Influence of silane solution pH on the rubber-metal bonding

Mohd Ali Piah, Hidayah (2021) Influence of silane solution pH on the rubber-metal bonding. Project Report. Universiti Teknikal Malaysia Melaka, Melaka, Malaysia. (Submitted)

	Text (24 Pages) Influence of silane solution pH on the rubber-metal bonding.pdf - Submitted Version Download (561kB)
	Text (Full Text) Influence of silane solution pH on the rubber-metal bonding.pdf - Submitted Version Restricted to Repository staff only Download (2MB)

Abstract

Silane coupling agents is a new approach of rubber-metal bonding due to the disadvantages of existing adhesive system, and its efficiency depends on the bonding conditions. Researchers found that mixed silanes promote adhesion of rubber-metal bonding, but the efficiency rubber-metal bonding depends on the chemical properties of silane solutions and pH condition of silanes. The aim of this study are to study the chemical properties of individual and mixed silane solutions and the effect of silane solutions pH on bond strength of rubber-metal assembly. The pH value of the mixed silane solutions was adjusted to pH 4-5 and 7-8 at fixed composition of 1:3 to amino:sulfur in order to study the effect of pH value of mixed silane solution on bond strength of the rubber-metal assembly. FTIR analysis was conducted to characterize the chemical properties the silane solutions and was found that all bis-amine, bis-sulfur and mixed silanes showed Si-O-Si peak located in the range of 1000-1100 cm-1 in the spectra, indicating that siloxane bond was present in the solutions. Once the rubber was successfully bonded with aluminium under compression moulding, peel test was performed under ASTM D429 B to examine the adhesion bond between natural rubber and aluminium while the optical microscope was used to identify the failure mode of the bonding. However, this process could not be conducted and analysis through critical review based on previous research was done due to the pandemic constraint. It is expected that an optimum adhesion strength would be achieved at low pH with cohesive failure mode due to fast hydrolysis but slow condensation reactions that producing a dense and three-dimensional molecular network while under neutral and high pH condition, the assembly would fail with adhesive failure mode. This is rendered to the premature gelation formed in the silane solution which reduces the number of water-resistant bonds. Therefore, application pH of silane solution is recommended between pH 4-5 in order to obtain optimum adhesion for rubber-metal bonding.

Actions (login required)

View Item