Rotational Moulding of Thermosets: Understanding of a Reactive Forming Process

L'auteur Abbas TCHARKHTCHI faisait parti en 2008 du Laboratoire d’Ingénierie des Matériaux (LIM). Depuis 2010, le LIM a fusionné avec deux autres unités de recherche en un seul laboratoire intitulé PIMM (Procédés et Ingénierie en Mécanique et Matériaux). Il fait parti du groupe de recherche : Procédés et Performance des Polymères et Composites.Physical and chemical transformations of polyurethane thermoset are studied by means of thermal analysis, infrared spectrophotometer and dynamic rheology. Gel point, which limits the material flow, is given as a function of conversion and as a function of time by kinetic law. Glass transition corresponding to a dramatic transformation of the material is also explored and connected to conversion and time. These ex situ characterizations are then exploited in terms of rotational moulding process parameters to improve the understanding and thus the control of the process. Therefore in situ thermal analyses are handled to confirm first results. Final parts thickness distribution is examined as a quantitative parameter of process quality. Finally, as a perspective, ultrasonic response is also studied as a new way to follow material evolution directly in the forming mould