Equations describing lamellar structure parameters and melting points of polyethylene-co-(butene/octene)s

Abstract

Time- and temperature-dependent SAXS-experiments were used to determine the effect of octene and butene co-units on the lamellar structure and the melting properties of polyethylene. As expected, melting points decrease with increasing co-unit content, but crystal thicknesses are not affected and depend on the crystallization temperature only. Results can be cast into some simple equations which describe the dependence:

1.Of the melting point T-f on the crystal thickness d(c) and the co-unit content x(B)

2.Of the equilibrium melting point T-f(infinity) on x(B)

3.Of d(c) on the crystallization temperature T-c

4.Of the long spacing L on T-c, x(B) and the molar mass

5.Of T-f on T-c.