화학공학소재연구정보센터
Macromolecules, Vol.32, No.5, 1576-1581, 1999
Crystallization of poly(ethylene oxide) and melt-miscible PEO blends
Spherulitic growth rates for poly(ethylene oxide) and four model, melt-miscible blends were measured over a range of crystallization temperatures. The miscible diluents fall into two classes: these exhibiting relatively weak intermolecular interactions with PEO and those exhibiting strong interactions. Generally, at a given crystallization temperature, growth rates for blends with the strongly interacting polymers are considerably lower than those with weakly interacting polymers with comparable T(g)s. To a first approximation, growth rates for PEO and the blends can be "superposed" when normalized by the degree of supercooling and T - T-g. In addition, at higher T-c and diluent concentrations, particularly for blends with strongly interacting diluents, the growth rate slows from G proportional to t(0) to G proportional to t(-1/2), consistent with a crossover to diffusion-controlled growth. Analysis of PEO growth rates using the LHM model yields sigma(e) similar to 40 ergs/cm(2) for crystallization in regime II. For the blends, the mobility as a function of T-c and diluent content was estimated from experimental growth rates and the nucleation constant for neat PEG. These mobilities were found to correlate well with diluent (or blend) T-g.