scholarly journals Photostability Study of Some Modified Poly(vinyl chloride) Containing Pendant Schiff’s Bases

2016 ◽  
Vol 13 (2) ◽  
pp. 188-195
Author(s):  
Baghdad Science Journal
Keyword(s):  
Vinyl Chloride ◽  
Rate Constant ◽  
Degradation Rate ◽  
Schiff’S Bases ◽  
Photo Degradation ◽  
Photo Oxidation ◽  
Modified Polymers ◽  
Poly Vinyl Chloride ◽  
Schiff's Bases ◽  
Degradation Rate Constant

The polymers modified Poly(vinyl chloride) differ in their tendency to photo oxidation comparing with that unmodified. It has been studied Photostability for modified Poly(vinyl chloride) chains using Schiff’s bases derivative of (5-amino-1, 3, 4-thiadiazole-2-thiol) in a manner casting of plastic chips with thickness (40) in a solvent Tetrahydrofuran. It has been determined the effectiveness Photostability of these modified polymers through the photo degradation rate constant for photostabilizer (kd) for the modified Poly (vinyl chloride). Attributed efficiency of these Poly(vinyl chloride) chips in Photostability by replace the atom Cl Poly(vinyl chloride) chains ends more stable than light stabilizer.

scholarly journals Controlling the Photo-Degradation Rate Constant of PS Containing Nickel(II) Complex

2019 ◽  
Vol 22 (3) ◽  
pp. 8-17
Author(s):  
Zainab Hussain ◽  
◽  
Raghda Alsayed ◽  
Atheel Alwash ◽  
Ahmed Ahmed ◽  
...  
Keyword(s):  
Rate Constant ◽  
Degradation Rate ◽  
Photo Degradation ◽  
Degradation Rate Constant

scholarly journals Photostability Study of Some Modified Poly(vinyl chloride) Containing Pendant Schiff’s Bases

2016 ◽  
Vol 13 (2) ◽  
pp. 188-195 ◽  
Author(s):  
Naser Shaalan ◽  
◽  
Nawres Laftah ◽  
Raad Muslih ◽  
Emad Yousif ◽  
...  
Keyword(s):  
Vinyl Chloride ◽  
Schiff’S Bases ◽  
Poly Vinyl Chloride ◽  
Schiff's Bases

scholarly journals Comparison of different photo-oxidation conditions of poly(vinyl chloride) for outdoor applications

2008 ◽  
Vol 27 (6) ◽  
pp. 743-751 ◽  
Author(s):  
L.E. Pimentel Real ◽  
A.M. Ferraria ◽  
A.M. Botelho do Rego
Keyword(s):  
Vinyl Chloride ◽  
Photo Oxidation ◽  
Poly Vinyl Chloride

scholarly journals UV-Absorbing Gallic Acid Derivatives as Functional Reinforcing Fillers in Poly(Vinyl Chloride) Films

2018 ◽  
Vol 3 (1) ◽  
pp. 40-45
Author(s):  
Raghad M. Omer ◽  
Emaad T. Bakir ◽  
Ahmed Ahmed ◽  
Ali Hasan ◽  
Emad Yousif
Keyword(s):  
Gallic Acid ◽  
Vinyl Chloride ◽  
Rate Constant ◽  
Poly Vinyl Chloride ◽  
Reinforcing Fillers ◽  
Effective Stabilizer

The poly(vinyl chloride) PVC was photostabilized by gallic acid derivatives (0.5% by weight). The photodecomposition rate constant was reduced significantly in the existence of gallic acid derivatives along with PVC (blank). R1 compound was found to be the most effective stabilizer in photostabilization of PVC. The photodecomposition rate constant for PVC films containing R1 was found to be 1×〖10〗^(-4) compared to 8×〖10〗^(-4) sec-1 for PVC films in the absence of any additives. Different mechanisms of photostability for PVC films that involve gallic acid derivatives have been proposed.

Sensitivity analysis using a diffuse pollution hydrologic model to assess factors affecting pesticide concentrations in river water

2010 ◽  
Vol 62 (11) ◽  
pp. 2579-2589 ◽  
Author(s):  
Koji Tani ◽  
Yoshihiko Matsui ◽  
Kentaro Narita ◽  
Koichi Ohno ◽  
Taku Matsushita
Keyword(s):  
Sensitivity Analysis ◽  
River Water ◽  
Rate Constant ◽  
Degradation Rate ◽  
Hydrologic Model ◽  
Adsorption Coefficient ◽  
Pesticide Concentration ◽  
Artificial Drainage ◽  
Degradation Rate Constant ◽  
Intermittent Irrigation

We quantitatively evaluated the factors that affect the concentrations of rice-farming pesticides (an herbicide and a fungicide) in river water by a sensitivity analysis using a diffuse pollution hydrologic model. Pesticide degradation and adsorption in paddy soil affected concentrations of the herbicide pretilachlor but did not affect concentrations of the fungicide isoprothiolane. We attributed this difference to the timing of pesticide application in relation to irrigation and drainage of the rice paddy fields. The herbicide was applied more than a month before water drainage of the fields and runoff was gradual over a long period of time, whereas the fungicide was applied shortly before drainage and runoff was rapid. However, the effects of degradability-in-water on the herbicide and fungicide concentrations were similar, with concentrations decreasing only when the rate constant of degradation in water was large. We also evaluated the effects of intermittent irrigation methods (irrigation/artificial drainage or irrigation/percolation) on pesticide concentrations in river water. The runoff of the fungicide, which is applied near or in the period of intermittent irrigation, notably decreased when the method of irrigation/artificial drainage was changed to irrigation/percolation. In a sensitivity analysis evaluating the synergy effect of degradation and adsorbability in soil, the degradation rate constant in soil greatly affected pesticide concentration when the adsorption coefficient was small but did not affect pesticide concentration when the adsorption coefficient was large. The pesticide concentration in the river water substantially decreased when either or both the degradation rate constant in soil and adsorption coefficient was large.

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