Abstract:
Photo-crosslinkable antifouling compositions, in particular antibacterial, antifungal and anti-algae ones, which include the combination of at least one telechelic oligoisoprene of a particular formula with an agent for crosslinking the oligoisoprene. The antifouling film is obtained by applying a thin layer of such a liquid composition on a substrate and is crosslinked at room temperature by exposure to visible and/or UV radiations. The film can be used for preventing the occurrence of a biofilm on any surface in a humid or aqueous environment, and can be used as an additive for preparing materials with a view to imparting bacteriostatic and/or bactericidal properties thereto.

Description:
FIELD OF THE INVENTION 
     This invention relates to cross-linkable antifouling and in particular antibacterial, antifungal and antalgic compositions, the films obtained from these compositions as well as the use of these films in particular for antifouling protection of surfaces immersed in a freshwater environment and in a seawater environment. 
     BACKGROUND OF THE INVENTION 
     The phenomenon of fouling corresponds to spontaneous colonization and accumulation of microorganisms, algae and animals on surfaces immersed for a variable period of time in a freshwater environment or in a seawater environment. Fouling is a significant nuisance, in particular for watercraft, because by deteriorating the surface of the hulls, it leads to an increase in maintenance costs and presents resistance to the forward movement of the watercraft, resulting in overconsumption of fuel and a reduction in speed. 
     To overcome this phenomenon, paints incorporating tributyltin, a very effective biocide, have been used for a number of years. Unfortunately, this molecule and its degradation products, released in the seawater environment, seriously affect ecosystems, which has resulted in their total prohibition since 2008. In addition, these residues, including tin, remain in the sediments of ports and immersion sites of dredged slurry. 
     By replacing tributyltin, a certain number of products that are in principle less toxic have been used: these are for the most part biocidal molecules of low molecular weight such as halogenated molecules, for example chlorinated derivatives (sold under the names: Seanine 211, Kathon 5287, Dichlofluanid, Daconil, Thiodan, Duron, etc.), metal-based derivatives such as zinc or copper (Zinc pyrithione, Ziram, Dithane, etc.) or nitrogenated heterocyclic derivatives (Irgarol 1051), which are incorporated in the matrix of the coating. 
     These molecules are, however, slowly released into the aquatic environment, thus producing, by accumulation, a certain toxicity in the environment. The European program REACH encourages abandonment of the addition of any organic product (of the herbicide or pesticide type, such as the derivatives described above) in the antifouling paint formulations. In addition, silicone-based paints have been developed, and admittedly demonstrate efficacy in the antifouling field, but have limited applicability, in particular due to their high production costs. 
     SUMMARY OF THE INVENTION 
     An objective of this invention is to propose molecules that are not additives, but actual constituents of the antifouling coating. 
     More recently, polyurethane-type polymers with a biocidal activity have been developed. However, these polymers are obtained by reacting hydroxy telechelic oligoisoprenes with isocyanates. Aside from the recognized toxicity of the latter, the polymerization reaction requires the addition of stannic catalysts, which are prohibited in antifouling applications. Finally, the implementation is more delicate and therefore presents a major disadvantage in industrial use. 
     Another objective of this invention is to develop polymer precursors not requiring a complex reaction to produce the polymer coating, with simple and quick implementation, capable of being performed on site. 
     The inventors have discovered that polymer films with antifouling properties could be prepared from photo-cross-linkable compositions based on certain telechelic oligoisoprenes. 
     To this end, the invention proposes a cross-linkable antifouling composition, in particular an antibacterial, antifungal and/or antalgic composition, 
     characterized in that it includes the combination of 
     at least one telechelic oligoisoprene of general formula (I): 
     
       
                 
         
             
             
         
      
     
     or such an oligoisoprene (I) partially hydrogenated, of formula (II): 
     
       
                 
         
             
             
         
      
     
     or a partially epoxidized compound of formula (I), of formula (III): 
     
       
                 
         
             
             
         
