This review highlights recent applications of the thiol-yne reaction in polymer synthesis and modification and also gives some representative examples of its application in small molecule ...(bio)organic chemistry. A brief introduction to the history of the thiol-yne reaction is given followed by a description of the mechanism for the common radical-mediated manifestation of the reaction. This is followed by a review of its use in network/gel syntheses and modification, as a tool for polymer synthesis and copolymer modification; its applicability in the preparation of dendrimers and hyperbranched polymers and finally how it has been employed as a tool for surface modification and functionalisation. This review is not intended to be exhaustive but rather to serve as an overview of research areas within which this important reaction is currently attracting interest.
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•We review recent applications of the thiol-yne reaction.•Background in small molecule chemistry is given followed by applications in polymer and materials science.•Monomer synthesis and polymer modification is highlighted.•Non-linear polymer syntheses, including networks, are discussed.•Recent advances in monohydrothiolation of alkyne bonds in polymer science are noted.
This contribution serves as an update to a previous review (
Polym. Chem.
2010,
1
, 17–36) and highlights recent applications of thiol–ene ‘click’ chemistry as an efficient tool for both ...polymer/materials synthesis as well as modification. This current contribution covers examples from the literature published up to
ca.
mid 2013. It is not intended to be exhaustive but rather serves to highlight many of the new and exciting applications where researchers have applied thiol–ene chemistry in advanced macromolecular engineering and materials chemistry.
This article reviews the current state of the art with respect to RAFT alcoholic dispersion polymerization processes that proceed with polymerization-induced self-assembly (PISA) and covers the bulk ...of the literature up to mid-2016. The article is arranged according to suitable comonomers that may employed in such copolymerizations. Where appropriate we have highlighted unusual nanoparticle morphologies that are accessible, and formulation specific, as well as interesting properties associated with certain final nano-objects.
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•RAFT dispersion polymerization with polymerization-induced self-assembly (PISA) proceeds in a range of alcoholic solvents.•Nanoparticles of ‘common’ and complex morphology are readily accessible.•Nano-objects responsive to changes in temperature and/or pH can be prepared.•Reversible order-order and order-disorder transitions have been observed.
The merits of thiol-click chemistry and its potential for making new forays into chemical synthesis and materials applications are described. Since thiols react to high yields under benign conditions ...with a vast range of chemical species, their utility extends to a large number of applications in the chemical, biological, physical, materials and engineering fields. This critical review provides insight into emerging venues for application as well as new mechanistic understanding of this exceptional chemistry in its many forms (81 references).
Reversible addition–fragmentation chain transfer (RAFT) radical polymerization has, since its discovery by CSIRO, evolved into an extremely powerful synthetic tool for polymer chemists. The ...versatility of RAFT, with respect to reaction conditions and monomer class, now facilitates the preparation of materials which, only 10 years ago, could not be prepared with well-defined molecular characteristics. One particularly advantageous feature of RAFT is its applicability to the synthesis of water-soluble (co)polymers both directly in aqueous media under homogeneous conditions as well as in organic media. The ease of access to an almost infinite number of RAFT mediating agents now affords the synthetic chemist the ability to polymerize virtually any activated, and some non-activated, water-soluble/hydrophilic monomers. We highlight herein the application of RAFT to the synthesis of water-soluble/dispersible (co)polymers under homogeneous reaction conditions in both aqueous and organic media. Additionally, we review the aqueous solution properties of advanced stimuli–responsive systems with a particular emphasis on the stimulus-induced, and often reversible, supramolecular self-assembly characteristics of the materials. Limitations of homogeneous aqueous RAFT are also highlighted.
Polymerization‐induced self‐assembly (PISA) is an extremely versatile method for the in situ preparation of soft‐matter nanoparticles of defined size and morphologies at high concentrations, suitable ...for large‐scale production. Recently, certain PISA‐prepared nanoparticles have been shown to exhibit reversible polymorphism (“shape‐shifting”), typically between micellar, worm‐like, and vesicular phases (order–order transitions), in response to external stimuli including temperature, pH, electrolytes, and chemical modification. This review summarises the literature to date and describes molecular requirements for the design of stimulus‐responsive nano‐objects. Reversible pH‐responsive behavior is rationalised in terms of increased solvation of reversibly ionized groups. Temperature‐triggered order–order transitions, conversely, do not rely on inherently thermo‐responsive polymers, but are explained based on interfacial LCST or UCST behavior that affects the volume fractions of the core and stabilizer blocks. Irreversible morphology transitions, on the other hand, can result from chemical post‐modification of reactive PISA‐made particles. Emerging applications and future research directions of this “smart” nanoparticle behavior are reviewed.
