Detail of "2633-66-1"

Reference

Highly isotactic poly([meth]acrylic acid esters) with narrower molecular weight distribution

Highly isotactic poly([meth]acrylic acid esters) with narrower molecular weight distribution. Fischer, Johann Paul; Cavagna, Friedrich; Duch, Eduard; Mueck, Karl Friedrich (Hoechst A.-G., Ger.). Ger. Offen. DE 2639669 9 Mar 1978, 16 pp. (German). (Germany). CODEN: GWXXBX. CLASS: IC: C08F120-18. APPLICATION: DE 76-2639669 3 Sep 1976. DOCUMENT TYPE: Patent CA Section: 35 (Synthetic High Polymers) Polymers with wt. av. mol. wt. (2-100) ′ 103, polydispersity <1.5, and isotacticity 390% are prepd. by polymg. C14-alkyl (meth)acrylates in nonpolar solvents at -94° to +30° in the presence of ortho-substituted phenylmagnesium halides. Thus, stirring 67 g iso-Pr acrylate, 1.7 mol % 2,4,6-Me3C6H2MgBr [2633-66-1], and 937 mL PhMe 2 h at -78° gives 60.9% polymer [29320-57-8] with no. av. mol. wt. 2.88 ′ 104, polydispersity 1.30, and isotacticity >95%.

Aryl and cycloalkyl magnesium initiators of methyl methacrylate

Aryl and cycloalkyl magnesium initiators of methyl methacrylate. NMR studies of the nature of the initiator solutions and its effect on stereospecificity and size distribution. Allen, P. E. M.; Fisher, M. C. (Dep. Phys. Inorg. Chem., Univ. Adelaide, Adelaide 5001, Australia). Eur. Polym. J., 21(3), 201-10 (English) 1985. CODEN: EUPJAG. ISSN: 0014-3057. DOCUMENT TYPE: Journal CA Section: 35 (Chemistry of Synthetic High Polymers) Stereoblock and isotacticlike PMMA [9011-14-7] was prepd. using Ph- [100-58-3], mesitylenyl- [2633-66-1] or cyclohexylmagnesium bromide [931-50-0] in PhMe contg. various amts. of THF [109-99-9]. The optimum mole fraction of THF for isotactic polymn. was 0.01-0.02 in the case of PhMgBr. The decline in efficiency and isotacticity of more extensively de-etherated initiator is due to loss of sol. bromide. The effects of THF concn. and temp. on the mol. wt. distributions and steric triad distributions were investigated. As temp. is increased and THF content decreased, the polymers change from stereoblock to isotacticlike when the Grignard reagent is used and from Bernoullian-distribution syndiotacticlike to stereoblock with analogous diarylmagnesiums. Mol. wt. distributions are polymodal and change in a complex manner. Mesitylenylmagnesium bromide was the most isotactic specific of the initiators, but it was inferior to tert-BuMgBr. The isotactic-directing power of a particular system correlated inversely with lability of the Schlenk equil. as indicated by the coalescence temp. of the individual 13C-NMR peaks of the RMgBr and R2Mg species.