      
     
     in which formulas:
         n is an integer between 5 and 100, preferably between 8 and 70   m and p are integers, less than n, preferably such that p&lt;m&lt;n   R 1  is a group chosen from: OH, C 1  to C 12  alkoxy, preferably C 1  to C 8  (for example, methyloxy, ethyloxy or octyloxy), aryloxy (for example, phenyloxy), acryloyl, —NR 3 R 4  with R 3  being H or a C 1 -C 12  linear alkyl and R 4  being H or a C 1 -C 12  linear alkyl   R 2  is a group chosen from: OH, acryloyl, —NR 5 R 6  or —N + R 5 R 6 R 7  with R 5  and R 6 , identical or different, being chosen from: H, alkyl hydroxyalkyl, cyanoalkyl and halogenoalkyl in C 1 -C 12 , in which R 7  is a C 6 -C 15  linear alkyl,       

     and at least one cross-linking agent of said telechelic oligoisoprene. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The oligoisoprene according to the invention is advantageously in the form of a liquid at room temperature, namely preferably between 5 and 35° C. (or a range of possible usage temperatures). 
     This oligoisoprene can be prepared from natural or synthetic rubber, having the advantage of possessing microstructures that can be chemically modified in a controlled manner. Its basic backbone is linear cis-1,4-polyisoprene obtained from non-toxic compounds (natural rubber). This cis-1,4-polyisoprene advantageously has a functionality equal to 2. 
     It is thus capable of being spread on a support in a thin layer, and, in the presence of a cross-linking agent, of polymerizing by visible and/or ultraviolet radiation, forming a flexible film. 
     It has been discovered that such a composition has biostatic properties, i.e. inhibiting the proliferation of living organisms on said surface, or biocidal properties, namely enabling any biological organisms in contact with the surface of the support to be destroyed. 
     The cross-linking agent is present in “catalytic” proportions, i.e. in proportions preferably up to 5% by weight of said compositions. 
     According to a first embodiment of the invention, in order to adjust the viscosity of the composition according to the invention and enable good spreading on the support, the latter may also include a photo-cross-linkable reactive diluting agent, advantageously under the same conditions as the oligoisoprene. Examples of diluting agents are TMPO (2-ethyl-2-(hydroxymethyl) oxetane) and HDDA (hexane diol diacrylate). This reactive diluting agent enables a substantial increase in reactivity, i.e. the polymerization rate which reduces the time and energy necessary to produce a coating. In addition, this agent significantly reduces the viscosity of the formulation, thereby facilitating its application on the surface to be treated. It is present in proportions of up to 40% by weight of the composition according to the invention. 
     According to a second embodiment of the invention, the composition does not contain a reactive diluting agent and consists solely of the combination of at least said linear telechelic oligoisoprene of formula (I), (II) or (III) and at least one cross-linking agent of said telechelic oligoisoprene. 
     However, the composition can also contain “neutral” constituents, i.e. not involved in the photo-cross-linking, such as dyes, pigments, active principles, metal particles, magnetic particles and reinforcing agents. 
     This invention also relates to an antifouling film, characterized in that it is obtained by applying a thin film of the liquid composition as described above onto a support and cross-linked by visible and/or ultraviolet radiation. This radiation can be provided by a continuous or discontinuous emission lamp, emitting at wavelengths between around 200 nm and 800 nm. 
     The films thus obtained are transparent or translucent, capable of being colored by the addition of pigments. In addition, they can be flexible (elastic) or rigid according to the quantity and nature of the diluent used. The surface roughness of the films can be controlled by controlling the cross-linking speed, in particular by means of the type of lamp used, by adjusting the dilution rate and the viscosity. Indeed, the higher the cross-linking speed, the greater the roughness of the film formed. 
     The film obtained surprisingly has biocidal or biostatic properties in particular with respect bacteria, fungi, microalgae and/or macroalgae, regardless of the degree of roughness of the surface. Such a film can thus coat surfaces intended to be immersed, such as watercraft hulls. 
     This invention also relates to any support coated with a film according to the present invention, in which the total thickness of said film is less than one millimeter, and is preferably between 10 μm and 500 μm. 
     Thus, the film according to the invention can advantageously be used for antifouling protection of a support immersed in freshwater or seawater, in particular watercraft hulls, in order to inhibit the appearance of a biofilm on medical instruments, catheters or implants, on walls in contact with an aqueous medium or in a moist environment, such as floor covering surfaces, external walls, pipelines, immersed apparatuses (in particular immersed optical apparatuses) or cooling tours. This list is not exhaustive. 
     This invention also relates to the use of the antifouling composition described above, as an additive in the preparation of materials, in order to confer bacteriostatic and/or bactericidal properties thereon; or in the medical field, in particular in order to produce medical instruments, biomaterials, catheters, prostheses and implants; or to produce coverings, packaging containers, in particular in the agrifood field. 
     This invention will be described in greater detail and illustrated with the following non-limiting examples. 
     EXAMPLES 
     I. Photo-Cross-Linkable Oligoisoprene Syntheses 
     The synthesis of photo-cross-linkable precursors is performed in a plurality of steps. First, the controlled degradation of 100% linear cis-1,4-polyisoprene, with a functionality equal to 2, provides access to a carbonyl telechelic oligoisoprenes with a well defined number average molar mass and chemical structure. Then, a plurality of chemical modifications on these oligomers produce the various photo-cross-linkable precursors. 
     All of the synthesized products are characterized by  1 H-NMR,  13 C-NMR, IRTF, and Steric Exclusion Chromatography. 
     Mode 1 
     I.1 Chemical Modifications of Carbonyl Telechelic cis-1,4-polyisoprene (CTPI) 
     I.1.1 Examples 1 to 4 
     Reduction of Aldehyde and Ketone Ends: Synthesis of cis-1,4-hydroxy Telechelic Polyisoprene (HTPI) 
     In a three-neck round-bottom flask equipped with a coolant and magnetic stirring, the CIPI dissolved in THF (0.07 mol/L) is added drop-by-drop to a sodium borohydride solution (NaBH 4 ) in THF (0.3 mol/L). The reaction mixture is then heated to 60° C. After 6 h, it is cooled and hydrolyzed with 20 g of ice dissolved in 20 ml, of THF, poured drop-by-drop by means of an adding ampoule. After a washing with a saturated sodium chloride (NaCl) solution, the organic phase is dried with MgSO 4 , filtered and concentrated with the rotary evaporator. The product obtained is then dried in a vacuum. 
     The process conditions and yields obtained are presented in table 1. 
     
