Coagulating and antifungal properties of wood vinegars in the preparation process of Hevea
brasiliensis natural rubber (NR) sheets were investigated and compared with those of formic
and acetic acids. The wood vinegars produced from biomasses such as inner coconut shell,
bamboo and Eucalyptus woods were evaluated. It was found that plasticity retention index,
Mooney viscosity and mechanical properties of NR coagulated by wood vinegars were
similar to those using acetic acid and better than using formic acid. The antifungal effi-
ciency of coagulants determined from a fungi growth area on NR sheet surfaces was found
in the following order: coconut shell wood vinegar > bamboo wood vinegar z Eucalyptus
wood vinegar > acetic acid z formic acid. The antifungal efficiency of the wood vinegars
was strongly depended upon their phenolic compound contents and confirmed through
the inhibitory growth of the main fungi, Penicillium griseofulvum, on potato dextrose agar.