Preparation and characterization of polymers formed by irradiation of β-pinene and other monomers

The gamma radiation-induced cationic polymerization of β-piene was carried out under super-dry conditions. Chemical characterization was accomplished by nmr, ultraviolet, and infra-red spectroscopic techniques. X-ray diffraction methods were used to obtain crystallinity data and other morphological information. Thermal and solubility characterizations were also carried out. Auto-oxidation of the polymer resulted in the formation of peroxy and ketonic groups. Elemental analysis was used to determine the amount of oxygen incorporated in the auto-oxidized polymer. These results are discussed in comparison to those obtained for the commercial Polyterpene Resin, prepared by Lewis acid catalysis. Poly(β-pinene) was also prepared by thermal polymerization at 1600C. The effect of additives indicated that the mechanism involved free radical propagation. The results of the x-ray diffraction and proton nmr spectroscopy of this polymer were similar to those of the polymer prepared by gamma irradiation indicating that the same repeat unit as well as the same crystal-line unit cell were present in both of these polymers