Irradiation of Isotactic Polypropylene and Polypropylene/Ethylene-Propylene-(diene-monomer) Blends
The influence of electron beam irradiation on rheological properties and morphology of polypropylene and polypropylene/ethylene-propylene rubber blends was studied. Electron beam irradiation of isotactic PP causes pronounced chain scission (degradation) at dosis ≤ 100 kGy. Melt viscosity can be controlled easily up to this dose for pure PP. For the blend, however, an anomalous rheological behaviour is observed.
Attempts have been made to induce a special morphology and to retain this morphology during subsequent shaping processes via fixation by radiation induced crosslinks.
Radiation crosslinking of the dispersed EPDM phase and a simultaneous grafting of PP onto EPDM is proposed to be the explanation for both the anomalous rheological and an enhanced morphology fixation. This idea is supported by gelfraction measurements.
KeywordsIsothermal Crystallization Chain Scission Electron Beam Irradiation Rubber Particle Isotactic Polypropylene
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- 1.Charlesby A., Atomic Radiation and Polymers, Pergamon Press, Oxford, 1960.Google Scholar
- 2.Makhblis F.A., Radiation Physics and Chemistry of Polymers, Keter Publishing House, Jerusalem, 1975, translated from Russian.Google Scholar
- 3.Black R.M. and Lyons B.J., Proc. Roy. Soc., London, A 253, 1959, 322–330.Google Scholar
- 5.Elemans, P.H.M., Van Gisbergen, J.G.M., Meijer, H.E.H., in the proceedings of the 3rd Rolduc Polymer Meeting, Elseviers Appl. Science Publishers, 1988.Google Scholar
- 6.C.R. Zeichner, P.D. Patel, “A Comprehensive Evaluation of Polypropylene Melt Rheology”, Report Hercules Inc., Wilmington, 1985.Google Scholar
- 7.M. Pahl, Praktische Rheologie der Kunststoff Schmelzen und Lösungen, VDI-Verlag, Düsseldorf, 1983.Google Scholar