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Structural rigidity control in arborescent graft polymers
Author(s) -
Gauthier Mario,
Möller Martin,
Burchard Walther
Publication year - 1994
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19940770108
Subject(s) - molar mass , branching (polymer chemistry) , polymer , polystyrene , materials science , size exclusion chromatography , polymer chemistry , small angle x ray scattering , macromolecule , light scattering , grafting , molecule , scattering , molecular mass , rigidity (electromagnetism) , chemistry , composite material , organic chemistry , optics , biochemistry , physics , enzyme
Successive chloromethylation‐anionic grafting sequences on polystyrene have led to well‐defined hyperbranched macromolecules. Polymers with branching functionalities f > 5000 and molar masses over 10 7 g/mol were thus prepared while maintaining a ratio of mass‐ to number‐average molar masses M w /M n = 1,1‐1,3. Three series of styrene polymers were prepared by varying the density of grafting sites along the chain, resulting in controllable stiffening of the molecular structure. Characterization of the branched molecules by size‐exclusion chromatography/low‐angle laser light scattering and light scattering confirmed a geometric increase in molar mass for successive generations, and a low ratio of mass‐ to number‐average molar masses. Static and dynamic light scattering experiments showed that the molecules behave like hard spheres in dilute solutions. Measurements in the semidilute range, however, showed a progressive structural stiffening effect as the branching density increases.