Detail of "922-66-7"

Reference

Isotactic and stereoblock poly(methyl methacrylates) produced by butylmagnesium initiators

Isotactic and stereoblock poly(methyl methacrylates) produced by butylmagnesium initiators. Allen, P. E. M.; Mair, C. (Dep. Phys. Inorg. Chem., Univ. Adelaide, Adelaide 5001, Australia). Eur. Polym. J., 20(7), 697-705 (English) 1984. CODEN: EUPJAG. ISSN: 0014-3057. DOCUMENT TYPE: Journal CA Section: 35 (Chemistry of Synthetic High Polymers) The use of tert- [2259-30-5], sec- [922-66-7], iso- [926-62-5] and n-BuMgBr [693-03-8] and chlorides in PhMe, THF, and mixed solvents to prep. Bernoullian, stereoblock and isotactic PMMA [25188-98-1] and the factors controlling the stereochem. are described. By careful control of solvent compn., highly isotactic polymer can be prepd. with all the butylmagnesium bromides, but none of the corresponding dibutylmagnesiums. The halide content does not influence stereospecificity when it is in excess of the Grignard stoichiometry but it influences the mol. 14627-81-7 is the cas registry number of certain chemical which is used as reagents here. wt. distribution and retards the polymn. The mol. wt. distributions are usually polymodal and dependent on the same factors that control stereospecificity. The effect of THF concn. on stereospecificity operates in a manner quite distinct from its effect on complex concn. and rate. The concn. of residual THF in PhMe-rich soln. dets. the type of initiation and propagating species that prevail. Structures are proposed for those responsible for stereospecific initiation and propagation. tert-BuMgBr is the most reliable and robust initiator for prepg. isotactic PMMA. .

Living and highly isotactic polymerization of methyl methacrylate by tert-C4H9MgBr in toluene

Living and highly isotactic polymerization of methyl methacrylate by tert-C4H9MgBr in toluene. Hatada, Koichi; Ute, Koichi; Tanaka, Katsuji; Okamoto, Yoshio; Kitayama, Tatsuki (Fac. Eng. Sci., Osaka Univ., Osaka 560, Japan). Polym. J. (Tokyo), 18(12), 1037-47 (English) 1986. CODEN: POLJB8. ISSN: 0032-3896. DOCUMENT TYPE: Journal CA Section: 35 (Chemistry of Synthetic High Polymers) Isotactic PMMA [25188-98-1] with narrow mol. wt. distribution was prepd. by polymn. of Me methacrylate (I) [80-62-6] in PhMe at -78° initiated by tert-BuMgBr [2259-30-5] prepd. in Et2O. The polymn. proceeded in a "living" manner in which the initiation reaction was fast and quant. whereas the propagation was slow. Polymns. of I by n- [693-03-8], iso- [926-62-5], and sec-BuMgBr [922-66-7] were also investigated in PhMe at -78°. With an increase in the bulkiness of the alkyl group the isotacticity of the polymer increased and the mol. wt. distribution became narrower. The addn. of MgBr2 also increased the isotacticity of the polymer. The results of block copolymns. of I and perdeuterated I or Et methacrylate were also described.