TY - JOUR
T1 - Synthesis and micellar characterization of cbabc type plga-peo-ppo-peo-plga pentablock copolymers
AU - Seong, Haseob
AU - Cho, Eun Bum
AU - Oh, Joongseok
AU - Chang, Taihyun
PY - 2014/8/20
Y1 - 2014/8/20
N2 - Poly(lactic-co-glycolic acid) (PLGA) were grafted to both ends of Pluronic® F68 ((EO)75(PO)30(EO)75) triblock copolymer to produce poly{(lactic acid)m-co-(glycolic acid) n}-b-poly(ethylene oxide)75-b-poly(propylene oxide) 30-b-poly(ethylene oxide)75-b-poly{(lactic acid) m-co-(glycolic acid)n} (PLGA-F68-PLGA) pentablock copolymers. Molecular weights of PLGA blocks were controlled and five kinds of pentablock copolymers with different PLGA block lengths were synthesized using in-situ ring-opening polymerization of D,L-lactide and glycolide with tin(II) 2-ethylhexanoate (Sn(Oct)2) catalyst. PLGA-F68-PLGA pentablock copolymers were characterized by 1H- and 13C-NMR, GPC, and TGA. The numbers (2m, 2n) of repeating units for lactic acid and glycolic acid inside PLGA segments were obtained as (48, 17), (90, 23), (125, 40), (180, 59), and (246, 64), with 1H-NMR measurement. From NMR data, the resultant molecular weights were determined in the range of 12,700-29,700, which were similar to those obtained from GPC. Polydispersity index was increased in the range of 1.32-1.91 as the content of PLGA blocks increased. TG and DTG thermograms showed discrete degradation traces for PLGA and F68 blocks, which indicate the weight fractions of PLGA blocks in pentablock copolymers can be calculated by TG profile and it is possible to remove PLGA block selectively. Hydrodynamic radius and radius of gyration of pentablock copolymer micelle were obtained in the range of 46-68 nm and 31-49 nm, respectively, in very dilute (i.e. 0.005 wt %) aqueous solution of THF:H2O = 10:90 by volume at 25°C.
AB - Poly(lactic-co-glycolic acid) (PLGA) were grafted to both ends of Pluronic® F68 ((EO)75(PO)30(EO)75) triblock copolymer to produce poly{(lactic acid)m-co-(glycolic acid) n}-b-poly(ethylene oxide)75-b-poly(propylene oxide) 30-b-poly(ethylene oxide)75-b-poly{(lactic acid) m-co-(glycolic acid)n} (PLGA-F68-PLGA) pentablock copolymers. Molecular weights of PLGA blocks were controlled and five kinds of pentablock copolymers with different PLGA block lengths were synthesized using in-situ ring-opening polymerization of D,L-lactide and glycolide with tin(II) 2-ethylhexanoate (Sn(Oct)2) catalyst. PLGA-F68-PLGA pentablock copolymers were characterized by 1H- and 13C-NMR, GPC, and TGA. The numbers (2m, 2n) of repeating units for lactic acid and glycolic acid inside PLGA segments were obtained as (48, 17), (90, 23), (125, 40), (180, 59), and (246, 64), with 1H-NMR measurement. From NMR data, the resultant molecular weights were determined in the range of 12,700-29,700, which were similar to those obtained from GPC. Polydispersity index was increased in the range of 1.32-1.91 as the content of PLGA blocks increased. TG and DTG thermograms showed discrete degradation traces for PLGA and F68 blocks, which indicate the weight fractions of PLGA blocks in pentablock copolymers can be calculated by TG profile and it is possible to remove PLGA block selectively. Hydrodynamic radius and radius of gyration of pentablock copolymer micelle were obtained in the range of 46-68 nm and 31-49 nm, respectively, in very dilute (i.e. 0.005 wt %) aqueous solution of THF:H2O = 10:90 by volume at 25°C.
KW - Pentablock copolymer
KW - PLGA-F68-PLGA
KW - Pluronic F68
KW - Poly(lactic acid-co-glycolic acid)
KW - Ring-opening polymerization
UR - https://www.scopus.com/pages/publications/84906351396
U2 - 10.5012/bkcs.2014.35.8.2342
DO - 10.5012/bkcs.2014.35.8.2342
M3 - Article
AN - SCOPUS:84906351396
SN - 0253-2964
VL - 35
SP - 2342
EP - 2348
JO - Bulletin of the Korean Chemical Society
JF - Bulletin of the Korean Chemical Society
IS - 8
ER -