Studies on the photodegradation of poly (methyl methacrylate)

Abouelezz, Mohamed; Waters, P F

doi:10.6028/nbs.ir.79-1766

Cited by 9 publications

(7 citation statements)

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“…The main aging mechanism of PMMA, photooxidation, has been extensively studied [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. The photodegradation mechanism of methacrylic and acrylic polymers has been followed by size exclusion chromatography and a distinction in behavior has been observed [ 22 , 24 , 25 ].…”

Section: Introductionmentioning

confidence: 99%

“…In both, scission and crosslinking are present, with scission being the dominant mechanism in acrylics, whereas in methacrylics crosslinking may compete depending on the volume of the side group, and it is therefore residual in PMMA (the methacrylic with the smallest side group, a methyl). Films and sheets of PMMA should absorb bellow 260 nm [ 13 , 15 , 16 , 17 , 18 , 19 , 20 ]; however, chromophores such as hydroperoxide groups are usually present in the polymer matrix as consequence of synthesis and processing, which may absorb radiation at wavelengths higher than the polymer and initiate photodegradation reactions [ 26 ]. The singularity of the stability of PMMA may be further explained by the fact that, to obtain the excellent optical properties typical of an acrylic sheet, the level of impurities must be extremely low [ 27 ].…”

Section: Introductionmentioning

confidence: 99%

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Characterization and Long-Term Stability of Historical PMMA: Impact of Additives and Acrylic Sheet Industrial Production Processes

et al. 2020

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This work aims at understanding the influence of the production processes and materials in the properties and long term behavior of acrylic sheet, i.e., poly(methyl methacrylate) (PMMA), a material generally considered very stable in museum collections. A comparative study was conducted in samples from cast acrylic sheets produced in the early 2000s, from which manufacturing details were known, and samples provided by the artist Lourdes Castro from acrylic sheets she had bought in the 1960s. Transparent and red opaque cast acrylic samples, containing cadmium red pigment, were used. All samples were artificially aged in a solarbox with irradiation λ > 300 nm for a total period of 8000 h, and alterations were followed by a multi-analytical approach which included Raman, infrared (FTIR-ATR) and UV-Vis spectroscopies; gravimetry; size exclusion chromatography (SEC); thermogravimetry (TGA); micro-indentation; colorimetry; and optical microscopy. Not all cast PMMA sheets presented similar stabilities. We have concluded that the production processes (which may include the polymerization conditions, the organic additives and the origin of the monomer) play a more important role in the properties and long-term behavior of these acrylic sheets than the presence of cadmium red and/or the age of the material.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Characterization and Long-Term Stability of Historical PMMA: Impact of Additives and Acrylic Sheet Industrial Production Processes

et al. 2020

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“…The results show that the absorbance peak in the ultraviolet range for pure PSF was at 268 nm, which represents the UV damage peak for the polymers [19][20][21], whilst the transmittance peak in the visible range for pure PSF was 712.5 nm. The transmittance peak indicates the real effectiveness for pure PSF [21].…”

Section: Characterizationmentioning

confidence: 91%

Polysulfone/Cellulose Acetate Butyrate Environmentally Friendly Blend to minimize the Impact of UV Radiation

Rm¹,

Za²,

Na³

et al. 2015

J Material Sci Eng

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An eco-friendly transparent blend for ultraviolet and visible light rays from polysulfone (PSF) and cellulose acetate butyrate (CAB) was prepared by melting and re-molding. Some optical, mechanical, thermal and morphological properties of the blend were studied by means of UV-Vis spectroscopy, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), scanning electron microscope (SEM) and X-ray diffraction (XRD). The UV-Vis spectroscopy results showed that the blend became more transparent in the ultraviolet region with an increase in CAB concentration, especially at the damage threshold (268 nm). The preferable blend sample contained 0.2% w/w CAB in the PSF/CAB blend, signifying low ultraviolet light absorption while preserving the transparency of the blend. The results also demonstrated that the amount of 0.2% CAB in PSF increased the modulus and thermal stability while decreasing the value of the glass transition temperature.

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“…The absorbance of high photon energy within the UV region led to scission in the polymer chain. More precisely, chromophoric groups, which are capable of absorbing the UV energy involved in the photochemical degradation reactions that occur via free radical mechanisms, led to the formation of hydroperoxides and chain scission of the polymer (Charlesby and Thomas 1962;Abouelezz and Waters 1978;Michelson et al 2012). The transmittance peak for pure PMMA in the visible region was 798 nm.…”

Section: Characterisationmentioning

confidence: 99%

“…Chromophoric groups such as the carbon-carbon double bonds (C=C) and carbonyl groups (C=O), which are able to absorb UV energy, will be involved in the photochemical degradation reactions that occur via free radical mechanisms, leading to the formation of hydroperoxides and chain scission (Davis and Sims 1983;Clough and Shalaby 1991;Dole 2013). The UV irradiation causes random chain scission, leading to variations in molecular mass, Tg, and spectra, as well as the loss of volatile particles from PMMA (Abouelezz andWaters 1978, Torikai et al 1990).…”

Section: Introductionmentioning

confidence: 99%

Miscible Transparent Polymethylmethacrylate/Cellulose Acetate Propionate Blend: Optical, Morphological, and Thermomechanical Properties

Raouf¹,

Wahab²,

Ibrahim³

et al. 2016

BioResources

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To obtain a high transmittance blend within ultraviolet and visible regions, various transparent samples of ascending percentages of polymethylmethacrylate (PMMA)/cellulose acetate propionate (CAP) were prepared by melt blending using a twin screw extruder. These blends were characterised by ultraviolet-visible spectroscopy, and the curves illustrated that the blending ratio of 10% CAP in PMMA meets the required purpose. The morphological, mechanical, and thermal properties for pure PMMA and the PMMA/CAP 10% blend were investigated using X-ray diffraction, scanning electron microscopy, dynamic mechanical analysis, and thermogravimetric analysis. The results showed that the PMMA/CAP 10% blend has an amorphous structure and low stiffness than pure PMMA. The miscible PMMA/CAP 10% blend exhibited mechanical stability below the glass transition temperature (Tg), with a slight increase in Tg value relative to that of pure PMMA. The study also demonstrated that the intermolecular interaction between blend elements has an effective influence on the physical properties of the blend.

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Studies on the photodegradation of poly (methyl methacrylate)

Cited by 9 publications

References 0 publications

Characterization and Long-Term Stability of Historical PMMA: Impact of Additives and Acrylic Sheet Industrial Production Processes

Characterization and Long-Term Stability of Historical PMMA: Impact of Additives and Acrylic Sheet Industrial Production Processes

Polysulfone/Cellulose Acetate Butyrate Environmentally Friendly Blend to minimize the Impact of UV Radiation

Miscible Transparent Polymethylmethacrylate/Cellulose Acetate Propionate Blend: Optical, Morphological, and Thermomechanical Properties

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