Page 150 - Handbook of Adhesion Promoters

8.4 Epoxy resin 143

8.4 EPOXY RESIN

Many commercial additives are proposed for the use in epoxy resins, such as multiple
grades of Chartwell (~40 grades), Chartsil (7 grades), Dow Corning (10 grades), Xiame-
ter, Geniosil, Dynasylan, Silquest, Ancamide, and lignin. There are too many products to
be listed by their names here but a full account of these additives can be found in Data-
book of Adhesion Promoters which also contains additional information on the use of
these additives.
Polyimide surface was modified by amine treatment to increase adhesion to epoxy
1
resin. Poly(amic amide) was formed by the reaction of a primary amine of diamines and
1
imide group of PI. The adhesion was improved by reinforcing the weak PI surface layer. 1
It is also possible that the chemical reaction of epoxide of the epoxy resin and unreacted
1
amine of poly(amic amide) improves adhesion. An optimum drying temperature has to be
1
selected for maximum adhesion strength after amine-treatment of PI surface.
The adhesion of aramid fiber to an epoxy matrix can be improved by a pretreatment
2
with an epoxy/hardener solution. The epoxy layer introduced onto the surface of fiber
2
improves adhesion. Polar interactions between the aramid fiber and epoxy molecules play
2
a dominant role in the interfacial adhesion mechanism.
Dimethylnorbornene ester copolymerized with dicyclopentadiene to yield a copoly-
mer plays a role of the adhesion promoter to an epoxy matrix (see the mechanism of adhe-
3
sion promotion in Figure 2.38).
Subcritical debonding (hot/wet adhesion) is of particular concern for microelectronic
4
packaging, coating, and adhesive applications. The effect of 3-aminopropyltriethoxysi-
lane and glycidoxypropyltrimethoxysilane, in subcritical debonding of epoxy/glass inter-
4
faces under hygrothermal conditions, was investigated. The hygrothermal aging lowers
the critical debonding driving energy required for debond extension and the threshold
4
strain energy release rate below which interfacial crack growth does not occur. The appli-
cation of silane adhesion promoters on glass surfaces increased the threshold strain energy
4
release rate values and decreased debonding growth rate.
The nanopolyaniline particles were used in epoxy paint formulation to impart a
5
smart corrosion resistivity of carbon steel. They work as an adhesion promoter and corro-
5
sion inhibitor.
Core-shell rubber, CaCO , and SiO particles were used as nanoparticles in polyure-
2
3
6
thane- and polyamide-modified epoxies which formed a flexible epoxy matrix. The nano-
sized inorganic particles have improved the impact-peel strengths of the epoxy systems

Figure 8.3. The deposition of epoxy resin on copper modified by amine-terminated thiol and dithiol self-assem-
bly. [Adapted, by permission, from Denayer, J; Delhalle, J; Mekhalif, Z, Appl. Surf. Sci., 257, 24, 10686-91,
2011.]