| 摘要 |
PROBLEM TO BE SOLVED: To obtain an estimation method in which a glass transition temperature can be estimated by setting the polymerization degree of an amorphous polymer inside a unit cell handled by a molecular dynamic simulation at a specific value and securing the equilibrium time of a specific value or longer when a temperature is higher than the glass transition temperature. SOLUTION: When a glass transition temperature is estimated by using a molecular dynamic simulation, a sufficient amorphous structure corresponding to an actual structure cannot be generated when a polymerization degree inside a unit cell is low at about 50 to 100 and the unit cell is placed under a periodic boundary condition. In addition, at a temperature which is higher than a temperature near the glass transition temperature, the change width of a density due to the simulation time is large, and the influence of an initial structure cannot be removed sufficiently in the time at, e.g. about several hundred picoseconds. Then, the polymerization degree of an amorphous polymer, whose glass transition temperature is to be estimated, inside the unit cell handled by the molecular dynamics simulation is set at about 200 monomer units or higher, the equilibrium time of about one nanosecond or longer is secured at a temperature which is higher than a temperature near the glass transition temperature, and the transition temperature is estimated quantitatively. |
