Bonding Mechanisms at Buried Interfaces between Carboxylic Polymers and Treated Zinc Surfaces

Abstract

The interfacial bonding properties of carboxylic polymers on a Zn substrate have been investigated. Poly(methyl vinyl ether-alt-maleic acid monobutyl ester) and cured propoxylated bisphenol A fumarate unsaturated polyester were applied on a set of differently treated Zn samples. The buried metal–polymer interface was studied by polymer removal and evaluation of the residue layers on Zn surfaces representing the metal–polymer interface region. Additionally, the interfacial bondings were mimicked by adsorption of the representative carboxylic monomers, i.e., succinic and myristic acids. The differently treated Zn surfaces were found to be capable of adsorption of the carboxyl functionality of the polymers, resulting in formation of carboxylates. A comparison of the interfacial bondings by the residue layers of the polymers with those formed due to the molecular adsorption showed comparable adsorption mechanisms. Additionally, it was found that the polymer–metal interfacial bonding density mainly depends on the Zn surface hydroxyl fraction, while Zn oxide semiconductor properties play an important role when a curing process occurs during the polymer interaction with Zn surfaces.

The influence of a Zr-based conversion treatment on interfacial bonding strength and stability of epoxy coated carbon steel

“…The buried metal/polymer interface can be reached with an IR beam passing through the thin deposited metal layer. IR peak intensities are recorded in-situ with time of exposure and can be correlated to chemical changes at the metal/polymer interface [36][37][38][39]. The IR beam penetration at the metal/polymer interface can be controlled by some analysis parameters e.g.…”

Studying interfacial bonding at buried polymer–zinc interfaces

“…The changes in the adsorbate densities versus the pretreatments and applied external potential proved the importance of the surface chemistry and semiconductor properties in the interfaces [25,28,44,48]. Additionally, the presence of identical active end groups on the polymer system and molecular model compounds provided the possibility to compare the interfacial bonding mechanisms.…”

“…In this case, the polymer is removed from the metal surface by various processes, such as water intrusion, electrochemical process, pulling-off, and thermal cycle [53]. For the polymers used in this study, a pull off method is utilized to mechanically remove the bulk polymer, while the thin residue film on metal surface was carefully chosen to avoid any bulk polymer for spectroscopic analyses [48]. Fig.…”

“…In this case, a higher level of flatband potential (E FB ) increased the electrons supplied by the metal oxide Fermi level for the metal and polymer interactions [48]. This in turn amplified the bonding strength and interfacial bonding density.…”

“…Moreover, during the adsorption procedure, the accompanying curing process released the expected stress within the polymer structure compared to the polymeric system with a large initial molecular weight [48,55].…”