Trifunctional Amine Research Articles

Self-assembled nanostructured membranes with tunable pore size and shape from plant-derived materials.

Nanostructured materials derived from sustainable sources are of interest as viable alternatives to traditional petroleum-derived sources in membrane applications due to environmental concerns. Here, we present the development of pore size-tunable nanostructured polymer membranes based on a plant-derived material. The membranes were fabricated using a tri-functional amine as the templating core species and a cross-linkable ligand synthesized from rose oil-derived citronellol. The self-assembly of a supramolecular complex between the template core and the ligand forms a hexagonally packed columnar (Colh) mesophase, the dimensions of which can be precisely controlled by changing the stoichiometric ratio between these constituents. Within the hexagonal mesophase stoichiometric range, the pore size of the nanostructured membranes can be tuned from 1.0 to 1.3 nm, with a step size of approximately 0.1 nm. The membranes exhibited a clear distinction in molecular size selectivity, as demonstrated by dye adsorption experiments. The membrane fabricated with a ligand-to-core ratio of 3 to 1 demonstrated shape-based selectivity, exhibiting a higher permeability for propeller-shaped penetrants and highlighting its potential for shape-selective transport. We anticipate that this straightforward approach, using plant-derived materials, can contribute to important sustainability aspects while enhancing the performance of current state-of-the-art nanostructured membranes by enabling precise control over pore size.

Nanocomposites of polyhydroxyurethane with Fe3O4 nanoparticles: Synthesis, shape memory and photothermal properties

AbstractThe nanocomposites of ferroferric oxide (Fe3O4) with polyhydroxyurethane (PHU) were fabricated via a physical mixing approach. This process involved grafting poly(N‐vinyl pyrrolidone) (PVPy) chains onto the surfaces of Fe3O4 nanoparticles via surface‐initiated living radical polymerization. The PVPy‐grafted Fe3O4 nanoparticles were directly incorporated into the precursors of PHUs [i.e., bis(cyclic carbonate) and a trifunctional amine] and the mixtures were cured at high temperatures to form organic–inorganic composites. This method ensured that Fe3O4 nanoparticles were finely dispersed within the PHU matrix through the strong intermolecular hydrogen bonding between PVPy and PHU. Compared to plain PHU network, the nanocomposites had enhanced thermomechanical properties, including higher glass transition temperatures (Tg's) and improved tensile mechanical properties. The inclusion of Fe3O4 nanoparticles also enhanced the shape memory properties of the PHU networks, improving shape recovery rates, fixity of transient shapes, and recovery of the original shapes. In addition, the nanocomposites demonstrated paramagnetic and photothermal properties and the photothermal behavior enabled a non‐contact control of shape recovery.Highlights Poly(N‐vinyl pyrrolidone)‐grafted Fe3O4 nanoparticles were synthesized. Nanocomposites of PHU with Fe3O4 were prepared via a physical blending approach. Incorporation of Fe3O4 resulted in improved thermomechanical properties. The nanocomposites had the photothermal properties.

Relationship between the polyurea underlayer structure and PEG surface coverage

Increasing the surface coverage of antifouling materials is essential to enhance the performance of antifouling coatings. In this study, polyurea thin-film underlayers were fabricated by co-depositing difunctional isocyanates with difunctional or trifunctional amines. The relationships among the underlayer structure, terminal group density before polyethylene glycol (PEG) termination, and PEG surface coverage were investigated. The results showed that employing trifunctional amines in the underlayer led to increased terminal group density before PEG termination. Moreover, the reduced hydrogen-bonding capability between the polyurea molecules contributes to enhanced PEG surface coverage.

Synthesis and Characterization of High-Performance, Bio-Based Epoxy–Amine Networks Derived from Resveratrol

