Licht- und Wetterbeständigkeit von Polyvinylchlorid. II. Teil. Abbauvorgänge an bewitterten PVC-Oberflächen und Strukturveränderungen an schlagzähem PVC (HIPVC) unter dem Einfluß von Wärme und Licht

Rigid PVC and High Impact Resistance PVC (HIPVC) stabilized by Ba/Cd- and Pb-phosphite has been investigated for the effects of natural and artificial wheathering with regard to their application and physico-chemical properties, both for the surface and the interior of moulded parts. Studies using Transmission and Scanning Electron Microscopy (TEM and SEM) explain some of the micromorphological characteristics. The interpretation of these results in conjunction with those of other authors provides essential information on final processing.     

Organische Phosphorverbindungen. VIII. Zur Solvolyse von Desmethyltrichlorphon (2,2,2-Trichlor-1-hydroxy-äthanphosphonsäuremonomethylester)

Organic Phosphorus Compounds. VIII. The Solvolysis of Desmethyltrichlorphone (2,2,2-Trichloro-1-hydroxy-ethanephosphonic Acid Monomethyl Ester) Desmethyltrichlorphone 3 , an in vivo metabolite of the insecticide Trichlorphone 1 , decomposes in aqueous solution to give monomethyl phosphate and dichloroacetaldehyde by a fragmentation and not – as hitherto supposed – by a rearrangement to desmethyl-DDVP 4 and its subsequent cleavage. In the same way desmethyl compounds of other Trichlorphone derivatives undergo fragmentation. In addition to the latter, 3 undergoes an HCl-elimination to the hydrate 19 of the 2,2-dichloro-1-oxo-ethanephosphonic acid monomethyl ester.     

Beiträge zur Schmelzepolykondensation von Polyäthylenterephthalat im offenen System. III. Zum Einfluß von Transportvorgängen bei der Schmelzepolykondensation von Polyäthylenterephthalat (Vorkondensation)

By considering the melt polycondensation of polyethylene terephthalate as an example, the overall reaction rate is shown to be determined by expelling the glycol formed in the reaction. The investigations performed are limited to the first stage of the polycondensation process, the pre-condensation, in which the turbulence caused by the given off glycol is comparatively high. In a reactor having only stationary internal parts the polycondensation process of PETP was traced by volumetric measurement of the glycol given off. Besides the layer thickness, the pressure was varied between 40 and 100 Torr. In some experiments up to 10 l/h nitrogen was injected for more intimate mixing and nucleation. In evaluating the kinetic equations the order of the overall reaction was found to vary between about 2 and 7.5, depending on the turbulence in the system. These high values suggest the overall rate of reaction to depend on the mass transport of the glycol evolved. The validity of this suggestion was investigated by a double layer method base on some simplified assumptions. In analogy to the determination of the SHERWOOD number the expression F. β = C. Re′^m, with Re′ as modified REYNOLDS number to the power m, F area of the phase interface and β mass transfer coefficient, was used. While the values of the chemical mechanism, as expressed in the order of the rate constant, are subject to extremely high variation, the values of C and particularly those of the REYNOLDS index m keep fairly close to one another. This leads to results allowing to describe the precondensation within the variables of the expression proposed for the mass transfer.     

Oberflächenstrukturierung polymerer Fasern durch UV-Laserbestrahlung. 4. Der Einfluß äußerer Spannungsfelder

This paper reports the results of UV-laser-irradiations of elastomer fibres under application of varying external tensions on the fibres and under varying laser conditions. It is known that tension as well as temperature fields can lead to these synergetic effects that are supposed to cause the surface structuring by UV-laser-irradiation. Therefore the purpose of the reported experiments was to evaluate whether tension or temperature as the source of the system instabilities eventually lead to surface structuring.     

