Epoxidized natural rubber latex

Epoxidized natural rubber (ENR) is an important modified form of natural rubber whose properties are close to those of special purpose synthetic rubbers. ENR is prepared by reacting natural rubber in latex form with performic acid formed in situ by the reaction of formic acid and hydrogen peroxide under controlled conditions. [45,46]. The double bonds of natural rubber react readily with peracids to yield epoxide groups. Though any level of epoxidation can be achieved, only up to 50 mole percent is used in practice. 50, 25, and 10 mole% epoxidized products are termed ENR-50, ENR-25, and ENR-10. Studies using NMR have shown that the epoxide groups are randomly distributed along the natural rubber backbone [47]. [Pg.426]

B.George, S. Abraham, and N. M.Mathew, In situ epoxidation of natural rubber latex by performic acid and kinetics of the reaction. Indian journal of Natural Rubber Research, 5 (1 2) pp. 179-187,1992. [Pg.435]

Uncontrolled oxidation of rubber is detrimental to its physical properties. Oxidation reactions take place readily at unsaturated groups in polymers and are often referred to collectively as epoxidation however, oxidation under controlled conditions can lead to useful products such as the epoxidized natural rubber introduced by the Malaysian Rubber Producers Association (Schults etal., 1983 Cunneen and Porter, 1965 Ceresa, 1965 Avery and Watson, 1956). Natural rubber in the latex form is treated with hydrogen peroxide dissolved in acetic acid. This gives 50% epoxidized natural rubber. This rubber shows very interesting physical properties and excellent carbon black dispersion. Similarly, nonaqueous epoxidizations of synthetic polyisoprene can be achieved... [Pg.530]

ENR, epoxidized natural rubber ESEM, environmental scanning electron microscopy FTIR, Fourier transform infrared spectroscopy GNP, gold nanoparticle NR, natural mbber NRL, natural rubber latex SEM, scanning electron microscopy XRD, X-ray diffraction. [Pg.86]

Epoxidized natural rubber (ENR) is produced in Malaysia from NR latex employing the hydrogen peroxide/formic acid in-situ route (Fig. 3) with the reaction conditions carefully controlled to avoid secondary... [Pg.88]