Premium
Formation of Crystallosolvates from Mixtures of Poly( L ‐lactide) and Diphenyl Ether
Author(s) -
Nakajima Hajime,
Wataoka Isao,
Ohara Hitomi,
Kimura Yoshiharu
Publication year - 2009
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200800528
Subject(s) - lamellar structure , amorphous solid , ether , spherulite (polymer physics) , polymer chemistry , materials science , optical microscope , morphology (biology) , crystallography , lactide , chemical engineering , atmospheric temperature range , solid state , chemistry , composite material , polymer , copolymer , organic chemistry , scanning electron microscope , meteorology , physics , biology , engineering , genetics
Poly( L ‐lactide) (PLLA) was mixed homogeneously with diphenyl ether (DE) at high temperature in a range of PLLA/DE compositions from 100/0 to 100/75 in wt.‐%. Cooling of the mixtures yielded white solid products without migration of the liquid DE. Their melting temperature was lowered from 173 to 123 °C as the DE content increased. At an optimum PLLA/DE composition of 100/60, a unique crystallosolvate consisting of large spherulite of PLLA, as detected using polarized optical microscopy, was exclusively generated in powder form. Wide and small angle X‐ray scattering revealed that the PLLA chains form a lamellar structure with a highly ordered crystalline state (α‐form) and that the lamellar spacing is extraordinarily thick, reaching 34 nm. It was therefore suggested that DE partitions into the amorphous layers sandwiched between the crystalline layers and that the specific solvation interaction between DE and PLLA may stabilize the crystallosolvates.