Functional Copolymers Research Articles

Preparation and biocompatibility of polyester films grafted with functional mPEG copolymers

The surface of poly(ethylene terephthalate)(PET) films is inert, hydrophobic, and incompatible with blood, which has limited its practical bioapplication. In this case, better biocompatibility could be achieved by surface modification. In this study, the grafted copolymer of functional methoxypolyethylene glycol(mPEG) derivatives and styrene from the PET surfaces was prepared via surface-initiated atom transfer radical polymerization(SI-ATRP). The structures, composition, properties and surface morphology of the grafted PET films were characterized by Fourier transform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy(XPS), contact angle measurements and scanning electronic microscopy(SEM). The results indicate that the surface of the PET films has been covered by a thick targeted copolymer layer that converted the hydrophobic surface of PET to an amphiphilic surface. The bacterial adhesion and cell culture results indicate the copolymer-grafted PET film may possess good biocompatibility.

Poly(ethylene oxide)-block-poly(methyl methacrylate) diblock copolymers as functional additive for poly(vinylidene fluoride) ultrafiltration membranes with tailored separation performance

In this work, poly(ethylene oxide)-block-poly(methyl methacrylate) (PEO-b-PMMA) diblock copolymers were established as functional additive for polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes, originally with the intention to increase their hydrophilicity and thereby decrease fouling. Additionally, however, it was found that copolymer micelles can be induced by complexing the PEO block of PEO-b-PMMA with specific metal salts. The formation of micelles as function of specific solution compositions was observed in dynamic light scattering and rheology experiments; the formation of PEO-metal ion complexes was shown via proton nuclear magnetic resonance (1H NMR) spectroscopy. Integration of micelle-forming compositions into typical PVDF-based casting solutions for UF membranes could lead to a higher surface porosity and a more regular barrier pore structure through microphase separation during the nonsolvent induced phase separation process used for membrane preparation. It was found that membranes containing small amounts of PEO-b-PMMA show a significantly higher permeance than membranes made from an otherwise equal casting solution without the copolymer, while maintaining the solute rejection properties. By using different types and amounts of metal salts to complex the PEO block it was possible to tailor the molecular weight cut-off of the membranes between 30kDa and 110kDa. Fouling studies in lab-scale cross-flow filtration cells showed an increased relative flux recovery compared to membranes without the functional copolymer additive. The results of this study are relevant because small fractions of a tailored diblock copolymer and metal salt as additives allow tailoring the barrier and separation properties at significantly higher overall performance within an otherwise unchanged membrane manufacturing process.

Novel functional copolymers based on glycidyl methacrylate: Synthesis, characterization, and polymerization kinetics

ABSTRACTA new methacrylate monomer 2-(4-nitrophenyl)-2-oxoethyl-2-methacrylate (NFM) was synthesized and its radical copolymerization with glycidyl methacrylate (GMA) was studied in 1,4-dioxane solution at 65°C using 2,2′-azobisisobutyronitrile as an initiator. The synthesized monomer and copolymers were characterized by FTIR, 1H and 13C-NMR spectroscopy. The analysis of reactivity ratios revealed that NFM is less reactive than GMA, and copolymers formed are statistically in nature. Thermogravimetric analysis of the polymers reveals that the thermal stability of the copolymers increases with an increasing in the mole fraction of NFM in the copolymers. Glass transition temperatures of the copolymers decreased with an increasing of NFM molar fraction in copolymers. In addition, according to the results obtained from the contact angle and zeta potential measurements the hydrophobic character of the polymer decreases (it means surface free energy increases) and its zeta potential becomes more negative with increase of NFM ratio in the copolymer. Polymers with carbonyl functional groups have been particularly interesting because of their use as photoresists.

A Practical Application of Solid-phase Extraction Using a Syringe Filled with Sorbent for the Determination of Lead and Cadmium in Water.

