ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The in situ epoxidation of natural rubber latex was successfully performed in chain-scissoring conditions. The chain-scissoring process could be carried out simultaneously or successively to the epoxidation, to a determined extent. The rate and the degree of epoxidation depend on temperature, pH, and H2O2/isoprene units ratio. The chain-scissoring reaction leads to a limited intrinsic viscosity range and, at pH 2-3, it was practically completed in 24-40 h. The gel content of epoxidized natural rubber (ENR) products are markedly reduced in the presence of reducing agent. Infrared spectra of ENR, thus prepared, are characterized by the presence of a typical weak band at 1550 cm-1, in addition to the other characteristic bands for normal ENR. At low pH and long-lasting reaction, the epoxide ring undergoes a ring-opening process, resulting in the formation of new OH, CO, ether groups, and slightly increased gel content. The Huggins constant, for a typical series of ENR obtained in redox conditions, was determined. © 1993 John Wiley & Sons, Inc.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1993.070500511
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