Synthesis and physicochemical characterization of PMMA and PNIPAM based block copolymers by using PEG based macro RAFT agents
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Dosyalar
Tarih
2022
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Indian Acad Sciences
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Polyethylene glycol (PEG) based macro-RAFT agents were synthesized by the condensation reaction of PEG (Mn: 2000 Da and 8000 Da) with the carboxylic acid functionalized trithiocarbonate [S-Dodecyl-S'-(alpha,alpha'-dimethyl-alpha ''-acetic acid) tritiocarbonate (DDMAT)] using dicyclohexylcarbodiimide (DCC)/4-(dimethylamino) pyridine (DMAP) as catalyst at room temperature. Then, N-isopropylacrylamide (NIPAM) and methyl methacrylate (MMA) monomers were polymerized, respectively, using synthesized new macro-RAFT agents and N, N'-azo bis isobutyronitrile (AIBN) as the initiator. In all RAFT polymerizations, dispersity values were found in the range of 1.04 to 1.47, which showed that RAFT polymerization was applied successfully. The synthesized polymers were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Proton Nuclear Magnetic Resonance Spectroscopy (H-1-NMR), Gel Permeation Chromatography (GPC) and Differential Scanning Calorimetry (DSC) techniques. The fractured surface images of PEG-b-PMMA block copolymers were obtained by Scanning Electron Microscopy (SEM). SEM images PEG-b-PMMA block copolymers have shown that the copolymers have a microporous structure. In addition, the swelling ratios and LCST values of the PEG-b-PNIPAM block copolymers were measured which were found to be very high. The lower critical temperature values of the copolymers are closer to that of the PNIPAM homopolymer, 32 degrees C, indicating its usability in drug delivery systems.
Açıklama
Anahtar Kelimeler
Raft Polymerization; Peg Based Macro-Raft Agent; Amphiphilic Block; Thermoresponsive Block Copolymer, Fragmentation Chain Transfer; Transfer Radical Polymerization; One-Step Synthesis; Graft-Copolymers; Molecular-Weight; Functional Polymers; Glass-Transition; Responsive Drug; Poly(N-Isopropylacrylamide); Brushes
Kaynak
Journal of Chemical Sciences
WoS Q Değeri
Q3
Scopus Q Değeri
Q3
Cilt
134
Sayı
2
