Abstract
Amphiphilic biodegradable mPEG–PCL diblock copolymers have been synthesized using rare earth catalyst: yttrium tris(2,6-di-tert-butyl-4-methylphenolate) [Y(DBMP)3] in the presence of monomethoxy poly(ethylene glycol) (mPEG, Mn=5000) as macro-initiator. The diblock architecture of the copolymers was thoroughly characterized by 1H NMR, 13C NMR and SEC. The molecular weights of mPEG–PCLs can be well controlled by adjusting the feeding molar ratio of ɛ-CL to mPEG. Thermal and crystallization behaviors of the diblock copolymers were investigated by DSC and POM (polarized optical microscope). The crystallization property of mPEG–PCL block copolymers depends on the length of PCL blocks. As the molecular weight of PCL block increased, the crystallization ability of mPEG block was visibly restrained. Aqueous micelles were prepared by dialysis method. The critical micelle concentration of the copolymers, which was determined to be 0.9–6.9mg/L by fluorescence technique, increased with the decreasing of PCL block length. The particle sizes determined by DLS were 30–80nm increasing with the PCL block length. TEM images showed that these micelles were regularly spherical in shape.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.