title: Synthesis, characterization, and self-assembly of linear poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ε-caprolactone) (PEO-PPO-PCL) copolymers.
abstract: Amphiphilic triblock copolymers of PEO-PPO-PCL with various block compositions have been synthesized by ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) initiated by the OH group of methoxy-poly(ethylene oxide)-poly(propylene oxide) (Me-PEO-PPO). Their structures were confirmed by Fourier transform infrared (FT-IR) measurements, and their self-assembly in aqueous solution was studied using fluorescence spectroscopy, transmission electron microscopy (TEM), UV-vis spectra, differential scanning calorimetry (DSC), and surface tension. For the copolymers studied in this paper, the critical aggregation concentrations (CAC) ranged from 5×10(3) to 2 mg/L. The critical micelle concentrations (CMC) decreased with increasing PCL block length, and the downtrend was more significant in the short PCL block length. All of the three copolymers were capable of solubilizing hydrophobic molecules (pyrene) in aqueous solution and copolymers with a longer PCL block exhibited a stronger solubilizing ability. The TEM images showed that the size and morphology of the aggregations could be tuned by varying the compositions or the concentration.
authors.affiliation: College of Science, China University of Petroleum, 66 West Changjiang Road, Qingdao, Shandong 266580, PR China.
authors.forename: Lifang
authors.initials: L
authors.lastname: Xu
authors.forename: Zhiqing
authors.initials: Z
authors.lastname: Zhang
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Dongdong
authors.initials: D
authors.lastname: Xie
authors.forename: Shan
authors.initials: S
authors.lastname: Yang
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.forename: Lijuan
authors.initials: L
authors.lastname: Feng
authors.forename: Chengchai
authors.initials: C
authors.lastname: Chu
mesh_terms: D015394:Molecular Structure; D010316:Particle Size; D011091:Polyesters / Q000138:chemical synthesis* / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000138:chemical synthesis* / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*; D011409:Propylene Glycols / Q000138:chemical synthesis* / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D011091:Polyesters; D011108:Polymers; D011409:Propylene Glycols; C016240:polycaprolactone; C012504:polypropylene glycol; D011092:Polyethylene Glycols