RESISTANCE OF MATERIALS TO MARINE BIOLOGICAL ATTACK 1099 



the abilit}^ of marine bacteria to utilize a compound as a carbon source 

 at the time of test. It will not reflect changes brought about in the ma- 

 terial clue to prolonged exposure in sea water, or ecological relationships 

 which might make the material more or less susceptible to attack by 

 certain bacteria. The other laboratory tests and natural exposure test 

 will help furnish data on c^uestions involving changes in materials due to 

 long-term marine exposure. 



Table I — Materials Tested Against Aerobic and 

 Anaerobic Marine Bacteria 



Designation 



Polyethylene^ 



2.0 melt index^ 



0.2 melt index (Source A) 



0.2 melt index (Source B) 



0.2 melt index + 5% butj-l rubber + antioxidant 



0.2 melt index + antioxidant 



0.7 melt index (high den.sity) nat. + antioxidant 



0.7 melt index (high density) + carbon black and antioxi- 

 dant 

 Poly {Vinyl Chloride^ 

 Plasticizer 



Polyester A 



Di-2-ethylhexyl phthalate (DOP) Shore A 88 



Tricresji phosphate (TCP) 



None (rigid) 



None^ 



None^ 



Tri-2-ethylhex3^1 phosphate 



Nitrile rubber/polyester C 



Di-2-ethylhexyl phthalate (DOP) Shore A 62 



Nitrile rubber 



Polyester E/DOP (BTL 46-55) 



None (PVC resin) 

 Casting Resins 



Epoxide (cast), unfilled straight epoxy resin cured with 

 amine hardener 



Stj-rene poljester, silica-filled 

 Elastomers^ 



GR-S jacket 



GR-A jacket 



Butyl jacket 



Natural rubber jacket 



Neoprene jacket 

 Jute 



Type 



P53 10466 

 P5304156 

 P53 12587 

 P5308396 

 P5308390 

 P5503135 

 P5503133 



BTL 24-54 



BTL 23-54 



BTL 529-53 



P5503087 



P5502078 



P5502077 



P5502081 



P5502074 



P5502082 



P5502076 



P5503115 



P5510645 



BTL 54-14 

 BTL 54-18 

 BTL 54-19 

 BTL S4-23 

 BTL 54-164 



1 Except where noted polymers are low density grades manufactured by the 

 high pressure process. 



2 ASTM D1238 



' With the exception of P5510645 all PVC compositions contained typical or- 

 gano-metallic type stabilizers (such as Ba, Cd, and Pb), fatty acid lubricants in 

 low concentrations, and in some cases small quantities of inorganic fillers. 



'' Semi-flexible PVC copolymer. 



^ These compounds all contain, in addition to the basic elastomers, sulfur, 

 accelerators, waxes, processing oils, and reinforcing ciuantities of carbon black. 

 (54-164 also contains clay.) 



