article

Abstract

A method was developed for the long-chain branching (LCB) of isotactic polypropylene (iPP) via modification in the solid state. PP long chains have been linked as branches to the original linear iPP chains using solid state reactions in the presence of a free radical initiator and a multifunctional monomer (co-agent). The modified samples of branched iPP were characterised by Gel Permeation Chromatography (GPC) and rheological measurements. Several methods were applied in order to estimate indirectly the extent of branching. A ranking was made of the co-agents according to their ability in inducing LCB as opposed to crosslinking and degradation of iPP. The furfuryl sulphide (FS) showed the highest efficiency for the branching reaction, while the Divinylbenzene(DVB) is not suitable for branching.

Keywords: isotactic polypropylene, long chain branching, peroxide modification, co-agents, melt strength, thermoforming

european Polymer journal, 44, 200-212, 2008

Long Chain Branching on Linear Polypropylene by Solid State Reaction