Zur unverträglichkeit von polymergemischen. VII. Lichtstreuungsmessungen an quaternären und quintären polymer-systemen polymer(1)/polymer (2)/polymer(3)/benzol und polymer(1)/polymer(2)/polymer(3)/polymer (4)/benzol

A polystyrene of high molecular weight was investigated by means of light scattering in isoerefractive polymer/benzene mixtures. Two or three of the following polymers are used, which are isorefractive with benzene: polymethylmethacrylate (PMMA), polybutadienne (PB), and polyisobutene (PIB). It is possible to determine the degree of incompatibility of the ?unvisible”? polymers by a comparison of the ?-points of PS in the multi-component systems with the ?-points PS in the ternary systems PS/polymer(2)/benzene. In all cases it turned out, that the degree of compatibility of PS with the other polymers increased by a further addition of a chemical different polymer.     

Über heteroorganische Verbindungen. IL. Zur Umsetzung von N-Morpholinoschwefelchlorid mit O-Alkyl-äthanthiophosphoniger Säure und O-Äthyl-äthan-dithiophosphonsäure

Heteroorganic Substances. IL. Reactions between N-morpholinosulfenylchloride and Ethane-alcoxy-thiophosphonous Acids and Ethane-ethyl-dithiophosphonic Acid The syntheses of bis-(ethane-alkoxy-thiophosphonyl)-monosulfides 3a – c and bis-ethane-ethoxy-thiophosphonyl)-trisulfide 5 are described. It is established, that the reaction path depends on the acidity of the starting compounds. In the first case (pK ∼ 7 the reactions between ethane-alkoxy-thiophosphonous acids and morpholinosulfenylchloride are three-step reactions, the intermediates being the unknown S-morpholino-ethane-alkoxy-dithiophosphonates 1a – c as well as the sulfenylchlorides of ethane-alkoxy-thiophosphonic acid 2a – c . In the second case (pK ∼ 3) a fourth reaction has to been taken into account. The intermediate sulfenamide derivatives are isolated and characterised. The sulfenylchlorides derivatives could not been isolated; their presence was indirectly demonstrated by chemical reactions.     

Gasdurchlässigeit von mit Hexamethylen-bis-methyloldihydroxyäthylenharnstoff vernetztem Zellglas. I. Synthese von Hexamethylen-bis-methyloldihydroxyäthylenharnstoff und Hexamethylen-bis-methyloldihydroxyäthylenharnstoff

The synthesis of two compounds, believed to be new, is described, which are partculary suitable for crosslinking of cellophane: Hexamethylen-bis-dihydroxyethyleneurea [(CH₂)₆ bis-DHÄH] = 1,6 bis-[4,5-dihydroxy-2-imidazolidinone-1-yl]-hexane (I) and hexamethylene-bis-methyloldihydroxyethyleneurea [(CH₂)₆ bis-MDHÄH] = 1,6 bis-[3-methylol-4,5-dihydroxy-2-imidazolidinone-1-yl]-hexane (II). (I) was prepared by addition of glyoxal to hexamethylenediurea. since (I) is very soluble in water and not crystallizable the byproducts and remainders had to be removed by a special ion-exchange method and by column chromtography. The same operation was applied to the purification of (II). Compouunds (I) and (II) have been checked by analysis of nitrogen and N-methylol groups, by molecular weight determinations and IR-spectra. The reaction-optimum was found by controlling with thin layer chromatography. Practically a 100% conversion was obtained with the addition of glyoxal (I) and a 95% conversion with the methylolation (11) under these conditions, either related to their initial ureas.     

Cyansäureester. 29. Benzoxazolin-thion-N-imidsäureester und ihre Folgereaktionen

Cyanic Acid Esters. 29. Benzoxazoline-thione-N-imid Esters and Their Consecutive Reactions Oxazoline-thiones-(2) and aryl cyanates react to form the corresponding isoureas 4 . These compounds are remarkably stable against electrophilic reagents. The aminolysis of 4 proceeds two pathways: a transformation of the imid ester residue to the amin and a ring opening reaction by attack of the amin to the CS-bond. The hydrazinolysis causes a ring-transformation of the oxazoline- to the 1,3,4-triazole system.