Compressibility of natural rubber at pressures below 500 kg/cm2

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 c...

Cooling Bose-Einstein condensates below 500 picokelvin.

Spin-polarized gaseous Bose-Einstein condensates were confined by a combination of gravitational and magnetic forces. The partially condensed atomic vapors were adiabatically decompressed by weakening the gravito-magnetic trap to a mean frequency of 1hertz, then evaporatively reduced in size to 2500 atoms. This lowered the peak condensate density to 5 x 10(10) atoms per cubic centimeter and coo...

Anomalous compressibility effects and superconductivity of EuFe2As2 under high pressures.

The crystal structure and electrical resistance of structurally layered EuFe(2)As(2) have been studied up to 70 GPa and down to a temperature of 10 K, using a synchrotron x-ray source and designer diamond anvils. The room temperature compression of the tetragonal phase of EuFe(2)As(2) (I4/mmm) results in an increase in the a-axis length and a rapid decrease in the c-axis length with increasing ...

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 ...