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Use of the branching theory in approximation of viscosity of the thermoset: Phenol‐formaldehyde resin and boron oxide
Author(s) -
Mamleev Vadim Sh.,
Gibov Konstantin M.
Publication year - 1997
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(19971010)66:2<319::aid-app12>3.0.co;2-t
Subject(s) - activation energy , thermosetting polymer , branching (polymer chemistry) , phenol formaldehyde resin , polymer chemistry , arrhenius equation , viscosity , thermodynamics , formaldehyde , monomer , boron oxide , curing (chemistry) , materials science , intrinsic viscosity , condensation polymer , oxide , chemistry , polymer , organic chemistry , composite material , physics
The kinetics of step polycondensation is described on the basis of the classical branching theory. A simple method is proposed for calculation of the average longest length ( L ) of the linear chain in a crosslinked molecule under arbitrary functionalities of original monomers. A viscosity of the system is represented as a product of a structure factor by a friction factor. The latter was taken as the Arrhenius exponent. The structure factor was chosen in the form of a power function of L . The method has been used for the approximation of the viscosity of phenol‐formaldehyde resin in the course of curing by boron oxide. An activation energy of 11.8 kcal/mol was found by the method of a best matching of the structure factor for the different viscosity kinetic isotherms in the scale of a reduced time of the reaction. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 319–328, 1997