Chlorinated polyethylene exhibits all the physical and chemical 

 resistive properties except for resistance to aromatic and chlorinated 

 hydrocarbons. Unlike PVC, chlorinated polyethylene coatings contain no 

 plasticizers and have excellent aging property characteristics. The 

 properties of tear and abrasion resistance of this material are not as 

 good as those exhibited by others in Table 3. However, tear resistances 

 can be improved considerably when the coating is used with a fabric 

 substrate such as nylon or polyester [24]. 



Chlorosulfonated polyethylene is superior to the chlorinated polyethy- 

 lene in that it exhibits excellent abrasion resistance and can also be 

 produced in a wide variety of colors. Its weak property is tear resistance 

 but this, as with the chlorinated polyethylene, is greatly improved when 

 the material is used with a polyester or nylon substrate [22]. 



Nitrile rubbers, after immersion in oils, retain their good strength 

 and abrasion resistance. Depending on the percentage of acrylonitrile 

 and butadiene nitrile rubbers can have a good balance of solvent resistance, 

 high temperature resistance, and low temperature flexibility [17]. The 

 weathering properties of nitrile rubbers are not as good as chlorosulfon- 

 ated polyethylene, however. 



Neoprene is a very resilient synthetic rubber that has excellent 

 flexural strength but is not as good as chlorosulfonated polyethylene in 

 all but tear resistance [17,22]. Although neoprene can be produced in 

 almost any color the lighter colors tend to discolor when exposed to 

 sunlight. No other information was available on the effects of colors 

 on the physical properties of neoprene or the resulting degradation with 

 exposure of colored neoprene to sunlight. 



Polypropylene is very low in density and offers good balance in 

 mechanical, physical and chemical resistive properties. Its resistance 

 to sunlight is only fair. Reference to its use as a coating for fabrics 

 has not been found in the literature except for reinforcement with 

 fiberglass which makes it stronger and more rigid [17]. 



While the coating materials presented in Table 3 do not represent 

 a complete list of those materials that may exhibit the desirable 

 properties, they are fairly representative of those being used today in 

 coated fabrics. An indefinitely large number of formulations, combina- 

 tions, and modifications are possible and each one can change the proper- 

 ties of the material and hence its suitability for use on containment 

 booms. This discussion has identified some of the primary properties of 

 the basic coating materials. 



MATERIAL EVALUATION 



The discussion in the previous sections identified woven substrate 

 and coating materials exhibiting the most promising characteristics for 

 use as containment booms. To determine the types of coated fabrics 

 currently being used in booms, a number of manufacturers were contacted 

 and information concerning the materials and their properties obtained. 



19 



