ISSN:
0887-6266
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Crystallization of trans-1,4-polyisoprene from the mixed solvent pair hexane/2-pentanone was carried out and the effects on the morphology of seeding and the solvent composition were studied. α-TPI lamellae obtained by crystallization from a single solvent, hexane, at 20°C and by mixed-solvent crystallization at 40°C were characterized by DSC, FTIR, and suspension epoxidation/C-13 NMR. Crystalline stem lengths of 14.5 and 18 and a fold length of 10 monomer units were found. Segmented block copolymers were prepared by reaction of TPI lamellae in acetone suspension with HCl at -7°C. These products were dissolved in 2-pentanone and precipitated at 0°C. A lamellar morphology, the details of which depend on the TPI block length, was observed by SEM; both preparations showed sharp endotherms; and the FTIR was characteristic of a combination of amorphous TPI, amorphous hydrochlorinated TPI, and of either the β crystalline form or both the α and β forms for TPI depending on the sample.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/polb.1989.090270513
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