The morphologies of poly(L-lactic acid)(PLLA)spherulites,when crystallized within the pre-existed poly(oxymethylene)(POM)crystal frameworks,have been investigated.PLLA/POM blend is a melt-miscible crystalline/crystall...The morphologies of poly(L-lactic acid)(PLLA)spherulites,when crystallized within the pre-existed poly(oxymethylene)(POM)crystal frameworks,have been investigated.PLLA/POM blend is a melt-miscible crystalline/crystalline blend system.Owing to the lower melting point but much faster crystallization rate than PLEA,POM crystallized first upon cooling from the melt state and then melted first during the subsequent heating process in this blend system.Lamellar assembly of PLLA crystals within the pre-existed POM spherulitic frameworks was directly observed with the polarized light microscopy by selectively melting the POM frameworks.The investigation indicated that PLLA crystals fully replicated the spherulitic morphology and optical birefringence of the POM crystal frameworks,which was independent of T_(o).On the other hand,POM could also duplicate the pre-existed PLLA morphologies.The result obtained provides us a possibility to design the lamellar assembly and crystal structures of polymer crystals in miscible crystalline/crystalline polymer blends.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21674033,21374027)National Key R&D Program of China(No.2017YFB0307704)
文摘The morphologies of poly(L-lactic acid)(PLLA)spherulites,when crystallized within the pre-existed poly(oxymethylene)(POM)crystal frameworks,have been investigated.PLLA/POM blend is a melt-miscible crystalline/crystalline blend system.Owing to the lower melting point but much faster crystallization rate than PLEA,POM crystallized first upon cooling from the melt state and then melted first during the subsequent heating process in this blend system.Lamellar assembly of PLLA crystals within the pre-existed POM spherulitic frameworks was directly observed with the polarized light microscopy by selectively melting the POM frameworks.The investigation indicated that PLLA crystals fully replicated the spherulitic morphology and optical birefringence of the POM crystal frameworks,which was independent of T_(o).On the other hand,POM could also duplicate the pre-existed PLLA morphologies.The result obtained provides us a possibility to design the lamellar assembly and crystal structures of polymer crystals in miscible crystalline/crystalline polymer blends.
