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Polyrotaxanes: Synthetic methodologies & characterization
Author(s) -
Gibson Harry W.,
Engen Paul T.,
Shen Xi Ya,
Sze Jean,
Lim Christina,
Bheda Mukesh,
Wu Charles
Publication year - 1992
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19920540139
Subject(s) - materials science , macromolecule , polymer , polyester , rotaxane , characterization (materials science) , amorphous solid , polystyrene , threading (protein sequence) , polyacrylonitrile , polymer chemistry , nanotechnology , chemistry , crystallography , supramolecular chemistry , crystal structure , composite material , biochemistry , protein structure
Abstract The synthesis of polyrotaxanes, comprised of linear macromolecules threaded through cyclic species, may be accomplished by either of two strategies: (1) statistical threading, in which the macrocycle is used as solvent and threading is predominantly entropically driven, or (2) template threading, involving an enthalpic driving force such as charge transfer or metal complexation. This paper summarizes our efforts in this field by describing syntheses by both step and chain growth methodologies and the characterization of the resultant polyrotaxanes. Examples include polyesters, polyethers, polyurethanes, polystyrene and polyacrylonitrile. The polyrotaxanes possess properties (thermal, solubility, mechanical, etc.) that differ from the corresponding linear polymers. In some systems phase separation occurs, producing morphologies that consist of crystalline macrocycles and either amorphous or crystalline linear backbones; these results demonstrate the ability of the macrocycles to move along the linear backbone in the melt without dethreading.