Reverse Atom Transfer Radical Polymerization of MMA in the Presence of CaCO3/SiO2 Two‐Component Composite Particles

Abstract

AbstractSummary: We previously discovered that structurally well‐defined polymer/inorganic composite particles, i.e., poly(methyl methacrylate) (PMMA)/CaCO3/SiO2 three‐component composite particles, can be achieved via reverse atom transfer radical polymerization (ATRP), using 2,2′‐azo‐bis‐isobutyronitrile as initiator and CuII bromide as catalyst. In the present study, the influence of the mass ratio of CaCO3/SiO2 two‐component composite particles to methyl methacrylate (MMA) on the rate and behavior of the polymerization was studied in detail. The results illustrate that increasing the mass ratio of CaCO3/SiO2 two‐component composite particles will decrease the overall rate of polymerization of MMA under standard reverse ATRP conditions. Thermal properties of the obtained well‐defined particles were characterized and determined by thermogravimetric analysis (TGA). The results indicate that well‐defined PMMA chains grafted on the surface of CaCO3/SiO2 particles were only degraded by random chain scission of CC linkages within the PMMA chain, which is different from the degradation of PMMA chains prepared via traditional radical polymerization. This difference is reasonably ascribed to the difference between the end groups of PMMA prepared via reverse ATRP and that via traditional radical polymerization, which has been confirmed by end group analysis measured by 1H–NMR spectroscopy.