Iranian Polymer Journal / Volume 5 Number 2 (1996) 6773 ISSN: 1026-1265/1996
Polyamide 6 Granules
(1) S.C. POLIROM S.A., Roman, Romania
(2) Department of Macromolecules, Technical University Gh. Asachi, Jassy, Romania
The heat and mass transfer has been studied in the case of solid/liquid extraction applied to polyamide 6 granules. A solution being proposed for the intensification of heat and mass transfer involving recirculation of the extraction waters by inducing a sinusoidal, low amplitude and high frequency velocity. The hydrodynamic calculations performed, evidenced an eight times increase in each of the individual heat transfer coefficient and an over five times increase in each of the individual mass transfer coefficient. Also, all attempts aimed at the optimization of the process have been materialized in the elaboration of a new spinning tube model as well as in the selection of a thermal agent suitable for the obtaining of the desired temperature profile in the extractor.
Iranian Polymer Journal / Volume 5 Number 2 (1996) 7586 ISSN: 1026-1265/1996
School of Chemical Engineering and Industrial Chemistry, University of New South Wales
Sydney, NSW 2052, Australia
Conductive polymer composite materials are fabricated by mixing high density polyethylene or polypropylene with conductive fillers. To overcome the deterioration in mechanical properties of carbon-polymer composites with high carbon loading, ethylene-propylene rubber is blended into the composites. The electrical and mechanical properties of the composite materials are studied. Because blending of polymeric phase with conductive particles influences the morphology which in turn affects the performance of the final composite, the morphology and microstructure of the blends and that of the composites are examined as well.
Iranian Polymer Journal / Volume 5 Number 2 (1996) 8795 ISSN: 1026-1265/1996
Organic Polymer Chemistry Research Laboratory, College of Chemistry
Isfahan University of Technology, Isfahan 84156, I.R. Iran
The reaction of trans-stilbene with 4-phenyl-1,2,4-triazoline-3,5-dione and 4-ethyl-1,2,4-triazoline-3,5-dione is investigated at room temperature. The reactions are slow compared to its isomeric compound 1,1-diphenyl ethylene and are completed in several hours. These reactions lead to the formation of two 2:1 adducts via double Diels-Alder and Diels-Alder/ene reactions in a ratio of 1:1.22 for R=Et and 1:1.17 for R=Ph. When R=Ph the two isomers are separated by chromatography, but with R=Et the ratio is determined by 1H‑NMR technique. These compounds are used as models for the step‑growth polymerization reactions. The reactions of bistriazolinediones with trans-stilbene are carried out in dimethylformamide and methylene chloride. The reaction gives new copolymers via repetitive double Diels-Alder and Diels-Alder/ene polyaddition reactions. These polymers have intrinsic viscosities in a range about 0.07 to 0.32 dL/g in dimethylformamide. Some physical properties and structural characterization of these copolymers are studied and reported.
Iranian Polymer Journal / Volume 5 Number 2 (1996) 97103 ISSN: 1026-1265/1996
NR Compounds Properties Using Random Mixing
(1) School of Industrial Technology, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia
(2) Rubber Process Engineering Center, Loughborough University of Technology, Loughborough, Leicestershire, UK
The effect of a diamine salt of fatty acid termed a multifunctional additive (MFA) on carbon black filled natural rubber properties using random mixing has been studied. A similar effect of the MFA on mechanical properties is obtained as in sequence mixing. The addition of MFA improves the mechanical properties of carbon black filled natural rubber compounds. However, the improvement of these properties can only be obtained if the amount of this additive used does not exceed the critical level. Above the critical level, a gradual deterioration of properties occurs as a result of a weak interaction at the MFA-MFA interface. These results confirm the previous works using the sequence mixing.
