Poly(dimethylsiloxane)-b-poly(methylmethacrylate) by Anionic Ring Opening Polymerization and ATRP

Abstract

In the construction of “microfluidic devices,” also named “lab on chip” it is important to consider the biocompatibility and good mechanical properties of the starting materials where polymers such as poly(dimethylsiloxane) (PDMS) and poly(methylmethacrylate) (PMMA) can be considered as a suitable options. Here, we report the synthesis of the copolymer poly(dimethylsiloxane-b-methylmethacrylate) through the combination of anionic ring opening polymerization and atom transfer radical polymerization (ATRP). PDMS macroinitiator was obtained by anionic polymerization of hexamethyltrisiloxane (D3) initiated by butyllithium. The living polymer was quenched with chlorodimethylsilane. This omega functionalized polymer was used as a hydrosilylating agent, when it was reacted with 2-Bromo-2-methyl-[3-buten-1-yl]-propanoate, producing a poly(dimethylsiloxane)-omega-functionalizated ATRP initiator which was prepared in 98% of functionalized (calculated from ¹H-NMR) and well defined molar mass distribution. Copolymerization with methylmethacrylate using PMDETA, copper bromide (CuBr) and methylethylketone as solvent drives to obtain the block colpolymer poly(dimethylsiloxane)-b-poly(methylmethacrylate) in high yield. Macroinitiator and block copolymer were both characterized by NMR, GPC, FT-IR, and DSC.

Keywords:

• PDMS block copolymer
• end functionalization
• ATRP

Acknowledgments

The authors thank the National Council of Science and Technology (CONACYT) for the financial support provided through the project number 61061. Also, thanks to Victor Comparan and Julieta Sanchez Salazar for the support in the analytical characterization of the prepared materials.