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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

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