The Cyclization of Natural Rubber

the cyclization of natural rubber

the effects of solvent, temperature, time, weight percent of catalyst on the rate and mechanism of cyclization of natural rubber (nr) was studied in toluene and xylene solutions having tin tetra chloride catalyst (sncl4). iodometric titration show, with 8% sncl4 (based on polymer weight) cyclization occurs, leaving 27.4% of the total unsaturation. infrared spectra of cyclized nr show decreased ...

Natural Rubber Latex Allergy

Natural rubber latex allergy.

Immediate hypersensitivity to natural rubber latex (NRL) has become increasingly common during the last 20 years. It is currently one of the most frequently encountered occupational diseases among the healthcare workers and a problem even in other occupations where protective gloves are used. Several groups at high risk for developing NRL allergy have been defined, including healthcare workers ...

Natural rubber-clay nanocomposites

The mechanical properties of non-vulcanized natural rubber and dialyzed natural rubber-clay nanocomposites have been studied by uniaxial deformations to evaluate the reinforcement efficiency of the clay. We show that while non-rubber molecules contribute to auto-reinforcement, removal of these molecules improves significantly the performance of clay as reinforcement agent. These mechanical prop...

Natural Rubber Latex Allergy

I n the past 10 years, IgE-mediated allergy to natural rubber latex has become a significant health problem in industrialized countries, especially among health care workers, patients with congenital malformations, and children with a history of multiple surgical interventions. Curative treatment inducing immunological tolerance in formerly sensitized patients is experimental and not yet genera...

Characterization of Natural Rubber mesostructure

To study NR mesostructure (macromolecular structure + aggregates or gels) (Figure 1), the NR sample is placed in a good solvent of polyisoprene (cyclohexane, toluene or tetrahydrofuran). In addition to a soluble fraction, there is always an insoluble fraction called macrogel (Figure 1) or gel depending on the authors [1-4]. The gel fraction of NR not only consists of an insoluble fraction or ma...