A process for producing controlled porous epoxy thermosets is presented. It is based on a two-step temperature cure: a polymerization-induced phase separation at a moderate temperature (100-120 °C) of a thermoplastic, poly(vinyl methyl ether) (PVME), in an epoxy-amine matrix followed by a high-temperature treatment (above 200 °C). A porous structure is created by the oxidative thermal degradation of PVME (extraction). Different porous or semiporous structures with submicrometer-sized voids (dispersed closed cells, i.e., spheres or open cells, i.e., bicontinuous percolating canals) are generated depending on the thermoplastic content and the phase-separation mechanism. The morphologies are analyzed quantitatively from transmission electron microscopy (TEM) photographs.

No abstract

No abstract

Vacuum assisted resin infusion (VARI) processes are widely used for the fabrication of large composite parts. For some years now, wind blades are designed with thermoset composite materials, however, recyclability is often the missing brick. The recent advent of thermoplastic materials such as ELIUM©, developed by ARKEMA, shows the possibility to consider the manufacture of very large parts such as wind turbine blades with recyclable constituents [1]. The French institute IRT Jules Verne is leading the research project ZEBRA, with a consortium of industrials, focusing on different thematics of the manufacturing of wind turbine blades, including process monitoring. In the objective of evaluating the possibility for anomaly detection during the ELIUM© infusion process, an infusion test bench was developed, equipped with different sensors including infrared camera, thermocouples and heat flow sensors. In this work, the thermal sensors are evaluated by the study of several infusion scenarios of plates fabricated under different process conditions and material parameters. Artificial anomalies are imposed into the process to evaluate the potential of these sensors to detect the induced disturbances. A numerical process modelling is developed, compared to the sensor outputs and used to achieve a better understanding of some effects observed during the process.