Synthesis and characterization of the hydrophobic diblock copolymers of poly(dimethylsiloxane)-block-poly(ethyl methyl acrylate) through atom transfer radical polymerization

摘要

The poly(dimethylsiloxane)-block-poly(ethyl methylacrylate) diblock copolymers (PDMS-b-PEMA) were synthesized by atom transfer radical polymerization (ATRP). The chemical structure of the copolymers was characterized by nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy. Thermal behaviors were observed via differential scanning calorimetry (DSC). In the DSC curve, the resulting copolymers appear two glass transition temperatures (T-g's), one at -123 degrees C corresponding to the PDMS block and the other at 65 degrees C ascribed to the PEMA segment. Moreover, the copolymer microstructure was investigated by transmission electron microscopy (TEM). The results show that the diblock copolymers are microphase separated if the bulk contains enough PEMA segment. The surface properties of the PDMS-b-PEMA diblock copolymers were searched by contact angle. The PDMS-b-PEMA diblock copolymers are of low surface energy. The polymerization kinetics was also investigated, and the results show that the reaction proceeds in a living manner. (C) 2008 Wiley Periodicals, Inc.