Abstract
There are extremely close relations between the structure of a plastics and its mechanical properties.
The structure of polyvinylchloride, which is a polymer of chain-form may be changed by an addition of plasticizer, or by controlling the temperature.
Such materials are used most effectively and appropriately, by observing the changes of mechanical properties taken place in respective conditions.
To extend their scope of application, various data concerning to 2nd transition were pursued.