       
         
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                   
                 NaBH 4   
                 T 
                 T 
                 Yield 
               
               
                   
                 Examples 
                 CTPI 
                 (g) 
                 (° C.) 
                 (h) 
                 (%) 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 1 
                 10 
                 2.18 
                 60 
                 6 
                 98 
               
               
                   
                 2 
                 8 
                 1.72 
                 60 
                 6 
                 93 
               
               
                   
                 3 
                 13 
                 2.84 
                 60 
                 6 
                 94 
               
               
                   
                 4 
                 7 
                 1.53 
                 60 
                 6 
                 97 
               
               
                   
                   
               
             
          
         
       
     
     The  1 H-NMR of the product obtained (HTPI) gives: 
     
       
                 
         
             
             
         
      
     
     with a number average molar mass between 700 and 5000, in which n is between 9 and 65. 
     I.1.2 Example 5 
     Hydrogenation of the HTPI: Synthesis of cis-1,4-hydrogenated Polyisoprene (HHTPI) 
     In a catalytic hydrogenation device, 2 g of HTPI are introduced, obtained according to one of examples 1 to 4, dissolved in 50 mL of ethyl acetate and 500 mg of palladium supported on carbon (Pd/C). The reaction mixture is subjected to mechanical stirring under hydrogen pressure (3 bars). The time and temperature of the reaction were varied so as to obtain different hydrogenation rates (up to around 83%). The palladium is then separated by filtration, the solution is concentrated with the rotary evaporator and the final product is dried in a vacuum. The yield obtained is 75%. 
     The product obtained is characterized by  1 H-NMR: 
     
       
                 
         
             
             
         
      
     
     Mode 2 
     I.1.3 Examples 6 to 9 
     Synthesis of cis-1,4-amino Carbonyl Telechelic Polyisoprene from CTPI 
     The reductive amination of the CTPI is performed selectively on the aldehyde function only. 
     In a three-neck round-bottom flask equipped with magnetic stirring and a coolant in an inert atmosphere, the CTPI in solution is introduced into dichloromethane (0.03 mol/L) and amine (2.1 equivalents). Then, sodium triacetoxyborohydride (NaBH(OAc) 3 ) (2.1 equivalents) is added to the solution. After 24 h at room temperature, the mixture is washed with a soda solution (NaOH, 1N). The organic phase is then separated, dried with MgSO 4  and the solvent is evaporated. 
     The process conditions and yields obtained are presented in table 2. 
     
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                   
                 CTPI 
                 M CTPI   
                 Amine 
                 NaBH(OAc) 3   
                 Yield 
               
               
                 Examples 
                 (g) 
                 (g/mol) 
                 (mL) 
                 (g) 
                 (%) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 6 
                 8 
                 1700 
                 Diethyliminodi- 
                 2.72 
                 98 
               
               
                   
                   
                   
                 acetate: 1.73 
               
               
                 7 
                 5.42 
                 1700 
                 Diethylamine: 0.96 
                 1.96 
                 80 
               
               
                 8 
                 6 
                 4500 
                 Diethylamine: 0.41 
                 0.83 
                 90 
               
               
                 9 
                 12 
                 4500 
                 Diethanolamine: 
                 1.56 
                 85 
               
               
                   
                   
                   
                 0.53 
               
               
                   
               
             
          
         
       
     
     The products obtained are, for example: 
     
