Modulated DSC (MDSC), introduced about five years ago, is a state of the art extension of conventional DSC. The laboratory of Physical Chemistry and Polymer science explored the possibilities of MDSC as a quantitative characterization tool for polymerization kinetics, vitrification and devitrification processes in reacting polymer systems. Micro-Thermal Analysis (mTA) will be introduced in 1998, and is a further extension of MDSC. mTA combines the capabilities of thermal analysis with atomic force microscopy (AFM). In this OZR-project, the know-how with MDSC will further be extended, in combination with an exploration of mTA on following topics: (1) mechanistic study of network formation : the influence of the initial composition of the reaction mixture, the rate constants of important reaction steps, and morphological effects in heterogenous systems will be studied. (2) Interpenetrating polymer networks (IPNs); Both the in situ production and properties of epoxy-polyacrylate IPNs will be investigated, using the mechanistic approach of topic (1), and the heat capacity and its derivative with temperature. (3) Reaction-induced phase separation in polymer networks: Reaction-induced phase separation of a thermoplastic additive, and the formation of liquid crystalline thermosets using precursors of special architecture will be studied. (4) Micro-Thermal Analysis of polymer networks (mTA): The reaction induced phase separation, heterogeneity, phases, interphases, and network architecture and the polymer systems described in topics (1)-(3) will be investigated with mTA. Both the mMDTA and the mTMA- mode of the new technique will be explored.