Mechanical degradation of PVC films monitored by photoacoustic spectroscopy

Abstract

SynopsisPVC films were subjected to mechanical degradation at room and elevated temperatures and monitored by photoacoustic spectroscopy. Broken bonds in the main PVC chain result in the-formation of "mechanc-radicals," which in turn yield a zipper reaction and the formation of submicrocracks in the PVC samples. The mechanistic schemes based on the formation of the mechanc-radicals are introduced and are successfully supported by the experimental r e sults.

Mechanodegradation

“…Rapid increase in torque marks extensive degradative processes. [12][13][14] Radical processes and the effect of nitroxyl radicals on PVC stabilization were investigated by torque rheometry. 10 Capillary rheometry can also be used to estimate the effect of shear rate (Figure 8.8), although again, temperature together with mechanical shear are essential factors controlling the degradation rate of PVC and thus stabilizer reaction rate.…”