Abstract:

Adductive crystallization is a special separation method. Terephthalic acid（TA）could be dissolved and re-crystallized in certain acylamide solvents such as N，N-dimethylacetamide（DMAC）spontaneously even at constant temperature，solvent adduct crystals could be formed with 1∶2 molar ratio of TA and DMAC through hydrogen bonding. This adductive crystallization method showed a high selectivity in TA recovery from the TA residue of the single-step crystallization，through which the 90%—95% colored impurities initially contained in the residue could be removed.

摘要：

加合结晶是一种特殊的结晶分离方法。对苯二甲酸（TA）在某些酰胺类溶剂如N，N-二甲基乙酰胺（DMAC）中的溶解与结晶在恒温条件下即可自发进行，生成的新晶体是TA∶DMAC（mol/mol）为1∶2的溶剂化加合物，溶质与溶剂通过O—H…O的氢键作用结合。这种加合结晶具有高度的选择性，在20～70 ℃，单步结晶即可去除中纯度对苯二甲酸（MTA）残渣中90%～95%的有色杂质，是一种高效的残渣回收方法。