The polymerization of methyl methacrylate (MMA) initiated with styrene/acrolein, [poly(St/AL)], or styrene/methyl vinyl ketone, [poly(St/MVK)] statistical copolymers was kinetically studied. The rates of polymerization, R,, were found to obey the following equations: R,= con~t.[poly(St/AL)]~~~~ [MMA] 1948 R,= const. [poly(St/MVK)] ' 9 50 [MM A] The overall activation energies were 58,6 kJ/mol (14 kcal/mol) [poly(St/AL)] and 62,8 kJ/ mol (1 5 kcal/mol) [poly(St/MVK)], respectively. Effects of several metallic ions on the polymerization rate were also studied, and thereby it was found that Fe(II), Fe(III), and Cu(I1) ions at adequate concentrations are able to promote the polymerization. ZUSAMMENFASSUNG: Die von den statistischen Copolymeren Styrol/Acrolein, [Poly(St/AL)], bzw. Styrol/Methylvinylketon, [Poly(St/MVK)], initiierte Copolymerisation von Methylmethacrylat (MMA) wurde untersucht. Dabei wurde gefunden, daB die Polymerisationsgeschwindigkeiten, R,, den folgenden Gleichungen gehorchen: R,= const.[Poly(St/AL)] [MMA] 1,48 R , = const. [ Poly(St/MVK)] ' 9 [ M MA] '3 Die Aktivierungsenergien der Bruttoreaktionen betrugen 58,6 kJ/mol(14 kcal/mol) [Poly-(St/AL)] bzw. 62,s kJ/mol (1 5 kcal/mol) [Poly(St/MVK)].

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A method for fabricating a low invasive microneedle which is three-dimensionally imitating mouthparts of mosquito was proposed. In this method, the microneedle is fabricated by casting of a thermoset epoxy resin into a micromold. Microneedles made of the thermoset epoxy resin were tried to fabricate using proposed method. As a result, the microneedles with fine-shaped tip were successfully formed when those diameters are larger than 100 µm. It was also confirmed that the fabricated microneedle can puncture into artificial skin (Young's modulus is 0.1 MPa) without buckling.