Characterization of time- and/or frequency-dependent material properties usually requires shifting of the measured segments according to the Time-Temperature Superposition principle. This paper presents a closed form mathematical methodology (CFS) which completely removes ambiguity related to the manual shifting procedures. The derivation of the shifting algorithm is presented, and its validation using several simulated- and real- experimental data. It has been shown that error caused by shifting performed with CFS is at least 10–50 times smaller then the underlying experimental error.
COBISS.SI-ID: 11702043
Low density polyethylene (LDPE) was exposed to multiple consecutive extrusion cycles to simulate the process of mechanical recycling. W characterized thermal, rheological, mechanical and morphological properties. The results show that simulated recycling did not significantly change thermal properties of LDPE. However, results from rheological measurement, crystallinity, creep measurement and GPC suggest that thermal degradation and gelation of LDPE occur after extensive extrusion which leads to crosslinking of the polymer chains.
COBISS.SI-ID: 11910427