Resveratrol is a sustainable and versatile bio-derived phenolic compound that has shown promise as a high glass-transition temperature (Tg), flame-resistant building block for thermoset networks. In this study, three components of epoxy thermoset resins were synthesized from resveratrol: trans-resveratrol trisepoxy (1), dihydroresveratrol trisepoxy (2), and a trifunctional amine, 4,4′-((5-(4-(4-aminophenoxy)phenethyl)-1,3-phenylene)bis(oxy))dianiline (4). The epoxy monomers were low melting solids (mp 2000 mg/L, and no cytotoxicity up to its solubility limit. The epoxy monomers were cured with 4,4′-methylenedianiline (3) and 4 to produce four epoxy–amine networks (A–D). Networks C and D, prepared with the resveratrol-derived aniline, contained up to 52.6% bio-based material. The moisture uptake, thermal stability, and dry/wet thermomechanical properties of the networks were measured. The networks had Tg’s as high as 285 °C, approximately 110 °C higher than networks based on petroleum-derived bisphenol A (BPA). In addition, the resveratrol networks had char yields as high as 51 and 46% in nitrogen and air, respectively, compared to ca. 15 and 5%, respectively, for BPA-based networks. Overall, this study shows the advantages of resveratrol-based epoxy and amine monomers as components of sustainable, low-toxicity, high-temperature resin systems.

Synthesis of polymer networks by means of addition reactions of tri-amine and poly(ethylene glycol) diacrylate or diglycidyl ether compounds

Polymer networks have been synthesized by addition reactions of tri-functional amine, tris(2-aminoethyl)amine (TAEA) or trimethylolpropane tris[poly(propylene glycol)amine terminated] ether (PPGTA), and poly(ethylene glycol) diacrylate (PEGDA), or poly(ethylene glycol) diglycidyl ether (PEGDE) in dimethyl sulfoxide (DMSO) as a solvent. These reactions yielded the gels in which the polymer networks were homogeneously swollen in DMSO. An increase in the monomer concentration increased Young’s modulus and breaking stress of the gels. The gels with PPGTA showed flexible features in comparison with those with TAEA due to the flexible molecular structure of PPGTA. The gels composed of TAEA and PEGDA or PEGDE with high molecular weight tended to show lower Young’s modulus and higher breaking strain than the gels composed of those with low molecular weight due to the decrease in the cross-linking density and/or increase in flexibility of the PEG unit accompanied by the increase in the molecular weight of PEG. The gels with PPGTA showed opposite tendency, indicating entanglement of PEG unit with high molecular weight, which would play a role of physical cross-linking points in the gels. The gels prepared in N,N-dimethylformamide (DMF) were flexible in comparison with the gels prepared in DMSO due to the high miscibility of the network and DMF. The reaction systems of TAEA and PEGDA with low molecular weight in ethanol formed porous polymeric networks derived from the phase separation during the polymerization. The porous polymeric networks were unbreakable by compression and absorbed various organic solvents.

The Introduction of the Radical Cascade Reaction into Polymer Chemistry: A One-Step Strategy for Synchronized Polymerization and Modification.

SummaryPolymerization and modification play central roles in polymer chemistry and are generally implemented in two steps, which suffer from the time-consuming two-step strategy and present considerable challenge for complete modification. By introducing the radical cascade reaction (RCR) into polymer chemistry, a one-step strategy is demonstrated to achieve synchronized polymerization and complete modification in situ. Attributed to the cascade feature of iron-catalyzed three-component alkene carboazidation RCR exhibiting carbon-carbon bond formation and carbon-azide bond formation with extremely high efficiency and selectivity in one step, radical cascade polymerization therefore enables the in situ synchronized polymerization through continuous carbon-carbon bond formation and complete modification through carbon-azide bond formation simultaneously. This results in a series of α, β, and γ poly(amino acid) precursors. This result not only expands the methodology library of polymerization, but also the possibility for polymer science to achieve functional polymers with tailored chemical functionality from in situ polymerization.

Catalyst-Free Vitrimers from Vinyl Polymers

Cross-linked networks feature exceptional chemical and mechanical resilience but consequently lack recyclability. Vitrimers have emerged as a class of materials that feature the robustness of thermosets and the recyclability of thermoplastics without compromising network integrity. Most examples of vitrimers have involved new polymers with exchangeable bonds within their backbones. In pursuit of a more universal, commercially viable route, we propose a method utilizing commercially available and inexpensive reagents to prepare vitrimers from vinyl monomer-derived prepolymers that contain cross-linkable β-ketoester functional groups. Controlled radical copolymerization of methyl methracrylate and (2-acetoacetoxy)ethyl methacrylate afforded linear prepolymers that were converted into vitrimers in a single step by treatment with a trifunctional amine. These materials displayed the characteristic features and reprocessability of vitrimers over as many as six (re)processing cycles. Critically, the networks pre...

