Effect of the combination of a benzotriazole‐type ultraviolet absorber with thermal stabilizers on the photodegradation of poly(vinyl chloride)

Abstract

The effect of the combination of a benzotriazole type of UV absorber (UV326) with different types of thermal stabilizers, including an organic calcium complex and an organotin mercaptide, on the photodegradation of poly(vinyl chloride) (PVC) was investigated by color difference measurements, UV-vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and viscosityaverage molecular weight (M Z ) determinations. Films of PVC containing 0.5 phr of UV326, with or without 2 phr of thermal stabilizer, were prepared by solution casting and subjected to accelerated UV weathering under xenon light with an irradiance of 0.51 W/(m 2 nm) at 658C. The results revealed that both UV326 and the mixture of UV326 with the organic calcium complex displayed good performance in inhibiting the photodehydrochlorination and photooxidation of PVC. In contrast, the combination of UV326 and the methyltin mercaptide remarkably accelerated the discoloration of PVC when the irradiation time increased from 300 to 400 h because of the UV sensitivity of the organotin. However, carbonyl index data indicated that a hydrogen abstraction reaction did not take place between UV326 and the methyltin mercaptide, so that the photooxidation of the PVC film was prevented effectively during the whole period of exposure, a result which may be attributed to the strong steric hindrance effect of the tert-butyl group at the 3-position of the phenyl ring in UV326. The changes of M Z were in good accordance with the results obtained from other characterizations.

Synthesis and characterization of rutile titanium dioxide/polyacrylate nanocomposites for applications in ultraviolet light‐shielding materials

“…Various UV stabilizers have been used for helping with the UV deterioration problem, which could be divided into four categories on the basis of the mechanism of UV shielding: UV absorbers, radical scavengers, radical quenchers, and UV‐shielding agents. UV absorbers usually include benzotriazole , benzophenone , and salicylate . However, such substances can easily be lost from the polymer matrix because of their low molecular weight.…”

Performance of polylactide against UV irradiation: Synergism of an organic UV absorber with micron and nano-sized TiO2

“…16,17 In this group, “benzotriazole-type” organic UV absorbers are known as one of the most effective one. In the literature, although there are certain numbers of studies revealing the effectiveness of this type of UV absorber for many polymeric materials including aromatic and aliphatic polyesters, 18–20 no work has been reported for the neat PLA structure. Therefore, one of the purposes of this study will be to indicate influence of benzotriazole-based organic UV absorber on the performance of PLA.…”

Transparent plasticised PVC film with ultraviolet and high-energy visible light shielding performance

“…UV326 can absorb the UV radiation from 320 to 400 nm, while UV531 can absorb the UV radiation from 300 to 350 nm. Generally, the UV light from 300 to 400 nm is mainly responsible for the photo-degradation of PVC samples [20]. As a result, UV absorber could protect packing films against UV degradation.…”