Investigation on thermo-stabilization effect and nonisothermal degradation kinetics of the new compound additives on polyoxymethylene

摘要

An increase in the thermal stability of several new additives on polyoxymethylene (POM) was attempted via thermogravimetric analysis (TGA) (static state) and balance torque testing (dynamic state), which truly reflec_ted the processing in practice. The thermal stability of РОМ was improved by adding some of additives actually, especially for the compound stabilizer with oxidized polyethylene wax (OPE), low molecular weight polyamide 6 (LMWPA6) and triphenyl phosphate (TPP) from the static and dynamic data. Furthermore, the kinetic parame_ters for compound stabilizers of РОМ degradation were calculated from thermogravimetry (TG) curves by Coats_Redfernd method. The results reveal that the degradation temperatures of РОМ can be obviously raised by com_pound stabilizers OPE/LMWPA6/TPP. The long-term thermo-stability test of POM shows that POM with stabi_lizing system above has no obvious decrease in impact strength after storage duration of 15 days in an oven at 140 °C.