NANOSCALE TOUGHENING FOR ADVANCED COMPOSITE MATRICES CURED BY ELECTRON BEAM ACTIVATION

摘要

The crosslinking polymerization of multifunctional monomers is known to yield rather brittle matrices, therefore limiting the development of this technique for the production of high performance composite materials. To improve composite damage tolerance, we are currently developing original acrylate-based formulations with interesting properties. Our toughened resins show optimized K_(Ic) values over 2 MPa.m~(0.5) while it is about 1 MPa.m~(0.5) for the unmodified resin. By studying the related toughening mechanisms, this improvement was found to be linked with the nanoscale features of the resins. High T_g values (over 160℃) are also reachable in conjunction with high toughness. Flexural properties are also satisfactory with corresponding moduli above 3 GPa. In addition, the low viscosity of some of these systems makes them very interesting for liquid based processes, such as Resin Transfer Molding (RTM) since the viscosity falls down to less than 1 Pa.s above 60℃, with still significant injection window. In order to demonstrate the feasibility of all the process sequence and to evaluate composite properties, a carbon-fiber reinforced plate showing superior damage tolerance was successfully manufactured using the RTM technique and X-ray initiated polymerization.