Research On Rheological Properties Of Room-Temperature Curing Epoxy Adhesive

Epoxy adhesive is widely used in many fields, such as sophisticated national defense technology, civil construction, automobile, etc. But in these areas the epoxy adhesives are often used in high temperature environment, meanwhile under conditions of large area construction with the restrictions of the application conditions and their environments, it is almost impossible to heat-cure epoxy adhesive, and it has to cure in the outdoor and even in the cold conditions. So it has important theoretical and practical significance for the research and development of the epoxy adhesives which cured in the room-temperature but has high heat resistance and excellent rheological mechanical properties under the high temperature environment for a long term.Room-temperature curing epoxy adhesive is a typical viscoelastic material. To study their rheological mechanical properties, the viscoelasticity which contain the static viscoelasticity and the dynamic viscoelasticity should usually be considered. There are many factors that influence its properties of the static and dynamic viscoelasticity, such as temperature, stress, frequency, strain and physical aging.In this paper, two kinds of the epoxy adhesives curing systems which were designed, made up synthesized by ourselves, are taken as the research objects, and the machine named EPLEXOR500N Dynamic and Static Thermodynamics Instrument made by GABO Company in Germany is used. In addition, the results of these tested two different epoxy adhesives are also compared and analyzed. The main works are as follows:①In the condition of different frequencies, the temperature scanning was used to acquire the temperature pictures of the two materials;②In the condition of different temperatures, the frequency scanning was used to acquire the frequency pictures of them;③In the condition of different temperature levels (20℃,30℃,40℃), creep tests was done in the short time and the suitable rheological model is used to describe the materials creep law.The main results of the works are as follows:①Tests show that their glass transition temperatures and cross-linkages were increased as the dosage of curing agent increased.②The creep curves of two kinds of samples under different temperature levels (20℃,30℃,40℃) were broadly similar in shape, the relaxation time was extended and the creep resistance was improved.(3) Creep curves of two kinds of samples were fitted under different temperatures according to several kinds of creep theories, compared and analyzed with the creep experimental curves, some of valuable results had been gotten. The results of the research have provided an important experimental basis for the new type of epoxy adhesive, trial-production and laid certain of theoretical foundation. To a certain extent it has also shown the wide application prospects.