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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

In this paper the behavior at elevated temperatures (thermal oxidation) of some new copolymers exhibiting photochromic properties has been studied. These copolymers were prepared by chemical grafting of some azoic dyes on the support-polymers chains. The thermal oxidation has been studied by DTA, TG and DTG in the range of 22°C - 500°C for both support-copolymers and grafted photochromic polymers. The experimental data suggest that, upon heating, various oxidation processes occurs which are accompanied by slight increasing of the sample weight (at moderate temperatures), and oxidative decomposition processes accompanied by more or less intense decreasing in sample weight (at higher temperatures, over 300°C). The temperature values corresponding to these transformations seem to be related to both the polymer and grafted substituent structures. Thus, the halogen containing substituents induced a significant increasing in stability, especially in the case of chlorine containing ones. The imide structure of these substituents seems to induce a higher stability as compared to amic one. Keywords: thermal oxidation, photochromic, azoic dyes

It was studied the possibility of using as texture agents in the formulation of some epoxy-polyesteric powder dyes of a cellulosic derivative - encoded AT1 and of an acrylic resin - encoded AT2. From the analysis of the influence of the texture agent AT1 and AT2 respectively, on three epoxy-polyesteric powder dyes (pure white powder, graphite grey and signal black, according to RAL Design Classic Card K7, RAL Farben, Germany), it was established that their main characteristics are not influenced by the presence in the composition of the texture agent. In order to realize the requested textured aspect of the coatings realiyed with epoxy-polyesteric powder dyes in which fornulation there were introduced these texture agents, their concentration must be correlated with the ligand content. Keywords: texture agents, coatings, powder dyes

The paperwork presents the principal constituent equations used on study of mincing rubber waste without insertion. These equations permit a study of mincing process on analytical ground, without being necessary, in some cases, to conduct experimental research. For verifying these equations, it is presented here an experimental part too, based on which it can be done a verification of constituent equations. Keywords: constituent equations, mincing rubber waste

This paper presents the effect of some rosemary and sage extracts on the thermal stabilization of low-density polyethylene (LDPE). IR and UV spectra of these extracts indicates that the major substances are carnosic acid, carnosol and epirosmanol. Chemiluminescence (CL) resulting from the exothermic termination reaction of peroxi radicals was used for the characterization of effectiveness of these extracts for protection of LDPE. Keywords: rosemary, sage, extraction, antioxidant, chemiluminescence

This paper describes the kinetic evolution, in solution, of styrene-N-phenylmaleimide alternating copolymerization. The rate of consumption for the echimolecular composition of the two monomers is shown by the empirical equation VP = kp[M]1.17[I]0.4; there were formulated hypothesys to explain those dependences. The copolymers obtained were analysed by IR and GPC; it was proved the structure of the alternant copolymer and the fact that it results high molecular products. Keywords: styrene-N-phenylmaleimide, alternating copolymerization,alternant copolymer

The main aim of this paper is to study the thermal stability of some aromatic copolyethers containing a tetramethylenic spacer. The polymers were synthesized using a phase transfer catalysis technique, starting from 1,4’-dichlorobutane and various bisphenols: 4,4’-dihidroxyazobenzene, 4,4’-dihidroxy-diphenyl, bisphenol A and 2,7-dihidroxynaphthalene. It was studied the correlation between structure - thermostability - degradation mechanism. There were used thermodynamic, thermogravimetric methods, derivative thermogravimetry and differential thermal analysis for the evaluation of the kinetic characteristics and for establishing the correlation between activation energies - the conversion rate. The thermal stability is determined by the azo moieties within the main chain. The thermostability of the copolymer is improved by raising the content of the co-monomer with the highest thermostability. The degradation mechanism derives from successive reactions, with a nucleation complex process. Keywords: thermal stability, liquid crystalline copolyether, azobenzene, thermal degradation mechanis

A series of bismaleimides with amide or ester linkages were prepared by condensation-dehydrochlorination reaction of 3(4)- a-chlorosuccinimidobenzoic acid chloride with diamine or diols. The monomers were characterized by thermal stability using dynamic thermogravimetric analysis (TEA) and DSC study. Keywords: bismaleimides, amide, thermogravimetric analysis