REINFORCEMENT OF NATURAL RUBBER LATEX BY NANOSIZE MONTMORILLONITE CLAY
Open Access
Author:
Tantatherdtam, Rattana
Graduate Program:
Materials Science and Engineering
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
June 25, 2003
Committee Members:
Ian Roland Harrison, Committee Chair/Co-Chair Paul Raymond Howell, Committee Member Sridhar Komarneni, Committee Member James Patrick Runt, Committee Member
Based on the unique character of montmorillonite namely its layer structure and the ability of silicate particles to separate into nanometer-size platelets, natural rubber (polyisoprene)/ clay composites were obtained by mixing rubber latex with clay-water dispersion and coagulating the mixture. The resulting film had greatly improved mechanical properties compared with films using micron-sized fillers. Further, both modulus and toughness were improved; in many composite system an improvement in modulus leads to a loss of toughness. X-ray diffraction results indicated that clay platelets dispersed in the rubber matrix on the nanoscale level with some macromolecules intercalated into the clay gallery. The observed considerable improvement in mechanical properties, coupled with a theoretical model of composite modulus suggests a dispersed structure of clay in the composite. While not all clay particles are exfoliated, data suggest that a reasonable fraction of exfoliated materials is required to explain the experimental results.
