Journal article
Computational evidence for self-initiation in spontaneous high-temperature polymerization of methyl methacrylate
The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory, v 115(6), pp 1125-1132
17 Feb 2011
PMID: 21265525
Abstract
This paper presents computational evidence for the occurrence of diradical mechanism of self-initiation in thermal polymerization of methyl methacrylate. Two self-initiation mechanisms of interest were explored with first-principles density functional theory calculations. Singlet and triplet potential energy surfaces were constructed. The formation of two Diels-Alder adducts, cis- and trans-dimethyl 1,2-dimethylcyclobutane-1,2-dicarboxylate and dimethyl 2-methyl-5-methylidene-hexanedioate, on the singlet surface was identified. Transition states were calculated using B3LYP/6-31G* and assessed using MP2/6-31G*. The calculated energy barriers and rate constants with different levels of theory were found to show good agreement to corresponding data obtained from laboratory experiments. The presence of a diradical intermediate on the triplet surface was identified. When MCSCF/6-31G* was used, the spin-orbit coupling constant for the singlet to triplet crossover was calculated to be 2.5 cm(-1). The mechanism of monoradical generation via a hydrogen abstraction by both triplet and singlet diradicals from a third monomer was identified to be the most likely mechanism of initiation in spontaneous polymerization of methyl methacrylate.
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Details
- Title
- Computational evidence for self-initiation in spontaneous high-temperature polymerization of methyl methacrylate
- Creators
- Sriraj Srinivasan - Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104, USAMyung Won LeeMichael C GradyMasoud SoroushAndrew M Rappe
- Publication Details
- The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory, v 115(6), pp 1125-1132
- Publisher
- American Chemical Society; Washington, DC
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Chemical and Biological Engineering
- Web of Science ID
- WOS:000287066000021
- Scopus ID
- 2-s2.0-79951523912
- Other Identifier
- 991014877770804721
InCites Highlights
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- Collaboration types
- Industry collaboration
- Domestic collaboration
- Web of Science research areas
- Chemistry, Physical
- Physics, Atomic, Molecular & Chemical