A fast and mild closed-loop recycling of anhydride-cured epoxy through microwave-assisted catalytic degradation by trifunctional amine and subsequent reuse without separation

Efficient recycling of anhydride-cured epoxy resin via microwave-assisted degradation by trifunctional amine without any waste discharge.

Polyurea spray coatings: Tailoring material properties through chemical crosslinking

Among the many desirable properties of polymeric coatings, the most important include ease of application, rapid cure time, adhesive properties and excellent mechanical properties. In this context, spray coated polyureas are finding increasing applications in niche areas that otherwise pose considerable challenge to the traditional coating chemistries. In this work, we demonstrate the effect of introducing chemical cross-linking on the mechanical, thermal and structural properties of spray coated polyurea. A long chain trifunctional amine was introduced as a co-reactant in the resin blend, the amount of crosslinker being varied from 0 to 3.5 mol % (crosslinking density 28–180 mol/m3, affine network model). The mechanical properties of spray coated polyurea films, both in quasi-static as well as dynamic conditions were determined. Physically crosslinked polyurea coatings (in the absence of chemical cross-linking) exhibited tensile strength ∼ 7.4 ± 0.7 MPa and elongation of 121 ± 3.7%. Introduction of long chain amine led to an improvement in these characteristic properties till maxima at 2.2 mol%, subsequent to which both strength and elongation decreased. Chemical cross-linking led to restraining of the segmental motions reflecting in terms of increased glass transition temperature, as evidenced by dynamic mechanical analysis and differential scanning calorimetry. The chemical resistance of polyurea also improved substantially due to crosslinking, which reflected in terms of decreased swelling ratio in different organic media.

Crosslinked polyurea-co-polyurethane aerogels with hierarchical structures and low stiffness

Resilient poly(urethane urea) aerogels are synthesized from aromatic diisocyanates, aromatic diamines, aliphatic polyols, and a trifunctional amine crosslinker. Polyurethane prepolymers are synthesized with isocyanate end groups by reacting the polyol with 4,4′-diphenylmethane diisocyanate in anhydrous N-methyl-2-pyrrolidone (NMP). The isocyanate-capped polyurethane segments are reacted with 4,4′-oxydianiline to obtain isocyanate end-capped poly(urethane urea) copolymers which are then crosslinked using 1,3,5 triaminophenoxylbenzene (TAB) to obtain the gel networks. The gel networks are tailored by the choice of the polyol and by varying the crosslink density. The gels are dried under supercritical condition after exchanging NMP with acetone and acetone with liquid carbon dioxide. The resulting aerogels show density between 0.20 and 0.35 g/cm3, porosity between 71 and 85%, and surface area between 47 and 163 m2/g. The data suggest that the polyol weight fraction can be used as a parameter to control the shrinkage of aerogel specimens. The shrinkage data also correlate well with the extent of hydrogen bonding involving urea and urethane groups. A reduction of the amount of TAB leads to reduction of the extent of urea hydrogen bonding and an increase of urethane hydrogen bonding. These materials exhibit an onset of thermal decomposition at about 300 °C and offer compressive moduli between 12 and 52 MPa. The compressive modulus shows strong dependence on aerogel density.

Synthesis and characterization of elastomeric, biobased, nonisocyanate polyurethane from natural rubber

ABSTRACTLinear and crosslinked polyhydroxyurethanes (PHUs) based on natural rubber (NR) were synthesized by a polyaddition reaction without a solvent or catalyst to exploit the reactivity of diamines or triamines with dicyclic carbonate groups. Oligo‐isoprenes were obtained from the controlled oxidative degradation of NR and successive modifications of the chain ends. The syntheses of linear PHU were carried out with two approaches. The first one consisted of a reaction between amino telechelic oligo‐isoprenes and aromatic or aliphatic dicyclic carbonates. The second approach proceeded through a reaction between oligo‐isoprenes bearing cyclic carbonate chain ends and difunctional or trifunctional amines. The evolution of these reactions was studied by Fourier transform infrared spectrometry. The influence of the carbonate‐to‐amine molar ratio, the chain length of the oligo‐isoprenes, and the reaction temperatures were investigated. The thermal properties of the PHUs were studied by differential scanning calorimetry and thermogravimetric analysis. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45427.

