The glass transition temperature of furanic polyesters varied according to structural criteria which were readily explained on the basis of classical considerations related to the ease of the onset of segmental motions. The therman stability of these polymers was comparable to that of the corresponding aromatic polyesters.
A. Chaabouni, S. Gharbi, M. Abid, S. Boufi, R. El Gharbi, A. Gandini
Polyesters, glass transition, furanic polymers
Pages 547-558
Nowadays, textile industry has an effective contribution to the development and growth of the Tunisian economy. Consequently, a large quantity of dyes is released into the environment. The methods used nowadays (biological, physico-chemical treatment, membrane filtration...) for the elimination of such compounds can only transform soluble pollutants into solid waste. However, the new solid waste management regulations penalize all kinds of solid waste rejection into the environment. The research of alternative treatment systems needs to be considered. Oxidation by ozone seems to be the most adequate solution for this problem. In this study, an extension of ozonation for some dyes used in textile industry was considered. After setting up a separation and analysis technique of the selected dyes, the study of their oxidation by ozone shows that the degradation of these compounds has good yields in acid conditions.
M. Khadrahoui, J. Bouzid, B. Elleuch
chromatography, HPLC, dyes, oxidation, ozonization
Pages 559-565
Membranes-Fluka and Eastmann DAC based-prepared according to Manjikian technique, lead to different reverse osmosis performances. These membranes are characterised by scanning electron microscopy, flux and selectivity. Basis polymers are characterised by viscosimetry. Our analysis show that membranes have different structures and that the initial two polymers have also different intrinsic viscosities.
E. Ferjani, M. S. Roudesli
cellulose diacetate, membranes, reverse osmosis, scanning electron microscopy, viscosimetry
Pages 567-573
The investigation of the environment around each formular group in the unit cell of the cis-1,2,3,6-tetrahydrophthalic anhydride crystalline structure provides evidence for the existence of molecular arrangements favorising specific nucleophile-electrophile intermolecular interactions between oxygen and carbonyl carbon atoms. The analysis in terms of geometrical criterions shows that the main interactions, essentially, of dipole-dipole type, appear to be between the local electric dipoles of carbonyl groups. The study of the influence of these interactions on packing effects allows us to justify the differences observed between the structures of formular groups in the unit cell.
A. Ben Fredj, S. Ben Rejeb
crystalline structure, anhydrides, intermolecular interactions
Pages 575-582
C33H22O2N2 , Mr = 478,53 g.mol-1, crytallizes in the triclinic system, space group P-1 . The cell parameters are: a = 9.182(5) Å ; b = 10.059(5) Å ; c = 13.490(4) Å ; α = 87.29(4)° , β = 104.40(4)° ; γ = 99.18(4)° ; V = 1191.3(9) A3 with Z = 2 . The heterocyclic skeleton is constituted by the four planar groups : chromenopyrrol, phenyl, paratolyl and oxoisoquinoleinyl. The arrangement of these groups is organized by N...H intramolecular hydrogen bonding. The O...H intermolecular hydrogen bonds interactions are responsible of the cohesion of the solid.
M. Msaddek, A. Haddad, M. Rammah
Pages 583-591
In the present work, we tried to determine the composition of the four main phases of the clinker: C3S, C2S, C3A and C4AF by using the scanning electron microscope (SEM). For this purpose, we have made polished sections of eight nodules of clinker from the two kilns I and II. The variation intervals of phase oxides were determined. The selection of analyses is based on the ratios CaO/SiO2, CaO/Al2O3 and Al2O3/Fe2O3 depending on the phase. In many cases, these ratios differ from their theorical values. We did not have difficulties in the analysis of C3S and C2S crystals because of their abundance and large size. Whereas, some difficulties were found in the analysis of C3A and C4AF.
N. Ben Jamaa, R. Saada, H. Bahrini
clinker, SEM, composition, phases
Pages 593-604
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