Synthesis and Characterization of Copoly(MMA-MA)-Cu Complex and Study on Its Leaching Behavior

The main difference between these two biocides is in the mode of leaching from the paint matrix to the surrounding sea water. Leaching of copper takes place by simple uncontrol led diffusionff whereas that of tin oc curs in a controlled manner by breaking the chemical bond and subsequent diffusion. 4 Another point of difference is the high threshold value of leaching. The thresh old value for copper is 10 / zg / cm2/day 5 which is about 25 times greater than that of tin (0 .4/xg/cm2/day) . 4 As the leaching of copper is uncontrolled, paints based on cuprous oxide throw large amounts of unnecessary cop per into sea water. The concentrat ion of copper in the Suez Canal was found to be several times higher than the threshold value for deteriorat ion of water quality. 6 Similarly, the increasing use of tributyltin based anti fouling coatings has raised concerns about their environmental effects, and the effects on non-target organisms of the toxic tr ibutylt in species released from the coatings. 7-1~ Bioassays with algae, 2 oys t e r ] crab, 11 mus sel larva, 8 mysid shrimp, 12 copepods, 13 and fish 14 have shown sub-lethal and lethal effects of tr ibutylt in at parts per billion and lower levels in water. Consequently, some nations have issued regulations to control the use of tributyltin-based antifouling coatings on small crafts in an at tempt to protect marine life near harbors. 15