抄録
Natural rubber is an excellent material in elasticity and abrasion resistance, so that it is used for tires of airplanes and heavy automobiles, such as a bus. It is impossible to make a synthetic rubber having the same physical properties as the natural rubber, even with the latest synthesis technology. However, the detailed structure of a natural rubber is still unclear. The aim of this study is to clarify the conformation and the thermochemical properties of a natural rubber. The conformational search and calculation of thermodynamic variables were performed with the computer chemistry program CONFLEX. In the calculation, we used two models; one with phosphate group and the with no phosphate group. The model having a phosphate group has a linear stable conformation, while the other has a coiled coherent one. As a result, we found that the end group of natural rubber has a significant effect on its stable structure. Moreover, natural rubber with a linear structure had relatively lower energy.
