Accession Number:

ADA213358

Title:

The Adhesive Bonding of Thermoplastic Composites

Descriptive Note:

Final rept. 23 Jul 1986-23 Sep 1989

Corporate Author:

IMPERIAL COLL OF SCIENCE TECHNOLOGY AND MEDICINE LONDON (UNITED KINGDOM) DEPT OF MECHANICAL ENGINEERING

Personal Author(s):

Report Date:

1989-09-19

Pagination or Media Count:

335.0

Abstract:

This thesis discusses the problems that occur when thermo plastic-based fibre-composite materials are bonded using structural engineering adhesives, such as epoxy and acrylic adhesives. A double-cantilever beam joint has been employed and it is shown that the value of the adhesive fracture energy, Gc, is very low when a simple abrasionsolvent-wipe surface pretreatment is used for the thermoplastic fibre-composites. This arises from crack growth occuring along the adhesivecomposite interface, which is relatively weak when such a pretreatment is employed. Secondly, the surfaces of the corona-discharge treated composites have been characterised using X-ray photoelectron spectroscopy, contact angle analysis and scanning electron microscopy. These studies revealed that the strong adhesion associated with corona pretreatment is via increasing the wettability and intrinsic adhesion of the thermoplastic fibre-composite materials. Thirdly, it is demonstrated how very effective a corona-discharge surface pretreatment may be for these materials. Indeed, when such a pretreatment is used, interfacial crack growth is no longer observed but the crack now propagates either cohesively in the adhesive or through the composite substate both failure modes lead to relatively high values of Gc, with the former resulting in the highest values of Gc being recorded. The thesis concludes by describing a study on designing efficient lap joints. AW

Subject Categories:

  • Adhesives, Seals and Binders
  • Laminates and Composite Materials

Distribution Statement:

APPROVED FOR PUBLIC RELEASE