ISSN:
0098-1273
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
It is demonstrated by several methods (DSC, infrared spectroscopy, and small-angle and wideangle x-ray diffraction) that bromination of suspensions of single crystals of trans-1,4-polybutadiene is selective at the fold surface. As the thickness of the single crystals is increased, a larger number of double bonds per fold are brominated, i.e. a larger number of repeat units become accessible to bromine. This is consistent with an increase in the thickness of disordered surface layers with the crystallization temperature. A reduction of 40-60% in overall apparent enthalpies of transition and of melting and reduced ability of brominated single crystals to refold following annealing are also observed. Crystallization from the melt of trans-1,4-PBD with [ CH2—CHBr—CHBr—CH2 ] units along the chain is interpreted by assuming that some of these units are incorporated in the crystal lattice as defects.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1976.180140113
