Abstract
dc:description.abstractThe effect of different levels of moisture on epoxide adhesive (BGEBA/DAB) joints has been investigated. On exposure up to 10 080 hours, using sandblasting treatment on aluminium prior to bonding, the joint strength had decreased far more rapidly at higher activities above 0.7 than at lower activities. The amount of moisture surrounding the joints play an important role in the durability of adhesive joints. To further elucidate the mechanism by which water degrades an adhesive joint, calculated data assuming Fickian diffusion through the resin to predict water distribution after certain exposure times was compared with the water distribution results obtained using the radio tracer technique. These results suggest that water may enter joints mainly through the resin as well as by wicking along the interface. Also the mode of failure using SEM was noticeably interfacial throughout the experiment. Once inside the joint, permanent damage may occur since, on redrying, joints exposed to moisture did not recover their strength. Stress analysis on compression test data showed no plasticisation. The significant level of water surrounding the joints above which their strength fails rapidly has been estimated to be around 0.7. There is therefore the possibility of a different rate of water attack and a different mechanism coming into play above 0.7 activity.
Degree
thesis:*- Name dc:type.qualificationname
- PhD
- Level dc:type.qualificationlevel
- Doctoral
- Grantor dc:publisher.institution
- De Montfort University
- Year dc:date.issued
- 1984
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Raval, Anita Kumari