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ERIC Number: EJ921620
Record Type: Journal
Publication Date: 2011-Jan
Pages: 6
Abstractor: As Provided
Reference Count: 53
ISBN: N/A
ISSN: ISSN-0021-9584
Polymerization Kinetics: Monitoring Monomer Conversion Using an Internal Standard and the Key Role of Sample "t[subscript 0]"
Colombani, Olivier; Langelier, Ophelie; Martwong, Ekkachai; Castignolles, Patrice
Journal of Chemical Education, v88 n1 p116-121 Jan 2011
The use of an internal standard is a conventional and convenient way to monitor the conversion of one or several monomers during a controlled radical polymerization. However, the validity of this technique relies on an accurate determination of the initial monomer-to-internal standard ratio, A[subscript 0], because all subsequent calculations of the conversion are based on this value. In most kinetic studies using an internal standard for the determination of the conversion, an incorrect determination of the value of A[subscript 0] will result in absurd conclusions and will thus be detected and corrected. However, an incorrect determination of A[subscript 0] can be significantly misleading in the case of controlled polymerization. This article shows that deviation of the kinetic plots from their true shape because of an error in A[subscript 0] will not look absurd in the case of controlled polymerization. On the contrary, the plots will fit with a possible deviation of the polymerization from a "quasi-living" to a less controlled process. As a consequence, an error on A[subscript 0] may not be detected and can result in a misinterpretation of the behavior of the system. (Contains 6 notes and 4 figures.)
Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: eic@jce.acs.org; Web site: http://pubs.acs.org/jchemeduc
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education; Postsecondary Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A