Near-Infrared Radiation Based Composite Repair Using Thermoplastics as Adhesives
Abstract
This research project concerns the adhesive films used for composite repair in the aircraft industry by the Navy and Air Force. The adhesive films currently used for composite repair are epoxy based thermoset materials, which after curing show, amongst other, remarkable properties in peel and shear strength. However, when expired, thermosets are still very environmentally harmful, and need to be disposed through a hazardous waste protocol, which can be a long and cost full procedure. Therefore this work investigates the capability of using thermoplastic materials as adhesive films for composite repair. The capability of using thermoplastics as adhesives for thermosets materials has been evaluated using a wide range of thermoplastics based on their adhesive strength. Amongst other, a Na(+)-based ionomer S1856 and an adhesion promoter Ethylene Metacrylic Acid (EMAA) have shown high peel resistance but poor shear strength due to the high elongation of these polymers. Therefore series of Polyamide 12 (PA12) alloys have been tested some of which were doped with Na+ ions for toughening, and other were alloyed with adhesion promoter EMAA. Another PA12 based epoxidized polymer was alloyed with Styrene Butadiene Copolymer (SBC). The results showed that a lower peel and shear resistance was achieved with a 30% EMAA promoter, while good resistance was seen with lower (15%) or no EMAA content. Little difference is seen between the 15% and the 0% EMAA PA12 alloys, for both the shear and the peel test. The influence of Na+ toughening could not be established; as the samples showed similar values in both cases. On the other hand, The PA12-epoxidized SBC showed high peel and shear strength; 0.648 kN/m for the peel strength, and 20.6 MPa for lap shear tests. Both values are higher than the thermosets baselines (AF563M from 3M, and FM300K from Cytec), and therefore the PA12-epoxidized SBC shows great potential for structural adhesives.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2007
- Accession Number
- ADA521069
Entities
People
- Masanori Kubota
- Shridhar Yarlagadda
Organizations
- University of Delaware