Impact of the In Situ Creation of an Epoxy Based Thermosetting Minor Phase on the Physical Properties of a PP Based Blend

Abstract

As an alternative to inorganic fillers based composites which present high density, an epoxy based thermosetting (TS) phase was in situ created in a polypropylene (PP) matrix and compatibilized by a polypropylene grafted maleic anhydride (PP-g-MA).The aim of this study is to scrutinize the chemistry and establish a relation between the morphology, the mechanical properties and the crystalline structure of this thermosetting/thermoplastic system. Depending of the components concentration, dispersed phase of around 0.5 μm diameter (even with smaller nodules) are created with the presence of PP-g-MA. Moreover, an increase up to 24 % of the Young's modulus of the system is observed and the resilience is maintained. The evolution of the PP crystallinity by Wide Angle X-rays scattering (WAXS) evidenced that TS is a  nucleating agent at the origin of an excellent toughness and impact strength.

Innovative polypropylene based blends by in situ polymerization of a polyimide dispersed phase by reactive extrusion

“…Morphological analysis revealed that the dispersion of PES nodules was 10 times finer in the case of in situ polymerization. Similarly, Barroso Gago et al [17] prepared PP/PP--g--MA/thermoset blends with the in situ synthesis of an epoxy based thermosetting phase by reactive extrusion. Thanks to the in situ synthesis, they observed a very fine dispersion of the thermoset phase in polypropylene with nodules of 0.5µm in diameter.…”

“…The PA6 particle size was reduced from >2µm to <0.5µm in the presence of the compatibilizing agent PP--g--MA. More recently in our group, Barroso Gago et al [17] developed PP/PP--g--MA/thermoset blends with the in situ synthesis of the epoxy based thermoset phase in a twin--screw extruder at 200°C. The thermoset phase (TS) was well dispersed in the PP matrix, with TS domains around 0.5 µm in diameter.…”