Reaction-induced phase separation decomposition

TEM can also be used to follow the development of structural features during spinodal decomposition [131] and reaction-induced phase separation [1]. 

The Spinodal Decomposition, also named reaction-induced [29] and also polymerization-induced phase separation [30], is the phase separation mechanism most observed on thermoset/thermoplastic blends, commonly initially miscible. In this mechanism the second-phase grows spontaneously, without a thermodynamic or energetic barrier, leading the blend to a immiscible region [27]. 

The formation of a dual-phase morphology in PEI-epoxy IPNs is explained in the following way [90,171]. Two cases were discussed. First, when phase separation is induced by the curing reaction, PEI-modified epoxy shows bimodal UCST behavior (Fig. 30). At composition (p (volume fraction of component 1) phase separation starts at conversion x when the curing temperature is Ti. Because of the spinodal mechanism of decomposition and due to the lower viscosity of the medium, the system will have macroscale phase separation and domains with volume fraction cp[ and. As the reaction proceeds and the conversion X2 is reached, an abrupt change in the equilibrium composition of the PEI-rich phase occurs from cp l to (p " in a very short time. This abrupt change is similar to the effect of the two-... 

CH3CH2OCH2CH3) solutions. The solutions are used directly after separating the aqueous phase and drying the ether (ethyl ether, CH3CH2OCH2CH3) phase. The preparation uses base-induced decomposition of A-nitrosomethylurea (Scheme 10.20), which, as shown in the same scheme, is produced by the reaction of aqueous solutions of methylamine hydrochloride (CHsNHs Cl") with urea (H2NCONH2) (Scheme 10.20). 

---