Direct imaging and elemental mapping of microgels in natural rubber particles

Autor: Rippel, Márcia M., Leite, Carlos A. P., Lee, Lay-Theng, Galembeck, Fernando
Zdroj: Colloid & Polymer Science; 20050201, Vol. 283 Issue: 5 p570-574, 5p
Abstrakt: Elemental distribution maps of Hevea brasiliensis natural rubber gels have been obtained using electron energy-loss spectroscopy imaging in a low-energy (80 kV) electron spectroscopy imaging transmission electron microscope. Two types of gels have been investigated: a microgel contained within the natural rubber particle, and a macrogel prepared by equilibrating dry natural rubber in toluene. Both types of gels are found to contain a high amount of calcium. The intraparticle microgel is dense and rich in calcium but poor in nitrogen, indicating the predominant role of calcium in cross-link formation. The macroscopic gel is inhomogeneous, with dense calcium-rich microgels interspersed in a matrix of a less dense gel. The significant level of nitrogen associated with the matrix of the less dense gel supports the role of proteinaceous materials in the formation of the macroscopic gel.
Databáze: Supplemental Index