       
         
               
               
             
           
               
                   
               
               
                 Amine used 
                 Product obtained 
               
               
                   
               
             
             
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
             
          
         
       
     
     I.1.4 Examples 10 to 13 
     Reduction of Carbonyl Functions of Aminocarbonyl Telechelic Oligoisoprenes 
     In a three-neck round-bottom flask in an inert atmosphere, an etherate-aluminum lithium hydride solution (LiAlH 4 ) at 1 mmol/mL (2 equivalents per polymer mole) is diluted in 10 mL of dry ether. Then, the aminocarbonyl telechelic oligoisoprene dissolved in anhydrous ether (0.01 mol/L) is added drop-by-drop. After 6 h under stirring and at room temperature, the excess aluminum lithium hydride is removed by hydrolysis and the product is extracted with dichloromethane. Finally, the organic phase is separated, dried with MgSO4 and the solvent is evaporated by means of a rotary evaporator. 
     The details of the process and the yields obtained are presented in table 3. 
     
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 3 
               
               
                   
               
               
                   
                 Oligomer 
                 M oligomer   
                 LiAlH 4   
                 Yield 
               
               
                 Examples 
                 (g) 
                 (g/mol) 
                 (mL) 
                 (%) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 10 
                 Oligomer 3 
                 1700 
                 6.2 
                 90 
               
               
                   
                 (4.29) 
               
               
                 11 
                 Oligomer 1 
                 1700 
                 9.1 
                 70 
               
               
                   
                 (7.91) 
               
               
                 12 
                 Oligomer 3 
                 4500 
                 2.38 
                 88 
               
               
                   
                 (4.41) 
               
               
                 13 
                 Oligomer 2 
                 4500 
                 2.76 
                 74 
               
               
                   
                 (5.12) 
               
               
                   
               
             
          
         
       
     
     In particular, the following is obtained: 
     
       
                 
         
             
             
         
      
     
     I.1.5 Examples 14 and 15 
     Synthesis of α-Propyl Amino, ω-Amino Dihydroxyethyl cis-1,4-polyisoprene from Oligoisoprene (2) 
     In a three-neck round-bottom flask in an inert atmosphere, and equipped with magnetic stirring, oligoisoprene (2) dissolved in dichloromethane (0.022 mol/L) and diethyl aminopropylamine (2.1 equivalents) is introduced. Then, sodium triacetoxyborohydride (2.1 equivalent(s) and glacial acetic acid (1 equivalent) are added. The reaction is maintained for 24 h at room temperature. Finally, the reaction mixture is washed with a soda solution (1 N) and the organic phase is separated, dried on magnesium sulfate, filtered and concentrated with the rotary evaporator. 
     The details of the process are presented in table 4: 
     
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
               
                   
                 Oligomer 
                 Diethylamino- 
                   
                 Acetic 
                   
               
               
                   
                 2 
                 propylamine 
                 NaBH(OAc) 3   
                 acid 
                 Yield 
               
               
                 Examples 
                 (g) 
                 (mL) 
                 (g) 
                 (mL) 
                 (%) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 14 
                 18 
                 1.93 
                 3.6 
                 0.3 
                 80 
               
               
                 15 
                 7.28 
                 0.77 
                 1.44 
                 0.12 
                 78 
               
               
                   
               
             
          
         
       
     
     The  1 H-NMR gives: 
     
       
                 
         
             
             
         
      
     
     II.2.6 Examples 16 to 18 
     Partial Epoxidation of Telechelic Oligoisoprenes 
     Regardless of the telechelic oligomer to be epoxidized, the process is the same. The amount of mCPBA needed is calculated by using the following equation:
 
 m   mCPBA =( m   oligomer )/68.8*( T   e /100)* n*M   mCPBA *(100/70)
 
     with
         T e : Epoxidation rate   (70/100): Purity of in mCPBA   (68.8): Molar mass of an isoprene unit   n: Number of isoprene patterns       

     The reaction is performed in a three-neck round-bottom flask equipped with magnetic stirring and placed in an ice bath. The oligomer dissolved in the dichloromethane (0.09 mol/L) is introduced into the flask and left under stirring for 30 min to reach a temperature of 0° C. The desired amount of epoxidation agent, in this case mCPBA (meta-chloroperbenzoic acid) (according to the desired epoxidation rate) in solution in 20 mL of CH 2 Cl 2  is then added drop-by-drop to the oligomer solution (see details in table 5). After the addition, the reaction mixture is stirred for 3 h at room temperature, then washed with a saturated sodium hydrogen carbonate solution. Finally, the organic phase is dried on MgSO 4 , filtered and concentrated. The concentrated product is dried in a vacuum for 24 h. 
     Concerning the aminotelechelic oligoisoprenes, washing with 5 N soda is performed after the reaction in order to regenerate the amine. Indeed, during the reaction, the tertiary amine is protonated. 
     
