Ion exchange resin types

Strongly Acidic Cation Exchange Resins (SAC) Functional groups —SO3– H+ Sulphonic acid What they do In sodium form, they remove hardness (essentially calcium and magnesium) from water and other solutions In hydrogen form, they remove all cations They are also used as acidic catalysts Examples (uniform) AmberliteTM HPR1200 Na (uniform) LewatitTM Monoplus S100 (conventional) AmberliteTM IR120 Na (conventional) LewatitTM S100 Typical total capacity 1.9 to 2.2 eq/L [Na+]

Weakly Acidic Cation Exchange Resins (WAC) Functional groups —COOH Carboxylic acid What they do In hydrogen form, they remove preferentially divalent ions (e.g. calcium and magnesium) from solutions containing alkalinity Examples (uniform) AmberliteTM HPR8300 H (conventional) AmberliteTM IRC83 H (conventional) LewatitTM CNP80 Typical total capacity 3.7 to 4.8 eq/L [H+]

Strongly Basic Anion Exchange Resins (SBA) Functional groups —N(CH3)3+ OH– Quaternary ammonium What they do In hydroxyl form, they remove all anions In chloride form, they remove nitrate, sulphate and several other ions Examples (uniform) AmberliteTM HPR4200 Cl (uniform) LewatitTM Monoplus M500 (conventional) AmberliteTM IRA402 Cl (conventional) LewatitTM M500 Typical total capacity 1.0 to 1.5 eq/L [Cl–]

Weakly Basic Anion Exchange Resins (WBA) Functional groups —N(CH3)2 Amines What they do After cation exchange, they remove chloride, sulphate, nitrate, and other anions of strong acids, but they do not remove weak acids (SiO2 and CO2) Examples (uniform) AmberliteTM HPR9600 (conventional) AmberliteTM IRA96 (uniform) LewatitTM Monoplus MP64 Typical total capacity 1.1 to 1.7 eq/L [free base]

Selective and chelating resins Functional groups Many different types What they do They remove metals, boric acid, perchlorate or other ions selectively Examples Function Resin type Removes Triethylammonium Amberlite PWA5 NO3 Thiol Ambersep GT74 Hg, Cd etc. Aminophosphonic Ambersep IRC747UPS Ca from brine Iminodiacetic Ambersep IRC748UPS Lewatit TP208 Ni, Cu etc. Methyl glucamine Ambersep IRA743 Amberlite PWA10 H3BO3 Bis-picolylamine Ambersep M4195 Metals at low pH Thiourea Lewatit TP214 Hg, Cd etc. See details in Resin structure.

Further reading:

• Laboratory photographs of various resins.
• Structure of the matrix and functional groups of ion exchange resins.
• All ion exchange resins in the World!
• Resin properties    
• Selectivity
• Selectivity tables for cation and anion exchange resins.
• Ion exchange capacity

Amberjet, Amberlite, Ambersep, and Dowex are trademarks of DuPont. Lewatit is a trademark of Lanxess.