TY - JOUR
T1 - Novel materials through stereocomplexation
AU - Brizzolara, Davide
AU - Cantow, Hans Joachim
AU - Mülhaupt, Rolf
AU - Domb, Abraham J.
PY - 1996
Y1 - 1996
N2 - Both (-)- and (+)-poly(lactide) (PLA) crystallize into a stereocomplex with a melting point that is 50°C higher than that of crystals of the same-handed enantiomers. According to Boyer et al. [Polym. Prepr., 36 (1995) 87] and Jiang et al. [J. Am. Chem. Soc., 117 (1995) 7037], alternating isotactic propylene-CO-copolymers (P(P-alt-CO)) also form a stereocomplex with a higher melting point (60°C). Force-Field-simulated structures for both polymer systems were found to agree well with X-ray data, irrespective of whether they had a chiral or racemic packing. The almost similar results for both stereocomplexes indicate that they might form a mixed stereocomplex of (-)-PLA and (+)-P(P-alt-CO). In acetonitrile, both enantiomers of an AB block copolymer derivative, poly(lactide)-poly(ethyleneglycol) (PLA-PEG), were found to crystallize exclusively into a racemic lattice. The influence of racemic packing on self-assembly of the two-block copolymer was analyzed by atomic-force microscopy. An equimolar mixture of (-)- and (+)-PLA-PEG formed spherical particles through stereocomplexation, in contrast to chiral block copolymers that formed large crystal needles and long rods.
AB - Both (-)- and (+)-poly(lactide) (PLA) crystallize into a stereocomplex with a melting point that is 50°C higher than that of crystals of the same-handed enantiomers. According to Boyer et al. [Polym. Prepr., 36 (1995) 87] and Jiang et al. [J. Am. Chem. Soc., 117 (1995) 7037], alternating isotactic propylene-CO-copolymers (P(P-alt-CO)) also form a stereocomplex with a higher melting point (60°C). Force-Field-simulated structures for both polymer systems were found to agree well with X-ray data, irrespective of whether they had a chiral or racemic packing. The almost similar results for both stereocomplexes indicate that they might form a mixed stereocomplex of (-)-PLA and (+)-P(P-alt-CO). In acetonitrile, both enantiomers of an AB block copolymer derivative, poly(lactide)-poly(ethyleneglycol) (PLA-PEG), were found to crystallize exclusively into a racemic lattice. The influence of racemic packing on self-assembly of the two-block copolymer was analyzed by atomic-force microscopy. An equimolar mixture of (-)- and (+)-PLA-PEG formed spherical particles through stereocomplexation, in contrast to chiral block copolymers that formed large crystal needles and long rods.
KW - AB block copolymers
KW - Alternating propylene-Co-copolymer
KW - Atomic force microscopy
KW - Force-field simulation
KW - Poly(ethyleneglycol)
KW - Poly(lactide)
KW - Powder diffraction
KW - Stereocomplex
UR - http://www.scopus.com/inward/record.url?scp=0030201934&partnerID=8YFLogxK
U2 - 10.1007/BF01185672
DO - 10.1007/BF01185672
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AN - SCOPUS:0030201934
SN - 0928-1045
VL - 3
SP - 341
EP - 350
JO - Journal of Computer-Aided Materials Design
JF - Journal of Computer-Aided Materials Design
IS - 1-3
ER -