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Licensed Unlicensed Requires Authentication Published by De Gruyter July 21, 2016

Coagent Modified Polypropylene Prepared by Reactive Extrusion: A New Look into the Structure-Property Relations of Injection Molded Parts

  • P. Tiwary , H. Gui , P. L. Ferreira and M. Kontopoulou


Peroxide-mediated reactive extrusion of linear isotactic polypropylene (L-PP) was conducted in the presence of trimethylolpropane trimethacrylate (TMPTMA) and triallyl trimesate (TAM) coagents, using a twin screw extruder. The resulting coagent-modified polypropylenes (CM-PP) had higher viscosities and elasticities, as well as increased crystallization temperature compared to PP reacted only with peroxide (DCP-PP). Additionally, deviations from terminal flow, and strain hardening were observed in PP modified with TAM, signifying the presence of long chain branching (LCB). The CM-PP formulations retained the modulus and tensile strength of the parent L-PP, in spite of their lower molar mass and viscosities, whereas their elongation at break and the impact strength were better. This was attributed to the finer spherulitic structure of these materials, and to the disappearance of the skin-core layer in the injection molded specimens.

*Correspondence address, Mail address: Marianna Kontopoulou, Department of Chemical Engineering, Queen's University, Kingston, Ontario K7L 3N6, Canada. E-mail:


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Received: 2015-11-16
Accepted: 2016-04-16
Published Online: 2016-07-21
Published in Print: 2016-08-12

© 2016, Carl Hanser Verlag, Munich

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