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Summary: Temperature-induced phase separation of P(EO75-ran-PO25)/PES and reaction-induced phase separation of DGEBA/MDA modified with PVME are studied using MTDSC as an in-situ tool. Phase separation can be probed by the onset of an 'excess' contribution in the MTDSC heat capacity signal, in good correspondence with the cloud point temperature. This feature enables the complete construction of the state diagram of P(EO75-ran-PO25)/PES. The detection of phase separation-induced partial vitrification of the high-T g phase (PES-rich phase) enables to sub-divide the LCST-type heterogeneous region in a zone 1 (no interference of partial vitrification) and a zone 2 (interference of partial vitrification of the PES-rich phase). This subdivision of the heterogeneous region has drastic implications on the remixing behavior of demixed blends. In DGEBA/MDA modified with PVME, reaction-induced phase separation accompanied by an increase in reaction rate, followed by a vitrification step of the epoxy-amine phase can be detected in-situ. In non-isothermal conditions, a diffusion-controlled reaction after vitrification and a final devitrification of the system is also observed.

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A quantitative method for the determination of the degree of substitution (DS) of extruded benzylated starch is developed (DS = 0.01 – 0.40). Sample pretreatment by freezing the product in liquid nitrogen and a methanol extraction of the reaction components (e. g. benzyl chloride, benzyl alcohol) is described. Aqueous formic acid solutions of the starch products were analyzed both with UV analysis (λ = 259 nm.) and with a NMR “coaxial tubing” analysis technique. Both techniques showed similar results with good correlation and a standard deviation < 0.01 DS.