Iranian Journal of Polymer Science and Technology / Volume 4 Number 2 (1995) 84–88 ISSN: 1017-6020/1995
The Synthesis of Poly(hydroxamic acid) and its Metal Complexes
S.H. Hosseini and A.A. Entezami
Polymer Chemistry Laboratory, Faculty of Chemistry, Tabriz University, Tabriz, I.R. Iran
Acrylcarbohydroxamic acid is synthesized, purified by azeotropic co-evaporation technique, and polymerized, under free radical condition. The complexes of poly(hydroxamic acid) with certain ions: Fe+3, Cr+3, Rh+3, Ir+3, Al+3, Cu+2, Pd+2, Ni+2, Pt+2, Co+2, at different pH are reported.
Iranian Journal of Polymer Science and Technology / Volume 4 Number 2 (1995) 90–97 ISSN: 1017-6020/1995
Electrochemical Synthesis of Processible Conducting Graft
Copolymers of Styrene‑Pyrrole, N‑Methylpyrrole and Aniline
H. Yeganeh Olad Adam and A.A. Entezami
Polymer Laboratory, Faculty of Chemistry, Tabriz University, Tabriz, I.R. Iran
The insolubility and infusibility of classical conducting polymers make their processing difficult and limit their applications. One way to improve the solubility is to synthesize copolymers of conducting polymers with soluble classical polymers. We describe the synthesis of 2‑vinylpyrrole, N‑methyl‑2‑vinylpyrrole and p‑aminostyrene via Wittig methodology, and copolymerization of these compounds with styrene. The monomers: pyrrole, N‑methylpyrrole and aniline are grown on resulting random copolymers via electrochemical oxidative polymerization.
Iranian Journal of Polymer Science and Technology / Volume 4 Number 2 (1995) 98–103 ISSN: 1017-6020/1995
Substituted Oxetanes in Polymer Synthesis; Polyesters Based on
3,3‑Bis(chloromethyl) Oxetane and 5‑Amino‑Sodium
V. Toader, N. Hurduc, D. Scutaru and V. Bulacovschi
Department of Macromolecular Chemistry, Chemical Engineering Faculty, Technical University “Gh. Asachi”, Romania
Department of Physics, University “Littoral”, Dunkerque, Cedex, France
The preparation of polyesters based on 3,3’‑bis (chloromethyl) oxetane (BCMO) and 5‑amino‑sodium isophthalate (5‑AIP) under the phase transfer conditions is discussed, together with the influence of reaction conditions upon the properties of the obtained polymers. The anisotropic properties of the polyesters and their thermal behaviour are investigated by DSC, TG and optical polarizing microscopy.
Iranian Journal of Polymer Science and Technology / Volume 4 Number 2 (1995) 104–109 ISSN: 1017-6020/1995
Liquid‑Crystalline Polymers (Part II): Thermal Analysis of Some
Copolyethers Based on Bisphenol A
4,4‑Dihydroxyazobenzene,4,4´‑dihydroxydiphenyl and 3,3´–Bis
Department of Macromolecular Chemistry, Technical University “Gh. Asachi”, Jassy, Romania
D. Ionescu and N. Hurduc
Department of Physical Chemistry, “Al. I. Cuza” University, Jassy, Romania
Research Center of Savinesti, Romania
The thermal stability of some polyethers and copolyethers, containing the oxetanic ring in the main chain, is presented. Some of these polymers can be used for obtaining liquid ‑ crystalline thermoset materials. The presence of azo bonds in copolyethers reduces the thermal stability, but we can say that this presence is necessary if we wish to obtain polymers with LC properties.
Iranian Journal of Polymer Science and Technology / Volume 4 Number 2 (1995) 110–117 ISSN: 1017-6020/1995
Measurement of Adhesion and Interfacial Thickness of Polymer‑
Polymer Interfaces with Electron Microscopy
E. Jabbari and N.A. Peppas
School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907-1283, USA
The interfacial thickness of polymer‑polymer bilayers is determined by the concentration profile of the two polymers across the interface. After intimate contact is established between two polymer films, adhesion takes place by interdiffusion of polymer chains across the interface. The combination of transmission electron microscopy and energy dispersive spectroscopy (TEM/EDS) is used to map the concentration profile at the interface of a poly(vinyl chloride) and poly(methyl methacrylate) bilayer. Thin sections in the order of 800 Å are cut using an ultramicrotome, examined with TEM, and the concentration profile is mapped with EDS. The intensity of x‑ray fluorescence is adjusted for variation in sample thickness by measuring the relative thickness across the interface with electron energy‑loss spectroscopy (EELS). The interfacial thickness of the bilayer after 6 hours at 120 °C was 1.5 mm. The concentration profile is fitted to the Fickian diffusion equation and an average interdiffusion coefficient of 8.0×10–14 cm2/s is obtained in good agreement with values reported in the literature.
