The Gel Point and Network Formation in the Polymerisation of an Epoxy-Amine System Including Ring Formation
The molecular scheme, accounting for intramolecular reaction, was constructed to predict the gel point in the RA4+R’B2 type polymerisation. The scheme is intended to be applied for the cure of a polyoxypropylene (POP) diamine and the diglycidyl ether of bisphenol A, and based on the classification of the reaction state of the POP diamine unit. The linear sequence of structural units for the chain growth in the cure was given to define the gelation following Ahmed-Rolfes-Stepto theory, where a ring-forming parameter (λa) and internal concentration (P ab) of the reactive groups can be applied to characterise the competition between intermolecular and intramolecular reaction. The chain growth was expressed by the fractional concentration of the reacted hydrogen atoms that belong to reactive amino groups, which corresponds to the extent of reaction determined experimentally. From the result of the calculation, the delay of gel point from Flory – Stockmayer criterion is shown to increase with the increase in the internal concentration.
KeywordsGel Points Network Ring Formation Epoxy – Amine Polycondensation
One of the authors, YT, acknowledges the financial support by Grant-in-Aid for Overseas Advanced Research Practice Support Program from the Ministry of Education, Culture, Sports, and Science and Technology of Japan.
- 1.P.J. Flory “Principles of Polymer Chemistry”, Chap.9., Cornell University Press (1953)Google Scholar
- 9.R. F. T. Stepto, in : Polymer Networks – Principles of their Formation Structure and Properties, ed. R. F. T. Stepto, Blackie Academic & Professional, London, Chapter 2(1998)Google Scholar
- 11.Dušek K, Ilavský M, Luňák S (1975) J Polym Sci 53:29Google Scholar
- 21.Tanaka Y, Stanford JL, Stepto RFT (2006) Abstract Booklet:Polymer Networks Group Conference T27Google Scholar
- 27.In: Allen G, Bevington JC(ed) Comprehensive Polymer Science, The synthesis, Characterization, Reactions & Applications of Polymers vol. 5 (1989) Hodd K, Epoxy Resins 667Google Scholar