The exploration of Michael-addition reaction chemistry to create high performance, ambient cure thermoset coatings based on soybean oil

• A novel highly functional bio-based acrylated resin was used. • The aza-Michael reaction was used to cure the acrylated resin with multifunctional amines. • Curing kinetics studies showed systems having rapid cure could be obtained. • Effects of solvent, curing agent, reactive diluent, on properties were explored. • Coating systems having good hardness and chemical resistance were achieved. Using Michael addition crosslinking technology, thermoset coatings were prepared from acrylated epoxidized sucrose soyate (AESS) and amine crosslinkers. AESS was synthesized from sucrose soyate, which is the sucrose ester of soybean oil fatty acids and has an average of about 12 functionalities per molecule. Due to the high functionality of AESS and fast reactivity of the amine crosslinkers, the coatings can be cured at ambient temperature (21 °C) in a relatively short period of time yielding good coatings properties. When AESS was reacted with 4′4′-methylene bis(cyclohexylamine), the acrylate group conversion was determined by FTIR to be up to 90%. It was also found that the type of solvent used in the coatings formulation affected the film formation and thus the coatings properties. The addition of 1,6-hexanediol diacrylate diluent in the formulations resulted in softer and lower T g coatings. Using a trifunctional amine such as diethylene triamine, coatings could be prepared without the addition of any catalyst. Overall, thermosets made from AESS Michael crosslinking technology provide a highly bio-based coating system with good hardness and chemical resistance.

Non-Isocyanate Polyurethane Soft Nanoparticles Obtained by Surfactant-Assisted Interfacial Polymerization.

Polyurethanes (PUs) are considered ideal candidates for drug delivery applications due to their easy synthesis, excellent mechanical properties, and biodegradability. Unfortunately, methods for preparing well-defined PU nanoparticles required miniemulsion polymerization techniques with a nontrivial control of the polymerization conditions due to the inherent incompatibility of isocyanate-containing monomers and water. In this work, we report the preparation of soft PU nanoparticles in a one-pot process using interfacial polymerization that employs a non-isocyanate polymerization route that minimizes side reactions with water. Activated pentafluorophenyl dicarbonates were polymerized with diamines and/or triamines by interfacial polymerization in the presence of an anionic emulsifier, which afforded non-isocyanate polyurethane (NIPU) nanoparticles with sizes in the range of 200-300 nm. Notably, 5 wt % of emulsifier was required in combination with a trifunctional amine to achieve stable PU dispersions and avoid particle aggregation. The versatility of this polymerization process allows for incorporation of functional groups into the PU nanoparticles, such as carboxylic acids, which can encapsulate the chemotherapeutic doxorubicin through ionic interactions. Altogether, this waterborne synthetic method for functionalized NIPU soft nanoparticles holds great promise for the preparation of drug delivery nanocarriers.

Polyimides cross‐linked with amino group‐containing compounds

The commercially available linear polyimide Matrimid® 9725 was crosslinked with amino groups containing both high‐molecular‐weight and low‐molecular‐weight compounds. The multi‐functional amine‐terminated hyperbranched polyimide precursor (hyperbranched polyamic acid), based on 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride and 4,4′,4″‐triaminotriphenylmethane, and its fully imidized form (amine‐terminated hyperbranched polyimide), bifunctional amine, 4,4′‐diaminodiphenylamine and trifunctional amine, 4,4′,4″‐triaminotriphenylamine, were used as the crosslinkers. Theoretically, 10% or 20% of the Matrimid imide groups was reacted with the amino groups of the crosslinking agent during the formation of the amide groups. The insoluble content (gel) in the final materials was very low at the crosslinking temperature of 80°C and was in the 55–90% range at the crosslinking temperature of 200°. The permeability coefficients of hydrogen, carbon dioxide and methane in the self‐standing, mechanically tough film (membrane) based on the combination of Matrimid and hyperbranched polyimide were approximately 30–45% higher compared with those in the membrane made of pure Matrimid at a comparable separating ability (selectivity). POLYM. ENG. SCI., 57:1367–1373, 2017. © 2017 Society of Plastics Engineers

CO2/CH4 separation performance of ionic-liquid-based epoxy-amine ion gel membranes under mixed feed conditions relevant to biogas processing

