Polyolefin ketones adhesive characteristics in model systems polymer-liquid

A contact angle test was applied to determine of energy characteristics of the surfaces of polyolefin ketones at various interfacial boundaries and the work of adhesion of polyolefin ketones was calculated in relation to model liquids of various polarities. A new approach was proposed to optimize the selection of polymers for composite materials. It was demonstrated that the contact angle test is a promising express method of forecasting possible branches of applications for polymer materials.     

Reactions of pentafluorobenzene with amino derivatives.

A metal hydrogen exchange seems to take place in pentafluorobenzene in reactions with strongly basic amino derivatives, such as lithium amide, lithium morpholide or N-lithium-N′,N′-dimethylhydrazide. On the other hand a fluorine substitution in pentafluorobenzene takes place with N-lithium-p-methoxy-anilide, N-lithium-N-methylanilide, N-1ithiumanilide, dimethylamine, methylamine, ammonia, morpholine, and hydrazine. No reaction occurred with N,N-dimethylhydrazine, p-phenylenediamine, p-methozyaniline, N-methylaniline or aniline.     

Acceleration mechanisms in curing reactions involving model systems

The mechanisms involving some of the most common accelerators in the curing reactions of epoxy resins have been investigated by use of model systems. Phenyl glycidyl ether was used as a model compound. The characterization of the reaction products was mainly carried out by High-Performance-Liquid-Chromatography and by preparative methods. Special attention was paid to the oligomerization reactions of the oxirane ring in the presence of tertiary amines. Three different types of oligomers depending on phenyl glycidyl ethers are discussed. The mechanisms of multifunctional accelerators such as imidazoles or phenol-MANNICH-base-compounds are much more difficult. The extraordinary interaction of imidazoles depends on the formation of different oligomers. Furthermore, the cleavage of the imidazole ring was observed. It is possible that the glycidyl ether oligomerization plays an important role in understanding the network structure. Some aspects of the accelerating effect of tertiary amines in the curing of glycidyl ethers with acid anhydrides were likewise discussed. The results obtained using these model reactions may be applied to influence the curing process in commercial epoxy resin systems.     

Synthesis and properties of nicotinic acid derivatives containing a 2,2,6,6- tetramethylpiperidine 1-oxyl residue

N¹-(Nicotinoyl)-N²-4-(2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl)hydraxine was obtained by condensation of nicotinoyl hydrazide with 2,2,6,6-tetramethyl-4-oxopiperidine 1-oxyl. Acylation of 2,2,6,6-tetramethyl-4-hydroxypiperidine 1-oxyl with nicotinoyl chloride gives nicotinic acid 2,2,6,6-tetramethyl-1-oxyl 4-piperidyl ester. A spin-labeled analog of nicotinamide was obtained by condensation of nicotinoyl azide with 4-amino-2,2,6,6-tetramethylpiperidine 1-oxyl. The synthesis of 1-N-(-D-ribofuranoside)-3'-N[4-(2,2,6,6-tetramethylpiperidine-1-oxyl)pyridinecarboxamide from 2,2,6,6-tetramethyl-4-nicotinoylaminopiperidine 1-oxyl and 2,3,5-tri-O-benzoyl--D-ribofuranosyl bromide proceeds without damage to the iminoxyl radical. The preparation of the corresponding spin-labeled nucleotide is hindered by destruction of the iminoxyl radical during ion-exchange chromatography.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 352–355, March, 1976.     

Reactions of hydrazine derivatives

Conditions were worked out for the synthesis of a number of 1-arylpyrazolidines with alkyl groups in the 4 and 5 positions of the five-membered ring by reduction of the corresponding 3- or 5-pyrazolidones with lithium aluminum hydride.See [1, 2] for communications XLVI And XLVII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 118–121, January, 1971.     

Reactions of hydrazine derivatives

On the basis of a combined study of chemical properties and UV, IR, PMR, and mass spectra, it has been shown that the product of the transformation of 3,4-tetramethylene-5, 5-pentamethylenepyrazoline under the action of sulfur has the structure of 3-pentyl-4,5,6,7-tetrahydroindazole.For part XLIV, see [1].     

Reactions in micellar systems

The notion of "green chemistry" has encouraged even synthetic organic chemists to include water as a solvent. Incredible selectivities and activities can be achieved through the addition of amphiphiles with a defined structure. The morphology of supramolecular assemblies or associates formed by surfactants vary according to the temperature and concentration. As a rule, reactions are typically conducted using simple spherical aggregates, that is, micelles in the nanometer range. The strong polarity gradient present between the hydrophilic surface and the hydrophobic core of the micelle means that both nonpolar and polar reagents can be solubilized. This solubilization results in reactants becoming more concentrated within the micelle than in the surrounding water phase and leads to an acceleration of the reaction and causes selective effects. The kinetic treatment of reactions in micellar systems can be accomplished by considering them as microheterogeneous two-phase systems.     

Reactions on the dimethylphenylbenzacridinones. VI. Hydrogenation of ortho-nitrophenyl derivatives

Catalytic hydrogenation of o-nitrophenylbenz[a], benz[c], dibenz[a,h] and dibenz[a,g]acridinones using Pd/C as catalyst, at 60 psi of pressure, gave the hiterto unknown benzoquinoacridine N-oxides and benzo-pyranonaphthyridine N-oxides. The structure of all products was corroborated by ir, ¹H- and ¹³C-nmr and mass spectra data.     

