Relationship between physical and mechanical properties of accelerated weathering and outdoor weathering of PVC-coated membrane material under tensile stress

Abstract

To estimate the photo-oxidation aging performance of PVC-coated membrane material in atmospheric conditions under tensile stresses, the relationship between physical and mechanical properties under accelerated weathering test and outdoor weathering test is studied with the same cumulative UV radiation energy. And then, both tensile strength and whiteness index were measured and compared to characterize the property change of membrane material after aging under four different tensile stresses (0%, 5%, 10% and 20% of the breaking strength), respectively. In addition, FTIR spectrometry was applied to characterize the chemical components of the samples under different weathering conditions, and the carbonyl index was extracted. The results show that there were significant differences of tensile strength and carbonyl index between two kinds of aging conditions, whereas with the increasing tensile stresses, the whiteness index represented a consistent increasing deviation of accelerated weathering from the outdoor weathering. However, the relationship have been built between both whiteness index and tensile strength retention of accelerated weathering and those of outdoor weathering conditions after a Schwarzschild’s modification. Therefore, the service lifespan of PVC-coated membrane materials can be evaluated by accelerated weathering tests under tensile stresses.

Anti-Gnawing, Thermo-Mechanical and Rheological Properties of Polyvinyl Chloride: Effect of Capsicum Oleoresin and Denatonium Benzoate

“…PVC degradation firstly induced the oxidation of these polyenes providing conjugated double bonds and the carbonyl groups [46]. The decrease in absorption band means that the PVC chains were maybe cut and the atoms decreased especially in polyene and the carbonyl groups by water, temperature and UV irradiation during weathering test [47].…”

Correlation between artificial and natural weathering of hemp fibers reinforced polypropylene biocomposites

“…Similarly, in another study, the increment of carbonyl absorbance (measured through infrared experiments) of PP against cumulative exposure energy highlighted outdoor exposure as more impactful than accelerated one for a same amount of UV exposure [13]. Yang et al attempted to correlate outdoor and artificial weathering (UV radiation followed by spray) of polyvinyl chloride (PVC) in terms of cumulative UV radiation energy Q [14]. When samples were subjected to a same Q value, desaturation and ultimate strength decrease were faster under accelerated ageing than under outdoor one.…”

“…So UV lamps are supposed to closely simulate spectral power distribution of sunlight [8]. The reciprocity law is classically used to correlate two ageing [9][10][11]. This law implies that for a same cumulative UV energy under two types of ageing, the degradation degrees are similar even if light intensities differ.…”

“…Short-period exposure in chamber reproduced same color variations as outdoor whereas longer duration caused darkening that was not observed under natural ageing. Nevertheless, Yang et al showed that when exposition continues further, the surface color of PVC could gradually change from chalky (1000 h) to dark (2000 h) [14]. Thus, this darkening can also result from too long artificial exposition.…”

Investigation of some weathering impacts on tearing properties of PVC-coated fabrics used for architectural purposes

“…However, in the case of tearing performance there is lack of information about such changes as, in the majority of cases, investigations focus on changes of tensile properties of textile architecture materials after aging. Decrease of tensile strength along with changes in other characteristics of coated fabrics was established analysing the results of effects of various artificial aging factors [34–36]. Some other studies pointed out that after aging tensile properties of the PVC coated fabric remain significantly unchangeable [4,5,37].…”