The vinyl ester resins and natural composites have emerged as a suitable alternative in tribological application due to mechanical behavior, which relates to the conversion of the double bonds. During tribological test the permanent contact between polymeric sample and counterpart can increase the temperature affecting the crosslinking of the samples. These variations have direct implications in the curing rate and the global conversion. In this work, the FTIR evaluation is used to evaluate possible changes on the global conversion of vinyl ester and their composites reinforced with Musaceae fiber bundles and cured using two hardeners, after a specific tribological test. Increments around 15% on global conversion of styrene double bonds were observed for neat matrix and composites using both hardeners, suggesting that during tribology test some alterations on resin structure takes place. These results open alternatives to manipulate the curing conditions in order to control the tribological behavior.