Experimental results for five series of linear oligomers of different molecular weights, having a common perfluorinated molecular body and five different pairs of equal foreign end units, generally demonstrate the substantial influence of the chemical nature of the end units on the Tg-x relation of polymers and copolymers, with progressive evidence when the molecular weight is lowered. Positive or negative deviations from the body Tg asymptotic value are observed with different types of end units. Previous experimental results and theoretical expectations for the T~ at low x values are reviewed briefly. As a first approximation, the applicability of the simplest two-parameter T~-x equations to the new results is discussed, as well as the situation when x is translated in terms of end copolymeric composition
Посилання на статтю:
End unit effect on the glass transition temperature of low-molecular-weight polymers and copolymers / F. Danusso* and M. Levi // Polymer. – 1993. – Vol 34. – P. 3687-3693.