

mentioning

confidence: 99%

Effects of coloration on the physical and mechanical properties and on the thermal stability of polyoxymethylene

2006

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ABSTRACT:The influence of coloring by using different batches on the crystallinity and the specific damage behavior of colored loudspeaker grills made from polyoxymethylene (POM) was studied. The investigations were performed by means of thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) under dynamic and isothermal conditions, pressure oxidative induction time studies (pOIt), melt volume rate (MVR), and perforation tests. The loudspeaker grills were made by injection molding and colored with 3 mass% master batch, added to the pellets during processing. The grills were tested after injection molding (as-received condition) and after accelerated ageing (oven storage up to 35 days at 140• C and UV irradiation). The results showed that the influence of the stabilizing system on the thermal and mechanical properties is stronger than the influence of the master batch substrate and the coloration. For the solely heat-stabilized material, coloration can reduce the susceptibility for UV irradiation but not as effectively as a UV stabilizer package.

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Über hochpolymere Verbindungen. Über die Konstitution der Polyoxymethylene

Abstract: Einleitung.

Cited by 132 publications

References 49 publications

NMR.‐Investigation of the Formaldehyde Addition and Oligomerisation Equilibria in the System Formaldehyde/Water/Acetic Acid/Hydrochloric Acid

NMR.‐Investigation of the Formaldehyde Addition and Oligomerisation Equilibria in the System Formaldehyde/Water/Acetic Acid/Hydrochloric Acid

Synthetic Uniform Polymers and Their Use for Understanding Fundamental Problems in Polymer Chemistry

Effects of coloration on the physical and mechanical properties and on the thermal stability of polyoxymethylene

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