Weakly Acidic Cation Exchange Resins
Weakly acidic cation exchange resins are weakly acidic IERs that have carboxylic acid groups as ion-exchangable groups, as Figs 1 and 2. DIAION™ WK10, made from methacrylic acid, and DIAION™ WK40, made from acrylic acid, are in this grouping.
WK10 grades (methacrylic-type) are weak acid cation exchange resins having carboxylic acid functionalities. They have a pK value of approximately 6. WK10 has a high reaction rate, and WK11 has a high total exchange capacity. These grades are mainly used for special applications such as purification of pharmaceuticals, foods and organic chemicals. WT01S has a high reaction rate and high adsorption capacity. It is mainly used for the purification of pharmaceuticals and foods. WT01S is offered in 100-300 μm particle distribution.
WK40L is a weak acid cation exchange resin with carboxylic acid functionality based on porous acrylic polymer matrix. It has a pK value of approximately 5.3. The acrylic type WK40L resin has a higher total capacity than methacrylic type resins. It is mainly used for water treatment applications for removal of hardness ions in the presence of bicarbonate alkalinity.
| Grade Name | DIAIONTM WK10 | DIAIONTM WK11 | DIAIONTM WT01S | DIAIONTM WK40L |
|---|---|---|---|---|
| Chemical Structure |  |  | ||
| Whole Bead Count | 95 min. | |||
| Shipping Density (g/L: approx.) | 635 | 660 | 750 | 765 |
| Salt-spliting Capacity (meq/mL-R) | 2.5 min | 2.9 min | 3.0 min | 4.4 min |
| Water Content (％) | 53 – 59 | 45 – 52 | 45 – 55 | 41 – 48 |
| Particle Size Distribution on 1180 μm (％) through 300 μm (％) through 425 μm (％) | 5 max. 1 max. | 300 – 1060μm 85 % min. | 10 % max. – 3 % max. | |
| Effective Size (mm) | 0.40 min. | 0.10 – 0.14 | 0.45 min | |
| Uniformity Coefficient | 1.6 max. | |||
| Effective pH Range | 5 – 14 | 4 – 14 | ||
| Operating Temperature (℃) | 150 max. | 120 max. | ||