In this study, at first the synthesis of 3-chloro-2-hydroxypropyl methacrylate-ethylene glycole dimethacrylate co-polymer beads and its modification with tris(2-aminoethyl) amine is described. Characterization of the polymer was done by FTIR and SEM. The functional co-polymer was filled in a disposable pipet tip and tightly connected to a 50-mL syringe for the separation and the enrichment of lead and cadmium prior to their determination by flame atomic absorption spectrometry. The sample and then the eluate were subsequently drawn and discharged to retain and desorb lead and cadmium by means of the syringe, respectively. Both analytes were quantitatively retained at pH 4 and eluted using 3.0 mol L-1 of HNO3 at flow rates of approximately 10 mL min-1. Under the optimum conditions, the enrichment factors of up to 50-fold both elements could be obtained by drawing and discharging 250 mL (5 × 50 mL) of the sample, and then 5 mL of the eluent. The recoveries were >90%. The limits of detection (3σ; N = 10 of blank) for Pb and Cd were 0.0034 and 0.0016 mg L-1 for a 50-fold enrichment, respectively. The analyte concentrations in a certified waste water reference agreed within the certified values in the 95% confidence range.

Syntheses of triblock bottlebrush polymers through sequential ROMPs: Expanding the functionalities of molecular brushes

Syntheses of triblock bottlebrush polymers through sequential ROMPs: Expanding the functionalities of molecular brushes

Robust Stimuli‐Responsive Membranes Prepared from a Blend of Polysulfone and a Graft Copolymer Bearing Binary Side Chains with Thermo‐ and pH‐Responsive Switching Behavior

A stimuli-responsive membrane exhibiting independent pH- and temperature-responsive behavior was fabricated from a blend of commercial polysulfone with a functional amphiphilic binary graft copolymer, namely, polysulfone-graft-(poly(isopropylacrylamide-co-acrylic acid)-random-poly(methyl acrylate)), denoted PSf-g-(P(NIPAAm-co-AA)-r-PMMA). Two graft copolymers with different lengths of P(NIPAAm-co-AA) side chains were designed and enriched on the membrane surface to serve as thermo- and pH-responsive on/off switches. The differences between the dual-responsive behaviors of the two kinds of polymer-blend membranes were studied by water-flux and contact-angle measurements. The PMMA side chains served to securely anchor the graft copolymers to the membrane substrate, and the blended membrane prepared from binary graft copolymer was more stable and exhibited more robust stimuli-responsive behavior than that prepared from mono-graft copolymer PSf-g-P(NIPAAm-co-AA).

Conducting Polymer with Orthogonal Catechol and Disulfide Anchor Groups for the Assembly of Inorganic Nanostructures

To combine several inorganic components with organic material in a controlled special and permanent manner still remains a difficult issue. Two specifically functionalized block copolymers were synthesized separately and combined in a second step. A heterofunctional poly(ethylene glycol) (PEG) block copolymer bearing a single amino unit, a short PEG spacer, and multiple catechol functionalities was obtained via anionic ring-opening polymerization (AROP). Using the reversible addition–fragmentation chain transfer (RAFT) radical polymerization technique, a semiconducting block copolymer with carbazole side groups was obtained. The second polyacrylate block contained reactive ester groups and was polymerized onto this hole conducting block. By substitution of the reactive esters with the amino functional PEG-catechol block copolymer and cysteamine methyl disulfide, a hole conducting polymer material with two orthogonal anchor groups for the coating of CdSe QDs, and also for TiO2, was obtained. TEM images sho...

A monolithic hydro/organo macro copolymer actuator synthesized via interfacial copolymerization

Synthetic polymer actuators have attracted increasing attention for their potential applications in artificial muscles, soft robotics and sensors. The majority of previous efforts have focused on smart hydrogels with bilayer structures that can change their shape in response to environmental stimuli, such as temperature, light and certain chemicals. However, the practical application of hydrogels is limited because of their low modulus and weak mechanical strength. Here we synthesized a robust monolithic actuator of a macro-scale hydro/organo binary cooperative Janus copolymer film. The process involves direct, one-step interfacial polymerization of immiscible hydrophilic and hydrophobic vinyl monomer solutions, and the resultant product exhibited binary cooperative shape transformation to multiple external stimuli. The Janus copolymer film can work in both aqueous solutions and organic solvents, with bidirectional and site-specific bending arising from cooperative asymmetric swelling/shrinking of the hydrogel and organogel networks. In addition, the as-prepared Janus copolymer film can act as a sensor element for solvent leakage detection. This binary cooperative strategy is applicable to most immiscible monomer systems and provides a general approach to developing novel functional copolymer materials.

