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Photodegradation of poly(methyl methacrylate) by monochromatic light: Quantum yield, effect of wavelengths, and light intensity
Author(s) -
Torikai Ayako,
Ohno Masakuni,
Fueki Kenji
Publication year - 1990
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1990.070410513
Subject(s) - quantum yield , photochemistry , irradiation , photodegradation , bond cleavage , materials science , monochromatic color , methyl methacrylate , poly(methyl methacrylate) , yield (engineering) , light intensity , oxetane , wavelength , chemistry , polymer chemistry , optics , polymer , optoelectronics , physics , organic chemistry , composite material , fluorescence , copolymer , photocatalysis , nuclear physics , catalysis
Poly(methyl methacrylate) (PMMA) was photolyzed with monochromatic light of wavelengths 260, 280, and 300 nm by the use of the Okazaki large spectrograph. The quantum yield of mainchain scission (ϕ cs ), effects of wavelength, and incident photon intensity on the photodegradation were investigated. It turned out that photodegradation of PMMA took place by the irradiation of 260–300 nm light, but did not by the irradiation at λ ⩾ 320 nm. The number of main‐chain scission ( N cs ) has a maximum value in the case of the irradiation with 280 nm light. Under the same conditions of wavelength and total photon intensity, a longer‐term irradiation with a weaker incident photon intensity tends to yield a greater amount of main‐chain scission. A linear relationship was found between the number of main‐chain scission and the incident photon intensity. The average values of ϕ cs obtained in this work were 2.1 × 10 −4 , 2.4 × 10 −4 , and 4.1 × 10 −4 , respectively, for the irradiations at 260, 280, and 300 nm. It was found that the photoinduced side‐chain scission initiates the main‐chain scission of PMMA.