The Role of Chemical Bonding in Adhesion.
Abstract
Strong positive effects have been found when a polybutadiene layer is adhered to a glass substrate by means of interfacial chemical bonds. The bond fracture energy increased by a factor of over 20 when a reactive polysiloxane coating was applied to the glass in comparison with a similar, but nonreactive, polysiloxane coating and the chemically-bonded layer failed cohesively instead of interfacially. Swelling stresses were found to discriminate between strongly bonded systems of this type. After a swelling period in pentane ranging from 10 minutes to over 72 hours, depending upon the proportion of chemical bonding introduced, the layer detached spontaneously. This suggests a possible test method for distinguishing between bonded systems which would normally all fail by cohesive rupture. Treatment of glass substrates with a monofunctional polybutadiene containing a dimethylmethoxysilane endgroup led to no significant improvement in adhesion. SEM Studies showed that less than 5 percent of the surface was covered by the monofunctional material. Thus it appears that the number of reactive sites per molecule is an important factor governing elastomer adhesion. An unexpectedly-high level of adhesion was observed between simple hydrocarbon elastomers and certain polymeric substrates: 2,6-dimethyl-1,4-polyphenylene oxide, polysulfone, and polycarbonate.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 21, 1977
- Accession Number
- ADA047091
Entities
People
- Alan Neville Gent
- M. L. Runge
- Patricia Dreyfuss
Organizations
- University of Akron