The present work aimed to synthesize new phenol resins via incorporation of structural modification through introducing new phenolic compounds containing cyclic imide moiety in reaction with formaldehyde. The synthesis of these new resins involved three steps. First, one of the three N-(hydroxyphenyl)tetrabromophtalamic acids 1-3 were processed via a reaction between tetrabromophthalic anhydride and aminophenols. Amic acids 1-3 were dehydrated in the second step by smelting, producing the identical N-(hydroxyphenyl)tetrabromophthalimides 4-6. The new imides represent the new phenolic component that was presented in condensation reaction with formaldehyde in the third step, creating the target phenolic resins 7-9. The work also involved curing the new resins through esterification of phenolic OH groups by treatment with benzoyl chloride. The chemical structures of prepared compounds were confirmed according to FT-IR, 1H NMR, and 13C NMR spectral data. As a conclusion, the present work supply of new phenolic resins and the presence of the cyclic imide (tetrabromophthalimide) moiety in their structures exhibit high softening points and resistance to solubility, which fit with some applications, while subsequent curing through esterification exhibits better solubility and lower softening points, which fit with other applications.
Abstract: Iatrogenic furcal root perforations are serious complications during dental treatment. This study was aimed to compare the sealing ability of new bioceramic root repair material TotalFill® with the other perforation repair materials (GIC, MTA and Biodentine) using a dye- extraction method.Materials and Methods: Forty extracted, human mandibular molars with non-fused well developed root were collected. Artificial perforations were made from the external surface of the teeth. Then the teeth were randomly divided into 4 experimental groups (n= 10) according to the type of repair material used in this study; Medifil glass ionomercement, TotalFill® bioceramic root repair material, BiodentineTM and MTA Plus. The specimens were then im
... Show Morein the present investigation new eight poly esrers as schiff bases wich containing pendant imine group were synthesized by treatment of poly acryloyl chlodire with ethanol amine group were synthesized by treatment of poly acryloyl chloride with ethanol
Introduction: The study was intended for Roseomonas gilardii NTCC 13290 strain pigment extraction and characterization. Methodology: The pigment-producing bacterial were cultured on Columbia blood agar and nutrient media agar. Then the pigments were extracted by ethanol. The candidate pigment was further characterized by different biotechnological techniques: UV-Vis spectroscopy, FT-IR to analyze the functional group of the targeted pigment, and TLC media. Results: The cultivation of Roseomonas gilardii on media showed pink color and nearly runny texture. The bacterial colonies were microscopically gram stained and examined, the R. gilardii was seen as coccobacillus colonies that mostly form pairs arranged as short chains. The R. gilardii b
... Show MoreSoil samples from fields cultivated with barley and wheat in addition to samples
from spoiled orange and apple fruits and carrot roots were collected with the aim to
isolate cellulase producing bacterial strains. Bacterial isolates obtained from these
samples were grown on a selective medium containing carboxymethyl cellulose
(CMC) as a sole source for carbon and energy. Results showed that nine isolates out
of fifty were able to produce cellulase.The specific activity of cellulase in culture
filtrate of the most efficient isolate was 1.601 u/mg protein.This isolate was
identified according to its morphological characteristics and biochemical tests, and
then by using Api 20-E and VITEK-II identification systems an
Continuous functions are novel concepts in topology. Many topologists contributed to the theory of continuous functions in topology. The present authors continued the study on continuous functions by utilizing the concept of gpα-closed sets in topology and introduced the concepts of weakly, subweakly and almost continuous functions. Further, the properties of these functions are established.
Research has included preparation of three of n Vthal acids Amec Bmentoj high of interaction vehicles Ortometta and bar aminophenol with phthalic anhydride was withdrawn water and ring closure of acids Alvthal AMEC prepared
Mercury-lead-antimony based superconductors with the formula Hg0.5 Pb0.5xSbxBa2Ca2Cu3O8+δ (x=0, 0.10 and 0.15) have been prepared by useing three step solid state reaction processes. Electrical resistivity, using four probe technique, is used to find the transition temperature Tc. It is found from that sample Hg0.5 Pb0.5Ba2Ca2Cu3O8.437 is semiconductor , sample Hg0.5 Pb0.4Sb0.1Ba2Ca2Cu3O8.353 is normal state with metallic behaviors, while sample Hg0.5 Pb0.35Sb0.15Ba2Ca2Cu3O8.233 is superconducting state with critical transition temperature (Tc) is 126K. X-ray diffraction (XRD) analysis showed a tetragonal structure with decrease in the c-axis lattice constant for the samples doped with Sb as compared with these which have no Sb
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