Abstract
New heavy metal selective resins (m and p-phenylene dithiourearesolcinol resins…m-and p-PR) were prepared from m-and p-phenylene diamine dihydrochloricacid and resolcinol. These resins had two thiourea radicals in each unit structure.
Their heavy metal exchange capacities were examined for Ag and Hg by pH titration method. The result showed chelate ring between resin and heavy metal was formed.
Comparison of exchange capacity was made between m-or p-PR and Hojo's 3hydroxyphenylene thiourea-phenol resin (3HPTU-phenol resin) containing one thiourea radical in each unit structure.
Measured exchange capacities of p-PR and 3HPTU-phenol resin were 1.6 and 2.2m mol Hg/g resin, while theoretical values of them were 5.25 and 3.45m mol/g resin, respectively. p-PR had smaller exchange capacity to the theoretical as compared with 3HPTU-phenol resin. This reason was that two large thiourea radicals of each unit structure in p-PR reduced a space of chelate ring with heavy metal.
