Polymerisable surfactants for polymethacrylates using catalytic chain transfer polymerisation (CCTP) combined with sulfur free-RAFT in emulsion polymerisation

Statistical copolymers of methacrylic acid and methyl methacrylate were synthesised via free radical catalytic chain transfer polymerisation (CCTP) in emulsion to form a hydrophilic emulsifier/surfactant. The vinyl-terminated oligomers were in turn utilised as chain transfer agents, with no further purification, for the formation of diblock copolymers with butyl and methyl methacrylate which constitutes the emulsifier via sulfur-free reversible addition–fragmentation chain transfer polymerisation (SF-RAFT). In turn these polymers were solubilized with various concentrations of ammonium hydroxide and utilised in the surfactant-free emulsion polymerization of butyl methacrylate using persulfate initiators, which also stabilized the polymer particles with observed no coagulation, with solid contents as high as 40%

Polymers for fluorescence imaging of formaldehyde in living systems via the Hantzsch reaction

Formaldehyde (FA) has been detected via the Hantzsch reaction for many decades. However, the Hantzsch reaction has been rarely used to detect FA in biological systems due to the disadvantages of small-molecule probes (including toxicity and poor water solubility). In this study, polymeric fluorescent probes were developed to resolve these issues associated with small molecules, and FA in living systems was successfully detected via the Hantzsch reaction. These water-soluble polymers were easily scaled-up (∼25 g) by radical polymerization using commercial monomers. These polymers exhibited similar, albeit better, sensitivity to FA compared to water-soluble small molecules, primarily indicative of the advantages of polymers for the detection of FA via the Hantzsch reaction. The polymer structures were highly biocompatible with the probes; thus, these polymers can effectively detect endogenous FA in cells or zebrafish in a safe manner. This result confirmed the superiority of polymers in safety as biocompatible materials. This study highlights a straightforward method for exploring probes for the detection of FA in living systems. It offers functional polymers for bioimaging and extends the application scope of the Hantzsch reaction, reflecting the utility of a broad study of organic reactions in interdisciplinary fields as well as possible key implications in organic chemistry, analytical chemistry, and polymer chemistry

A simple and versatile route to amphiphilic polymethacrylates : catalytic chain transfer polymerisation (CCTP) coupled with post-polymerisation modifications

Amphiphilic polymers have become key figures in the fields of pharmacology, medicine, agriculture and cosmetics. The use of reversible deactivation radical polymerisation (RDRP) techniques has allowed advances in the synthesis of amphiphilic polymers. However, the high price to performance ratio of these methods can limit their industrial application. Herein, poly(glycidyl methacrylate) polymers of varying molecular weights were first synthesised by catalytic chain transfer polymerisation (CCTP). Amphiphilic polymers were then prepared using a simple one-pot, post-polymerisation modification process involving Michael-thiol addition in the presence of a range of hydrophobic mercaptans, followed by ring-opening of the epoxide groups with ethanolamine using microwave-assisted synthesis. This procedure allows for the synthesis of fully functional polymers within 3 hours. A range of well-defined materials are prepared and characterised by GPC, NMR, FTIR, DLS, TGA, and TEM

Self-healing and mechanical performance of dynamic glycol chitosan hydrogel nanocomposites

Evaluation of Schiff base nanocomposite hydrogels properties using a benzaldehyde multifunctional amphiphilic polyacrylamide crosslinker in conjunction with glycol chitosan

Automatic peak assignment and visualisation of copolymer mass spectrometry data using the “genetic algorithm”

Copolymer analysis is vitally important as the materials have a wide variety of applications due to their tunable properties. Mass spectrometry data for copolymer samples can be very complex due to the increase in the number of species when the polymer chains are formed by 2 or more monomeric units. In this paper, we describe the use of the genetic algorithm for automated peak assignment of copolymers synthesised by a variety of polymerization methods. We find that in using this method we are able to easily assign copolymer spectra in a few minutes and visualise them into heatmaps. These heatmaps allowed us to look qualitatively at the distribution of the chains, showing how they alter with different polymerization techniques, and by changing the initial copolymer composition. This methodology is shown to be simple to use and requires little user input, which makes it well suited for use by less expert users. The data outputted by the automatic assignment may also allow for more complex data processing going forward

