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Stereocomplexation and morphology of enantiomeric poly(lactic acid)s with moderate‐molecular‐weight
Author(s) -
Wang Yaming,
Mano João F.
Publication year - 2007
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.27260
Subject(s) - spherulite (polymer physics) , differential scanning calorimetry , materials science , morphology (biology) , crystallite , polymer chemistry , lactic acid , optical microscope , polarized light microscopy , chemical engineering , glass transition , enantiomer , composite material , scanning electron microscope , chemistry , polymer , organic chemistry , biology , bacteria , physics , genetics , metallurgy , thermodynamics , engineering , optics
Abstract The thermal behavior and spherulitic morphologies of poly( L ‐lactic acid) (PLLA)/poly( D ‐lactic acid) (PDLA) 1/1 blend with weight‐molecular‐weight of 10 5 order, together with those of pure PLLA and PDLA, were investigated using differential scanning calorimetry and polarized optical microscopy. It was found that in the blend, stereocomplex crystallites could be formed exclusively or coexisted with homocrystallites depending on thermal history. Banded to nonbanded spherulitic morphological transition occurred for melt‐crystallized PLLA and PDLA, while the blend presented exclusively nonbanded spherulitic morphologies in the temperature range investigated. The spherulite growth of the blend occurred within a wider temperature range (≤180°C) compared with that of homopolymers (≤150°C), while the spherulite growth rates were comparable for both the blend and homopolymers. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008