Creep of Thermoplastics in Air and in Physiological Solution,

Creep of polymeric materials has been studied mainly under conditions of static monoaxial tension. We have now established the existence of elastic, resilient-elastic nonsteady-state and viscous steady-state components of total creep. In this case, the full deformation under constant tensile load and at constant temperature, as well as the duration of load, are interrelated. We studied the creep of polymers under normal conditions in air and in a liquid medium - a physiological solution 0.9 NaCl solution in distilled water under static bending and pressure. The subjects of the study were polyamide - 12 P-12, a copolymer of trioxane with dioxalene STD, fluorinated polymethyl methacrylate PMMAF, and molding polyethylene terephtalate PETF.