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Published in Gabriel O. Shonaike, George P. Simon, Polymer Blends and Alloys, 2019
Rudolph D. Deanin, Margaret A. Manion
Functional end groups can sometimes be produced directly during the polymerization reaction. In vinyl addition polymerization this is done by the choice of initiators and/or chain-transfer agents. In condensation polymerization it is done by the use of a slight excess of the proper monomer. In either case, the original end group can also be converted into a more desirable one by a postpolymerization reaction. Popular end groups include hydroxyl, carboxylic acid, amine, and isocyanate. These can be used for compatibilization through either block or graft copolymers.
Telechelic Polymers by Ring-Opening Polymerization
Published in Eric J. Goethals, Telechelic Polymers: Synthesis and Applications, 2018
End-group functionalities can be introduced in polymer chains by initiation, by end-capping, or by transfer. To obtain functional end-groups at both chain ends, a combination of two methods or a subsequent reaction (e.g., chain coupling) may be necessary.
Molecular mass determination
Published in D. Campbell, R.A. Pethrick, J.R. White, Polymer Characterization, 2017
D. Campbell, R.A. Pethrick, J.R. White
Identification of the nature of an end group using spectroscopic techniques may also be important in order to determine the method used for synthesis or the susceptibility of the polymer to undergo further polymerization or degradation. NMR techniques have been developed to identify very small concentrations of end groups but these are usually not sufficiently quantitative to allow their use in molar mass determination.
Interaction between the end groups and the main chain of conjugated polymers by time-resolved EPR and fluorescence spectroscopy
Published in Molecular Physics, 2019
Motoko S. Asano, Sho Hashimoto, Takuya Shinozuka, Yasutaka Fushimi, Kotohiro Nomura
Conjugated polymers have attracted considerable attention because of their potential application for optoelectronic and electrochemical devices [1–8]. Precision in synthesis of defect-free, structurally regular and chemically pure conjugated polymers is crucial to not only controlling the polymer properties but also developing new materials with higher device efficiency [4–7]. Recently it has been reported that the end-group modification of conjugated polymers introduces considerable deviation in the nature of the original conjugated polymers [9–26], and the interaction between the end-group and main conjugated chain is recognised as one of the key features that controls polymer properties.