Thermal Properties, Degradation and Stability of Poly(vinyl chloride) Predegraded Thermooxidatively in the Presence of Dioctyl Phthalate Plasticizer

Abstract

Thermooxidative degradation of poly(vinyl chloride) (PVC) is inevitable during processing of PVC. Recycling of this polymer requires reprocessing in most of the cases, and due to the low thermal stability of PVC, it is of paramount importance to reveal the effect of thermooxidation on the thermal stability of this commercially important polymer. However, detailed systematic investigations are lacking on this crucial problem. In this study, the thermal behavior of PVCs thermooxidized in dilute dioctyl phthalate (DOP) (di(2-ethylhexyl) phthalate, DEHP) plasticizer was investigated by DSC, thermal gravimetry and isothermal degradation under inert atmosphere. It was found that thermooxidation leads to PVCs with certain extent of internal plasticization by DOP chemically bound to the PVC chains and by the oxidized chain segments as well. These striking results also indicate that the decreased thermal stability caused by thermooxidation in the course of the primary processing of this polymer should be taken into account in order to efficiently stabilize PVC products for reprocessing and recycling.2

Epoxidized castor oil‐based diglycidyl‐phthalate plasticizer: Synthesis and thermal stabilizing effects on poly(vinyl chloride)

“…The thermogravimetric results for F0, F1, F2, F3, and F4 are shown in Figure (b). The five films are thermally stable below 190 °C in nitrogen gas and undergo two thermal degradation steps above 190 °C in each curve, which closely coincides with previous reports . The first degradation step (at ~250‑350 °C) is attributed to the thermal decomposition of the plasticizer and to PVC dechlorination.…”

“…The first degradation step (at ~250‑350 °C) is attributed to the thermal decomposition of the plasticizer and to PVC dechlorination. The greatest weight loss occurred in the first step, while the second step (at ~430‑500 °C) corresponded to the formation of aromatic compounds . Characteristic thermal degradation data are summarized in Table ( T i , T 5 , T 10 , T 50 , T 70 , and R 400 ).…”

Photostability, thermal and mechanical properties of poly(vinyl chloride)/novel acrylate terpolymer blend

“…The changes of the molecular structure of the PVC by the effect of UV light are important issue that has attracted the attention of many researchers . Formation of conjugated polyene sequences resulting from UV irradiation gives rise to discoloration of the polymeric matrix and other damaging effects in its physical properties . As known, polymeric materials in general are extensively used in industries because of the ease production, ductile and also their light weight nature.…”

Preparation and characterization of innovative cellulose diacetate/epoxy resin blends modified by isophorone diamine

“…Liquid epoxy resin (EP) contains a large number of epoxy groups and hydroxyls, which have good compatibility with CA, which contains a lot of ester bonds . Moreover, the molecular chains of liquid EP are longer than those of conventional plasticizers …”