Environmental Engineering Reference
In-Depth Information
Initial
paint
surface
Polymer
matrix with
soluble
pigment or
biocide
(Cu
2
O)
Dissolving
pigment or
biocide
Seawater
Erosion of paint surface with time
Figure 2.16
Schematic illustration of the action of TBT SP paints
2.5.2.2 Tin-free Self-polishing Copolymer Technology
Tin-free SPC also have a similar reaction mechanism to TBT-SPC paints with seawater.
The chemical reaction is through hydrolysis of copper, zinc, and silyl acrylate.
The tin-free anti-fouling coatings can be divided into two groups:
(i) Controlled depletion systems (CDP), and
(ii) Tin-free SPC.
The CDP coating is an advance in soluble matrix technology by including new
reinforcing resins with the same anti-fouling mechanism as the traditional resin
matrix paints. The tin-free SPC coatings function in a similar way to TBT-SPC but
do not have tin in the coating [62].
Table 2.4
illustrates the commercially available
TBT free paints and their mode of action.
2.5.2.2.1 Booster Biocides used in Self-polishing Copolymers
Copper containing coatings target specific fouling organisms. Thus, to these
copper containing coatings, some booster biocide that is lethal to macroalgae,
