A simple and efficient method for the synthesis of polyaspartamide-based brush copolymers usingAtom Transfer Radical Polymerization (ATRP) is here presented. The syntheses were performed by using twosubsequent steps. In the first step the macroinitiator was obtained by the conjugation of a proper number of2-bromoisobutyryl bromide (BIB) residues to the R, -poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA) side chains,obtaining the PHEA-BIB copolymer. PHEA-BIB copolymer was used as “multi-functional macroinitiator” forthe polymerization via ATRP of hydrophilic methacrylic monomers, such as methacrylic acid (MA), obtainingPHEA-IB-poly(MA) copolymer, sodium methacrylate (MANa+), obtaining PHEA-IB-poly(MANa+) copolymer,or hydrophobic monomer such as butyl methacrylate (BMA), obtaining PHEA-IB-poly(BMA) copolymer.BMA was also homopolymerized subsequently MANa+ polymerization, extending the poly(MANa+) chains bypoly(BMA) chains arising PHEA-IB-poly(MANa+)-block-poly(BMA) copolymer. Different solvent andtemperature conditions were used in order to obtain the best ATRP conditions for each monomer in term of highpolymerization efficiency in PHEA side chain. All the synthesized PHEA-based brush copolymers were widelycharacterized and copolymer self-assembling properties in aqueous media were evaluated by turbidimetrymeasurements, light scattering and SEM analyses. PHEA-IB-poly(MANa+) resulted able to form sphericalmicroparticles at pH 2, with a diameter from 1 - 5 μm. PHEA-IB-poly(MANa+)-block-poly(BMA) copolymerformed particles at elliptic shape and an internal hollow architecture with an outer diameter of 1-4 μm. Finally,PHEA-IB-poly(BMA) copolymer resulted able to produce microfibers in aqueous medium, with an homogeneoustube shape and a thickness ranging from 3 to 5 μm.
|Numero di pagine||11|
|Stato di pubblicazione||Published - 2009|
All Science Journal Classification (ASJC) codes
- Organic Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Materials Chemistry