Chemical and structural modification of polymers by matrix polymerization

✍ Scribed by I.M. Papisov; O.E. Kuzovleva; S.V. Markov; A.A. Litmanovich

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 509 KB
• Volume: 20
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(84)90209-x

✦ Synopsis

The condensation polymerization of urea and formaldehyde in water in the presence of a macromolecular matrix, polyacrylic acid, as well as properties of composites obtained by the matrix polymerization, have been studied. The chemical structure of the urea lbrmaldehyde polymer was changed by the presence of the matrix. The products of matrix polymerization are composites consisting of a stoichiometric polycomplex of polyacrylic acid with the urea-formaldehyde polymer and an excess of one of the components, depending on the initial composition of the system. Introduction of matrix macromolecules into the reacting system leads to a fibrillized structure of the urea-formaldehyde polymer. The polycomplex, as well as composites with high content of polyacrylic acid, arc glasses characterized by high compressive strength and ability to forced elastic deformation. They swell in water. The highly cooperative character of potentiometric titration curves for swollen gels and the quantitative yield in intermolecular amidation indicate an ideal structure of the polycomplex stabilized by hydrogen and ionic-type bonds.