Methanol-Induced Crack Healing in UV-Irradiated Poly(methyl methacrylate)
碩士 === 國立清華大學 === 材料科學工程學系 === 102 === The effect of UV irradiation on the methanol transport in poly(methyl methacrylate) has been studied at temperatures from 20oC to 35oC. It was found that photodegradation of PMMA irradiated by UV of wavelength less than 300 nm includes main-chain scission and s...
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| Format: | Others |
| Language: | en_US |
| Published: |
2014
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| Online Access: | http://ndltd.ncl.edu.tw/handle/83972172512737923720 |
| Summary: | 碩士 === 國立清華大學 === 材料科學工程學系 === 102 === The effect of UV irradiation on the methanol transport in poly(methyl methacrylate) has been studied at temperatures from 20oC to 35oC. It was found that photodegradation of PMMA irradiated by UV of wavelength less than 300 nm includes main-chain scission and side-chain scission, which decreases mechanical properties of PMMA. The irradiated PMMA showed faster mass transportation at higher temperature and greater dosage. Harmon`s model is used to fit the transport curve, the activation energies for diffusion (ED) and relaxation processes (EV) were calculated from the Arrhenius plots of D and v.
Cracked PMMA sample can be healed by methanol treatment. Crack healing occurs because the effective glass transition temperature treatd by methanol treatment is lower than the operating temperature. Such treatment could heal the crack and repair strength of PMMA. After UV irradiation, crack healing curve changed. We could study how the crack heals under the influence of UV irradiation.
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