Poly(ethylene succinate) (PES) and poly(ethylene oxide) (PEO) were miscible blends of two crystalline polymers, which were crystallized at 50 oC to study the possibility of simultaneous crystallization of the two components by optical microscopy. It was found that down to PES/PEO = 40/60 PES crystallized first and filled the whole space before PEO could nucleate. However, for PES/PEO =20/80, PES and PEO crystallized simultaneously and the formation of interpenetrated spherulites of PES by PEO was observed. It was proposed that the density of lamellae in PES spherulites was lower than that in PEO spherulites, and PEO spherulites continued to penetrate into PES spherulites on contact.
This paper was selected as HEART CUT paper by ACS websit in 2002.