Iranian Polymer Journal / Volume 5 Number 2 (1996) 105112 ISSN: 1026-1265/1996
with Poly(p-N-chlorostyrenesulphonamide) Synthesized by Direct
and Indirect Methods
Department of Chemistry, Faculty of Science, Bu-Ali Sina University, Hamadan, I.R. Iran
Poly(p‑N‑chlorostyrenesulphonamide) synthesized via direct and indirect methods are efficient polymeric oxidizing reagents which can be used in equimolar amounts for oxidation of primary and secondary alcohols to their corresponding carbonyl compounds in the presence of dimethyl sulphide. The oxidation reactions by polymers obtained through direct synthesis starting from 4‑vinylbenzenesulphonic acid sodium salt is more effective and economical however than the indirect method involving reactions initiated on polystyrene.
Iranian Polymer Journal / Volume 5 Number 2 (1996) 113117 ISSN: 1026-1265/1996
Department of Chemistry, Sardar Patel University, Vallabh, Vidyanagar 388120, India
New maleimide derivatives, N-(4-acetothiosemicarbazone phenyl)maleimide [ATPM] and N-(4-acetosemicarbazone phenyl)maleimide [ASPM] have been prepared by condensation of N-(4-acetylphenyl)maleimide with thiosemicarbazide and semicarbazide hydrochlorides, respectively. These are homopolymerized and copolymerized with styrene and divinylbenzene to give chelating ion exchange resins. They are analyzed by elemental analysis IR spectral study, TGA, DSC and viscosity measurements.
Iranian Polymer Journal / Volume 5 Number 2 (1996) 119126 ISSN: 1026-1265/1996
Department of Chemistry, Faculty of Science, University of Mazandaran, Babolsar 47414, I.R. Iran
An investigation is conducted into some of the properties of epoxy resin formulations. Diglycidyl ether of bisphenol A epoxy resin is cured with an amine, an anhydride/catalyst and a polyamide as curing agents. Water adsorptions of the cured resins are compared with each other. The chemical resistance of cured epoxy/diethylene triamine and epoxy/polyamide systems is studied in acetone, sulphuric acid and sodium hydroxide solutions. The properties of epoxy/polyamide system show similar trend in comparison with epoxy/diethylene triamine system but they are different in magnitudes. Thermal oxidation of cured epoxy/diethylene triamine system is studied by measuring the carbonyl group formation index. Water absorption of the oxidized resin showed some differences from the unoxidized sample.
Iranian Polymer Journal / Volume 5 Number 2 (1996) 127131 ISSN: 1026-1265/1996
Department of Chemistry, University of Sofia, 1126 Sofia, Bulgaria
Viscosity behaviour of the membrane separated whey protein concentrates and the weak whey protein gels, produced by the chemically induced whey protein aggregation, are compared. Viscosity and the thixotropic loop width for the latter are greater than those for the former. The critical non‑Newtonian protein concentration for membrane concentrates is 2.3 times that for gels, whilst the ks value, characterizing the concentration dependence at the flow curve exponent for gels is 1.9 times that for concentrates. These distinctions reveal further possibilities to control the rheology behaviour of the whey protein concentrates via the method of their production. On the other hand, they confirm the formation of the weak protein gel by the sulphydryl group/ disulphide bond interchange reaction during the thermally or the chemically induced whey protein aggregation.
Iranian Polymer Journal / Volume 5 Number 2 (1996) 133138 ISSN: 1026-1265/1996
Department of Chemistry, Cumhuriyet University, 58140 Sivas, Turkey
In this study, binding of herbicides such as p-chlorophenoxyacetic acid, 2,4-dichlorophenoxyacetic acid and the ammonium salt of 2,4-dichlorophenoxyacetic acid onto poly(N-vinyl pyrrolidone) and the adsorption of these herbicides to crosslinked poly(N-vinyl pyrrolidone) are investigated. It is shown that there are electrostatic interactions between anionic sites of the herbicides with cationic sites of poly(N-vinyl pyrrolidone). The adsorption of these herbicides to crosslinked poly(N-vinyl pyrrolidone) shows Type III adsorption isotherms. The values of percentage sorption of the low concentrations of herbicides are higher than those at the high concentrations of herbicides.