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Thermal stability of low density polyethylene stabilized with different diamine compounds: N-phenyl-1-naphtyl-amine, N-cyclohexyl-N’-phenyl-p-phenylen-diamine, N-(1,3-dimethyl-butyl)-N’-phenyl-p-phenylen-diamine and N, N’-di-(1,4-dimethylpentyl)-p-phenylen-diamine was investigated by chemiluminescence method. Kinetic parameters depicting the progress in thermal degradation at various temperatures, concentrations and irradiation doses were calculated. Energetic considerations on thermal stability induced by diamine presence are commented and antirad effect of this kind of compounds is emphasized. Keywords: low density polyethylene, diamine compounds

This paper presents a study of the reactivity for some acrylates and methacrylates with two double bonds: diethylene glycol diacrylate (DEGDA), tetraethylene glycol diacrylate (TTEGDA), dipropylene glycol diacrylate (DPGDA), tripropylene glycol diacrylate (TPGDA), ethylene glycol dimethacrylate (EGDMA), triethylene glycol dimethacrylate (TEGDMA). The reactivity was studied by photopolymerization (Du Pont de Nemours 930 DPC) and thermal polymerisation (DSC 204 Netzsch). The used initiators are Lucirin TPO and Irgacure 1700 (3%w for photopolymerization) and benzoyl peroxide (POB 1 and 3% w for thermal polymerization). Correlations between monomers structure and theirs reactivity were established. Keywords: activation energy, diethylene glycol diacrylate, tetraethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, DSC, DPC

Two macromolecular products, of polyethyleneimine and of polyamineamide type, were synthesized by the polycondensation of triethylenetetramine with 1,2 dichloroethane with adipic acid and e-caprolactam, respectively. The secondary amine groups of the two polymers were substituted with specific agents, e.g. the reaction product between triethylamine and epichlorohydrin and/or 1,2 dichloroetane, in order to produce their cationization. The intermediates and the polymers were characterized by FTIR spectroscopy, elemental analysis, solution viscometry and polyelectrolyte titration. Some properties of the synthesized polymers such as molecular weight, charge density, inability to crosslink, recommended them as retention or drainage agents in the papermaking, or as purification agents in the waste water treatment. Keywords: polyetyleneimine, polymineamide, retention aid, flocculation, polyelectrolyte titration

The aim of this study is to calculate the kinetic parameters for thermal cracking of waste PET in presence of radical donors. The thermal decomposition of PET is carried out at different temperatures (693-773 K), high pressure and by using heavy paraffinic hydrocarbons as radical donors. A simple first order kinetic model was proposed for thermal cracking and kinetic parameters (A and E) were calculated. Radical donors assure a high degree of waste PET decomposition in valuable products as gas fraction, gasoline and middle distillate. The coke is very spongious and a small quantity of undecomposed PET is blocked inside of the cavities. Keywords: Thermal, cracking, waste, PET, radical donors

The expresion of the twin screw extruder flow rate was established in correlation with the filling degree and pressure variation along the screw. Starting from the twin screw extruder flow rate expression, the pressure evolution and the maximum pressure in the melting area have been calculated. Keywords: twin-screw extruder, flow rate, crew

This paper contains the results of an experimental research regarding the synthesis of some types of thermoplastic polyurethane based on 1,6-hexanedyol polyadipate (PAH), 1,4-buthanedyol and ethyleneglycol polyadipate (PABE) and ethyleneglycol polyadipate (PAE) and pure 4,4’-diphenyl-methane-diisocyanate (pure MDI). The thermoplastic polyurethanes were physically and mechanically characterized by observing the characteristics variation mode after the synthesis and also after their processing by dissolution and squeeze for the obtaining of marks with preordained properties. Keywords: polyester, di-isocianate, thermoplastic polyuretane, physical-mechanical properties

Based on the evaluation of the position occupied by silicones in biomaterials field in general, and in hydrolytically degradable materials in particular, some original results obtained in this direction are presented. Keywords: biomaterials, silicone, siloxane-organic copolymers, hydrolytic degradability

Atom transfer radical polymerization (ATRP) is one of the most versatile controlled/living radical polymerization (CLRP) method for the production of well-defined materials. As a consequence, ATRP has been employed for the synthesis of a large variety of materials, e. g. end-functional oligomers (telechelics, macromonomers), copolymers (statistical, gradient, block, graft, brush, star), hyperbrached polymers, organic - inorganic hybrids (organic - inorganic block and graft copolymers, polymer - layered silicate nanocomposites and polymer - grafted nanoparticles and flat surfaces), etc. The present paper briefly reviews these ATRP applications, in completion to the previous article dealing with ATRP fundamentals [1]. Keywords: atom transfer radical polymerization, block copolymers, graft copolymers, end-functional oligomers, organic-inorganic hybrids

The expresion of the twin-scren extruder flow rate was established in correlation with the filling degree and pressure variation along the screw. The authors used the hypothesis of the single-screw extruder flow analysis and the relation of the single-screw extruder flow rate. This relation has been corrected by correcting the hypothesis used in the single-screw extruder flow rate relation. Starting from the twin-screw extruder flow rate expression, the pressure evolution and the maximum pressure in the melting area have been calculated. Keywords: twin-scren extruder, flow rate, screw

This paper presents some background aspects of the applications of polymers in the area of the screening of stationary, quasistationary and nonstationary electric and magnetic fields on the Black Sea coast. Some solutions for the electromagnetic depollution involving polymers are proposed. Keywords: polymer, electromagnetic pollution, electromagnetic field polymeric materials, dielectric polymers