Leaching and stabilizing characteristics of copper diethyl dithiocarbamatein an acetic acid solution

The leaching and stabilizing characteristics of synthetic copper diethyl di thiocarbamate (Cu-DDTC) under 1 N acetic acid solution were characterized u sing semi-dynamic leaching test (SDLT), ultraviolet-visible spectrophotomet er (UV-visible), X-ray diffractometer (XRD), fourier transform infrared spe ctrophotometer (FTIR), and scanning electron microscopy (SEM) techniques. T he analyses of leached species of leaching solution by SDLT and UV-visible indicated that the degree of degradation of various elements from the Cu-DD TC complex could be classified as: N (25%) > S (20%) > Cu (0.7%) and no dit hiocarbamate species in the liquid phase were detected. The copper species of insoluble Cu-DDTC complexes were much more stable than those of copper s olidification in cementitious matrix. The investigation of crystallinity sh owed that there were two unidentifiable peaks present in the XRD pattern of the leached Cu-DDTC complex that might be attributed to new chemical inter actions. The spectra obtained by FTIR analyses obviously showed that the ma jor functional groups, such as C-N, S-C-S, C=S, Cu-S, and C-H groups, were both present in the unleached and leached Cu-DDTC complex. Microstrctural a nalyses by SEM revealed that the unleached and leached Cu-DDTC complexes ha d the same morphologies, but the grain size of the leached Cu-DDTC complex is much larger and compact than that of the unleached complex. Thus, it was suggested that the leaching and stabilizing characteristics of the insolub le Cu-DDTC complexes consisted of the dissolution and decomposition of Cu-D DTC and the chelating reaction between copper and NDDTC.