The IERs with primary, secondary and tertiary amine groups as active functional groups show weak basicity, so they are called weakly basic anion exchange resins (WBAERs). There are several types of WBAERs: one with only one kind of amine groups and the other with more than two kinds of amine groups, as shown in Fig5 DIAION™ WA10 (acrylic acid type with tertiary amine groups), WA20, WA21J (mixtures of primary and secondary amine groups), and WA30 (tertiary amine groups), are our product names in this category.
<Fig.5> Chemical structure of the tertiary amine type weakly basic anion exchange resin
WA10 resin is based on a gel-type polymer matrix. It has tertiary amine functionality with high regeneration efficiency. The acrylic polymer matrix provides good chemical stability and good resistance to organic fouling. WA10 is mainly used for pretreatment of starch hydrolysates (such as corn syrup) containing purification of dextrose, beet sugar solutions, and formaldehyde.
WA20 and WA21J do not have any neutral salt splitting capacity. They have high total exchange capacity and high regeneration efficiency. The porous styrene polymer imports high chemical stability, high mechanical strength against attrition loss, high thermal stability and high durability against organic fouling.
These resins are used for the removal of strong mineral acids in standard water treatment applications. They can also be applied in special process separations such as the treatment of organic solvents.
It should be noted that WA21J has a highly porous structure and provides excellent mechanical strength for more rigorous industrial applications.
WA30 resin is a weak base anion exchange resin based on high porous, styrene/ DVB polymer matrix. WA30 has tertiary amine functionality with high regeneration efficiency. The high porous styrenic matrix imparts excellent chemical stability, excellent mechanical and osmotic strength (to minimize attrition), high thermal stability and excellent durability against organic fouling. The high porous matrix of WA30 provides a high reaction rate.
WA30 is the benchmark that all macroporous weak base anion exchange resins are compared with. WA30 is used for a wide variety of applications, such as removal of organic substances of high molecular weight, pretreatment of raw waters containing organic foulants, deionization, and decolorization of starch hydrolysates (such as corn syrup, dextrose, HFC’s and sugar solutions) and purification of glycerine and enzymes.