Iranian Journal of Polymer Science and Technology / Volume 4 Number 2 (1995) 118–124 ISSN: 1017-6020/1995
Imaging of Macromolecules on Surfaces by
Scanning Tunneling Microscopy
M.H. Zareie, K. Piskin and E. Piskin
Chemical Engineering Department, Bioengineering Division and Faculty of Medicine, Hacettepe University, Ankara, Turkey
Scanning tunneling microscopy (STM) measures quantum tunneling to produce an atomic scale electron density image of a surface. STM has become one of the most powerful instruments in surface science studies. Recently we constructed a scanning tunneling microscope and studied several macromolecules on highly oriented pyrolytic graphite (HOPG) and mica surfaces. We obtained image of human serum albumin. The graphite substrates also were treated by pure nitrogen gas plasma for different periods. The images of both single stranded DNA fragments and DNA double helix are obtained and their interactions with smaller molecules (e.g., calcium chloride) are also demonstraded.
Iranian Journal of Polymer Science and Technology / Volume 4 Number 2 (1995) 126–133 ISSN: 1017-6020/1995
Viscosity of Whey Protein Solutions
M.R. Alizadehfard and D.E. Wiley
UNESCO, Centre for Membrane Science & Technology, School of Chemical Engineering and Industrial Chemistry
The University of New South Wales, Sydney, Australia 2052
The apparent viscosity of whey protein solutions is studied as a function of shear rate, temperature and shearing time (at pH 6.5), using a coaxial cylinder and cone & plate viscometer (Haake \/T500). Aqueous solutions containing up to 54 wt% whey are subjected to shear rates between 10 and 3200 s–1. For concentration up to 25 wt% the viscosity is independent of the shear rate and time. For whey concentrations of 30 wt% and above, the viscosity decreases asymptotically with an increasing shear rate. The power law index is approximately constant over the range 30‑40 wt% whey. The viscosity of 30‑35 wt% solutions is independent of time of shearing, but it is dependent on time for solutions of 40 wt% and greater. A thixotropic hysteresis effect (for T < 50 °C) and a rheopectic hysteresis effect (for T=52 °C) are observed for solutions of 40 wt% and greater.
Iranian Journal of Polymer Science and Technology / Volume 4 Number 2 (1995) 134–140 ISSN: 1017-6020/1995
Impact, Compressive and Flow Properties of Fibre Reinforced
M. Razavi Nouri and J. Morshedian
Polymer Research Centre of Iran, Tehran, I.R. Iran
An experimental study on the effect of fibres on impact and compressive strengths as well as flowability is reported. The expansion during hydration of cement in water and the drying shrinkage of fibre reinforced cementitious composites are also investigated. Cementitious samples are prepared containing varying amounts of E‑glass and two types of polyacrylonitrile fibres (Dolanit 10 & 11). Results show that while E‑glass and Dolanit 11 could somewhat increase the compressive strength of cementitious samples, Dolanit 10 shows an opposite effect when incorporated into cement. All fibres, depending on their nature and volume fractions, improve the impact strength of the composite considerably. Furthermore, inclusion of fibres reduces the drying shrinkage of cementitious samples, although the flowability of mixtures decreases with increasing of volume fraction of fibres.
Iranian Journal of Polymer Science and Technology / Volume 4 Number 2 (1995) 142–145 ISSN: 1017-6020/1995
Structure and Properties Peculiarities of Butyl Rubber and High
Density Polyethylene Copolymers
R.M. Aliguliyev, A.A. Shibayeva, A.I. Babayev and S.M. Akhmedov
Scientific Industrial Association “OLEFIN”, Baku, Republic of Azerbaijan
Butyl rubber (BR) and high density polyethylene (HDPE) grafted copolymers, relating to thermoplastic elastomers, are synthesized under ultrasound exposure (USE). Investigating the kinetics of macroradical accumulation and structural transformations in BR and HDPE under USE of various duration we found the objective laws of copolymer synthesis. The peculiarities of BR+ HDPE copolymers structure formation at the molecular and overmolecular level are investigated in a wide range of compositions. According to the deformational strength and dielectric indices, it is established that the copolymers obtained under USE demonstrate the most optimum properties in comparison with the copolymers obtained by other methods.
Iranian Journal of Polymer Science and Technology / Volume 4 Number 2 (1995) 146–152 ISSN: 1017-6020/1995
Carbon Black Dispersion in Rubber
M.R. Vaseghi, D.W. Southwart and G.A.W. Murray
Institute of Polymer Technology and Materials Engineering, Loughborough University of Technology
Loughborough, Leics., LE11 3TU, UK
A new method for characterizing dispersion of carbon black in elastomers measures the intensity of light reflected from a freshly cut surface of a sample. A microscope with a dark field illumination is used. The equipment and software measure the illumination in each of 100 squares and calculate parameters such as average and standard deviation. This is called a "dark field carbon black" (DFCB) test. The relevance of the test to experimental error made it necessary to carry out dark field carbon black tests (DFCB) using a very large number of samples so that the underlying pattern of results could be clearly seen. The work investigated how the changes in dispersion produced in a two roll mill can be presented in the test. It is found that for the first five passes, the DFCB parameters change very rapidly and slightly change after 50 passes.