Biaxial Orientation in Triple Centrifuged Natural Rubber

Natural rubber (NR) latex was purified through triple centrifugation process and film samples were prepared. The strain-induced crystallization was studied during the uniaxial elongation of the NR samples at room temperature. Crystalline orientation was detected by wide angle x-ray diffraction (WAXD) measuring the intensity of 200 and 120 reflections. The WAXD patterns were compared with the aspect ratio (width/length) of the original NR films. The results indicate that the induced crystals have a biaxial orientation (BO), where the c-axis is parallel to the draw direction and the a-axis is parallel to the film surface. Using the WAXD through patterns, we distinguish the highly oriented BO region in the samples. In order to analyze the structure and properties of the NR, the effect of BO is an essential factor.

[1]  N. Toyama,et al.  Centrifuging Effect on the Structure and Property of Natural Rubber Latex Films , 2003 .

[2]  S. Toki,et al.  Strain-induced crystallization of natural rubber as detected real-time by wide-angle X-ray diffraction technique , 2000 .

[3]  James L White,et al.  A comparative study of stress‐induced crystallization of guayule, hevea, and synthetic polyisoprenes , 1982 .

[4]  P. Phillips,et al.  High‐pressure phases in polymers. II. Spherulitic growth morphology in cis‐polyisoprene , 1975 .

[5]  B. C. Edwards.  The nature of multiple melting transitions in cis‐polyisoprene , 1975 .

[6]  P. Reed.  The influence of crystalline texture on the tensile properties of natural rubber. I , 1974, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[7]  E. H. Andrews,et al.  The influence of morphology on the mechanical properties of crystalline polymers , 1972 .

[8]  E. H. Andrews.  Microfibrillar textures in polymer fibers , 1966 .

[9]  E. H. Andrews,et al.  Crystalline morphology in thin films of natural rubber II. Crystallization under strain , 1964, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[10]  E. H. Andrews,et al.  Spherulite morphology in thin films of natural rubber , 1962, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[11]  C. Bunn.  Molecular structure and rubber-like elasticity I. The crystal structures of β gutta-percha, rubber and polychloroprene , 1942, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.