Synergism between Hydrogen Bond-type Ultraviolet Absorbers and Hindered Amine Light Stabilizers

Ohkatsu, Yasukazu; Takenaka, Hiroyuki

doi:10.1627/jpi.51.88

Cited by 4 publications

(4 citation statements)

References 5 publications

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“…Similar to the addition of single T770, the photooxidation of PVC with T770/UV531 possessed three steps: accelerated propagation (in the first 100 h of irradiation), increase slowly (100–300 h) and accelerated propagation (the last 100 h). These phenomena confirm that benzotriazole UVA more efficiently facilitates HALS in preventing photooxidation compared with benzophenone for UVA [35]. This may be due to the inherent higher efficacy of UV326 than UV531, or there were some unknown reactions that took place in PVC with T770/UV531 and intercepted the normal transfer of internal hydrogen bond.…”

Section: Resultssupporting

confidence: 52%

Combined effect of hindered amine light stabilizer and ultraviolet absorbers on photodegradation of poly(vinyl chloride)

Chai

Chen

Zhang

2012

Vinyl Additive Technology

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The combined effect of a basic hindered amine light stabilizer (HALS) and ultraviolet absorbers (UVAs) on casted poly(vinyl chloride) (PVC) films, during photodegradation, was studied by color change, ultraviolet‐visible (UV–vis) spectroscopy, Fourier‐transform infrared (FTIR) spectroscopy, and viscosity‐average molecular weight. It was found that the basic amine groups in the HALS (T770) could promote the dehydrochlorination, thereby accelerating the photooxidation of PVC films. Meanwhile, T770 could scavenge the radicals formed and restrain the aging of PVC to some extent. The above‐mentioned aspects were competing factors: the former played a dominant role during the first 100 h, while the latter counteracted the former effect to some extent between 100 and 300 h. A benzotriazole derivative (UV326) absorbs more UV radiation in the UV‐A region (320–400 nm), which mainly causes the photodegradation of PVC samples, than a benzophenone derivative (UV531). Thus, UV326 is a more efficient UV absorber than UV531 in prohibiting the photooxidation and chain scission of PVC films. The combination of T770 and UV326 effectively protected PVC films from dehydrochlorination and photooxidation. The combination of T770 and UV531 accelerated the dehydrochlorination and discoloration of PVC films. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers

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Section: Resultssupporting

confidence: 52%

Combined effect of hindered amine light stabilizer and ultraviolet absorbers on photodegradation of poly(vinyl chloride)

Chai

Chen

Zhang

2012

Vinyl Additive Technology

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“…A mixture of M2 (0.1 g, 0.37 mmol), Ag 2 O (0.7 g, 3 mmol), and anhydrous sodium sulfate (1.0 g) was stirred in CH 2 Cl 2 (5 mL) at room temperature for 50 min in the dark . The resulting reaction mixture was filtered, and the filtrates were condensed by rotary evaporation, producing light brown crystals.…”

Section: Methodsmentioning

confidence: 99%

“…A mixture of M2 (0.1 g, 0.37 mmol), Ag 2 O (0.7 g, 3 mmol), and anhydrous sodium sulfate (1.0 g) was stirred in CH 2 Cl 2 (5 mL) at room temperature for 50 min in the dark. 22 The resulting reaction mixture was filtered, and the filtrates were condensed by rotary evaporation, producing light brown crystals. The product was redissolved in tetrahydrofuran (8 mL) and mixed with GSH (0.17 g, 0.56 mmol) or NAC (0.09 g, 0.56 mmol) dissolved in H 2 O (200 μL), followed by 4 h stirring at room temperature.…”

Section: ■ Experimental Proceduresmentioning

confidence: 99%

Metabolic Activation and Cytotoxicity of Propafenone Mediated by CYP2D6

Shi

Chen

et al. 2022

Chem. Res. Toxicol.

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Propafenone (PPF) is a class IC antidysrhythmic drug, which is commonly used for the treatment of atrial fibrillation and other supraventricular arrhythmias. It is also a β-adrenoceptor antagonist that can cause bradycardia and bronchospasm. Hepatotoxicity is one of the adverse reactions reported, with clinical manifestations including acute cholestasis and hepatocyte necrosis. However, the mechanism of PPF-induced hepatotoxicity remains unclear. The present study was conducted to identify reactive metabolite(s) to determine related metabolic pathways and define the possible association of the bioactivation with PPF cytotoxicity. An O-demethylation phase I metabolite (M1), a further position C5 hydroxylation (para-position of the benzene ring) metabolite (M2), glutathione (GSH) conjugates (M3 and M4), and N-acetylcysteine (NAC) conjugates (M5 and M6) were detected in rat liver microsomal incubations containing PPF and GSH or NAC as trapping agents. The corresponding GSH conjugates and NAC conjugates were found in the bile and urine of rats after PPF administration, respectively. The observed GSH and NAC conjugates indicate that a quinone metabolite was generated in vitro and in vivo. Recombinant P450 enzyme incubations showed that CYP2D6 was the principal enzyme catalyzing this metabolic activation. Quinidine, a selective inhibitor of CYP2D6, attenuated the susceptibility of hepatocytes to the cytotoxicity of PPF. The results suggest that PPF was metabolized to a p-quinone intermediate which may be involved in PPF-induced hepatotoxicity.

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“…In addition, even if HALS nitrosonium oxidizes benzophenone to 2-benzoyl-p-quinone, this is promptly reduced to a new UVA by HALS NOH. Table 4 summarizes the semi-quantitative evaluation of the interactions of HALS and UVA 43) . The upper line shows the synergistic effect of both additives in the photo-oxidation of styrene in the presence of UVA and HALS NOH.…”

Section: 2 Synergistic Interaction Of Hals and Uvamentioning

confidence: 99%

Search for Unified Action Mechanism of Hindered Amine Light Stabilizers

Ohkatsu

2008

J. Jpn. Petrol. Inst.

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Hindered amine light stabilizers (HALS) possess many functions unlike other additives and are frequently used to extend the service life of polymeric materials, but show particular compatibility with certain other additives. However, combination does not always show synergistic actions, but sometimes has antagonistic effects. Most previous research into the interaction of HALS with other additives has focused on qualitative high synergism to high antagonism, and no common understanding has been reached. HALS and homologs have many derivatives which are classified here as "good" HALS and "bad" HALS, including a new HALS derivative, HALS nitrosonium. The investigation of the antagonism of HALS with other additives has been based on only "good" HALS. The present study discusses the chaotic interactions of HALS with other additives kinetically and thermodynamically by separately considering the synergism of "good" HALS and the antagonism of "bad" HALS. This approach has lead to a new technique for unified evaluation of the interaction semi-quantitatively. The results summarized here clarify the complex and diverse characteristics of HALS and present the possibility that the action mechanism of HALS alone and together with other additives can be discussed based on a unified mechanism. Such united ideas can determine additive formulation much more easily and facilitate the development of new additives, resulting in more stable and functional polymeric materials.

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Synergism between Hydrogen Bond-type Ultraviolet Absorbers and Hindered Amine Light Stabilizers

Cited by 4 publications

References 5 publications

Combined effect of hindered amine light stabilizer and ultraviolet absorbers on photodegradation of poly(vinyl chloride)

Combined effect of hindered amine light stabilizer and ultraviolet absorbers on photodegradation of poly(vinyl chloride)

Metabolic Activation and Cytotoxicity of Propafenone Mediated by CYP2D6

Search for Unified Action Mechanism of Hindered Amine Light Stabilizers

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