Véronique Bounor-Legaré

Reactive processing of thermoplastic polymers: A review of the fundamental aspects

Abstract The review is devoted to the fundamental aspects of the reactive processing of thermoplastic polymers. First of all, some reactive processing examples, including polymer grafting (vinyl silane, maleic anhydride) and/or functionalization, bulk polymerization (urethane, lactams, acrylate, ∊-capolactone), polyester modification and new copolymers synthesis, are presented. From a fundamental point of view, the review covers the state of the art in the domains of rheology (specifically modelling of rheo-kinetics), diffusion and mixing in highly viscous reactive or non reactive media. Finally, 1, 2 and 3-D simulation of the reactive extrusion process in twin-screw extruder is reported at the end of the review.

Organic-Inorganic Hybrid Material Synthesis by on Line Coupling Twin Screw Extruder with a Microwave Oven

Abstract A new process for elaborating continuously organic-inorganic hybrid materials by reactive extrusion is presented. This synthesis consists in formulating a copolymer of ethylene and vinyl acetate (EVA)/tetrapropoxysilane (TPOS or Si(OC3H7)4)/catalyst blend by a corotating twin screw extruder followed by two successive reaction steps: on line microwave crosslinking reaction and hydrolysis-condensation reactions leading to a silica network cografted onto the organic matrix. Extrusion feed rate (Q), temperature, microwave oven power (P), and microwave curing time (tmw) were studied. Crosslinking density was evaluated before and after hydrolysis-condensation reactions and compared with the previous results obtained in static conditions. These materials tailored by an on line process present a permanent elasticity at high temperature (up to 200°C) and a certain optical transparency. This new approach offers the possibility to synthesize massive samples based on organic-inorganic hybrid material.