a process for preparing a functionalized petroleum resin which comprises the steps of : dissolving a petroleum resin having a norbornene moiety with a double bond in a solvent to form a solution ; adding to the solution a borane compound having the formula : ## str1 ## wherein r 1 and r 2 are alkyl or cycloalkyl groups having about 1 to about 10 carbonations ; reacting said petroleum resin with said borane compound at about room temperature for a sufficient period of time to form a borane intermediate ; and reacting said borane intermediate with a chemical agent to convert said borane intermediate into said functionalized petroleum resin .