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6SAYYAH, SABBAH and SAID: Characterization and radiometric studies on poly(methy1 methacrylate) chain a n d t h e adjacent molecules of either solvent or polymer (in a melt). In such a case, t h e above formulation would apply with t h e variation of pressure replacing ST in eqs. (13) a n d (14) a n d t h e variation of volume replacing SU. T h e complex bulk modulus of t h e same form as in eq. (15) will result, but in this case it will have a n isothermal contribution, possibly exceeding t h e thermal one. T h e latter can be verified experimentally, since it is t h e isothermal longitudinal modulus that governs t h e fluctuations observed b y correlation spectroscopy methods in t h e light scattering experiments. Furthermore n o correlation with C&, values is t o be expected for t h e structural mechanism, if t h e volume changes are more important than those of t h e enthalpy. This picture which involves structural rearrangements does n o t conform t o t h e model of a chain interacting with its surroundings as a macroscopic object does with a viscous medium. It is quite possible t h a t t h e latter model, in spite of its great success in explaining t h e general features of viscoelastic behaviour, will have t o be exchanged for t h e more detailed molecular picture when more subtle properties are considered. T h e above considerations seem t o show t h a t this can b e done without losing t h e benefits of t h e continuous-medium approach, while at t h e same time leaving room for t h e concepts underlying t h e theories of transition t o t h e glass-like behaviour. The desirability of such incorporation has already been mentioned [I, 11, 161.Some p-phenylene diamine condensation products with different organic acids were synthesized. The effect of y-irradiation on PMMA films doped with three samples of these amines was investigated by ultraviolet spectroscopy. A change in the intensity of absorption bands with increasing irradiation dose was recorded. The use of PMMA films doped with this type of amines as dosimeter is suggested. Charakterisierung und radiometrische Untersuchung von mit Aminderivaten dotiertem PoZy(methyZmethacry2at)Einige Kondensationsprodukte von p-Phenylendiaminen mit verschiedenen organischen Sauren wurden synthetisiert. Der EinfluB von y-Bestrahlung auf PMMA-Filme, die mit drei Proben dieser Amine dotiert wurden, wird mittels UV-Spektroskopie untersucht. Es wurde eine Zunahme der Intensitat der Absorptionsbanden mit steigender Bestrahlungsdosis registriert. Die Verwendung der dotierten PMMA-Filme in der Dosimetrie wird vorgeschlagen. Xapakmepucmuxa u paauoMempuueckue uccfieaosanus noJcumemuJcmemaxpuJcama, ~omuposannozo npouesoanbwu m u n aCHHTeTH3E1pOBaHbI HeKOTOpbIe IIpORYKTbI KOHJ(eHCa~HE1 n-@?HHJIeH~E1aM%iHOB C pa3JIHqHbIMM OpraHHYeCKUMM KMCJIO-TPMII. c I I O M O 4 b H ) Y@-CneKTpOCKOIIHE1 IlCCJIeROBaJIOCb BJIHFIHIle y-JIyqe8 H a IIJIeHKIl E 1 3 nMMA, ROTHPOBaHHbIe TPeMFI Ha aTMX aMIlHOU. HaBn~o~anocb YUeJIllqeHHe IlHTeHCHBHOCTIl a6cop6qm C POCTOM R03bI 06JIyYeHHX. ripen-JIaraeTCx ...

