• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.4039-4045
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• 2014

The crystallization behavior of irradiated polypropylene (PP) and the blend is an important parameter for polymer processing. Blends of PP/low density polyethylene (LDPE) with different LDPE contents were prepared by melt mixing in a twin screw extruder. The effect of the LDPE content on the irradiation effectiveness of the PP/LDPE blend with trimethylolpropane-trimetacrylate (TMPTMA) as a crosslinking co-agent was investigated in conjunction with the LDPE loading in the blend. The non-isothermal crystallization and crystal structure were measured by DSC, X-ray diffraction (XRD), and polarized optical microscopy (POM). A decrease in the melting temperature of PP was observed due to irradiation, which may be due to the PP chain scissioning effect of irradiation. The Ozawa component n represents a rod shaped, disc shaped and sphere-shaped geometry of the crystal if the value corresponds to 2, 3 and 4, respectively. Based on Ozawa analysis, the values of n were 3.8 and 2.3 for the pure PP and PP blends with 30 wt% LDPE, respectively. The fact that the crystal geometry of PP changed from spherical to disc and rod shaped was confirmed by Ozawa analysis and POM. The ${\beta}$ form XRD peak of the PP/LDPE blend at $16.1^{\circ}$ disappeared after irradiation due to the crosslinking reaction.

• Clean Technology
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• v.6 no.2
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• pp.93-99
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• 2000

Effect of amount of red mud and processing method on the tensile and impact properties of polymers were investigated when the red mud was added as a filler to polypropylene (PP), low density polyethylene (LDPE) and PP/LDPE blend. Especially in case of PP, increase in the tensile strength, elongation at break and absorbed energy was observed when extrusion was carried out more than two times. Tensile strength showed a very remarkable increase when master batch was used in comparison with simple multiple extrusion. In case of LDPE, 10% addition of red mud resulted in the increase of tensile modulus and impact strength, while 20% addition caused a decrease in the same properties. Addition of 5% EVA could reverse this trend. Addition of 20% red mud to PP/LDPE blend gave a decrease in impact strength but 5% EPR compatibilizer could improve the impact properties. Above results showed that the processing method is a very important factor in the utilization of red mud as a plastic fillers and master batch is one of the very effective way of red mud addition.