       
         
               
               
               
               
               
               
             
           
               
                 TABLE 5 
               
               
                   
               
               
                   
                 Oligomer 2 
                 M oligomer   
                 mCPBA 
                 T e   
                 Yield 
               
               
                 Examples 
                 (g) 
                 (g/ml) 
                 (g) 
                 (%) 
                 (%) 
               
               
                   
               
             
             
               
                 16 
                 HTPI (4.35) 
                 1700 
                 1.46 
                 10 
                 95 
               
               
                 17 
                 HTPI (5) 
                 4500 
                 1.73 
                 10 
                 92 
               
               
                 18 
                 Oligomer 4 
                 1700 
                 1.73 
                 10 
                 89 
               
               
                   
                 (5) 
               
               
                   
               
             
          
         
       
     
     The  1 H-NMR gives: 
     
       
         
               
               
             
           
               
                   
               
               
                 Starting product 
                 Product obtained 
               
               
                   
               
             
             
               
                 HTPI 
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 HHTPI 
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 oligomer 4 
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 oligomer 5 
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
             
          
         
       
     
     II.2.7 Examples 19 to 22 
     Attachment of Acrylate Functions at the Chain Ends 
     In a three-necked round-bottom flask placed in a bath at 0° C.; and under argon circulation, the oligomer is introduced in solution in anhydrous dichloromethane (0.08 mol/L). Then, triethylamine (2.3 equivalents, except for oligomer 5 (3.5 equivalents)) is added, then acryloyl chloride (2.3 equivalents, except for oligomer 5 (3.5 equivalents)) is added drop-by-drop (see details in table 6). The mixture is left under stirring and at room temperature for 24 h. At the end of the reaction, it is washed with a soda 1 N solution, then the organic phase is dried on magnesium sulfate, filtered and concentrated. The product is dried in a vacuum for 24 h. 
     
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 6 
               
               
                   
               
               
                   
                   
                 Acryloyl 
                   
                   
               
               
                   
                 Oligomer 
                 chloride 
                 Triethylamine 
                 Yield 
               
               
                 Examples 
                 (g) 
                 (mL) 
                 (mL) 
                 (%) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 19 
                 HTPI (7.25) 
                 0.88 
                 1.5 
                 92 
               
               
                 20 
                 Oligomer 4 
                 0.45 
                 0.77 
                 88 
               
               
                   
                 (3.86) 
               
               
                 21 
                 Oligomer 5 
                 0.96 
                 1.65 
                 85 
               
               
                   
                 (5.52) 
               
               
                 22 
                 Oligomer 6 
                 0.34 
                 0.59 
                 85 
               
               
                   
                 (3.20) 
               
               
                   
               
             
          
         
       
     
     
       
         
               
               
             
           
               
                   
               
               
                 Starting product 
                 Product obtained 
               
               
                   
               
             
             
               
                 HTPI 
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 HHTPI 
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 EHTPI 
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 oligomer 4 
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 oligomer 5 
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 oligomer 6 
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
             
          
         
       
     
       1 H-NMR: 
     I.1.8 Examples 23 to 25 
     Quaternization of Amine Functions of Aminotelechelic Oligoisoprenes 
     In a three-necked round-bottom flask placed in a heating bath, the oligomer to be treated (see table 7), dissolved in a dichloromethane/acetonitrile (3/1) (0.02 mol/L), is introduced. Then, the alkyl halogenide is added (5 equivalents/amine function) and the reaction mixture is heated to 40° C. in the case of octyl iodide and to 65° C. in the case of octyl bromide. After 24 h, the solvents are evaporated with the rotary evaporator and the excess alkyl halogenide is removed by high vacuum evaporation. 
     
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 7 
               
               
                   
               
               
                   
                 Oligomer 
                 Triethylamine 
                 Yield 
               
               
                 Examples 
                 (g) 
                 (mL) 
                 (%) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 23 
                 oligomer 6 (4.2) 
                 0.8 
                 100 
               
               
                 24 
                 oligomer 11 (2.3) 
                 0.55 
                 100 
               
               
                 25 
                 oligomer 13 (10) 
                 6.2 
                 100 
               
               
                   
               
             
          
         
       
     
     The  1 H-NMR gives: 
     
       
                 
         
             
             
         
      
     
     II. Example 26 
     Preparation of Coatings by Photo-Cross-Linking 
     The different coatings are prepared either by using only one of the precursors described above or in the presence of reactive diluents. Examples of some formulations are described in table 8 below. 
     
