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Precision Aliphatic Polyesters with Alternating Microstructures via Cross‐Metathesis Polymerization: An Event of Sequence Control
Author(s) -
Li ZiLong,
Zeng FuRong,
Ma JiMei,
Sun LinHao,
Zeng Zhen,
Jiang Hong
Publication year - 2017
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.201700050
Subject(s) - polyester , polymerization , monomer , polymer chemistry , materials science , metathesis , differential scanning calorimetry , polymer , acyclic diene metathesis , chemical engineering , chemistry , composite material , physics , engineering , thermodynamics
Sequence‐regulated polymerization is realized upon sequential cross‐metathesis polymerization (CMP) and exhaustive hydrogenation to afford precision aliphatic polyesters with alternating sequences. This strategy is particularly suitable for the arrangement of well‐known monomer units including glycolic acid, lactic acid, and caprolactic acid on polymer chain in a predetermined sequence. First of all, structurally asymmetric monomers bearing acrylate and α‐olefin terminuses are generated in an efficient and straightforward fashion. Subsequently, cross‐metathesis (co)polymerization of M1 and M2 using the Hoveyda–Grubbs second‐generation catalyst (HG‐II) furnishes P1 – P3 , respectively. Finally, hydrogenation yields the desired saturated polyesters HP1 – HP3 . It is noteworthy that the ε‐caprolactone‐derived unit is generated in situ rather than introduced to tailor‐made monomers prior to CMP. NMR and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) results verify the microstructural periodicity of these precision polyesters. Differential scanning calorimetry (DSC) results reflect that polyesters without methyl side groups exhibit crystallinity, and unsaturated polyester samples show higher glass transition temperatures than their hydrogenated counterparts owing to structural rigidity.