ISSN:
1022-1352
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Polymerization of phenylacetylenes (PAs) having various ortho-substituents were examined by using MoOCl4 - n-Bu4Sn - EtOH (mole ratio 1:1:1) as catalyst. Phenylacetylenes with no or sterically small ortho-substituents did not polymerize in a living fashion. On the other hand, in the polymerization of phenylacetylenes having medium-sized substituents (e.g., CH3, Cl, Br, and iPr), the number-average molecular weights Mn of polymers increased in direct proportion to monomer consumption, while the polydispersity ratios were 1,2- 1,3, which is in favor of living polymerization. Further, monomers having bulky ortho-groups (CF3 and Me3Ge) exhibited excellent living nature with small polydispersity ratios of ≈ 1,1. Thus, it is concluded that not the electronic but the steric effect of the ortho-substituent is important to achieve living polymerization.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1995.021960531
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