Synthesis and characterization of functional photoactive organic-inorganic block copolymers of poly(methylphenylsilane) and disperse red 1 methacrylate and study of their optical and photophysical properties

ABSTRACTFunctional photoactive organic-inorganic block copolymers of poly(methylphenylsilane) (PMPS) and disperse red 1 methacrylate (DR1MA) were synthesized in a quartz tube using UV-technique. The synthesized block copolymers were characterized by FTIR, NMR, GPC and thermal analyses and studied for their optical and photoluminescence properties. The weight average and number average molecular weights of such a synthesized block copolymer are 2.47 × 103 and 2.27 × 103, respectively. The appearance of two glass transition temperatures indicated the synthesized polymers as block copolymers. The functional organic-inorganic block copolymers exhibited optical absorbance at 276 nm due to aromatic ring associated with both the blocks and at 325 nm due to σ-electron delocalization of Si-Si chain of PMPS block. Also, the optical absorbance appeared at 472 nm is due to combining the contribution of n-π* and first π-π* charge transfer electronic transition of the azobenzene chromophore of DR1MA unit. Two photoemissions were observed at 307 nm and 415 nm when such a polymer was excited at 275 nm. The photoluminescence was also observed at 415 nm when excited by 325 nm. The multi-emission spectra appeared between 510 nm to 580 nm are presumed to be due to exciton coupling between azobenzene chromophore of DR1MA and and Si-Si σ-conjugation of PMPS block. The synthesized copolymers are thermally stable up to 260°C. Such functional photoactive block copolymers may find novel optoelectronic application.

Effects of alkyl or alkyloxy side chains in poly[4,6-bis(3′-dodecylthien-2′-yl)thieno-[3,4-c][1,2,5]thiadiazole-5′,5′-diyl-alt-2,5-di(alkyl or alkyloxy)-1,4-phenylene]: Synthesis, photophysics, and spectroelectrochemical and photovoltaic properties

New low-bandgap donor-acceptor functional copolymers, CDTDP and CDTDOP, composed of 4,6-bis-(3′-dodecylthien-2′-yl)thieno[3,4-c][1,2,5]thiadiazole (DT) and 2,5-didodecyl-1,4-phenylene (DP) or 2,5-didodecyloxy-1,4-phenylene (DOP) structural units, respectively, were synthesized by a rapid Suzuki coupling reaction of the corresponding comonomers in high-boiling-point solvents. The influence of alkyl and alkyloxy side-chains attached to the benzene ring on photophysical, thermochromic and electrochemical properties are reported. CDTDP exhibits absorption in the visible spectral region with long-wavelength maxima at 401–410 nm and 673–703 nm in solutions and at 461–467 nm and 827–841 nm in thin films. The absorption of CDTDOP in solution is significantly red-shifted, extending up to the near infrared region. CDTDOP shows more pronounced thermochromic changes. Both copolymers possess similar high values of electron affinity. CDTDOP with an alkyloxy side chain exhibits a lower ionization potential than that of CDTDP due to the stronger donor character of the substituted benzene unit, which narrows the bandgap value to 1.15 eV compared to that of 1.3 eV for CDTDP. Both copolymers exhibited interesting electrochromism. Spectroelectrochemical properties are shown for both oxidation and reduction. Optical switching is demonstrated and it is shown that response times depended on the side chain nature. Fast response times were detected for CDTDOP with alkyloxy side chains. Photovoltaic (PV) devices made of blends using the copolymers and a fullerene derivative, [6,6]-phenyl-C61-butyric acid methyl ester ([60]PCBM), exhibited different performances. PV devices with an active layer containing CDTDP exhibited higher power efficiency.

