The Characterization of some methacrylate and acrylate homopolymers, copolymers and fibers via direct pyrolysis mass spectroscopy

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2012

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Özlem Gündoğdu, Suriye

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Poly(methyl methacrylate) possesses many desirable properties and is used in various areas. However, the relatively low glass transition temperature limits its applications in textile and optical-electronic industries. Monomers containing isobornyl, benzyl and butyl groups as the side chain are chosen to copolymerize with MMA to increase Tg and to obtain fibers with PMMA. In this work, thermal degradation characteristics, degradation products and mechanisms of methacrylate homopolymers, poly(methyl methacrylate), poly(butyl methacrylate), poly(isobornyl methacrylate) and poly(benzyl methacrylate), acrylate homopolymers, poly(n-butyl acrylate), poly(t-butyl acrylate), poly(isobornyl acrylate), two, three and four component copolymers of MMA and fibers are analyzed via direct pyrolysis mass spectrometry. The effects of substituents on the main and side chains, the components present in the copolymers and fiber formation on thermal stability, degradation characteristics and degradation mechanisms are investigated. According to the results obtained, the depolymerization mechanism yielding mainly the monomer is the main thermal decomposition route for the methacrylate polymers, acrylate polymers degradation occurs by H-transfer reactions from the main chain to the carbonyl groups. However, when the alkoxy group involves -H, then, H-transfer reactions from the alkoxy group to the CO group also takes place leading to a complex thermal degradation mechanism. The thermal degradation mechanisms and the relative yields of products are affected by copolymerization due to the inter and intra-molecular interactions. As a consequence of transesterification reactions new fragments can be generated. In general, the samples taken from different parts of the fibers do not show different thermal degradation behavior. However, upon fiber formation, enhancements in intermolecular interactions decreasing the thermal stability and changing the product distribution are detected.

Subject Keywords

Polymers., Copolymers., Pyrolysis., Mass spectrometry.

URI

http://etd.lib.metu.edu.tr/upload/12615308/index.pdf
https://hdl.handle.net/11511/22168

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Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

S. Özlem Gündoğdu, “The Characterization of some methacrylate and acrylate homopolymers, copolymers and fibers via direct pyrolysis mass spectroscopy,” Ph.D. - Doctoral Program, Middle East Technical University, 2012.