Influence of Polymer Additives on Reactive Crystallization of Benzoic Acid

Reactive crystallization of benzoic acid was carried out in the solution of some polymers, polyethylenimine (PEI); poly(acrylic) acid (PAA); poly(vinyl) alcohol (PVA); Methylcellulose (MC); sodium carboxymethyl cellulose (CMC). These polymer additives modified the growth mechanism and caused the change of morphology. The kind of molecular unit of polymer chain was a factor to select the growth mechanism; surface integration growth and agglomeration growth. When the molecular unit is carbon such as PEI, PAA and PVA, surface integration growth was selected. And when the molecular unit is sugar such as MC and CMC, agglomeration growth was selected. The author found that this selection mechanism could be kinetically and thermodynamically explained.