关键词:
POROSITY
POLYTEF
RADIATION
IRRADIATION
VISCOUS flow
SURFACE tension
摘要:
The X-ray degree of crystallinity, chi, and the density, rho, of suspension-polymerized polytetrafluoroethylene after its irradiation above the melting temperature of the crystalline phase are studied. A comparison of dose dependences of chi and rho makes it possible to infer that pores occur in the initial polytetrafluoroethylene and that porosity substantially decreases during irradiation. The time of pore contraction in polytetrafluoroethylene after its radiation modification above the meting temperature is estimated with respect to the order of the magnitude. This estimate is based on the consideration of viscous flow under the action of surface-tension forces.