THE EFFECT OF PEEK FIBERS AND POWDER ON JOINTS MADE WITH A HIGH-TEMPERATURE ADHESIVE

High temperature adhesives typically exhibit low levels of peel streng th since they tend to be more brittle than typical toughened adhesives used for lower temperature applications. It was found that incorporat ing thermoplastic fibres or powder into the bondline of a joint made w ith a high temperature epoxy-based adhesive resulted in significant im provements in peel strength. Poly(ether ether ketone) (PEEK) fibres an d powder were incorporated into the adhesive resin and used in alumini um joints. These were tested in peel and single lap shear using a rang e of fibre lengths, orientations and volume fractions. It was seen tha t large increases in peel strength could be achieved but that lap shea r strength was degraded with most types of modification. However, some modifications resulted in significant increases in peel strength with limited decrease in lap shear strength. These improved properties hav e been achieved using physical modifications rather than chemical alte ration of the resin.