Properties of epoxy-thiokol materials based on the products of the preliminary reaction of thioetherification

Abstract

In order to improve the adhesive and physical-mechanical properties of epoxy-thiocol compositions cured without heat treatment, we propose to carry out the reaction of interaction between thiokol mercaptan groups and oxirane cycles of epoxy resin at an elevated temperature before introducing a curing agent, and then use the product of this thioetherification reaction for curing at room temperature. The temperature range of the thioetherification reaction (90–1800С) was determined by the method of differential scanning calorimetry. The optimal temperature (1600С) and duration of the preliminary thioetherification reaction (2 hours) were determined, which ensure the maximum level of adhesive strength and physical-mechanical properties. It was shown that composite materials based on the products of the thioetherification reaction significantly outperform analogs based on mechanical mixtures of epoxy resin and thiokol in terms of cohesive and adhesive strength, deformation capacity, fracture work and specific impact strength. The impact resistance and shear strength of adhesive joints are especially significantly increased during the curing of the compositions without external heat supply.

Dynamic Mechanical Properties of Epoxy Composites Modified with Polysulphide Rubber

“…3c), their change depending on the concentration of rubber is in many respects similar to the static modulus of elasticity. 12 Formation of low intensity maxima on the dependences E′ 298 vs. C at a thiokol content of ~ 10 pts. wt.…”

“…It was previously shown [10][11][12][13][14][15][16] that in order to increase the adhesive and physicomechanical properties of epoxy-thiokol compositions cured without heat treatment, it is necessary to carry out a preliminary thioetherification reaction (PRTE) prior to the introduction of the curing agent due to the interaction of thiokol mercaptan groups and oxirane cycles of epoxy resin at elevated temperature, and then use the product of this reaction to cure at room temperature. Composite materials based on the products of the thioetherification reaction are revealed to significantly surpass analogs based on mechanical mixtures of epoxy resin and thiokol in terms of cohesive and adhesive strength, deformation capacity, fracture work, and specific impact number.…”

Вплив Поліоксипропілентріаміну Та Вмісту Оксиранових Циклів На Властивості Епоксидно-Полісульфідних Композитів

“…Previously, it has been shown [22] that in order to improve the adhesion and physicomechanical properties of compositions based on epoxy resin and polysulfide rubber cured without heat treatment, it is necessary to carry out a preliminary thioetherification reaction (PRTE) due to the interaction of mercaptan groups of rubber and oxirane cycles of epoxy resin at elevated temperature, and then use the product of this reaction to cure at room temperature. The composite materials based on thioetherification reaction products are shown to be significantly superior to analogs based on mechanical mixtures of epoxy resin and thiokol in terms of cohesive and adhesive strength, deformation capacity, fracture work, and specific impact strength.…”