The CO2/CH4 separation performance under humidified mixed feed conditions relevant to biogas separation is reported for supported, epoxy-amine-based ion gel membranes containing fixed-site amine facilitated CO2 transport carriers. The chemical composition of the ion gel membranes consists of combination of the bis(epoxide)-IL monomer and trifunctional amine monomer in a mole ratio 3:2 plus either 50 or 75wt% free [EMIM][Tf2N], impregnated into a Omnipore™ support film.Prepared samples were examined for fundamental structure/property relationships via permeation and sorption methods. Gas sorption confirmed specific gas interactions, showing elevated CO2 sorption compared to CH4 with increasing equilibrium feed pressure. Single gas permeation demonstrated almost a three-fold increase in CO2 permeability from 195 barrer for 50wt% of free [EMIM][Tf2N] to 525 barrer for 75wt% of ionic liquid while the ideal selectivity α(CO2/CH4) stayed almost the same (20 and 18, respectively).The effects of feed composition, feed pressure, and relative humidity (32% and 54%) on the CO2/CH4 separation performance were elucidated for mixed-gas feeds. Under simulated biogas processing conditions, an increase of CO2/CH4 separation factor from 25 to 35 with increasing humidity and low feed pressure was observed.Such behavior indicates that the fixed-site-carrier facilitated CO2 transport mechanism enhances also the CO2/CH4 separation performance of studied membranes, as observed for the CO2/N2 mixtures studied previously.This feature also enables them to reach a performance level close to the 2008 Robeson plot upper bound.

End-crosslinking of controlled telechelic poly(N-isopropylacrylamide) toward a homogeneous gel network with photo-induced self-healing

Telechelic poly(N-isopropylacrylamide) (PNIPAAm) was designed to prepare homogeneous and self-healable gels by end-crosslinking. The PNIPAAm with carboxyl groups at both polymer ends and trithiocarbonate (TTC) in the main chain was obtained by reversible addition-fragmentation chain transfer (RAFT) polymerization of NIPAAm with a symmetric TTC compound (CTA-1) as a RAFT agent. The obtained polymers of a series of molecular weights were well-defined within a narrow molecular weight distribution (Mw/Mn~1.1). Then, the end groups of the resultant PNIPAAms were quantitatively transformed into activated esters as reactive sites for gelation. These designed PNIPAAms were employed for an end-crosslinking reaction with trifunctional amine crosslinker, and it was found that gelation condition was closely related to the molecular weight and the concentration of the telechelic prepolymers. Furthermore, the obtained gel showed the characteristic ultraviolet-induced self-healing owing to the chain exchange reaction of TTC groups. Self-healable gel was designed by end-crosslinking of controlled telechelic polymer carrying a trithiocarbonate group in the middle of the chain. The prepolymers, which were precisely synthesized by RAFT polymerization, were crosslinked with branched crosslinker using activated ester chemistry to produce the network with same molecular weight network chain between crosslinking points. The obtained gel showed UV-induced self-healing owing to the function of the trithiocarbonate groups.

Michael Addition Polymerization of Trifunctional Amine and Acrylic Monomer: A Versatile Platform for Development of Biomaterials.

Michael addition polymerizations of amines and acrylic monomers are versatile approaches to biomaterials for various applications. A combinatorial library of poly(β-amino ester)s and diverse poly(amido amine)s from diamines and diacrylates or bis(acrylamide)s have been reported, respectively. Furthermore, novel linear and hyperbranched polymers from Michael addition polymerizations of trifunctional amines and acrylic monomers significantly enrich this category of biomaterials. In this Review, we focus on the biomaterials from Michael addition polymerizations of trifunctional amines and acrylic monomers. First we discuss how the polymerization mechanisms, which are determined by the reactivity sequence of the three types of amines of trifunctional amines, i.e., secondary (2°) amines (original), primary (1°) amines, and 2° amines (formed), are affected by the chemistry of monomers, reaction temperature, and solvent. Then we update how to design and synthesize linear and hyperbranched polymers based on the understanding of polymerization mechanisms. Linear polymers containing 2° amines in the backbones can be obtained from polymerizations of diacrylates or bis(acrylamide)s with equimolar trifunctional amine, and several approaches, e.g., 2A2+BB'B″, A3+2BB'B', A2+BB'B″, to hyperbranched polymers are developed. Further through molecular design of monomers, conjugation of functional species to 2° amines in the backbones of linear polymers and the abundant terminal groups of hyperbranched polymers, the amphiphilicity of polymers can be adjusted, and additional stimuli, e.g., thermal, redox, reactive oxidation species (ROS), and light, responses can be integrated with the intrinsic pH response. Finally we discuss the applications of the polymers for gene/drug delivery and bioimaging through exploring their self-assemblies in various motifs, e.g., micelles, polyplexes particles/nanorings and hydrogels. Redox-responsive hyperbranched polymers can display 300 times higher in vitro gene transfection efficiency and provide a higher in vivo siRNA efficacy than PEI. Also redox-responsive micelle carriers can improve the efficacy of anticancer drug and the bioimaging contrast. Further molecular design and optimization of this category of polymers together with in vivo studies should provide safe and efficient biomaterials for clinical applications.

