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http://dx.doi.org/10.5762/KAIS.2014.15.6.4039

Effect of irradiation and LDPE content on crystal formation of PP  

Dahal, Prashanta (Major in Polymer Science and Engineering, Kongju National University)
Kim, Youn Cheol (Major in Polymer Science and Engineering, Kongju National University)
Publication Information
Journal of the Korea Academia-Industrial cooperation Society / v.15, no.6, 2014 , pp. 4039-4045 More about this Journal
Abstract
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.
Keywords
Crosslinking; Crystal Structure; Irradiation; PP/LDPE blend;
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