A few days ago, the issue of epoxy modifier was specifically answered. HELOXY epoxy active modification contains one or more epoxy groups, which participate in the reaction of epoxy resin and curing agent, which are used to reduce the viscosity of epoxy resin to improve maneuverability and applicability, improve the mechanical properties of cured products, and Focus and flexibility. Diluents can be divided into active and inactive diluents. Common solvents are called inactive diluents. They do not react with epoxy resins and curing agents. They are purely physical infiltration and volatilize with the curing reaction. The cured product leaves pores and increases the shrinkage rate, which will affect the performance of the cured product in severe cases, so it cannot be used for thicker coatings. Although there are also high-boiling liquids, plasticizers such as dibutyl phthalate, trimethyl phosphate, etc., there is a tendency for migration and exudation, especially after being immersed in liquids and solvents. Obviously, and greater surface tension will seriously affect the leveling and surface quality of the material. Regarding the classification of HELOXY epoxy modifiers, experts said that epoxy reactive diluents are divided into monoepoxides and polyepoxides. According to their types, they are divided into aliphatic and aromatic types. In theory, monocyclic Oxides will lower the thermal deformation temperature, while polyepoxides have less effect. The aliphatic type has better dilution effect than the aromatic type, while the aromatic type has better acid and alkali resistance.
The name of HELOXY epoxy modifier is usually based on its chemical formula. For example, H61 is often called BGE because its chemical name is N-butyl glycidyl ether. H63 is often called PGE because its chemical name is phenyl glycidyl ether. This naming method is very necessary to distinguish products of the same type from different manufacturers. The main differences between products of the same type from different manufacturers are: product purity and free Epichlorohydrin content, residual alcohol content, and intermediate product content, these different substances have a very significant impact on product performance. Usually we only need one kind of epoxy modifier in coating application, so how to effectively choose a suitable modifier according to the needs is very necessary. We list 16 kinds of HELOXY epoxy modifier and epoxy resin EPON 828 In the same addition ratio (HELXY: 828=20: 80) and TETA (triethylene tetramine) curing performance, including viscosity, mechanical properties, acid and alkali resistance, thermal deformation temperature and other 11 items. Generally speaking, the diluting ability of single epoxy epoxy active modifier is greater than that of multi-epoxy active modifier, and multi-epoxy active diluent has better performance in maintaining epoxy products. It can be seen through the chart: H61, H7, H8 This kind of aliphatic mono-epoxy reactive diluent has particularly outstanding viscosity reducing ability.
Compared with the unmodified system, HELOXY epoxy modifier usually prolongs the gel time of the mixture. Usually aliphatic epoxy modifiers have low reactivity. For example, H8 can significantly increase the gel time of the mixture, while the aromatic The family has little effect on the gelation time. In addition to the chemical type, the molecular weight also affects the reactivity. The low molecular weight epoxy modifier has a higher reactivity. Regarding the thermodynamic properties of HELOXY epoxy modifier, the expert first introduced the thermal deformation temperature (HDT)-the critical temperature at which an object begins to deform when heated is an important indicator to measure the epoxy cured product. The crosslinking density of the agent is high, so the thermodynamic performance loss is less than that of the mono-epoxy modifier, and the aromatic modifier has a better rigid structure, so the thermodynamic performance loss is less than that of the aliphatic modifier. The effect of HELOXY epoxy modifier on mechanical properties is the same as that of thermodynamic properties: multi-epoxy modifiers have high crosslinking density, so they have better mechanical properties than mono-epoxy modifiers, and aromatic modifiers have better mechanical properties. Therefore, the rigid structure has better mechanical properties than aliphatic modifiers. Long molecular chain modifiers such as H8 have good toughening ability, which has a good effect on improving the rigidity and low toughness of epoxy products. The effect of HELOXY epoxy modifiers on chemical properties is the same as that of thermodynamic mechanical properties. Of course, some studies have pointed out that water resistance also depends on the content of hydrocarbon groups and molecular polarity, and acid and alkali resistance is mainly related to the quality of the curing agent. related.