A COPOLYMERS are important compounds today because of their wide applications in various industrial and medical fields and in other fields. Therefore, the study of preparing many of these polymers has been studied. This research involved preparing linear polyester contain Schiff-base unit by interfacial polycondensation three type diacid chloride (Succinoyl Chloride, Adipoyl Chloride and sebacoyl Chloride) in a chloroform /water system employing phase transfer catalyst with monomer containing two hydroxyl which is derived from a 4-hydroxy aniline reacted with a 4-hydroxy benzaldehyde monomer. The monomer (EM1) and polyester (EM2, EM3, and EM4) were characterized by FTIR, 1 H NMR, 13 C NMR and TGA analysis. The polyester-Schiff base so obtained show good thermal stability.
Thin films of nanometer sized cadmium sulfide were directly prepared by aerosol-assisted chemical vapor deposition (AA-CVD) method, cadmium ethyl xanthate complex was used as precursor material at 225 o C, 250 o C and 275 o C. The thermal decomposition of complex was characterized by thermal analysis, (thermogravimetric analysis (TGA) and a differential scanning calorimetry (DSC)). The prepared CdS thin films have been characterized by XRD and SEM-EDX analysis. TGA curves ensured that the rapid decomposition of [Cd(S2COEt)2] gives a CdS in single step between 150 o C and 200 o C. XRD patterns confirmed that the CdS particles crystalized as a hexagonal crystallographic phase at low temperatures. The grain size of particles increased with increasing the preparation temperatures from 225 o C to 275 o C,. The spherical CdS nanoparticals were observed in SEM analysis.
The kinetics of tetrahydrofuran oxidation by sodium N-chloro-p-toluene sulfonamide in the hydrochloric acid medium was studied in this work at 308 K. The reaction rate shows a first-order dependence on [CAT] and fractional-order dependence each on [THF] and [H+]. The derivative rate law, which suitable for experimental results, is Equation 24. The first-order rate constant has been evaluated from the relationship of the plot of Log [CAT] versus Time. The variation of the ionic strength by the addition of sodium perchlorate (NaClO4) and chloride ion on the medium showed no significant effect on the reaction. The reaction rate raised with decreasing dielectric constant (D), while the addition of p-toluene sulfonamide retards the rate of reaction. The oxidation reaction of tetrahydrofuran have been studied at a different temperature, The equilibrium constants for the formation of hypochlorous acid, protonated hydrochlorous acid and protonated hydrochlorous acid–THF complex and its decomposition constant have been estimated. Also, the rate constant for the slow (rate-determining step) and the activation parameter have been calculated. A suitable mechanism for the oxidation reaction of tetrahydrofuran was proposed based on the experimental finding. The mechanism includes the reaction of active species (H2OCl) of the oxidizing agent with the tetrahydrofuran in a fast step to give the complex(X). This complex will then transformed into complex (X̅ ) in slow step then to γ-butyrolactone in another fast step.
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