The Preparation Of Carboxymethyl Chitosan Salt/Nano Cu₂O Enclosed By Chitosan And The Study Of Their Usage In Marine Antifouling Paint

Concerning the high toxicity of organotin paints, the need to develop new environment- friendly antifouling paints have been highlighted. To tin-free environment-friendly antifouling paints,less toxic or nontoxic antifoulant plays a very significant role. Chitosan, derived by deacetylation of chitin, is recognized as a natural, biocompatible, biodegradable, non-toxic and multifunctional resource. Chitosan and its derivatives have already been widely used in many fields such as agriculture, light industry, medicine, biomedicial materials and environmental protection. And recently they have also been applied in antifouling paints. In this paper, the cupric, zinc and bismuth salts of carboxymethyl chitosan and acrylic- polymer with hydroxyl and amidocyanogen were designed and synthesized. These salts contain the group resembling the self-polishing function group of organotin antifouling resin. And all of the salts are characterized and conformed by FTIR and XRD. After that, marine antifouling paints are prepared with newly synthesized CMC salts or ACM salts.For these synthesized CMC and ACM salts, the attachment inhibition assay against the representative marine algae in the laboratory shows their inhibition ability to algae declines in the order ACM-Cu-B, ACM-Zn-B, ACM-Cu, ACM-Zn, CMC-Zn, CMC-Zn-B, CMC-Cu-B, CMC-Cu, ACM-Bi, CMC-Bi-B, ACM-Bi-B, CMC-Bi;the rule of inhibition ability of CMC and ACM salt to algae: the CMC-M-B type salt which is stronger than corresponding CMC-M type salt and the same as to ACM salt; To the same kind of salt, cupric salt is tronger than zinc salt and zinc salt /which is stronger than bismuth salt, and which is the same as to ACM salt;ACM salt is stronger than the corresponding CMC salt. The marine antifouling paints with 13% CMC-Cu,CMC- Cu-B,CMC-Zn,CMC-Zn-B,ACM-Cu or ACMC-Cu exhibit good antifouling ability during the experiment period in the sea, and their inhibition ability to fouling biology declines in the following order: ACM-Cu, ACM-Cu, CMC-Cu-B, CMC-Cu, CMC-Zn-B, CMC-Zn.And in this paper, nano-Cu₂O enclosed by chitosan has also been synthesized through the reduction of CuSO₄ by Na₂SO₄ in the presence of chitosan, furthermore characterized by XRD, SEM and TEM. In contrast to normal Cu₂O, nano-Cu₂O enclosed by chitosan enhance apparently the subsidence-resistance ability, attachment ability and antifouling ability of antifouling paint; nano-Cu₂O enclosed by chitosan can controll the release of Cu²⁺ in antifouling paint well.