       
         
               
               
               
               
               
             
           
               
                 TABLE 8 
               
               
                   
               
               
                 Formu- 
                   
                   
                   
                   
               
               
                 lation 
                   
                 Photo-initiator 
                 Diluent 
                 Photo-cross- 
               
               
                 No. 
                 Precursor 
                 (%)* 
                 (%)** 
                 linking mode 
               
               
                   
               
             
             
               
                 1 
                 EHTPI 
                 Degacure 
                 — 
                 Cationic 
               
               
                   
                   
                 KI85 5% 
               
               
                 2 
                 EHTPI 
                 Degacure 
                 TMPO 30% 
                 Cationic 
               
               
                   
                   
                 KI85 5% 
               
               
                 3 
                 EHTPI + 
                 Degacure 
                 — 
                 Cationic 
               
               
                   
                 oligomer 14 
                 KI85 5% 
               
               
                   
                 (50/50) 
               
               
                 4 
                 oligomer 8 
                 Darocur 1173 
                 — 
                 Free radical 
               
               
                   
                   
                 3% 
               
               
                 5 
                 oligomers 
                 Darocur 1173 
                 — 
                 Free radical 
               
               
                   
                 (8 + 15) (50/50) 
                 3% 
               
               
                 6 
                 oligomers 
                 Darocur 1173 
                 — 
                 Free radical 
               
               
                   
                 (8 + 15) (75/25) 
                 3% 
               
               
                 7 
                 oligomers 
                 Darocur 1173 
                 — 
                 Free radical 
               
               
                   
                 (8 + 14) (50/50) 
                 3% 
               
               
                 8 
                 oligomer 9 
                 Darocur 1173 
                 HDDA 30% 
                 Free radical 
               
               
                   
                   
                 3% 
               
               
                   
               
               
                 *Mass percent with respect to the mass of the precursor or precursor + diluent 
               
               
                 **Mass percent with respect to the total mass of the mixture 
               
             
          
         
       
     
     The photo-initiators and diluents used in this example are presented below: 
     
       
                 
         
             
             
         
      
     
     The formulations are spread on a support by means of Conway bars, which makes it possible to control the thickness of the coatings capable of ranging from 10 μm to 500 μm. The irradiation intensities are 50 and 13 mW/cm 2 , respectively, for the cationic and free radical polymerization. 
     In the conditions described above, the coatings obtained by the free radical mode have roughnesses between 15 and 20 Å and those obtained by cationic mode have a greater roughness (between 40 and 45 Å). 
     The supports, which are glass, metal or Plexiglas, were tested. 
     The adhesion on these different surfaces was excellent, by contrast with the comparative trials performed on polyurethane-based films, which swelled in an aqueous medium and separated from the supports. 
     Tests Evaluating Antifouling Properties 
     Formulations 1 to 8 above were tested with respect to marine organisms which are indicators of biofouling and commonly used for laboratory tests: bacteria, fungi, microalgae and macroalgae. Each biological test was performed at least six times in order to ensure the reputability of the results. 
     Placing the Coatings in Contact with the Bacteria 
     The marine bacteria selected for this work ( Pseudoalteromonas elyakovii Shewanella putrefaciens, Cobetia marina, Polaribacter irgensil and Vibrio aestuarianus ) are recognized as major components of marine biofilms. The evaluation of the potential antimicrobial activity of the formulations was performed by the classic microplate method. The bacteria were cultivated on the MHB medium (Mueller Hinton Broth, SIGMA) enriched with NaCl (15 g/l). The films, cut by means of a punch, were deposited in the wells of a microplate (Fisher, 96 wells). The seeding of the microplates was then performed: 100 μL of a bacterial suspension containing 2.10 8  cells/mL were deposited in each well in a sterile manner. After incubation (48 h at 30° C.), the antimicrobial activity was observed by comparison of the bacterial growth between the formulations and the control (C). 
     In the first screening series, three bacterial strains were chosen ( Pseudoalteromonas elyakovii, Shewanella putrefaciens, Cobetia marina ). The results presented in table 9 (first series of tests) show, by comparison with the control, that formulations 1-3 and 5-7 enable inhibition of the growth of the three strains tested. Formulations 4 and 8 have antibacterial properties with respect to two of the three strains selected. This clearly demonstrates the antibacterial character of the films of this invention. 
     
