ISSN:
0887-624X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Several stereoregular poly(propylene oxide) (PPO) samples were synthesized employing either trimethyl aluminum hydrolyzates or Pruitt-Baggett type catalysts. Dilute isooctane solutions of these samples were fractionally crystallized by stepwise cooling from 333 K down to 273 K. The fractions which dissolve at 273 K were noncrystallizable and were further fractionated by GFC. The isolated fractions were characterized by 13C-NMR, DSC, and viscometry techniques. Both structural (head-to-head and tail-to-tail linkages) and steric (syndiotactic dyads) irregularities were found in otherwise isotactic chains and their abundance apparently increased as the melting point and the chain length of the fractions decreased.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pola.1989.080270526
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