Hierarchal Structure and Properties of Natural Rubber

Hierarchal Structure and Properties of Natural Rubber

Seiichi Kawahara and Yoshimasa Yamamoto

Department of Materials Science and Technology, Faculty of Engineering,

Nagaoka University of Technology, Nagaoka 940-2188, Japan

*Tel.: 81-258-47-9301; fax: 81-258-47-9300 E-mail: kawahara@mst.nagaokaut.ac.jp

Morphology of natural rubber was observed by transmission electron microscopy. Nanomatrix of non-rubber components such as proteins and phospholipids was found to be inherently formed in natural rubber, in which natural rubber particles of about 0.5 ƒÝm in average diameter were dispersed. The nanomatrix of non-rubber components disappeared after deproteinization of natural rubber with urea. Stress at break of serum rubber was higher than that of deproteinized natural rubber, while strain at break did not change. When amount of the non-rubber components increased, the stress at break became significantly dependent upon the amount of non-rubber components. Viscoelastic properties of natural rubber were also dependent upon the nanomatrix of non-rubber components. Storage modulus of natural rubber increased significantly, when the amount of the non-rubber Components increased.