       
         
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 9 
               
               
                   
                   
               
               
                   
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
                 7 
                 8 
                 C 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 
                   Pseudoalteromonas 
                 
                 + 
                 + 
                 + 
                 − 
                 + 
                 + 
                 + 
                 + 
                 − 
               
               
                 
                   elyakovii 
                 
               
               
                 
                   Shewanella 
                 
                 + 
                 + 
                 + 
                 + 
                 + 
                 + 
                 + 
                 − 
                 − 
               
               
                 
                   putrefacients 
                 
               
               
                 
                   Cobetia marina 
                 
                 + 
                 + 
                 + 
                 + 
                 + 
                 + 
                 + 
                 + 
                 − 
               
               
                   
               
             
          
         
       
     
     A second series of tests was performed, in which the bacteria presented in table 10 were placed in the presence of films of formulation 1, 4 and 7 and the control. 
     A portion of films 4 and 7 was first subjected to an “extraction”, i.e. washing with dichloromethane at reflux at 40° C. for 24 hours in order to remove any precursors remaining on said films. The results obtained are presented in table 10. 
     
       
         
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 10 
               
               
                   
                   
               
               
                   
                   
                   
                 4 (ex- 
                   
                 7 (ex- 
                   
               
               
                   
                 1 
                 4 
                 traction) 
                 7 
                 traction) 
                 C 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 
                   Pseudoalteromonas 
                 
                 + 
                 + 
                 + 
                 + 
                 + 
                 − 
               
               
                 
                   elyakovii 
                 
               
               
                 
                   Shewanella 
                 
                 + 
                 + 
                 + 
                 + 
                 + 
                 − 
               
               
                 
                   putrefacients 
                 
               
               
                 
                   Cobetia marina 
                 
                 + 
                 + 
                 + 
                 + 
                 + 
                 − 
               
               
                 
                   Polaribacter 
                 
                 + 
                 + 
                 + 
                 + 
                 + 
                 − 
               
               
                 
                   irgensii 
                 
               
               
                 
                   Vibrio 
                 
                 + 
                 + 
                 + 
                 + 
                 + 
                 − 
               
               
                 
                   aestuarianus 
                 
               
               
                   
               
             
          
         
       
     
     Key to Tables 9 and 10 
     Fi: no. film 
     C: control (reference surface: polystyrene) 
     (+): presence of an inhibition halo, zone in which the bacteria do not cross over or under the film 
     (−): the bacteria, push over and/or under the films 
     No difference in efficacy was observed between films 4 and 7 subjected to extraction or not. The “antibacterial” action is not therefore due to any presence of residues. 
     Placing the Films in Contact with the Microalgae 
     The phytoplanctonic algae selected ( Amphora caffeaeformis, Cylindrotheca closterium, Pleurochrysis roscoffensis, Chlorarachnion globosum, Navicula jeffreyi  and  Exanthemachrysis Gayraliae ) were chosen for their importance in biofouling phenomena in a seawater environment and for their capacity to form EPS (exopolysaccharides playing a crucial role in the permanent attachment of biofilms). The inhibition of their attachment and growth is therefore a major challenge for the development of new antifouling solutions. 
     The evaluation of the antimicroalgae potential of the different films 1 to 8 was performed by the microplate method. The strains are cultivated on the F/2 medium. The films cut by means of a punch were deposited in the wells of a microplate (Fisher, 96 wells). The seeding of the microplates was then performed: 100 μl of an algae suspension containing 1 μg/mL of chlorophyll were deposited in each well in a sterile manner. After incubation (5 days at 25° C.), the anti-microalgae activity was observed by optical microscopy, and the count of the adhering microalgae was performed on thirty different optical fields. The average of the algae attached per surface unit is then determined. 
     Table 11 below shows the percentage (%) of adhering cells on the films with respect to the number of adhering cells on the reference surface (C). 
                                                                                                       TABLE 11                       1   2   3   4   5   6   7   8   C                                      Amphora     4   6.3   2.36   2.1   1.1   1.2   1   4.2   100         coffeaeformis           Cylindrotheca     3   4.6   2.75   2.3   1.07   0.76   0.95   3.76   100         closterium           Pleurochrysis     4.2   4.5   1.44   1.85   1   0.87   0.7   4   100         Roscoffensis     5         Chlorarachnion     3.1   3.5   1.7   1   1.05   1.2   2.9   2.6   100         glosobosum           Navicula jeffreyi     1.8   3   1.7   1.83   1.3   1.22   0.9   2   100         Exanthemachrysis     1.3   2   1.1   1.4   0.75   1.2   1   1.6   100         Gayraliae                      
Placing the Coatings in Contact with the Macroalgae
 
