The expression a = constant x CL ~ is proposed for the lateral surface free energy that appears in polymer crystallization theory ; Coo is the characteristic ratio of the polymer molecules in the melt and the constant consists of known parameters. Given Coo, the theory predicts an accurate value of a for polyethylene. It is shown that Coo for polyethylene in the melt state can be obtained directly from the nucleation rate constant gg and the fold surface free energy a~ (Co~(th~o~.)= 6.53 for melt, C~(expt ) : 6.7 from chain dimensions in dilute 0 solvents). The corresponding results for i-polystyrene are Coo(theor./ = 10.45 for the melt and C~(~xpt ) = 10.5 from chain dimensions. The treatment clarifies the meaning of the empirical parameter and shows prospects for being applicable to other polymers.
Посилання на статтю:
The relationship of C~ to the lateral surface free energy a: estimation of C~ for the melt from rate of crystallization data* / John D. Hoffman // Polymer. – 1992. – Vol 33. – P. 2643-2644.