Nanoparticles made by polymerization‐induced self‐assembly can show reversible stimulus‐triggered polymorphism (“shape‐shifting”) that differs from the phase behaviour known for unimeric smart polymers. This review explains the background of this promising behaviour and summarises the current state‐of‐the‐art.
Reversible addition-fragmentation chain transfer (RAFT) radical dispersion polymerization (RAFTDP) has been employed to polymerize 2-phenylethyl methacrylate (PEMA) using poly2-(dimethylamino)ethyl ...methacrylate (PDMAEMA) macromolecular chain transfer agents (macro-CTAs) of varying average degree of polymerization (
X&cmb.macr;
n
). RAFTDP of PEMA in ethanol at 70 °C with PDMAEMA macro-CTAs yields well-defined AB diblock copolymers that self-assemble in solution during polymerization leading to the formation of well-defined diblock copolymer nanostructures. A full morphology transition (from spheres to worms to vesicles) is observed with these formulations that is sensitive to (i) the target
X&cmb.macr;
n
of the solvophobic polyPEMA block, (ii) the total solids content at which the PEMA block copolymerization is performed and (iii) the target
X&cmb.macr;
n
of PDMAEMA as a macro-CTA. Finally, we demonstrate the ability to convert the PDMAEMA-PPEMA based nanoparticles to the corresponding sulfopropylbetaine analogues by the facile reaction of the DMAEMA residues with 1,3-propanesultone.
Reversible addition-fragmentation chain transfer (RAFT) radical dispersion polymerization (RAFTDP) has been employed to polymerize 2-phenylethyl methacrylate (PEMA) using poly2-(dimethylamino)ethyl methacrylate (PDMAEMA) macromolecular chain transfer agents (macro-CTAs) of varying average degree of polymerization (
X&cmb.macr;
n
).
This Minireview details the current state‐of‐the‐art relating to (co)polymerizations mediated by well‐defined RhI‐ethynyl, vinyl, and aryl complexes. In particular, we focus on RhI species suitable ...for the (co)polymerization of phenylacetylenes, arylisocyanides, as well as propargyl esters and amides.
Rhodium chains: This Minireview details the current state‐of‐the‐art relating to (co)polymerizations mediated by well‐defined RhI‐ethynyl, vinyl, and aryl complexes. The focus is on RhI species suitable for the (co)polymerization of phenylacetylenes, arylisocyanides, as well as propargyl esters and amides.
Poly(stearyl methacrylate) (PSMA) homopolymers, prepared by RAFT radical polymerization, have been employed in the RAFT dispersion polymerization (RAFTDP) of 3-phenylpropyl methacrylate (PPMA) in ...n-tetradecane. RAFTDPs yielded block copolymers with narrow molecular weight distributions and tunable compositions and allowed for ready access to different polymorphic nanoparticle phases. Polymerization of PPMA at 20 wt %, for a fixed PSMA average degree of polymerization (X̅ n) of 19, allowed for the in situ preparation of soft matter nano-objects with spherical, worm, and vesicular morphologies. For a fixed block copolymer composition increasing total solids (from 10 to 40 wt %) favored the formation of nanoparticles with higher ordered morphologies. For block copolymer samples that formed soft physical gels at ambient temperature, a macroscopic thermoreversible degelation–gelation phenomenon was observed. The fundamental reason for this was a worm-to-sphere morphology transition that was facilitated, in part, by the low glass transition temperature of the core-forming PPPMA block and an associated increase in the solvation of the core with increasing temperature. Finally, we note that degelation can also be effected by simple dilution with this macroscopic change now due to simple worm disentanglement and not a fundamental morphology transition.
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