Interfacial chemistry of adhesives on hydrated aluminium and hydrated aluminium treated with an organosilane

Abstract

The adsorption of a commercial adhesive and two of its major components -an amine curing agent [2,4-toluene diisocyanate urone (TDI urone)] and an adhesive prepolymer resin [diglycidyl ether of bisphenol A (DGEBA)] -on a hydrated aluminium surface and the hydrated surface coated with gglycidoxypropyltrimethoxysilane (GPS) has been investigated by x-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The study of TDI urone adsorption indicated that adsorption was of the chemisorption type, and a specific interaction involving this molecule and the GPS immobilized on the hydrated aluminium surface was identified. From XPS and ToF-SIMS data it was found that the types of interaction of the curing agent with the bare substrate were of the donor-acceptor type.Study of the DGEBA adsorption showed different-shaped isotherms for the bare and the GPS-coated substrates. It was found that the typical Langmuir isotherm type was obtained for the GPS-coated substrate whereas no adsorption plateau was observed for the bare substrate within the concentration range studied. This resulted from a change in the conformation of the DGEBA molecule on the substrate when the concentration of DGEBA solution was increased. The bonding of DGEBA with both types of substrates was assumed to be via acid-base interactions (i.e. donor-acceptor interactions).Adsorption of the commercial adhesive on the hydrated surfaces was of BET Type IV form, rather than the simple monolayer adsorption isotherm (Langmuir type). This indicates multilayer adsorption, presumably in the pores of the hydrated substrate, as a result of a process analogous to adsorption condensation.

The effect of silane incorporation on a metal adhesive interface: A study by electron energy loss spectroscopy

“…from the already existing oxide towards the adhesive deposited. Hence, the extra oxide thickness may result in the formation of a composite layer, with a mix aluminium-oxide and organic material present at the interface (Kinloch et al, 2000;Watts et al, 2004).…”

The characterisation of the interfacial chemistry of adhesion of rigid polyurethane foam to aluminium

“…The ToF-SIMS intensities for particular fragment ions under consideration are evaluated using the concept of relative peak intensity (RPI), which is the ratio of the intensity of the ion of interest relative to the total ion intensity from m/z = 1 to 850 u 13 :…”

Interfacial reactions in an interpenetrating polymer network thin film on an aluminum substrate

“…[1,2] However, the weak linkage between the metal and the polymer affects the composites' stability and therefore restricts their long-term applications. [3,4] Thus, reinforcing the interfacial adhesion between metal and polymer is of scientific and technical importance. [5] The interpenetrating polymer network (IPN) is capable of providing such excellent interfacial interpenetration and forced miscibility that it is highly efficient to transfer or connect with other heterogeneous materials within its temperature transitional ranges (Tgs).…”