Synthesis and characterization of star-shaped block copolymers composed of poly(3-hydroxy octanoate) and styrene via RAFT polymerization
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Date
2022
Journal Title
Journal ISSN
Volume Title
Publisher
Taylor & Francis Inc
Access Rights
info:eu-repo/semantics/closedAccess
Abstract
This study investigated a macro reversible addition fraction chain transfer (RAFT) agent based on three-arm hydroxylated star-shaped poly(3-hydroxy octanoate). The utilization of this star-shaped poly(3-hydroxy octanoate) macro-RAFT agent in the RAFT process resulted in efficient control in the preparation of star-shaped block styrene copolymers. Poly(3-hydroxy octanoate) (PHO) was reacted with diethanol amine (DEA) in order to obtain three-arm hydroxylated poly(3-hydroxy octanoate) (PHO-DEA). A carboxylic acid-functionalized RAFT agent (2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid) was reacted with the PHO-DEA in order to obtain a star-shaped PHO macro-RAFT agent (PHO-R2). A series of AB(3) type PHO-polystyrene (PHO-PS) star-shaped block copolymers were obtained via the polymerization of styrene (S) using the PHO-R2 in toluene at 80 degrees C. The RAFT polymerization was seen to obey the polymerization kinetics of controlled free radical polymerization. The plasticizing effect of the PHO soft segments was influenced by the glass transition temperature (Tg) of polystyrene. This was clearly observed in the block copolymers. Moreover, it was clear that this plasticizing effect disappeared in the block copolymers as a result of the increase in polymerization time. The molar masses of the obtained copolymers increased in parallel with increases in the polymerization time. Structural, physiochemical, and thermal characterization of the obtained products was carried out using size-exclusion chromatography (SEC), proton nuclear magnetic resonance (H-1 NMR), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA) techniques. The polymerization kinetics of the star-shaped block copolymers were also investigated in detail.
Description
Keywords
Poly(3-Hydroxy Octanoate); Macro Raft Agent; Three Hydroxylated Pho; Pho-Ps Star-Shaped Block Copolymers; Biomaterials, Chemical-Modification; Bacterial Polyesters; Triblock Copolymers; Polyhydroxyalkanoates; Biosynthesis; Elastomers; Chemistry; Polymers; Micellization; Polystyrene
Journal or Series
Journal of Macromolecular Science Part A-Pure and Applied Chemistry
WoS Q Value
Q3
Scopus Q Value
Q2
Volume
59
Issue
8
