As essentially pinene polymers, principally polymers from β-Pinene, the terpene resins exhibit properties typical of polymeric hydrocarbons including chemical inertness. They are inert to dilute mineral acids, alkalies, and salt solutions, and are characterized by acid numbers and saponification numbers less than four and approaching zero. Similarly, they are resistant to heat over a wide range of temperatures, varying only in fluidity with temperature. The commercially available Polyterpene Resins are produced with a variety of softening points (measured by the A.S.T.M ring-and-ball method E28-51T), ranging from 10~135 °C, corresponding to a range from viscous liquid to hard, brittle solid polymers at ordinary temperatures.
