The goal of this SBIR project is to develop and demonstrate feasibility of a resistant, non-reflective carbon nanotube (CNT) composite resin that can be directly applied with minimal training as an RAM protective and absorptive layer. Carbon nanomaterial additives will be utilized to increase the radar absorptive and mechanical properties of the overall polymer matrix. Multiple commercially available acrylic polyurethane products will be impregnated with CNTs and deposited onto a generalized ceramic substrate. This class of resin was chosen because of the constituent polymers seawater-resistant, UV-resistant, and mechanical properties. Acrylic elements will serve chemically resistive, adhesive, and UV-resistance while urethane elements will incorporate further seawater resistance as well as tensile strength. Both paint-on and spray-on applications will be explored. Functional groups characteristic to the monomers of each component will encourage hydrogen bonding surface interactions between the RAM substrate and the protective layer to combat the observed peeling phenomena of current protective layers. Deposited polymer formulations will be partially characterized to determine a best base resin. Once a prime candidate is chosen and its associated percolation threshold is found, samples of impregnated polymer will be mixed and deposited onto a generalized ceramic substrate serving as a substitute for RAM material. Rigorous testing on these samples will be performed by Keystone Compliance. Samples of ceramic-deposited polymer as well as liquid pre-polymer will serve as deliverables.
Benefit: We chose to solve the current problem of RAM protective layer peeling by selecting an acrylic-based copolymer coating impregnated with CNTs. The acrylic nature of the polymer lends itself to excellent adhesive properties and peel resistance. Hydrolyzed urethane elements of the polymer will also create a friction resistant surface to mitigate external force that may also cause peeling. We chose to solve the current problem of intensive training requirements for depot level application and repair of the RAM protective layer by choosing a sprayable or paintable polymer formulation. The two-part polymer can be mixed with its associated curing agent and immediately deposited via brush or sprayer, involving minimal training and introducing the possibility of touch-up repair. This could be done without docking the ship. Solving both problems while maintaining the resistive and radar-absorbing properties of current protective layers will assist the Navy in their goal of RAM protection on the DDG 1000 Zumwalt-class destroyer. A product like this may be extended to many other classes of ships where protection of radar-absorbing materials is a consideration.
Keywords: Carbon-Fiber Reinforced Polymer, Carbon-Fiber Reinforced Polymer, Field-level Maintenance, Peel Resistance, Seawater Resistance, Radar Absorption, Acrylic, polyurethane, Protective layer
