Influence of viscoelastic properties of the matrix and of the type of plasticizer on the optical strength of transparent polymers

An experimental investigation was made of the influence of the viscoelastic properties of the polymer matrix and of the type of plasticizer on the optical strength of transparent polymers subjected to the action of laser pulses of wavelengths 0.69 and 1.06 μ at temperatures from –55 to +180 °C. A considerable increase was observed in the optical strength at temperatures close to the glass-transition temperature. A study was made of the damage to a polymer occurring in several stages corresponding to the formation of scattering centers, formation of luminescence centers, and macrodamage. It was established that the viscoelastic properties of the matrix affect mainly the macrodamage process. It was also found that the optical strength of polymers may be increased considerably by introduction of admixtures which retard effectively the formation of scattering centers.