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Synthesis of star‐shaped poly(ϵ‐caprolactone) by samarium‐based tetrafunctional initiator and its dilute‐solution properties
Author(s) -
Xi Xiujuan,
Jiang Liming,
Ling Jun,
Sun Weilin,
Shen Zhiquan
Publication year - 2006
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.23448
Subject(s) - tetrahydrofuran , samarium , polymer chemistry , polyester , polymerization , caprolactone , ring opening polymerization , materials science , toluene , solvent , polymer , chemistry , organic chemistry , composite material
An in situ –generated tetrafunctional samarium enolate from the reduction of 1,1,1,1‐tetra(2‐bromoisobutyryloxymethyl)methane with divalent samarium complexes [Sm(PPh 2 ) 2 and SmI 2 ] in tetrahydrofuran has proven to initiate the ring‐opening polymerization of ϵ‐caprolactone (CL) giving star‐shaped aliphatic polyesters. The polymerization proceeded with quantitative conversions at room temperature in 2 h and exhibited good controllability of the molecular weight of polymer. The resulting four‐armed poly(ϵ‐caprolactone) (PCL) was fractionated, and the dilute‐solution properties of the fractions were studied in tetrahydrofuran and toluene at 30°C. The Mark–Houwink relations for these solvents were [η] = 2.73 × 10 −2 M w 0.74 and [η] = 1.97 × 10 −2 M w 0.75 , respectively. In addition, the unperturbed dimensions of the star‐shaped PCL systems were also evaluated, and a significant solvent effect was observed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 175–182, 2006