Exploiting catalytic chain transfer polymerization for the synthesis of carboxylated latexes via sulfur‐free RAFT

We present a systematic study of incorporating carboxyl groups into latex particles to enhance colloidal stability and the physical properties of the latex. Statistical copolymers of methacrylic acid and methyl methacrylate) were synthesized via catalytic chain transfer polymerization (CCTP) in emulsion. The vinyl‐terminated oligomers were in turn successfully utilized as chain transfer agents for the formation of diblock and pseudo triblock copolymers via sulfur‐free reversible addition–fragmentation chain transfer polymerization (SF‐RAFT). These copolymers were characterized using 1H NMR, size exclusion chromatography (SEC), dynamic light scattering (DLS), dynamic mechanical analysis (DMA), contact angle measurements and matrix‐assisted laser desorption/ionization time of flight mass spectroscopy (MALDI‐TOF‐MS) techniques. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 201

Exploiting catalytic chain transfer polymerisation and applications for the synthesis of diblock and multi block co-polymers via sulphur free RAFT polymerisation

Polymers are generally categorised into two main categories: natural or synthetic. Natural polymers occur in nature and are can be extracted, studied and replicated for global use for diverse application: from pharmaceuticals to cosmetic industries. Nature has, through billions of years of evolution, assembled a vast number of polymeric macromolecules capable of exquisite molecular recognition. These functionalities within naturally occurring polymers, arise from the precise control exerted over their biosynthesis that results in key residues being anchored in the appropriate positions to interact with target substrates. Examples of common and widely studied natural polymers are silk, wool, DNA, cellulose and proteins. Nucleic acids, such as DNA and RNA, display ordered sequences based on four-nucleotide monomer units, whilst in proteins, 20 amino acids (monomers) are used to form precisely controlled monomer sequences. Such precise positioning of monomer units (or functionalities) has an important influence on polymer structure and results in unique properties, such as molecular recognition which spans functions as diverse as the transport of oxygen by haemoglobin, the detection of pathogens by our immune system and the control of metabolic pathways by enzyme catalysts of enviable specificities

Reversible bond formation via sulfur free reversible addition fragmentation in photo-3D printing

An addition-fragmentation monomer (AFM) has been used as a crosslinker in photopolymerization-based 3D printer resins in order to try and reduce shrinkage due to polymerisation. This results in reversible network formation via photo crosslinking with reversible covalent bond formation to effect mechanical performance. The 3D printing conditions were optimized with regards to print quality, print speed, etc. The AFM was synthesized via catalytic chain transfer polymerization (CCTP) and characterized using NMR and size exclusion chromatography (SEC). The incorporation of the AFM as a crosslinker allows for rapid reversible covalent bond formation during network formation in 3D photopolymerization printing resulting in a reduction in both polymerisation shrinkage and stress higher molecular weight crosslinkers lead to less shrinkage and reversible bond formation to less stress build up. Curing was monitored via photo-rheology and Fourier Transform Infrared Spectroscopy (FT-IR). At lower contents of AFM, the mechanical properties (strength and Young’s modulus) are improved without compromising material properties, printing conditions and curing time. At higher AFM content, the kinetic analysis of the photopolymerization reaction shows a reduced final conversion of the vinylic bonds along with a delay of the gel point. The thermal and mechanical properties were evaluated with incorporation of different concentrations of AFM added to the resin formulations

Photo‐induced controlled/living polymerizations

Application of photochemical protocols to polymer synthesis are of interest due to the unique possibilities such as topological and temporal control, rapid polymerization processes and environmentally benign features provided finding application in adhesives, coatings, adaptive manufacturing, etc. In particular, utilization of photochemistry in controlled/living polymerizations offers the precise control over the macromolecular structure and chain lengths in addition to advantages associated with photochemistry. Herein, the latest developments on photocontrolled living radical and cationic polymerizations and their combinations for macromolecular syntheses are discussed. The review summarizes and spotlights the recent studies in the emerging area of photoinduced controlled/living polymerizations. A discussion of mechanistic details highlights differences as well as parallels between different systems for different polymerization methods and monomer applicability