Heat induced separation networks

Richburg, A. and El-Halwagi, M. M. (1995). A graphical approach to the optimal design of heat-induced separation networks for VOC recovery. AlChE Symp. Ser., 91(304), 256-... 

CHAPTER TEN Synthesis of heat-induced separation network... 

El-Halwagi MM, Srinivas BK, Dunn RE Synthesis of optimal heat-induced separation networks. 

Today the network theory is generally accepted for ordinary glass. It appears, however, that some complex multicomponent types of glass may also consist to some extent of very small ordered zones in an amorphous network matrix. This is especially true after heat treatment, which can induce phase separation and crystallisation. 

Figure 2.115. Reaction-induced phase separation (RIPS) occurs when a homogeneous mixture of epoxy (bifunctional sticks ), amine (tetrafunctional sticks ), and polymeric modifier (dashed line) is heated and the epoxy-amine network formation induces phase separation. The position of Tcure to the glass transition of the modifier Tgniod determines whether vitrification of a phase rich in this component will occur during cure.

Crosslinking was not observed in annealing studies with PES/PI XU 218 blends all samples with and without TMS could be dissolved in methylene chloride to form transparent solutions after thermally induced phase separation and annealing. However, PES/PI 2080 samples heated to 350°C several times could not be dissolved in DMAc suggesting that a network structure had fomied. 

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