Photodegradation profiles of PVC compound and wood/PVC composites under UV weathering

Abstract

Abstract. This work aimed to study the effect of different ultraviolet (UV) weathering conditions (natural and accelerated) on the photodegradation of polyvinyl chloride (PVC) and wood/polyvinyl chloride (WPVC) composites by considering the structural and physical changes of PVC and WPVC samples as well as examining the photodegradation profiles at different depths from the sample surfaces. The photodegradation of PVC and WPVC composites under natural weathering conditions were lower than those under accelerated weathering conditions. The addition of Tinuvin P stabilizer at 2 phr was sufficient to stabilize PVC and WPVC composites, whereas the presence of wood appeared to accelerate the photodegradation of PVC under both natural and accelerated weathering conditions. When considering the photodegradation profiles at different depths of the samples, it was found that the polyene and carbonyl sequences of PVC and WPVC composites were high at the sample surfaces and tended to decrease rapidly with increasing depth from the specimen surface before stabilizing at a depth of 60 µm for PVC and 80 µm for WPVC composites. The differences in specimen depths for the stabilization of polyene and carbonyl sequences in PVC and WPVC samples implied that the presence of wood particles enhanced the absorption of UV radiation by the WPVC composite samples.

Preparation and Characterization of Novel PVC/Silica–Lignin Composites

“…Production of PVC composites containing fillers from renewable materials, including natural plant fibers such as jute, bamboo, sisal, and rice straw [16][17][18][19], as well as wood fiber and lignin [20][21][22][23][24][25][26][27][28][29], leads to materials with advantageous properties that may be successfully used as construction materials as well as in the automotive and furniture industries.…”

Effects of UV-accelerated weathering and natural weathering conditions on anti-fungal efficacy of wood/PVC composites doped with propylene glycol-based HPQM

“…Both natural weathering and QUV-accelerated weathering aging had similar effects on the anti-microbial performance changes for PVC and WPVC composites, but the changes were slower for natural weathering. This can also be explained by the differences in energy provided by natural weathering and QUV aging, as discussed earlier and in Chaochanchaikul et al [33]. Tables 3 and 4 show the flexural and physical properties of PVC and WPVC before and after QUVaccelerated weathering aging and natural weathering.…”

“…The flexural strength of neat PVC increased during QUV-accelerated weathering aging and natural weathering. The increased flexural strength after aging can be explained by the presence of polyene [33]. In the case of WPVC-50 and WPVC-100, the flexural strength decreased during QUV-accelerated weathering aging and natural weathering.…”

“…Moreover, the presence of wood appeared to accelerate the photodegradation of WPVC under QUV-accelerated weathering aging conditions and to decrease the Timeline of release behavior of HPQM in the WPVC matrix when exposed to QUV-accelerated weathering aging and natural weathering mechanical properties of the WPVC. This can be explained by the induced dipole-dipole interaction between OH-groups of wood flour and Cl atoms on the PVC chain [33]. The flexural strength of neat PVC increased during QUV-accelerated weathering aging and natural weathering.…”

“…When comparing between QUV weathering ( Figure 2) and natural weathering (Figure 4), the reduction of anti-fungal efficacy for neat PVC and WPVC was more pronounced for QUV weathering. It is known that radiation from sunlight under natural weathering conditions includes visible light, UV, and infrared radiation; whereas the radiation from a UVB lamp under QUV weathering conditions contains only UV radiation (280-380 nm) [33]. In general, radiation at UV Srimalanon et al -eXPRESS Polymer Letters Vol.10, No.4 (2016) wavelengths is primarily responsible for PVC degradation.…”