     The algae used  Ulva intestinalis , an opportunistic green algae and one of the species most heavily involved in marine fouling. It was collected the day of the tests on the coast of Portsmouth (Great Britain). 
     The fertile parts (in sporulation) of the algae are selected and placed in a Von Stosch medium. After several minutes, the spores are released in the medium, and their presence is controlled by observation with an optical microscope. 
     The polymer film samples are cut into small circles as above and placed in a 96-well microplate. Then, 100 μL of the medium containing 25,000 spores are injected into each well (concentration of 250,000 spores/mL). Empty wells are used as references (C) and six replicates are produced for each sample. The plates are placed in the dark for two hours in order to enable the spores to attach. 
     After two hours, the wells are emptied and rinsed with the Von Stosch solution in order to remove the unattached spores, then 100 μL of the medium are added. The plates are placed in an incubator at 15° C., under illumination of 45 μmoles photons m −2 s −1  (photo-period: 16 hours of light/8 hours of darkness) for one week. 
     The observations are performed by optical microscopy. The count of attached spores as well as that of the germinated spores were performed on thirty different optical fields. Averages of attached/or germinated spores per surface unit are then determined and presented in table 12. 
     
       Ulva intestinalis 
     
     
       
         
               
               
               
               
               
               
               
             
           
               
                 TABLE 12 
               
               
                   
               
               
                   
                   
                   
                 4 (ex- 
                   
                 7 (ex- 
                   
               
               
                 Film 
                 1 
                 4 
                 traction) 
                 7 
                 traction) 
                 C 
               
               
                   
               
             
             
               
                 Adhering 
                 3120 
                 35 
                 59 
                 21 
                 32 
                 11800 
               
               
                 spores/cm 2   
               
               
                 Percentage/ 
                 27% 
                 0.3% 
                 0.5% 
                 0.17% 
                 0.27% 
                 100% 
               
               
                 control 
               
               
                 Germinated 
                 1090 
                  0 
                  0 
                  0 
                  0 
                  9500 
               
               
                 spores 
               
               
                 % spores 
                 35% 
                   0% 
                   0% 
                   0% 
                   0% 
                  85% 
               
               
                 germinated 
               
               
                 with respect 
               
               
                 to fixed 
               
               
                 spores 
               
               
                   
               
             
          
         
       
     
     By inhibiting almost all of the spore adhesion and the germination thereof, films 4 and 7 appear to be excellent anti-algae, with regard to  Ulva intestinalis.    
     The adhesion and the growth of this algae is also strongly inhibited on film no. 1. 
     Placing the Coatings in Contact with Fungi 
     The antifungal activity of the films was tested, using the method described by Hellio et al. (2000, Appl. Microbiology and Biotechnology, 54, 543-549), with regard to five marine fungal strains of the culture collection of the University of Portsmouth (School of Biological Sciences—Great Britain). 
     
       Halosphaeriopsis mediosetigera  
     
     
       Asteromyces cruciatus  
     
     
       Lulworthia uniseptata  
     
       Zalerion  sp 
     
       Monodietys pelagica  
     
     The fungal strains were cultivated on inclined corn agar. Each flexible film sample was incorporated in 200 μL of corn agar at 12%, pH 6 (Sigma). The test plate was inoculated in a sterile medium at, the center with a pellet 2 mm in diameter of agar containing mycelium. All of the tests were performed in duplicate. After incubation at 25° C. for four weeks, the activity was evaluated by observing the growth of the fungal colonies. The results are presented in table 13. 
     
       
         
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 13 
               
               
                   
                   
               
               
                   
                   
                   
                 4 (ex- 
                   
                 7 (ex- 
                   
               
               
                   
                 1 
                 4 
                 traction) 
                 7 
                 traction) 
                 C 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 
                   Halosphaeriopsis 
                 
                 − 
                 + 
                 + 
                 + 
                 + 
                 − 
               
               
                 
                   mediosetigera 
                 
               
               
                 
                   Asteromyces 
                 
                 − 
                 + 
                 + 
                 + 
                 + 
                 − 
               
               
                 
                   cruciatus 
                 
               
               
                 
                   Lutworthia 
                 
                 − 
                 + 
                 + 
                 + 
                 + 
                 − 
               
               
                 
                   uniseptata 
                 
               
               
                   Zalerion  sp 
                 − 
                 + 
                 + 
                 + 
                 + 
                 − 
               
               
                 
                   Monodictys 
                 
                 − 
                 + 
                 + 
                 + 
                 + 
                 − 
               
               
                 
                   pelagica 
                 
               
               
                   
               
             
          
         
       
     
     −=normal growth=no differences with the control 
     +=inhibition of growth 
     Films 4 and 7 are also excellent antifungal agents.