Bio‐Based Anti‐Biofoulant with Copper(II) as Intramolecular Catalyst for Radicals Formation

Abstract

but was completely banned by the International Maritime Organization in 2002 due to its ability to form enrichment effect in organisms through the food chain, affecting food safety. [9,10] At present, copper oxide, organic copper or a combination of several copper-based antifoulants are the mainstream anti-biofoulants used in antifouling coatings. [11,12] Copper oxide is the most widely used antifouling agent due to its low cost and broadspectrum bactericidal effect. [13] However, it has become evident that copper is highly toxic to marine invertebrates in the marine environment, especially to their larvae. Some research have shown that CuCl 2 at a concentration of 0.38 µmol L −1 in the environment can cause complete arrest of oyster (Crassostrea gigas) larvae, while the semi-lethal concentration (LC 50 ) and absolute lethal concentration (LC 100 ) for Virginia oyster (Crassostrea virginica) embryos are 0.78 and 0.98 µmol L −1 , respectively. [14] For crustaceans, copper was able to kill 50% of different crustacean species after 48 h of exposure to the environment, and juveniles were more sensitive than adults. According to statistics, more than 3000 metric tons of copper are currently imported from the coating into seawater each year. [15] Especially in some bays or closed water bodies where water exchange is poor, copper-containing antifouling coating has a significant effect on the copper content of the water body. [13] In addition to copper-containing antifoulants, chlorothalonil, Irgarol 1051, Sea-Nine 211, diuron, zinc dioxane, etc., are commonly used as eco-friendly antifoulants, but these antifoulants are still required to be combined with cuprous oxide or other copper-containing antifoulants because of their weak inhibitory effect on large fouling organisms. [16][17][18] Therefore, the development of efficient and eco-friendly antifoulants that can replace and significantly reduce of copper-containing antifoulants is crucial for antifouling coatings.Oxime compounds are one of the most important precursors for the preparation of biologically active antibacterial, [19] and copper ions can initiate oxime to produce iminoxyl radicals via the homolytic cleavage of OH bonds, [20] which have highly reactive free radicals in exerting effective antibacterial activity in vitro against most Gram-negative organisms. [21] In the early experiment, some of the antifouling coatings were accidentally contaminated by 2,5-diformylfuran dioxime (DFFD) and its metal chelates. These contaminated antifouling coatings were free from any microorganisms, while some control coatings containing antimicrobial agents showed different degree of microbial growth. Additionally, the solubility of DFFD is Highly efficient and eco-friendly antimicrobial agents are crucial to the development of future marine antifouling coatings. A high efficient and low bio-toxicity bio-based anti-biofoulant, 2,5-diformylfuran dioxime chelating with copper ions (E-DFFD-Cu), is evaluated. Its minimal bactericidal concentration and the concentration for 50%...

Evaluation of a Biobased Furanic Polyoxime Ether Polyol for the Synthesis of Intrinsically Antimicrobial Poly(Oxime-Urethane)

“…Specifically, the stretching vibration peaks of POU at 3324, 1684–1714, and 1097 cm –1 correspond to N–H, CO, and C–O groups in carbamate, respectively . The peaks at 3324 cm –1 are broader due to the presence of a large number of hydrogen-bonded N–H groups, and a typical stretching vibration peak for CN bonds is observed at 1637 cm –1 . Additionally, the stretching vibration peaks of CC and C–O–C groups on the furan ring are observed at 1529 and 1031 cm –1 , respectively.…”

“…13 The peaks at 3324 cm −1 are broader due to the presence of a large number of hydrogenbonded N−H groups, 24 and a typical stretching vibration peak for C�N bonds is observed at 1637 cm −1 . 22 Additionally, the stretching vibration peaks of C�C and C−O−C groups on the furan ring are observed at 1529 and 1031 cm −1 , respectively. The bending vibration peak of the furan ring itself is at 777 cm −1 .…”

“…2,5-Diformylfuran dioxime (DFFD) is a biobased aromatic compound that contains a furan ring and two oxime groups. , The aromatic furan ring can enhance the mechanical and thermal properties of polyurethanes, while the oxime group can be etherified with diols due to its alcohol properties. Furthermore, DFFD has excellent antimicrobial properties, , making it a promising candidate for biobased aromatic ring diols. Thus, the PoEP was synthesized by etherifying DFFD and EG, followed by polymerization with 4,4-diisocyanate dicyclohexylmethane (HMDI) and polytetrahydrofuran (PTMG-650).…”