Thermo- and photo-oxidative stability and improved processability of polyamide stabilized with a new functional additive

During processing polyamides can undergo thermo-mechanical degradation due to the mechanical stress and to the high temperature applied to the melt. Degradation can occur also during the polyamides lifetime due to many driving forces, like temperature, ultraviolet radiations, etc. The mechanisms of degradation are not well understood and the stabilization with usual stabilizers, like phenol antioxidants, is not so efficient as for other classes of polymers. The aim of this work is the study of the effects of the addition of a new multifunctional additive on the processing and on the thermo- and photo-stabilization of polyamide-6. This additive is able to prevent the thermo-mechanical degradation and also to enlarge the molecular weight distribution improving the processability of this polymer in operations where the elongational flow is involved. Moreover, the presence of this additive extends significantly the lifetime of the polyamide when subjected to thermo- and photo-oxidative stress. Copyright © 2005 John Wiley & Sons, Ltd.