ISSN:
0025-116X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
(E)-2-Methyl-1,3-pentadiene was polymerized with the AlEt2Cl-Nd(OCOC7H15)3-Al(iBu)3 system to a polymer consisting of 98-99% 1,4-cis-structure. The crude polymer was fractionated by successive extractions with boiling diethyl ether, heptane and toluene. Examination of the soluble fractions and of the residue to toluene extraction by NMR, X-ray and DSC techniques indicated that the crude polymer consists of macromolecules differing in stereoregularity. Evidence is reported that the crystalline residue after the toluene extraction has a 1,4-cis-isotactic structure. The existence of two different crystalline phases is shown and the respective cell parameters have been determined. α-Phase: a = 10,74, b = 13,04, c = 7,87 Å (-120°C), space group Pbca, Z = 8, Dc = 1,00 g · cm-3. β-phase: a = 9,30, b = 7,73, c = 7,90 Å (25°C), space group P212121Z = 4, Dc = 0,96 g · cm-3.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1988.021890916
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