Non-invasive monitoring of in vivo degradation of a radiopaque thermoreversible hydrogel and its efficacy in preventing post-operative adhesions.

While a variety of biomaterials have been extensively studied, it is rare to monitor in vivo degradation and medical efficacy of a material after being implanted deeply into the body. Herein, the radiopaque thermoreversible hydrogel developed by us not only holds desirable performance on the prevention of post-operative abdominal adhesions, but also allows non-invasive monitoring of its in vivo degradation with CT imaging in a real-time, quantitative and three-dimensional manner. The methodology based on CT imaging provides important insights into the in vivo fate of the hydrogel after being deeply implanted into mammals for different biomedical applications and significantly reduces the amount of animals sacrificed.

Interference lithography with functional block copolymer blends: Hierarchical structuration and anisotropic wetting

This manuscript describes the preparation of hierarchically, i.e. micro and nanometer scale ordered surfaces with variable functionality by simultaneously combining the microfabrication using Laser Interference Lithography (LIL) and the self-assembly of block copolymers occurring at the nanometer scale. The block copolymers employed in this study are a double hydrophobic poly(2,3,4,5,6-pentafuorostyrene)-block-polystyrene (P5FS31-b-PS21) and an amphiphilic polystyrene-block-poly(acrylic acid) (PS20-b-PAA9) diblock copolymer. The incorporation of these block copolymers in the photosensitive mixture resulted in surfaces with hierarchically micro and nanostructured interfaces with either hydrophobic or hydrophilic surface chemical composition. Moreover, in comparison with microstructured surfaces prepared using statistical copolymer with similar composition, the use of block copolymers enhanced both the surface wettability changes and the final anisotropic wetting. We evidenced herein that by preparing unidirectional micrometer size patterns with either P5FS31-b-PS21 or PS20-b-PAA9 the wetting anisotropy increases with the hydrophobicity or the hydrophilicity of the surface.

Direct Access to Functional (Meth)acrylate Copolymers through Transesterification with Lithium Alkoxides.

A straightforward and efficient synthetic method that transforms poly(methyl methacrylate) (PMMA) into value-added materials is presented. Specifically, PMMA is modified by transesterification to produce a variety of functional copolymers from a single starting material. Key to the reaction is the use of lithium alkoxides, prepared by treatment of primary alcohols with LDA, to displace the methyl esters. Under optimized conditions, up to 65% functionalization was achieved and copolymers containing alkyl, alkene, alkyne, benzyl, and (poly)ether side groups could be prepared. The versatility of this protocol was further demonstrated through the functionalization of both PMMA homo and block copolymers obtained through either radical polymerization (traditional and controlled) or anionic procedures. The scope of this strategy was illustrated by extension to a range of architectures and polymer backbones.

Rationally designed dual functional block copolymers for bottlebrush-like coatings: In vitro and in vivo antimicrobial, antibiofilm, and antifouling properties.

Current antimicrobial coatings are often associated with concerns such as antibiotic resistance, environmental pollution, short-time antimicrobial activity, biofouling, poor blood compatibility and cytotoxicity, etc. To overcome these drawbacks, a robust PEGylated cationic amphiphilic peptides-based bottlebrush-like surface coating is demonstrated here, which fulfil the requirements of antimicrobial and antifouling as well as biocompatibility in the meantime. Briefly, the rational designed g-PEGn-b-AMP block copolymers (n=10/45/90) were synthesized and grafted on silicone surface. This bottlebrush-like coating efficiently kill the contacted bacteria and prevent the biofilm formation, greatly reduced protein and platelet adhesion. It also exhibits excellent blood compatibility and low cytotoxicity in vitro. In particular, g-PEG45-b-AMP coating exhibits significant anti-infection effect in vivo. This coating offering an effective strategy for combating biomedical devices-associated infections.

