Abstract
Glycidyl methacrylate (GMA) is an example of a heterobifunctional monomer, a so-called "Jekyll and Hyde" monomer, in that one functional group can be polymerized via conventional free radical polymerization and the other via cationic ring-opening polymerization. Laterally linked diblock copolymers differ from conventional linear diblock copolymers in that the blocks are not linked via their termini but at a point some way along each chain. This architecture has therefore some of the characteristics of a graft copolymer. Free radical copolymerization of a low level of GMA with methyl methacrylate (MMA) yields MMA/GMA copolymers with a few pendent epoxide groups. Likewise cationic ring-opening copolymerization of low levels of GMA with tetrahydrofuran (THF) yields THF/GMA copolymers with a few pendent methacrylate groups. Subsequent cationic polymerization of the first copolymer type with THF, and subsequent free radical polymerization of the second copolymer type with MMA, yields laterally linked block copolymers of MMA and THF. The two strategies are complementary but the polymerization of the THF block first followed by the MMA block is more efficient and leads to good incorporation of both of these monomer segments. Typically mole ratios of THF/MMA segments approaching 1/1 are achievable with copolymer recoveries up to similar to 60% and overall M-w values up to 125 kDa. While the products are significantly more heterogeneous in terms of the molar mass distributions of the blocks and the backbone architecture than are conventionally produced diblock copolymers, we believe that they are complementary to, rather than competitive with, conventional diblocks and that this new synthetic strategy and ease of synthesis offers potential for the exploitation of these materials.
Original language | English |
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Pages (from-to) | 3183-3189 |
Number of pages | 7 |
Journal | Macromolecules |
Volume | 40 |
Issue number | 9 |
DOIs | |
Publication status | Published - 1 May 2007 |
Keywords
- RING-OPENING POLYMERIZATIONS
- ONE-STEP SYNTHESIS
- METHYL-METHACRYLATE
- DIBLOCK COPOLYMER
- INITIATOR
- CRYSTALLIZATION
- ATRP