Abstract
Elastic modulus E1 of crystalline regions of polymers in the direction parallel to the chain axis and its temperature dependence has been reviewed. Examination of the data so far accumulated led us to success in relating the E1 value viz. the extensivity of a polymer molecule to the molecular conformation in the crystal lattice. Knowledge of the E1 value is of interest from another point of view. That is in connection with mechanical properties of polymer, because it gives us the maximum value for the specimen modulus of a polymer. E1 value of many polymers decreased at high temperature, and thermal contraction of chain molecule is also enhanced at same temperature region. Temperature dependence of E1 value is considered to be due to the molecular motion in the crystalline regions, and a small amount of contracted portions such as kinked chain were incorporated to the chain at high temperature.
