Autonomous healing of damage is a common phenomenon in living organisms but hardly ever encountered synthetic materials. Disulfide chemistry used to introduce self-healing ability covalently cross-linked rubber. cut takes place at moderate temperatures and leads full recovery mechanical properties. This result achieved by introducing disulfide groups the network that are able exchange, leading renewal cross-links across damaged surfaces. The process can be repeated many times. combination...

Abstract Pulsed‐laser polymerization (PLP) in conjugation with molecular weight distribution (MWD) measurement has emerged as the method of choice for determining propagation rate coefficient k p free‐radical polymerizations. Detailed guidelines using this technique (including essential internal consistency checks) and reporting results therefrom are given by authors, members IUPAC Working Party on Modeling kinetics processes polymerization. The PLP‐MWD measurements from many laboratories...

Pulsed-laser polymerization (PLP) in conjunction with the analysis of molecular weight distribution (MWD) via size-exclusion chromatography (SEC) remains recommended by IUPAC Working Party on Modeling polymerisation kinetics and processes as method choice for determination propagation rate coefficients, kp, free-radical polymerization. kp data from PLP-SEC studies several laboratories ethyl methacrylate (EMA), butyl (BMA) dodecyl (DMA) bulk polymerizations at low conversion ambient pressure...

Abstract Investigations into the kinetics and mechanism of dithiobenzoate‐mediated Reversible Addition–Fragmentation Chain Transfer (RAFT) polymerizations, which exhibit nonideal kinetic behavior, such as induction periods rate retardation, are comprehensively reviewed. The appreciable uncertainty in coefficients associated with RAFT equilibrium is discussed methods for obtaining RAFT‐specific detailed. In addition, mechanistic studies presented, target elucidation fundamental cause...

New thermoset systems based on disulfide bonds were synthesized with self-healing capabilities. The mechanism is not related to disulfide–disulfide exchange reactions, but thiol–disulfide reactions that are pH-dependent. Stress relaxation experiments showed large for having PTM2 as a curing agent, which indicates the system can rearrange its molecular structure release stress. However, rates decreased samples tested longer after production. This disappearance of thiol-groups probably caused...

Reversible addition–fragmentation chain transfer (RAFT) was applied to the copolymerization of styrene and maleic anhydride. The product had a low polydispersity predetermined molar mass. Novel, well-defined polyolefin-based block copolymers were prepared with macromolecular RAFT agent from commercially available polyolefin (Kraton L-1203). second consisted either polystyrene or poly(styrene-co-maleic anhydride). Furthermore, colored, labile dithioester moiety in polymerizations could be...

In situ 1H nuclear magnetic resonance (NMR) spectroscopy has been used to directly investigate the processes that occur during early stages (typically first few monomer addition steps) of an AIBN-initiated reversible addition−fragmentation chain transfer polymerization styrene in presence RAFT agent cyanoisopropyl dithiobenzoate at 70 and 84 °C. The change concentration important species as a function time investigated. It was found reaction extremely selective period consumption initial...

Abstract The reversible addition–fragmentation chain transfer (RAFT) polymerization technique has been employed to synthesize linear α,ω ‐telechelic polymers with either hydroxyl or carboxyl end groups. Methyl methacrylate, butyl and acrylate were polymerized RAFT polymerization. polymerizations exhibited the usual characteristics of living processes. Telechelic polymethacrylates obtained from a monofunctional polymer two‐step chain‐end modification procedure dithioester group. consisted an...

Chain transfer to polymer (CTP) in conventional free-radical polymerizations (FRPs) and controlled radical (ATRP, RAFT NMP) of n-butyl acrylate (BA) has been investigated using (13) C NMR measurements branching the poly(n-butyl acrylate) produced. The mol-% branches are reduced significantly as compared FRPs. Several possible explanations for this observation discussed critically all except one refuted. observations explained terms differences concentration highly reactive short-chain...

Rheumatoid arthritis (RA) is an autoimmune disease with unclear pathogenesis. Hydroxychloroquine (HCQ), despite its moderate anti-RA efficacy, among the few clinical drugs used for RA therapy. Macrophages reportedly play a vital role in RA. Here, we designed and explored macrophage-targeted HCQ nanotherapeutics based on mannose-functionalized polymersomes (MP-HCQ) Notably, MP-HCQ exhibited favorable properties of less than 50 nm size, glutathione-accelerated release, M1 phenotype macrophage...

The IUPAC method uses monomer composition, conversion, and copolymer composition to find reactivity ratios. Shown the optimal ratios in red a 95% Confidence Interval blue.

