Polymer micelle-like aggregates of novel amphiphilic biodegradable poly(asparagine) grafted with poly(caprolactone) |
| |
Authors: | Jae Hyun JeongHyung Seok Kang Seung Rim YangJong-Duk Kim |
| |
Affiliation: | a Department of Chemical and Biomolecular Engineering, and Center for Ultramicrochemical Process Systems, Korea Advanced Institute of Science and Technology, 373-1 Kusong-dong, Yusong-gu, Daejon 305-701, South Korea b Nanotechnology Research Laboratory, Pacific R&D Center, Yongin-si 449-729, Kyunggi-do, South Korea |
| |
Abstract: | Novel amphiphilic graft copolymers composed of poly(asparagine) (PAsn) as the hydrophilic backbone and poly(caprolactone) (PCL) as the hydrophobic segment were successfully synthesized by grafting PCL-HMDs to poly(succinimde). After tosylating PCL-diol with p-toluenesulfonylchloride (TsCl), tosylated poly(caprolactone) (PCL-OTs) was then reacted with hexamethylenediamine (HMD). The reaction of the amine terminated PCL with poly(succinimide) (PSI) and the following aminolysis resulted in poly(aspargine)-graft-poly(caprolactone) (PAsn-g-PCL). The degree of substitution (DS) and grafting reaction was confirmed by 13C NMR, FT-IR spectroscopy and elemental analysis. X-ray diffraction and DSC thermogram showed that the crystalline domain originated from PCL became apparent with an increase of DS. The amphiphilic comb-type graft polymer formed self-aggregates in aqueous solution when precipitated and dialysed against distilled water. Strong hydrophobic interaction of associated PCL grafts facilitated primary aggregate formation with DS, significantly reducing critical aggregation concentration and secondary aggregates also appeared in DLS measurements. Self-aggregates showed a bimodal size distribution originated from the self-aggregation and kinetically controlled particle aggregation, although the smaller primary aggregates was predominant. Spherical and dispersed aggregates of about 20 nm in diameter were observed by a transmission electron microscope. |
| |
Keywords: | Poly(caprolactone) Poly(asparagine) Self-aggregates |
本文献已被 ScienceDirect 等数据库收录! |
|