- Tytuł:
- Synthesis and morphology characteristics of new highly branched polycaprolactone PCL
- Autorzy:
-
Strachota, Adam
Zioło, Aleksandra
Mossety-Leszczak, Beata
Raczkowska, Joanna
Strachota, Beata
Janiszewska, Natalia
Walczak, Małgorzata
Awsiuk, Kamil - Opis:
- A simple and efficient method for the synthesis of biodegradable, highly branched polycaprolactone (PCL) is presented. The solvent-free (bulk) reaction was carried out via ring opening polymerization (ROP), catalyzed by tin octanoate Sn(Oct)2, and it employed hyperbranched polyamide (HPPA) as a macro-initiator. The core–shell structure of the obtained products (PCL-HPPA), with the hyperbranched HPPA core and linear PCL chains as shell, was in the focus of the product characterization. $^{1}$H nuclear magnetic resonance ($^{1}$H NMR) and elemental analysis confirmed the covalent incorporation of the HPPA in the products, as well as a high degree of grafting conversion of its amino functional groups. Confocal Raman Micro spectroscopy, and especially Time-of-Flight Secondary Ion Mass Spectrometry, further supported the existence of a core–shell structure in the products. Direct observation of macromolecules by means of cryogenic transmission electron microscopy, as well as gel permeation chromatography (GPC), suggested the existence of a minor ‘aggregated’ product fraction with multiple HPPA cores, which was attributed to transesterification reactions. Differential scanning calorimetry, as well as X-ray diffraction, demonstrated that the PCL-HPPA polymers displayed a similar degree of crystallinity to linear neat PCL, but that the branched products possessed smaller and less regular crystallites.
- Dostawca treści:
- Repozytorium Uniwersytetu Jagiellońskiego
Artykuł