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The formation and structure of polymers of the insoluble cross-linked type

1937; Royal Society; Volume: 163; Issue: 913 Linguagem: Inglês

10.1098/rspa.1937.0222

2053-9169

Ronald George Wreyford Norrish, E. F. Brookman,

Various Chemistry Research Topics

Staudinger, in a series of papers (1934,1935,1936) describes the formation of an insoluble polymer of styrene by the addition to the styrene, before polymerization, of small quantities of p -divinyl-benzene. This insolubility he explains by suggesting the formation of cross-linkages of divinyl-benzene between the long thread-like molecules of polystyrene to give three-dimensional macromolecules of exceedingly high molecular weight. By using increasing proportions of divinyl-benzene Staudinger obtained a series of polymers which varied from polystyrenes soluble in benzene through polymers of high swelling capacity to completely insoluble pro­ducts. He considers that the cross-linkages of divinyl-benzene prevent the dispersion of the substance throughout the solvent, while it does not prevent the solvation of the long polystyrene chains. Thus, when few such cross-linkages are present, i. e. when the concentration of divinyl-benzene is low, the polymer will have a great tendency to go into solution through the solvation of the polystyrene chains, but will be prevented from becoming completely dispersed by the presence of the cross-linkages. The product will therefore have a high swelling capacity in those solvents in which the straight chain polystyrenes are soluble. This swelling capacity will decrease as the concentration of divinyl-benzene increases until com­pletely insoluble polymers are obtained.