Fungal Resistance of Southern Pine Impregnated with Methyl Fluorophenyl Carbamates or Reacted with Fluorophenyl Isocyanates

Fluorine substituents in the phenyl ring of methyl fluorophenyl carbamates and fluorophenyl isocyanates were varied to determine the influence of fluorine substituents on fungal resistance of wood containing them. In southern pine impregnated with methyl fluorophenyl carbamates, increased fluorine substitution of the phenyl ring increased fungal resistance. Methyl pentafluorophenyl carbamate and methyl meta-trifluoromethylphenyl calbamate were the most effective preservatives, whereas methyl 4fluorophenyl carbamate was the least effective. Pine reacted with fluorophenyl isocyanates to form bonded carbamates in situ was effective in preventing attacks by fungi but required a much higher molar ratio of chemicals than did wood impregnated with methyl fluorophenyl carbamates. The fluorophenyl carbamyl groups in reacted wood are more stable than carbamates impregnated in wood and less subject to loss by hydrolysis.