Is ion exchange resin a "resin"? What are its main properties

Resin was originally a general term for gel like substances secreted by crown trees, similar to pine resin secreted by pine trees. Later, people called some substances similar to resins as "resins", such as epoxy resin, phenolic resin, ion exchange resin, etc. Ion exchange resin is an artificially synthesized polymer compound, whose performance depends on manufacturing process, raw material formula, polymerization temperature, crosslinking agent, functional groups. The main performance can be described both physical chemical aspects: ammonium salt

1、 Physical performance

1) Appearance. Resin is a transparent semi transparent substance, but with different varieties colors. Generally, with more impurities crosslinking agents in the raw material, the color of the resin is slightly darker. During the operation of the resin, the color may sometimes change due to various reasons. The resin has a spherical shape requires a sphericity of over 90%.

2) Particle size. The size of resin particles will affect exchange rate, pressure loss, backwashing effect, etc. The particle size of ion exchange resin used for water treatment should be 20-40 mesh. The particle size should differ too much. The particle size is represented by the effective particle size non-uniformity coefficient.

3) Density. It is related to the water treatment process resin filling volume. The methods for expressing density include: kilotrue density (usually around 1.6g/cm3), wet true density (usually between 1.04-1.30), wet apparent density (usually between 0.60-0.80).

4) Moisture content. The higher the moisture content of the resin, the greater the porosity the lower the crosslinking degree.

5) Swelling rate. Resin undergoes swelling when placed in water, which is related to crosslinking degree, active group exchange capacity, electrolyte density in water, the properties of exchangeable ions. During the exchange regeneration process, resin undergoes swelling contraction, repeated swelling contraction can make the resin prone to brittle cracking.

6) Wear resistance. Reflecting the mechanical strength of the resin, ammonium salt should ensure that the annual loss due to mechanical wear does exceed 7%.

7) Solubility. When the resin contains oligomers, it will dissolve during use affect the water quality.

8) Heat resistance. Generally, cation resins can withstand temperatures of around 100 ℃, strong alkaline anion resins can withstand temperatures of 60 ℃, weak anion resins can withstand temperatures of 80 ℃. When it is below 0 ℃, it will break due to freezing.

9) Conductivity: Dry resin does conduct electricity, while wet resin can conduct electricity.

2、 Chemical properties

1) The exchange reaction of ion exchange resin is reversible, so it can be exchanged, regenerated, reused.

2) It has acidity alkalinity. The performance of H positive OH negative ion exchange resins is the same as that of electrolyte acids bases, they can ionize H positive OH negative in water.

3) It has neutralization hydrolysis properties. Due to its electrolyte properties, it can undergo neutralization reactions with acids bases, as well as hydrolysis.

4) Ion exchange resins have different abilities to absorb various ions exhibit selectivity.

5) Exchange capacity. The amount of ion exchange it can exchange is often used in design operation management. It can be represented by full exchange capacity, working exchange capacity, balanced exchange capacity, etc. The unit is millimoles per liter millimoles per gram, etc.