The Influence of Mixing Methods of Epoxy Composition Ingredients on Selected Mechanical Properties of Modified Epoxy Construction Materials.

Izabela Miturska,Miroslav Müller,Anna Rudawska,Monika Hromasová

doi:10.3390/ma14020411

Izabela Miturska, Miroslav Müller + Show 2 more

Open Access

https://doi.org/10.3390/ma14020411

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Abstract

The proper process of preparing an adhesive composition has a significant impact on the degree of dispersion of the composition ingredients in the matrix, as well as on the degree of aeration of the resulting composition, which in turn directly affects the strength and functional properties of the obtained adhesive compositions. The paper presents the results of tensile strength tests and SEM microphotographs of the adhesive composition of Epidian 57 epoxy resin with Z-1 curing agent, which was modified using three fillers NanoBent ZR2 montmorillonite, CaCO3 calcium carbonate and CWZ-22 active carbon. For comparison purposes, samples made of unmodified composition were also tested. The compositions were prepared with the use of six mixing methods, with variable parameters such as type of mixer arm, deaeration and epoxy resin temperature. Then, three mixing speeds were applied: 460, 1170 and 2500 rpm. The analyses of the obtained results showed that the most effective tensile results were obtained in the case of mixing with the use of a dispersing disc mixer with preliminary heating of the epoxy resin to 50 °C and deaeration of the composition during mixing. The highest tensile strength of adhesive compositions was obtained at the highest mixing speed; however, the best repeatability of the results was observed at 1170 rpm mixing speed. Based on a comparison test of average values, it was observed that, in case of modified compositions, the values of average tensile strength obtained at mixing speeds at 1170 and 2500 rpm do not differ significantly with the assumed level of significance α = 0.05.

Highlights

The strength of structural adhesive joints depends on many technological and constructional factors
The most important factors, the optimization of which may significantly increase the strength of structural adhesive joints, include the method of preparing the surfaces of the bonded elements, the type of adhesive used and the method of its preparation, the manufacturing technology considering the geometry of the joint, the method of loading and the conditions of curing the adhesive joint [1,2]
The correct process of preparation of the adhesive composition has a significant impact on the degree of dispersion of the composition ingredients in the matrix, as well as on the degree of aeration of the created composition

Summary

Introduction

The strength of structural adhesive joints depends on many technological and constructional factors. It should be emphasized that the mixing process depends on many factors, including the type and properties of the components (including viscosity, chemical composition), the amount of the mixture prepared (which is of great importance due to the exothermic reaction) and the order of adding the ingredients. The mixing method and the technological parameters of this process are very important, as it determines, e.g., the correct mixing of the components (no agglomerates in the adhesive composition, no sedimentation of the components, no gas bubbles, etc.). For this reason, it is very important to develop a technology for mixing the components of adhesive compositions

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