Synthesis, nanoprecipitation and pH sensitivity of amphiphilic linear–dendritic hybrid polymers and hyperbranched-polydendrons containing tertiary amine functional dendrons

Abstract

The combination of linear polymers with dendritic chain-ends has led to numerous studies of linear-dendritic polymer hybrid materials. Interchain branching within the linear segment of these materials has recently extended this concept to the formation of soluble hyperbranched-polydendrons. Here, the introduction of amphiphilicity into hyperbranched-polydendrons has been achieved for the first time through the use of tertiary amine functional dendritic chain-ends and branched hydrophobic polymer segments. The synthesis and aqueous nanoprecipitation of these branched materials is compared with their linear-dendritic polymer analogues, showing that chain-end chemistry/generation, precipitation medium pH and polymer architecture are all capable of influencing the ability to generate nanoparticles, the resulting nanoparticle diameter and dispersity, and subsequent response to changes in pH.

A Combination of Factors: Tuning the Affinity of Europium Receptors for Phosphate in Water

“…The amine intermediate 1 was previously synthesized as reported in the literature. 58 Removal of the Boc protective groups with TFA exposed the three amino groups. This tripodal backbone was subsequently coupled with the N-hydroxysuccinimide-activated and benzyl-protected podant, HOPO(Bn)-OSu 6, to yield the protected ligands 7−10.…”

Role of highly branched, high molecular weight polymer structures in directing uniform polymer particle formation during nanoprecipitation

“…17,18 Studies of the impact of polymer architecture and molecular weight on nanoprecipitation outcomes are very rare. 15 We have reported a new complex polymer architecture -''hyperbranched polydendrons'' [19][20][21] -that overcomes the complexity of dendrimer synthesis by branching between linear-dendritic hybrid polymer chains during propagation (Scheme 1); weight average molecular weights 410 6 g mol À1 , representing 490 conjoined primary linear-dendritic chains, have been achieved. Hyperbranched polydendrons contain considerable variation in: (1) the number of branched chains (Fig.…”

“…The polymers were synthesised using previously reported approaches, [19][20][21] namely copper-catalysed methanolic atom transfer radical polymerisation at 30 1C, initiated using a new generation 2 (G 2 ) dendron initiator, 1, and a monomer mixture of 2-hydroxypropyl methacrylate, 2 (HPMA), and ethylene glycol dimethacrylate, 3 (EGDMA) in a 1 : 2 : 3 molar ratio of 1 : 50 : 0.8 (target number average degree of polymerisation for each primary chain of 50 monomer units). This ratio also ensures o1 brancher per primary chain and avoids gelation.…”

Synthesis of a Hierarchically Branched Dendritic Polymer Possessing Multiple Dendrons on a Dendrimer-like Backbone

“…This potentially new class of dendritic molecules can be viewed as dendronized dendritic polymers featured by the structure of multiple dendrimers/dendrons on a dendrimer-like skeleton with relatively narrow distribution of molecular weights. It is different from the previously reported classes of dendritic polymers, such as hyperbranched polydendrons − and dendron functionalized core cross-linked star polymers; in both systems, dendron initiators are being synthesized and used to initiate, in the former, the copolymerization of vinyl/divinyl monomers to form broad distribution products, while in the latter, the homopolymerization of vinyl monomers followed by end-linking using divinyl monomers. In this paper, we report, as a proof of concept, the first synthesis of such a hierarchically branched dendritic structure with multiple carbonate-based dendrons on a dendrimer-like polystyrene trunk.…”