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The paper deals with the synthesis and characterisation as plasticizers and/or lubricants of some unsymmetrical diesters of sebacic acid by using superior branched aliphatic alcohols, such as 2-ethyl-hexanol, isodecanol and isotridecanol, along with complex aliphatic-aromatic alcohols, like 2-phenoxyethanol, 2-[(o-sec-butyl)phenoxy]ethanol and 2-[(p-nonyl)phenoxy]ethanol, respectively. Valuable plasticizing and/or lubricating properties were recorded, as a function of the polar / unpolar ratio within each structure of the considered product. A semnificative improved thermal resistance was also observed. In this way, the valability and consistency of the theoretical premises admitted, like the asymmetry and polyfunctionality principles, were fully proved. Keywords: unsymmetrical sebacic diesters, plasticizers, lubricants, phenoxy-ethanols

It was studied the influence of urheomelamineformaldehydic resin adds, as flow modifier, on the main characteristics of some epoxi-polyesteric powder dye of white signal type and of cover films made with these. It was established that the introducing in the forming of the uhreomelaminoformaldehydic resin ensures the decrease of the gelification time, the disappearence of needle shots and of craters appearing in the cover film made with the standard dye and the reducing of the orange skin aspect intensity. In order to ensure these positive influences it is necessary to introduce in the forming relatively high ratios (9.1%) of urheomelamino-formaldehydic resin. By also introducing an acrylic flow modifier, the positive influences may be obtained with smaller ratios (~ 3.2%) of urheomelaminoformaldehydic resin. Keywords: adds, main, forming, needle shots, forming

The 2,6-di-tert-butylphenol (DtBP) can be oxidated with O2, in the presence of some catalysts based on M(II) complexes with Schiff bases, in DMF. The metal complexes contain Mn and tetradentate Schiff bases derived from salen, as ligands. The transformation degree, the nature and contents of the products obtained were followed by 1H RMN spectroscopy and gas chromatography. Kinetic data indicate that the reaction is of the pseudo-first-order, as compared with dioxygen consumed. Keywords: kinetics, oxidation, Mn(II) Schiff bases complexes

New aromatic aldehydes were prepared in the conventional literature manner by Williamson etherification reaction of p-chlorobenzaldehyde with p-substituted phenols, or by esterification reaction of cyanoacetic acid with p-hydroxybenzaldehyde in the presence of dicyclohexylcarbodiimide (DCC). The obtained monomers have been confirmed structurally by IR, 1H-NMR spectroscopy, elemental analysis and characterized by solubility, thermal behavior and refraction index. Keywords: monomer, aromatic aldehyde, mesogenic precursor

Glass transition temperatures were determined by differential scanning calorimetry (DSC) for the polymer mixtures of polystyrene(PS)/polysulfone(PSF) and their chloromethylated derivatives (CMPS/CMPSF). The polymer mixture was prepared by precipitation method from a common solvent. The glass transition temperature values (Tg) for every compound did not depend on its content in the solid mixture. This behavior is attributed to the incompatibility of the polymers at least in the case of the mixtures obtained by co-precipitation method. The introduction of the chloromethylated groups in para-position of benzene ring for polystyrene and in a, b positions of benzene rings of Bisphenol A leads to the increase of Tg with 10% for polystyrene and to decrease of Tg with 10% for polysulfone. The chloromethylated reaction improves the thermal characteristics of polystyrene and polysulfone and mixture of CMPS/CMPSF. Keyword: glass transition temperatures, DSC, polysulfone, polystyrene, chloromethylated polysulfone, chloromethylated polystyrene

The main route of obtaining bismaleimides is the reaction between maleic anhydride and primary diamines. First stade occured with forming maleamic acid, then cyclicised to bismaleimide in presence of the acetic anhydride, sodium acetate or other dehydration agents. In the reaction mixture there appeared secondary products as bisisomaleimide, bisacetamide and unreacted bismaleamic acid. A study of their presence and influence on the polyaminobismaleimide resin processability and properties using DSC, ATG and IR methods was performed. Keywords:bismaleimides, secondary products, polyaminobismaleimide

This paper proposes a genuine mathematical pattern for the study of the unsteady phenomena that characterize the working out of natural gas polyethilene pipeline networks. The calculation programme elaborated on the basis of the mathematical model allows the determination of the period of the two steady regimes between which the unsteady movement takes place, for each pipeline of the network. Keywords: pipeline, natural gas, network, unsteady movement

New aromatic polyimides have been synthesized by polycondensation reaction of 3,3’-dimethyl-4,4’-diaminodiphenylmethane with benzophenontetracarboxylic dianhydride or hexafluoroisopropylidene diphthalic anhydride in N-methylpyrrolidinone as a solvent, followed by chemical imidization in the presence of acetic anhydride and pyridine at 100°C for 4 h. The obtained polyimides presented excellent solubility, high thermal stability and good film forming ability. The degree of polyimides cure has been observed to have a profound influence on the films fluorescence . Keywords: 3,3’-dimethyl-4,4’-diaminodiphenylmethane; polyimides; solubility; cure; fluorescence

Polyurethanes (PUs) based on polyester polyol and aromatic diisocyanate are used as passive isolation bearings in buildings applications. In the present study polyesterdiol and 4,4-diphenylmethane diisocyanate (MDI) have been used in polyurethanes, using glycerine, ethylene or diethylene glycols as chain extenders. Effect of varying the concentrations of diisocyanates and structure of chain extenders on PUs have been discussed with reference to mechanical properties. IR and thermal analysis techniques (TGA and DSC) were used for characterization. The results expose that aromatic character of diisocyanates raises the temperature required to achieve the flexibility in the polymer. Based on their mechanical properties, PUs has great potential for applications where excellent wind and earthquake loads resistance, dynamic-to-static stiffness ratio and vertical and lateral load characteristics are required. Keywords: polyurethanes, passive isolation systems, polyester polyol, aromatic diisocyanate

The textile coating is an important process giving rise to new materials. The study of polymer emulsion rheological behavior is very important for establishing the optimal conditions for obtaining the best coated products. The mathematical study of the rheological properties for a printing paste has been presented. Some conclusions in connection composition of coating paste versus rheological behavior have been established. Keywords: rheology, polyacrylate, textile coating