Change of Microgel Structure on Curing Epoxy Polymers in Fractal Space

Change of Microgel Structure on Curing Epoxy Polymers in Fractal Space 

This chapter considers the reasons for a variation of microgel structure characterised by its fractal dimension, D, formed in the cure of epoxy resin systems. Quantitatively, change of D during the increase of reaction time is well described within the framework of mechanism of aggregation cluster - cluster. The fractal space, in which the reaction curing proceeds, is formed by a structure of the greatest cluster in system. 

The kinetics of a halogen containing oligomer cured with hexachlorobenzene (EPS-1) have been investigated. This oligomer is cured by 4,4 -diaminodiphenylmethane (DDM) at stoichiometric ratio DDM EPS-1 [2]. 

The curing kinetics of system EPS-l/DDM was studied by a method of inverse gas chromatography [2]. The basic parameter determined from processing of experimental data, was a degree of conversion Q, as function of curing time t, determined for a part of kinetical curve up to t 3 x 10 s. Ketones (methyl ethyl ketone, 1,4-dioxane, cyclohexanone) were chosen as standard substances, and argon was used as the carrier gas. 

The curing temperature of system EPS-l/DDM was 393 K. Values of fractal dimension D of microgels varied within the limits of 1.61-2.38 [1]. 

---