ACTIVE THINNERS COMBINED SYSTEMS FOR EPOXY RESINS

Анотація

The influence of inert solvents and active diluents on the curing processes of epoxy resin ED-20 at a temperature of 20-40 0C. Polyethylenepolyamine was used as a hardener. The initial rate and temperature coefficient of the curing reaction at the initial stages, up to 30% conversion, were determined. More than 40 inert solvents and active diluents have been investigated as modifiers. The use of 25% cyclohexanone reduces the temperature coefficient of the curing reaction from 2 to 1.3, and 12% hydroxypropyloxyran to 1.4. The maximum values of the temperature coefficient of the reaction can reach 4.6 when using esters and 5.7 when using aliphatic amines. Without the use of modifying additives, the reaction temperature coefficient is 2.0. The use of a combined system with an equal ratio of inert solvent and active diluent allows reducing the temperature coefficient of the reaction to 1.25 with 12% modifying additive. The speed was determined by a special method using composite dilatometers, centrifuges and catheters. It is shown that, at various times, in significant numbers, more than 10% of the main rosettes, as well as the internal solvents will need a folding, step-by-step mode of hardening for reaching the highest physical and mechanical characteristics. After completing the form at 20 °C for 24 hours, they carried out a lead at 80 °C for 5 hours, then we were waiting 3 days and then turned on at 125 °C for 2 hours. The proposed system allows the manufacture of a cylinder with a diameter of 60 mm and a height of 60 mm, which is necessary to obtain samples for physical and mechanical tests. The proposed modifiers reduce the initial viscosity of the system by more than 100 times, which is important when forming orthotropic polymer composite materials in a constant magnetic field, using highly dispersed ferromagnetic powders as a filler. The hardness and impact strength of the epoxy polymer when using the proposed modifier is 10-15% stronger than unmodified.