Thermal stability and thermal decomposition study of hindered amine light stabilizers

Balabanovich, A.I.; Klimovtsova, I. A.; Prokopovich, V. P.; Prokopchuk, N. R.

doi:10.1016/j.tca.2007.03.012

Cited by 12 publications

(12 citation statements)

References 5 publications

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“…After oxidation of the amine moiety, the formed nitroxide can act as radical scavenger. More important, the nitroxy radicals can react with polymeric alkyl radicals to form alkyloxy hindered amine derivatives, which are postulated to further react with alkylperoxy radicals, forming dialkylperoxides and regenerating the active nitroxy radicals [32]. In addition, HALS can be used to enhance flame retardancy of polymeric materials.…”

Section: Resultsmentioning

confidence: 99%

“…HALS 1 possesses a hydrogen atom at the piperidine nitrogen, whereas HALS 2 bears an alkoxy chain. The bond enthalpy is higher for N-H bond than N-O bond (i.e., 93 versus 55 kcal • mol −1 ), meaning that the homolytic cleavage of the N-O bond is much easier [32]. The degradation of PDMS with HALS 2 is more pronounced and can be explained by an easier formation of radicals that contribute to the degradation instead to trap the radicals formed by the degradation of the PDMS.…”

Section: A Hindered Amine Light Stabilizers As Polydimethylsiloxane mentioning

confidence: 97%

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Polydimethylsiloxane/Additive Systems for Thermal and Ultraviolet Stability in Geostationary Environment

Planes¹,

Coz²,

Soum³

et al. 2016

Journal of Spacecraft and Rockets

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The development of radiation resistant materials is an ongoing challenge for space industry. High-energy irradiation (ultraviolet, electrons, neutrons, protons) induce damage to materials and electronic components in spaceships. Silicone resins are often used and play a key role as coatings and adhesive materials for satellites. Polydimethylsiloxanes show material exhaustion after long-term exposure to ultraviolet irradiation. Consequently, solutions are required to increase their thermo-and photostability under solar irradiation. Three different families of additives, namely ultraviolet absorbers, hindered amine light stabilizers, and a carbazole derivative are investigated. Those ultraviolet stabilizers were mixed with polydimethylsiloxane, then a cross-linking process was run by hydrosilylation. When ultraviolet absorbers could not be used due to a miscibility problem, addition of 0.5 wt % of bis (2,2,6,6-tetramethylpiperidin-4-yl)decanedioate (hindered amine light stabilizer 1) was shown to increase the thermal stability, measured by thermogravimetric analysis, from 360 to 395°C (Td 5%). Using visible near-infrared spectroscopy and after 450 equivalent solar hours of ultraviolet irradiation, an average increase of 2.6% in the ultraviolet stability was also obtained in the wavelength range from 250 to 400 nm. A polydimethylsiloxane/ dibromocarbazole 1.0 wt% did not improve the ultraviolet stability but exhibited a strong increase (about 100°C) of the degradation temperature of the polydimethylsiloxane.

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Section: Resultsmentioning

confidence: 99%

Section: A Hindered Amine Light Stabilizers As Polydimethylsiloxane mentioning

confidence: 97%

Polydimethylsiloxane/Additive Systems for Thermal and Ultraviolet Stability in Geostationary Environment

Planes¹,

Coz²,

Soum³

et al. 2016

Journal of Spacecraft and Rockets

View full text Add to dashboard Cite

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“…Hindered amine light stabilizer (HALS, mainly 2,2,6,6‐tetramethylpiperidine derivatives) is one of the most efficient photostabilizers which has been developed since the 1970s and its application has been broadened increasingly [9–11]. The stabilizing mechanism of HALS is believed to involve radical scavenging, and through the well‐known Denisov cycle the nitroxide is a significant stabilizing substance [12].…”

Section: Introductionmentioning

confidence: 99%

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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“…In the current work, another type of light stabilizer, hindered amine light stabilizers (HALS), was attempted to incorporate into the semi-alicyclic CPI films so as to improve the UV stability. Different from the benzotriazole UV absorbers, the HALS photo-stabilizer can achieve the photo-stabilization of the polymers by capturing the free radicals produced during the photo-oxidation and degradation, and decompose the hydrogen peroxide and quenching the excited state energy [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. This operation mechanism is quite suitable for the photo-stabilization of CPI films according to the photodegradation mechanism of the polymers.…”

Section: Introductionmentioning

confidence: 99%

Enhancement of Ultraviolet Light Resistance of Colorless and Transparent Semi-Alicyclic Polyimide Nanocomposite Films via the Incorporation of Hindered Amine Light Stabilizers for Potential Applications in Flexible Optoelectronics

Wei

He²,

Yuan³

et al. 2022

Polymers

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Optically transparent polymer films with excellent thermal and ultraviolet (UV) resistance have been highly desired in advanced optoelectronic fields, such as flexible substrates for photovoltaic devices. Colorless and transparent polyimide (CPI) films simultaneously possess the good thermal stability and optical transparency. However, conventional CPI films usually suffered from the UV exposure and have to face the deterioration of optical properties during the long-term service in UV environments. In the current work, the commercially available hindered amine light stabilizers (HALS) were tried to be incorporated into the semi-alicyclic CPI matrix with the aim of enhancing the UV exposure stability. For this target, a CPI-0 film was first prepared from hydrogenated pyromellitic dianhydride (HPMDA) and 2,2′-dimethylbenzidine (DMBZ) via a one-step polycondensation procedure. Then, the commercially available HALS were incorporated into the CPI-0 (HPMDA-DMBZ) film matrix to afford four series of CPI/HALS composite films. Experimental results indicated that the Tinuvin® 791 HALS showed the best miscibility with the CPI-0 film matrix and the derived CPI-D series of composite films exhibited the best optical transmittances. The CPI-D nanocomposite films showed apparently enhanced UV exposure stability via incorporation of the 791 additives. For the pristine CPI-0 film, after the UV exposure for 6 h, the optical properties, including the transmittance at the wavelength of 350 nm (T350), lightness (L*), yellow indices (b*), and haze obviously deteriorated with the T350 values from 55.7% to 17.5%, the L* values from 95.12 to 91.38, the b* values from 3.38 to 21.95, and the haze values from 1.46% to 9.33%. However, for the CPI-D-10 film (791: CPI-0 = 1.0 wt%, weight percent), the optical parameters were highly maintained with the T350 values from 61.4% to 53.8%, the L* values from 95.46 to 95.36, the b* values from 1.84 to 1.51, and the haze values from 0.69% to 3.34% under the same UV aging conditions.

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Thermal stability and thermal decomposition study of hindered amine light stabilizers

Cited by 12 publications

References 5 publications

Polydimethylsiloxane/Additive Systems for Thermal and Ultraviolet Stability in Geostationary Environment

Polydimethylsiloxane/Additive Systems for Thermal and Ultraviolet Stability in Geostationary Environment

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

Enhancement of Ultraviolet Light Resistance of Colorless and Transparent Semi-Alicyclic Polyimide Nanocomposite Films via the Incorporation of Hindered Amine Light Stabilizers for Potential Applications in Flexible Optoelectronics

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