الفهرس 
AcknowledgmentOnly 14 pages are availabe for public view
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Abstract
Tailoring the properties of a polymer for specific application is a major task for many researches in the field of polymer science and polymer engineering. Different external effects are followed to alter the macromolecular structure of a polymer to a desirable arrangement. Strong magnetic fields (up to 10 Tesla) were applied either on the final stable product or during the polymerization of the polymer. Some relatively weak effectiveness were observed and documented. In the present work, a practical trial is done in order to initiate remarkably macromolecular structural variations by less strength magnetic fields. Powerful set of permanent magnets were used instead of the traditionally used big electromagnets and the field was inserted when the polymer structure was reached the minimum chain inter-attraction force. To examine the efficiency of the magnets array to affect the polymeric structure, a special optical system is constructed to record effects of the magnetic field on the growth rate of polyethylene glycol (PEG) spherulites. A magnetic field of 355 mT accelerated the growth rate of spherulites markedly when the field lines are crossing the sample normally to its surface. When the field lines are passed tangential to the sample`s surface, 100 mT was enough to produce the same acceleration for the rate of spherulites growth, approximately. High density polyethylene (HDPE) and polypropylene (PP) film samples were treated magnetically during the phase transition from liquid to solid and then some physical properties in order to detect the type and amount of the magnetically induced variations. Infrared (IR) spectrum is measured to determine the induced chemical variations, if any. No chemical changes were detected in the treated HDPE through magnetic field strength up to 153 mT. PP samples showed increasing in bending vibrations where a weak absorption peak was observed. X-ray diffraction patterns were recorded to identify changes in crystalline state of HDPE and PP. The mean orientation factor is deduced from the X-ray diffract-graph. HDPE treated samples did not show any chain orientation enhancement due to their high crystallinity. PP treated samples showed formation of new crystallites or more chain orientation enhancement. The melting temperature for both HDPE and PP samples, showed little shift down the melting point of the stable untreated samples, which means reduction in the chains interattraction forces. Mechanical properties of treated samples showed distinct variations, but are not in a systematic correlation with the strength of the applied magnetic field, which may be due to some internal defects during the sample preparation or treatment. Obtained values of mechanical parameters are tabulated in single table for ease comparison.
All data are presented in coloured graphs and table. Some digital images for the PEG spherulites during growth are extracted from a video clip taken during the growing process using special constructed optical system.