Study on the effect of galbanic acid on photo-oxidative degradation of linear low density polyethylene (LLDPE) films

Abstract

Photo-oxidative degradation of LLDPE films (~ 250 μm thick) containing varying amounts of galbanic acid (a type of coumarin derivatives) was investigated by exposing the films to an artificial sunlight (emitted by 300 W OSRAM UltraVitalux lamps) at 40 ○ C for extended time periods. Photo-oxidative degradation of the neat polymer film and the LLDPE films containing benzophenone (an active photo-initiator for PE) and coumarin alone were also studied under similar conditions for comparison. The rate of photo-oxidation was assessed by measuring tensile properties, gel content, carbonyl index, molecular weight and density. It was shown that galbanic acid was highly effective in accelerating photo-oxidation of LLDPE films and an outstanding acceleration of photo-oxidation was observed for the film containing 0.2 wt % of galbanic acid in comparison with the film containing the same amount of benzophenone. However, the film containing coumarin did not exhibit considerable difference in behaviour in photo-oxidation relative to the neat LLDPE film during the exposure time. On the basis of the obtained results, the prooxidant activity of galbanic acid was described in terms of activity of the functional groups existing in the substituted moiety of its molecules.

Characterization of microplastics and its Pollution load index in freshwater Kumaraswamy Lake of Coimbatore, India

“…According to (Wang et al 2018), the most abundant microplastic forms in Hong Lake and Dongting Lake were polyethylene and polypropylene. Gopinath et al (2020) identi ed high-density polyethylene and polypropylene microplastics in Chennai's Red Hills Lake, and their spectra show similar characteristic peaks 2919 and 2847 cm − 1 (-CH), 1470 cm − 1 (-CH), and 716 cm − 1 (-CH) of polyethylene and polypropylene spectra shows wavenumbers of 2866 cm − 1 , 2836 cm − 1 , 2950 cm − 1 as well as linear low-density polyethylene microplastic were also reported in (Jahanmardi and Assempour 2008) studies. These polymer types are widespread in lakes and may oat and move long distances in wind and water due to their low density (High-density polyethylene:0.93 to 0.97 g/cm 3 , Linear low-density polyethylene: 0.915-0.925 g/cm 3 , and Polypropylene:0.85 g/cm 3 ) (Ashraf 2015).…”

Synthesis, biosynthesis and biological activities of galbanic acid – A review

“…Investigations of photo-oxidative degradation of LLDPE films containing various amounts of GA revealed that GA was highly effective in accelerating photooxidation of LLDPE films. Jahanmardi and Assempour (2008a) reported that an outstanding acceleration of photooxidation observed for the film containing 0.2% wt of GA in comparison with the film containing the same amount of benzophenone. Also, GA was known as an effective photosensitizing agent in polyethylene.…”