In situ 1H nuclear magnetic resonance spectroscopy was used to directly investigate the processes that occur during early stages (the first few monomer addition steps) of azobis(isobutyronitrile)-initiated reversible addition−fragmentation chain transfer (RAFT) polymerizations styrene in presence cumyl dithiobenzoate at 70 and 84 °C. The change concentration important species as a function time investigated. predominant type growing under reaction conditions carries end group. initialization...

The copolymerization of styrene and maleic anhydride has received significant attention in academia as well industry. Nevertheless, the underlying mechanism is still a point debate. In this paper, an overview given that provides compelling evidence favor penultimate unit model correct choice to describe process chain growth. addition new developments terms living radical are discussed from mechanistic view.

Two xanthate end-functional poly(ethylene glycol)s (PEGs) were tested as macromolecular chain-transfer agents (macroCTA) in the reversible addition−fragmentation transfer-mediated polymerization of vinyl acetate (VAc) and N-vinylpyrrolidone. The macroCTA leaving group played a determining role preparation block copolymers. PEG-b-PVAc PEG-b-PVP diblock copolymers obtained when had propionyl ester group, whereas under same experimental conditions with phenylacetyl inhibited polymerization. In...

Plantaricin 423, produced by Lactobacillus plantarum, and bacteriocin ST4SA Enterococcus mundtii, were electrospun into nanofibers prepared from different combinations of poly(D,L-lactide) (PDLLA) poly(ethylene oxide) (PEO) dissolved in N,N-dimethylformamide (DMF). Both peptides released the with a high initial burst retained 88% their original antimicrobial activity at 37 °C. Nanofibers have potential to serve as carrier matrix for bacteriocins open new field developing controlled delivery...

Since its introduction, click chemistry has received a considerable amount of interest. In this contribution, the term and reactions that fall under are briefly explained. The main focus review is on application in conjunction with living radical polymerization for synthesis advanced macromolecular architectures. Therefore most powerful (LRP) techniques discussed an overview different synthetic schemes given. A large number examples shown include block copolymers, star-shaped polymers,...

Polymer stabilized nanodiscs are self-assembled structures composed of a polymer belt that wraps around segment lipid bilayer, and as such capable encapsulating membrane proteins directly from the cell membrane. To date, most studies on these have used poly(styrene-co-maleic acid) (SMA) with term SMA-lipid particles (SMALPs) coined to describe them. In this study, we determined physical thermodynamic properties made two different SMA copolymers. These include widely commercially available...

ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication the EditorNEXTControlled Radical Polymerization in EmulsionStefan A. F. Bon, Michiel Bosveld, Bert Klumperman, and Anton L. GermanView Author Information Laboratory of Polymer Chemistry, Eindhoven Laboratories (EPL), University Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands Cite this: Macromolecules 1997, 30, 2, 324–326Publication Date (Web):January 27, 1997Publication History Received11 July 1996Revised13...

The kinetics of CuBr-mediated homogeneous atom transfer radical polymerization (ATRP) methyl methacrylate (MMA) using 2-hydroxyethyl-2-bromoisobutyrate (HEBIB) as initiator and N-(n-hexyl)pyridylmethanimine (NHPMI) ligand was investigated. experimental results showed that initially added Cu(II) can have strong effects on the ATRP depending [Cu(II)]0/[Cu(I)]0 ratio. When ≤10% relative to Cu(I) at beginning polymerization, be well described by Fischer's equation (ln([M]0/[M]) ∝ t2/3).9...

1. INTRODUCTION The ability of solvents to affect the homopropagation rate many common monomers has been widely documented. For example, Bamford and Brumby [1] showed that propagation kp methyl methacrylate (MMA) at 25°C was sensitive a range aromatic solvents. Burnett, Cameron, Joiner [2] found styrene (Sty) depressed by increasing concentrations benzonitrile, bromobenzene, diethyl phthalate, dinonyl malonate, while in other studies [3, 4], they for MMA enhanced halobenzenes naphthalene....

The atom transfer radical copolymerization (ATRP) of methyl acrylate (MA) with 1-octene was investigated in detail. Well-controlled copolymers containing almost 25 mol % were obtained using ethyl 2-bromoisobutyrate (EBriB) as initiator. Narrow molar mass distributions (MMD) for the ATRP experiments. feasibility copolymerizations independent ligand employed. Copolymerizations carried out 4,4'-dinonyl-2,2'-bipyridine (dNbpy) resulted good control, significant octene incorporation polymer....