Synthesis and Characterization of Polyurea Resin for Dielectric Coating Applications

ABSTRACTIn this article, polyurea coatings were synthesized by reaction between toluene diisocyanate, and polyether difunctional and trifunctional amines PO-1 and PO-2 by incorporating urea linkage. The isocyanate-terminated prepolymers formed were further reacted with short-chain amines as chain extender as well as curing agents. These resins were synthesized by varying the molar ratio of amines and isocyanate and keeping the molar ratio of other monomers constant. The presence of functional groups were determined using Fourier transform infrared spectroscopy. The thermal stability of polymers was determined using the thermogravimetric analysis and differential scanning calorimetry. The polymers were further tested for mechanical and electrical properties. It was observed that on increasing the hard segments in the polymer the electrical properties increase whereas elongation decrease. As isocyanate content increases, crosslinking increases resulting in improvement in dielectric properties. The maximum dielectric strength observed was 45 kV mm−1 and dissipation factor was 0.068.

Effects of shell crosslinking on polyurea microcapsules containing a free‐radical initiator

ABSTRACTMicroencapsulation of a material is often used when a controlled release of a substance is desired. This study examines the effects of crosslinking in polyurea microcapsule shells on stability of microcapsules containing the free‐radical initiator cumene hydroperoxide (CHP). Crosslinking of polyurea shells was varied by using amine monomers containing different amine functionalities, and/or changing the isocyanate/primary amine ratio. Thermogravimetric analysis was performed to determine thermal properties of these microcapsules, and the pot lives of monomer systems containing these microcapsules were measured. Thermal stability is greater with a moderate degree of crosslinking from a trifunctional amine, and decreases when crosslinking is increased through use of higher amine functionality. Stability in monomer media generally increases with increased crosslinking through higher amine functionality, but is less predictable due to crosslinks formed between capsules. Generally, increasing crosslinking through altering the isocyanate to primary amine ratio decreases capsule stability in both dry and monomer storage. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42408.

PH‐ and Redox‐Responsive Poly(ethylene glycol) and Cholesterol‐Conjugated Poly(amido amine)s Based Micelles for Controlled Drug Delivery

An optimized condition is identified to prepare linear poly(amido amine)s via Michael Addition polymerization of trifunctional amine, 4-(aminomethyl)piperidine (AMPD), with an equimolar diacrylamide, N,N-cystaminebis(acrylamide) (BAC). Poly(ethylene glycol) (PEG) and cholesterol (CE) are conjugated to linear poly(BAC-AMPD) through the reactions with the secondary amino groups in the backbone, respectively, to form poly(BAC-AMPD)-g-PEG-g-CE. The chemical structures of poly(BAC-AMPD) and poly(BAC-AMPD)-g-PEG-g-CE are characterized using NMR and gel permeation chromatography (GPC). Transmission electron microscopy (TEM), dynamic light scattering (DLS) and (1)H NMR results show that micelles with PEG shells and hydrophobic cores composed of poly(BAC-AMPD) and CE are formed via self-assembly of poly(BAC-AMPD)-g-PEG-g-CE in aqueous solution, and the micelles of poly(BAC-AMPD)-g-PEG-g-CE can be degraded by the presence of L-dithiothreitol and show a limited cytotoxicity in vitro. The anti-cancer drug, doxorubicin (DOX), can be loaded into the micelles. The DOX loaded micelles of poly(BAC-AMPD)-g-PEG-g-CE show pH- and redox-responsive drug release and redox-induced formation of aggregates, and it is shown that the DOX loaded micelles can deliver DOX into cells and show a higher efficacy in killing cancer cells than free drug.