Nonpolluting Composites Repair and Remanufacturing for Military Applications: Formulation of Electron-Beam-Curable Resins with Enhanced Toughening

Polymer-matrix composite material and structural adhesive repair and manufacturing have significant environmental costs. These costs were recently documented based on current and anticipated future Department of Defense (DOD) use of these materials. The principal issues for reducing the environmental impact and its associated cost are (1) reduction in hazardous waste by eliminating shelf-life limitations, (2) reduction in nitrogen oxides by replacing global heating of the part with localized heating, (3) reduction in volatile organic compound (VOC) emissions by accelerated curing and containment, and (4) reduction in hazardous waste by minimizing production debris through processing step management. The predicted reduction in hazardous waste, which affects both raw materials and waste-disposal costs, is 78% for composite materials and 95% for adhesives. Nitrogen oxides and VOC emissions can be reduced by 100% and 50% by replacing autoclave curing with radiation curing. Electron-beam (E-beam) curing has successfully been applied to E-beam-curable prepegs, adhesives, and vacuum-assisted resin transfer molding (VARTM) resins while maintaining process-specific viscosities and application-specific thermal performance. For the first time, there is credible evidence that E-beam-curable resin systems can be formulated to have sufficient toughness while maintaining other required process and performance criteria. In this work, both free radically and cationically cured E-beam resin systems have been formulated.Army Research Lab Aberdeen Proving Ground is the author of 'Nonpolluting Composites Repair and Remanufacturing for Military Applications: Formulation of Electron-Beam-Curable Resins with Enhanced Toughening' with ISBN 9781423535607 and ISBN 142353560X.