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Synthesis of well‐defined poly(alkyl methacrylate)‐ graft ‐polylactone by sequential living polymerization
Author(s) -
Mecerreyes David,
Dubois Philippe,
Jérôme Robert,
Hedrick James L.
Publication year - 1999
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/(sici)1521-3935(19990101)200:1<156::aid-macp156>3.0.co;2-c
Subject(s) - polymer chemistry , polymerization , chemistry , alkyl , living anionic polymerization , living polymerization , methacrylate , anionic addition polymerization , copolymer , alkoxide , living free radical polymerization , dispersity , chain transfer , methyl methacrylate , reversible addition−fragmentation chain transfer polymerization , radical polymerization , organic chemistry , polymer , catalysis
A novel combination of living polymerization reactions has been proposed for the controlled synthesis of poly(alkyl methacrylate)‐ graft ‐polylactones. This strategy relies upon the sequential living polymerization of alkyl methacrylates and aliphatic lactones, with an intermediate chemical transformation for shifting from the first mechanism to the second one. In the first step, an alkyl methacrylate (methyl and butyl) is copolymerized with 2‐trimethylsiloxyethyl methacrylate (TMSEMA). This living anionic polymerization is initiated with diphenylhexyllithium( DPHLi) in the presence of a μ‐ligand, lithium chloride, in THF at –78°C. The trimethylsiloxy groups are then hydrolyzed with release of hydroxyl groups which are reacted with triethylaluminum in order to form a multifunctional macroinitiator of the Al alkoxide type. The second step consists of the ring opening polymerization (ROP) of aliphatic lactones ( ϵ ‐caprolactone, δ ‐valerolactone and 1,4,8‐trioxaspiro[4.6]‐9‐undecanone (TOSUO)) with the formation of novel graft copolymers. As a result of the livingness of both the anionic and the ROP polymerization steps, the molecular weight of both the main backbone and the grafts is predictable, the apparent polydispersity is narrow ( M w / M n from 1.05 to 1.30) and the grafting density can be controlled being dependent on the distribution of the hydroxyl groups within the precursor backbone.