Development of Branching in Atom Transfer Radical Copolymerization of Styrene with Triethylene Glycol Dimethacrylate

Abstract

The branching copolymerization of styrene with triethylene glycol dimethacrylate (tri-EGDMA) as the branching agent was carried out using atom transfer radical polymerization (ATRP) in anisole at 90 °C. The resulting copolymers were analyzed using 1H NMR and triple detection size exclusion chromatography (TD-SEC). The NMR analysis shows that the pendent vinyl groups react even in the early stages of the polymerization. Analysis of the changes in the molecular weight and polydispersity of the copolymers suggests that the reaction system contains three components: the primary chains, the slightly branched chains comprising of two primary chains, and the highly branched chains consisting of more than three primary chains. The coupling reaction mainly takes place between the primary chains, resulting in the slightly branched chains in the early stages of the reaction, the weight fraction of the branched chains and the degree of branching increase gradually with monomer conversion, highly branched chains mainly form at relatively high monomer conversions.

Controlled multi-vinyl monomer homopolymerization through vinyl oligomer combination as a universal approach to hyperbranched architectures

“…1 H NMR analysis during the reaction shows that the majority of combination events occur when the initiator is nearly exhausted. Gas chromatography (GC) was also performed to monitor composition evolution during the early period of polymerization 34 ( Supplementary Fig. S4).…”

Doxorubicin-loaded aromatic imine-contained amphiphilic branched star polymer micelles: synthesis, self-assembly, and drug delivery

“…It is well known that controlled radical copolymerization of the divinyl and monovinyl monomers in an appropriate recipe produces branched copolymers, and degree of branching (DB) is determined by the ratio of divinyl monomer/monovinyl monomer. 49 Table 1. Similar to the branched copolymerization with divinyl monomer as a divergent agent in a previous report, 49 high yields (~99%) of the resultant branched copolymers were obtained (Table 1).…”

“…49 Table 1. Similar to the branched copolymerization with divinyl monomer as a divergent agent in a previous report, 49 high yields (~99%) of the resultant branched copolymers were obtained (Table 1). Their M w and M w /M n were characterized by GPC, all the GPC traces in Figure S1 display bimodally, and their M w /M n are broad, which is consistent with controlled radical copolymerization of the mono-and divinyl monomers, because the branched polymers are formed via step polymerization of the linear polymer chains.…”

“…Their M w and M w /M n were characterized by GPC, all the GPC traces in Figure S1 display bimodally, and their M w /M n are broad, which is consistent with controlled radical copolymerization of the mono-and divinyl monomers, because the branched polymers are formed via step polymerization of the linear polymer chains. 49,50 To understand branched structure and compositions of the obtained polymers, their 1 H-NMR spectra were measured, and a typical 1 H-NMR spectrum of the branched copolymer, BP-3, is shown in Figure 2A Table 1. We can see that the molar ratios of [DMAEMA]: [MAEBA] in the polymers are higher than that in the feed, indicating lower reactivity of MAEBA in comparison with DMAEMA, probably owing to bulky side group of the MAEBA monomer.…”

Synthesis of Hyperbranched Poly(ε-caprolactone) Containing Terminal Azobenzene Structure via Combined Ring-Opening Polymerization and “Click” Chemistry

“…Until 1988, the first example of this type of macromolecule was reported by Kim and Webster [12]. Since then, hyperbranched polymers have attracted much attention in polymer science owing their unique physical and chemical properties [13][14][15], such as less entanglement in the solid state, fast molecular motion and high solubility in various solvents. Compared with dendrimers obtained from step-by-step synthesis, hyperbranched polymers could be considered as irregular analogues of the dendrimers with narrow polydispersity and predictable molecular weights [16], Moreover, hyperbranched polymers can easily be synthesized by direct one-pot polymerization based on functional ABx-type (x ≥ 2) monomers [17,18], which were better suited for application in highly functionalized globular production.…”