Precise Synthesis of Functional Block Copolymers by Living Anionic Polymerization of Vinyl Monomers Bearing Nitrogen Atoms in the Side Chain

Precise synthetic methods to prepare functional block copolymers with heteroatoms (nitrogen, oxygen, sulfur, phosphorous, halogen, etc.) have received much attention for the fabrication of practical nanomaterials. Specifically, well‐defined materials containing nitrogen‐based functional groups show unique electrical, optical, and amphiphilic properties. To synthesize these products, living anionic polymerization is the most powerful method. However, the disruption of undesirable reactions is considered to be a great challenge in the anionic polymerization of functional monomers with heteroatoms. To overcome these problems, facile methods such as polymerization at low temperature, careful choice of additives and initiators, and the introduction of protective groups can be used. In this review, recent advances in the anionic polymerization of vinyl monomers with triphenylamine, carbazole, and pyridine moieties in the side chains will be discussed. Also covered is the morphological control of these polymers to obtain well‐defined block copolymers for practical applications such as organic memory devices and light emitting diodes. image

Label-Free LSPR Detection of Trace Lead(II) Ions in Drinking Water by Synthetic Poly(mPD-co-ASA) Nanoparticles on Gold Nanoislands

Using self-assembly gold nanoislands (SAM-AuNIs) functionalized by poly(m-phenylenediamine-co-aniline-2-sulfonic acid) (poly(mPD-co-ASA)) copolymer nanoparticles as specific receptors, a highly sensitive localized surface plasmon resonance (LSPR) optochemical sensor is demonstrated for detection of trace lead cation (Pb(II)) in drinking water. The copolymer receptor is optimized in three aspects: (1) mole ratio of mPD:ASA monomers, (2) size of copolymer nanoparticles, and (3) surface density of the copolymer. It is shown that the 95:5 (mPD:ASA mole ratio) copolymer with size less than 100 nm exhibits the best Pb(II)-sensing performance, and the 200 times diluted standard copolymer solution contributes to the most effective functionalization protocol. The resulting poly(mPD-co-ASA)-functionalized LSPR sensor attains the detection limit to 0.011 ppb toward Pb(II) in drinking water, and the linear dynamic range covers 0.011 to 5000 ppb (i.e., 6 orders of magnitude). In addition, the sensing system exhibits robust selectivity to Pb(II) in the presence of other metallic cations as well as common anions. The proposed functional copolymer functionalized on AuNIs is found to provide excellent Pb(II)-sensing performance using simple LSPR instrumentation for rapid drinking-water inspection.

Functional multisite copolymer by one-pot sequential RAFT copolymerization of styrene and maleic anhydride

Functional multisite copolymers with a controlled number and position of side chains were synthesized by a one-pot RAFT polymerization process and post-functionalization.

Unique alternating peptide-peptoid copolymers from dipeptides via a Ugi reaction in water.

Herein, we developed a straightforward aqueous synthesis of unprecedented alternating peptide-peptoid copolymers via a Ugi four-component reaction applied to dipeptides. Functional peptide-peptoid copolymers as well as block copolymers were produced in a single step in the presence of acrylic acid and carboxylic acid-terminated poly(ethylene glycol). The thermoresponsiveness of these polymers is highlighted.

Loess surface grafted functional copolymer for removing basic fuchsin

Loess clay (LC), a very abundant clay with granules and high hydrophilicity, was modified by surface grafting copolymerization of acrylate and styrene monomers with functional side groups, which afforded a LC surface grafting copolymer.

Erratum: Coding and decoding libraries of sequence-defined functional copolymers synthesized via photoligation.

Nature Communications 7: Article number: 13672 (2016); Published 30 November 2016; Updated 23 December 2016 Figures 1 and 6 of this Article contain errors that were introduced during the production process. In Fig. 1, the reaction conditions required to convert 1 to 7d, 2e to 9c and 1d to 10d shouldbe described by (i) and not (iv).