Journal Article

The reaction of esters with ammonia, hydroxylamine and hydrazine to produce the corresponding amide, hydroxamic acid or hydrazide are well known. Cohn and Meyer reported a reaction between methyl salicylate and phenylhydrazine, and Baidakowski, Reformatski and Slepak prepared a few phenyhydrazitdes by heating the ester and phenylhydrazine in a sealed tube at 210°, but no other examples of this reaction have since been reported.

The reaction of 1-acetyl-2-phenylhydrazine with ethoxymethylenemalononitrile yielded [(4-cyano-1-phenylpyrazol-3-yl)aminomethylene]propanedinitrile. Hydrolysis followed by annulation with methyl isocyanate provided a synthetic route to 2-phenylpyrazolo[3,4-d]pyrimidines.

This paper presents a number of qualitative and semi-quantitative observations on the effect of small concentrations of water on the polymerizations of butyl cyanoacrylates by tertiary amines in THF. It reports also that, in the absence of other bases, large concentrations (approx. 1 mol/l) of water can cause the polymerization of ethyl cyanoacrylate, in THF, even in presence of normally inhibiting amounts (10−5 mol/l) of p-toluenesulfonic acid. A formal kinetic scheme of a stationary-state polymerization, initiated by hydroxyl anions, is presented and discussed.

Dissolution with suitable solvents is one of the cheapest and more efficient processes for polystyrene waste management. In this work the solubility of polystyrene foams in several solvents benzene, toluene, xylene, tetrahydrofuran, chloroform, 1,3-butanediol, 2-butanol, linalool, geraniol, d-limonene, p-cymene, terpinene, phellandrene, terpineol, menthol, eucalyptol, cinnamaldheyde, nitrobenzene, N,N-dimethyl- formamide and water has been determined.

Polystyrene (PS) is currently used as packaging, insulating and storing material in various industrial or domestic fields. As a result, a large quantity of PS wastes is produced. Plastic wastes are not usually biodegradable, so it is necessary to suggest a technology to recycle them. Landfills and incineration are reasonably cheap methods but are not environmentally acceptable, therefore, alternative methods for polymer recycling are required. The general purpose of PS foam recycling is to recover a more compact polymeric material without degradation.

The mechanical properties of the adhesively bonded joints with ethyl-2-cyanoacrylate and ethyl-2-cyanoacrylate modified with poly(methylmethacrylate) were determined. The modifier lowers tensile stiffness, increases deformability and relaxation of the adhesive bond and improves impact resistance. A morphological structure similar to an interpenetrating network system is suggested which arises from the rapid polymerization of the solvent. The results obtained may be helpful for the design of joints with cyanoacrylate bonding.

Filled cyanoacrylate adhesive compositions possessing electro- and heat-conducting properties have been developed. These compositions are recommended for panel wiring of electro- and radioelements and hermetic sealing of aluminum casting.

The influence of type and size of filler particles and viscosity of the cyanoacrylate component on the volume resistivity, conductivity mechanism and adhesive strength of the resultant bond has been investigated. Various carbon and metal fillers were used to make conductive cyanoacrylate adhesive compositions and the best results were obtained when Ag, Ni or Mo powders (5–10 μm) were incorporated in thickened ethyl 2-cyanoacrylate with a viscosity of 50–100 cP

The introduction of high molecular weight poly(methyl methacrylate) or poly(butadiene-co-acrylonitrile) into ethyl 2-cyanoacrylate produced viscous adhesives with a homogeneous or heterogeneous structure after cure. Steel joints bonded with these adhesives are shown to have improved tensile shear strength, deformability and stress relaxation of bonds compared with pure cyanoacrylate adhesive. Poly(methyl methacrylate)-modified adhesive is recommended for static load-bearing joints while poly(butadiene-co-acrylonitrile)-modified adhesive is more suited to cyclic or vibrating loads.

The lap shear strengths of stell joints bonded with ethyl 2-cyanoacrylate adhesive containing various amounts of acetic acid have been determined, and an optimum adhesion promoting effect was found at an acetic acid content of 0.25% by weight. Further tests showed that adhesion promotion with acetic acid was dependent on the nature and surface treatment of various metal adherends, with selectivity being shown towards steel, stainless steel and duraluminium.