Reaction-induced phase separation RIPS

Recently, a new concept in the preparation of TPVs has been introduced, based on the reaction-induced phase separation (RIPS) of miscible blends of a semicrystalline thermoplastic in combination with an elastomer, with the potential for obtaining submicrometer rubber dispersions. This RIPS can be applied to a variety of miscible blends, in which the elastomer precursor phase was selectively crosslinked to induce phase separation. Plausible schematic representation of the morphological evolution of dynamic vulcanization of immiscible and miscible blends is shown in Fig. 9. For immiscible blends, dynamic vulcanization leads to a decrease in the size... 

Depending on applications, both procedures used to generate two-phase morphologies in modified-thermosets (a) reaction-induced phase separation (RIPS) and (b) the use of preformed particles - have their advantages... 

Reaction induced phase separation (RIPS) from a homogeneous initial mixture. A third component which is initially soluble in the epoxy precursors but segregates during the chemical reaction (usually a thermoplastic or an elastomer) is incorporated in the system. Segregation generates the final two-phase morphology. 

There are several methods used to mix polymers. Reaction-induced phase separation (RIPS) is one way to make useful polymer blends, and much research has been previously done on this topic (Visconti and Marchessault 1974 Manzione etal. 1981 Yamanakaandinoue 1989,1990 Yamanakaetal. 1989 Chenetal. 1994 Okada et al. 1995 Kojima et al. 1995 Inoue 1995). As explained before, many polymer blends are immiscible, and it is difficult to make them form a desirable... 

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.

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