Investigations into the Chemical Modification of Polyolefin Surfaces by Radical Reactions during Molding

The surfaces of polyolefin parts are usually modified by separate processing steps. In this paper, we investigate how an in situ surface modification of polyolefins could be realized during molding, based on radical reactions, by which a macromolecule with functional groups is grafted to the polyolefin surface. The temperature of the melt is used to initialize the reactions. The different steps of the radical reaction chain were analyzed using model reactions. A modifier composition consisting of dibenzoylperoxide, potassium persulfate and poly(vinyl alcohol) revealed to be suitable. This composition was used for injection molding experiments. The bondability of the injection molded parts was largely enhanced.

     

Geminal systems. 16. Reactions of N-chloro-N-alkoxy-N-alkylamines with amines

Conclusions The reactions of N-chloro-N-alkoxy-N-tert-alkylamines with amines are characterized by nucleophilic substitution at the nitrogen atom with formation of the corresponding N-alkoxyhydrazines which are stable in the case of ethyleneimine and pyridine; give diazenes as in the case of MeNH₂, EtNH₂, and Me₂ or yield products of further transformations as in the case of NH₃, Me₂NH, and MeO(Me)NH. Nucleophilic substitution is repressed in the reaction with Et₂NH and Et₃ N by one-electron reduction with the formation of azoxy compounds.For Communication 15, see previous article [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2327–2334, October, 1981.     

Reactions in binary iodide systems

Several factors that influence the interactions between iodides are considered based on the results of thermoanalytical experiments. The iodides are grouped according to the cation valence and are arranged in the increasing order of the cation polarizing powers (CPPs). The deviations of the liquidus in real eutectic iodide systems from an ideal liquidus are analyzed. Compound formation in melts, incomplete solid solubility, or immiscibility are observed in many systems. The structure of the melting-point diagram is found to correlate with the type of interaction in the system.     

Reactions of metal carbonyl derivatives : XIV. Bridged phosphido derivatives of iron and ruthenium

The tertiary phosphines P(C₆H₅)₂R [RM π-C₅H₅)(CO)₂ M(π-C₅H₅(CO)₂ (M = Fe or Ru)] readily effect the displacement of the chloro group in [M′(φ-C₅H₅)(CO)₂Cl] (M′ = Fe or Ru) to give bridged cationic species of the type [MM′(φ-C₅H₅)₂(CO)₄P(C₆H₅)]⁺. Treatment of [Fe₂(CO)₉] with P(C₆H₅)₂R [RRu(φ-C₅H₅)(CO)₂] leads to the formation of the neutral mixed-metal derivatives [FeRu(φ-C₅H₅)(CO)₆P(C₆H₅)₂] and [FeRu(φ-C₅H₅)(CO)₅P(C₆H₅)₂].     

Reactions of some new thienothiophene derivatives

Facile and convenient syntheses of bisdimethylthieno[2,3-b]thiophen-2,5-diyl bis(oxazole-2-amine), bis(1H-imidazol-2-amine), bis((3a)-H-indole),[1,2-a]pyrimidine), bis(1H-imidazo[1,2-b][1,2,4]triazole) and bis(9H-benzo[d]imidazo[1,2-a]imidazole) derivatives incorporating a thieno[2,3-b]thiophene moiety from the versatile and readily accessible 1,1'(3,4-dimethylthieno[2,3-b]thiophene-2,5-diyl)-bis(2-bromo-ethanone) (1) are described.     

Deactivation of excited states in polyurethanes by energy transfer to salicylic acid derivatives and its application to the photo-stabilisation of polyurethanes

The fluorescence of TDI-based polyurethanes is quenched by salicylic acid esters, amides and hydrazides. Quenching approximately obeys the Förster, as well as the Perrin, equation and is accompanied by a sensitisation of the fluorescence of the salicylic acid derivatives. The photo-yellowing of the polyurethane, too, is inhibited by the salicylic acid derivatives, but there is no simple quantitative correlation between the efficiencies of the inhibitors in fluorescence quenching and photo-stabilisation.     

Reactions in aminosilane-epoxy prepolymer systems. II. Reactions of alkoxysilane groups with or without the presence of water

The hydrolysis and reactions of alkoxy silane groups have been studied on a model compound (TA) prepared from 2 mol of phenyl glycidyl ether and 1 mol of aminopropyl triethoxy silane. At low (40°C) and high (140°C) temperatures, the monomer conversion and the evolution of the molecular mass are followed by size exclusion chromatography (SEC). During the same reaction time, the evolution of the functional groups, hydroxyl CH? OH, ethoxy ? O? C₂H₅, and siloxane Si? O? Si, is observed by FTIR spectroscopy. Without the presence of water, reactions between hydroxyl and ethoxy silane lead to gelation at the end of the reaction. A by-product, probably a cyclic tetramer is also formed. After the hydrolysis, the reaction of the model compound is quite different. The product of reaction is always soluble, even after a treatment at high temperatures, and the evolution of the molecular mass versus the reaction time seems to correspond to the condensation giving a dead cyclic tetramer. From this study it is evident that the curing cycle has a great influence on the properties of the interface of a composite based on a epoxy matrix.