In contrast to metals the mechanical properties of polymers are distinctively time-dependent. In this thesis we studied the relation of relaxation modulus of polymers PTFE, PC, PVC, PP, ABS and PA6 with time when subjected to a constant deformation. For this purpose, we developed a tensile testing device with pneumatic grips and a computer interface.
We have concluded that the relaxation modulus-time relation followed the predicted behaviour. The greatest difference between modulus values in t = 1 s and t = 1001 s was observed with PTFE (39,9 %), while the smallest was observed with PC (10,5 %).