SIX series of cationic polyurethane surfactants were synthesized by the reaction between different six esters (which prepared by condensation of fatty alcohols namely: octanol, decanol, dodecanol, tetradecanol, hexadecanol and octadecanol with bromoacetic acid) and polyurethane as quaternizing agent. The chemical structures of these surfactants were confirmed using elemental analysis, FTIR spectra, + HNMR and UV analysis. The surface activities of the synthesized cationic thiol polyurethane surfactants showed their tendency towards adsorption at the air/water interface. The adsorption tendency was estimated from the values of surface tension and the depression of surface tension at the critical micelle concentration. The studied surfactants were evaluated as antimicrobial agents against pathogenic and sulfur reducing bacteria using inhibition zone diameters and minimum inhibition concentration values. The synthesized cationic thiol polyurethane surfactants showed good antimicrobial activities against the tested microorganisms including Gram positive, Gram negative as well as fungi. The synthesized compounds were tested for the activity as corrosion inhibitors against carbon steel corrosion in 2N H 2 SO 4 at 50, 100, 200, 400 and 600 ppm. The inhibition efficiencies of the tested compounds showed good inhibition and protection of the carbon steel. The corrosion inhibition tendency correlated to the surface activity and chemical structure of the compounds.Keywords: Cationic surfactants, Surface activity, Adsorption , Antimicrobial activity, Corrosion inhibition, Polyurethane. IntoductionCorrosion inhibitors are added to prevent metal dissolution during its surface cleaning from oxides and other adherent materials [1]. Also, corrosion inhibitors may be liquids or powder form that effectively reduces the corrosion rate by adsorbing on the metal surface [2,3]. Corrosion inhibition efficiency of organic compounds is related to their adsorption properties [4]. Corrosion protection of steel in acidic media is of great importance for both industrial facilities and theoretical aspects [5]. The adsorption of these molecules depends mainly on certain physicochemical properties of the inhibitor molecule such as the presence of heteroatoms including: oxygen, sulfur, nitrogen atoms and multiple bonds in the molecule through which they are adsorbed on the metal surface [6][7][8][9][10].Heteroatoms such as nitrogen, oxygen, and sulfur are capable of forming coordinate covalent bond with metal owing to their free electron pairs and thus acting as inhibitor. Compounds with π bonds generally exhibit good inhibitive properties due to the interaction of π orbital with metal surface [11][12][13]. The selection of a suitable inhibitor for a particular system is a difficult task because of the selectivity of the inhibitors and wide variety of corrosive environment. As a result, several types of corrosion inhibitors were developed to fit the different types of corrosion processes and also the medium where the corrosion takes place. Cor...

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A series of cationic polyurethane surfactants ] were synthesized by the reaction of alkyl bromoacetate (namely: octyl-, decyl-, dodecyl-, tetradecyl-, hexadecyl-, and octadecyl bromoacetate) as quaternizing agents and modified polyurethane contains tertiary amine species. Modified polyurethane was prepared by the reaction of toluene diisocyanate (TDI) and triethanol amine monomercaptoacetate. The chemical structures of the prepared surfactants were confirmed using elemental analysis, Fourier transform infrared spectroscopy (FTIR), and Proton nuclear magnetic resonance ( 1 H NMR) spectroscopy. The molecular weight measurements of the prepared polymers showed that the segments of each polymer contain average 10 units of the urethane-triethanol amine mercaptoacetate. The surface activities of the prepared surfactants including: surface tension (γ), effectiveness (π cmc ), concentration at micelle formation (CMC), efficiency (Pc 20 ), maximum concentration at the interface (Γ max ), and the average area occupied by each surfactant molecule at the interface at equilibrium (A min ) of surfactants solutions were established at 25 C. The surface tension and the critical micelle concentration values of the prepared surfactants were gradually decreased by the gradual increase of their alkyl chain length. The prepared cationic surfactants showed efficient activity as inhibitors for dissolution of carbon steel in an acidic medium and also as a biocide against the growth of bacteria, fungi, and yeast.

New modified alkyd varnishes were prepared by partial replacement of phthalic anhydride with methylene disalicylic acid. Incorporation of this phenolic derivative led to significant improvement in hardness, gloss, and alkali resistance performance.

New modified alkyd compositions 0.164 0.432 0.000 0.552 0.164 0.428 0.004 0.552 0.164 0.410 0.022 0.552 0.164 0.389 0.043 0.552 0.164 0.367 0.065 0.552 0.164 0.346 0.086 0.552 0.164 0.324 0.108 0.552 Acta Polyrnerica 38 (1987) Nr. 9 543 0.111 0.568 0.000 0.768 0.111 0.562 0.006 0.768 0.111 0.540 0.028 0.768 0.111 0.511 0.057 0.768 0.111 0.483 0.085 0.768 0.111 0.454 0.114 0.768 0.111 0.426 O.lft2 0.768