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Showing papers in "Journal of Polymer Science Part A in 2016"


Journal ArticleDOI
TL;DR: In this paper, a review of petro-based and bio-based plasticizers for PVC is presented, focusing on the most important categories of PVC plasticizers, namely phthalates and polysaccharidic or lipidic structures.
Abstract: Polymeric materials, in particular PVC, can find various industrial utilizations thanks to the use of plasticizers added during their processing. The most famous applications include wires and cables, coatings, flooring, paintings, packaging… After some generalities concerning plasticization theories and the description of plasticized petro- and bio-based polymers, this review details the well-known different petro-based plasticizers and more particularly phthalates which represent the most important category of PVC plasticizers. Owing to migration problems, impact on the human health and the environment, alternative candidates have been developed by researchers. Renewable resources and their wastes offer a large platform for the design of bio-based plasticizers using polysaccharidic or lipidic structures. In an in-depth analysis, the bio-based plasticizer structures, their groups and substituents (ester groups, alkyl chains, aromatic rings…) are gathered and examined in order to be able to predict their plasticizing efficiency and design new molecular and macromolecular plasticizers from natural resources. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 11–33

246 citations


Journal ArticleDOI
TL;DR: It will be discussed how the inherent dynamic nature of the dynamic covalent bonds on the molecular level can be translated to the macroscopic level of the polymer, giving access to a range of applications, such as stimuli‐responsive or self‐healing materials.
Abstract: This Highlight presents an overview of the rapidly growing field of dynamic covalent polymers. This class of polymers combines intrinsic reversibility with the robustness of covalent bonds, thus enabling formation of mechanically stable, polymer-based materials that are responsive to external stimuli. It will be discussed how the inherent dynamic nature of the dynamic covalent bonds on the molecular level can be translated to the macroscopic level of the polymer, giving access to a range of applications, such as stimuli-responsive or self-healing materials. A primary distinction will be made based on the type of dynamic covalent bond employed, while a secondary distinction will be based on the consideration whether the dynamic covalent bond is used in the main chain of the polymer or whether it is used to allow side chain modification of the polymer. Emphasis will be on the chemistry of the dynamic covalent bonds present in the polymer, in particular in relation to how the specific (dynamic) features of the bond impart functionality to the polymer material, and to the conditions under which this dynamic behavior is manifested. © 2016 The Authors. Journal of Polymer Science Part A: Polymer Chemistry Published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3551–3577.

143 citations


Journal ArticleDOI
TL;DR: In this article, the authors discuss the fundamental aspects of the thiol-epoxy reaction and its utility in the preparation and post-polymerization functionalization of polymers and crosslinked networks.
Abstract: Base-catalyzed reaction between a thiol and an epoxide group is a simple fusion process that leads to the formation of a β-hydroxythio-ether linkage. This reaction is efficient, regio-selective, and fast. In addition, it produces a reactive hydroxyl group upon completion. Therefore, it is of considerable potential in synthesis of reactive and functional soft materials. Here, we discuss the fundamental aspects of this process, the so-called thiol-epoxy “click” reaction, and its utility in the preparation and post-polymerization functionalization of polymers and crosslinked networks. Furthermore, its application in surface modification of solid substrates is also considered. Finally, utility of multifunctional materials created using the thiol-epoxy reaction is discussed in the biomedical arena. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3057–3070

99 citations


Journal ArticleDOI
TL;DR: In this article, a new class of water-soluble photoinitiators (PIs) for radical polymerization was proposed, which achieved state-of-the-art biocompatibility, storage stability and reactivity.
Abstract: The monoacylphosphineoxide (MAPO) salts Na-TPO and Li-TPO and the bisacylphosphineoxide (BAPO) salts BAPO-ONa and BAPO-OLi define an important and in the latter case a new class of water-soluble photoinitiators (PIs) for radical polymerization. These compounds showed excellent water-solubility of at least 29 g/L for Na-TPO and up to 60 g/L for BAPO-ONa in deionized water, thus exceeding the solubility of the state of the art PI for water-based systems Irgacure 2959 (I2959) 6- to 12-fold. However, biocompatibility, storage stability, and reactivity were equally important to replace the state of the art compounds. Concerning these properties, the MAPO and BAPO salts were at least in the same range (biocompatibility, stability) or showed even better results (reactivity) and had the additional advantage of visible light initiation. Na-TPO and Li-TPO achieved double bond conversions of an aqueous solution of N-acryloylmorpholine over 97% with broad band irradiation (320–500 nm), Li-TPO showed additionally very good biocompatibility (LC50 = 3.1 mmol/L) and BAPO-OLi showed highest reactivity with visible light irradiation. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 473–479

96 citations


Journal ArticleDOI
TL;DR: This review is focused on the chemical design and synthesis of polymer-based drug delivery systems, in particular with stimuli-responsive nanoplatforms for cancer treatment, and provides a brief description of the properties, synthesis and advantages of amphiphilic block copolymers, including polyether-polyester and poly ether-polyanhydride.
Abstract: This review is focused on the chemical design and synthesis of polymer-based drug delivery systems, in particular with stimuli-responsive nanoplatforms for cancer treatment. We provide a brief description of the properties, synthesis and advantages of amphiphilic block copolymers, including polyether-polyester and polyether-polyanhydride. As for stimuli-responsive polymers, we detail the recent innovative techniques for constructing smarter, more precise and optimally tuned nanocarriers that release drug in the disease site. This review is presented in the context of polymer science research, with special attention focused on the tailor-made polymers containing specific chemical functionalities. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3525–3550

89 citations


Journal ArticleDOI
TL;DR: A review of cyclic polymers can be found in this article, where the authors focus on the recent progress in the design and development of a cyclic polymer with an emphasis on its synthesis and bio-related properties and applications.
Abstract: Polymer topologies exert a significant effect on its properties, and polymer nanostructures with advanced architectures, such as cyclic polymers, star-shaped polymers, and hyperbranched polymers, are a promising class of materials with advantages over conventional linear counterparts. Cyclic polymers, due to the lack of polymer chain ends, have displayed intriguing physical and chemical properties. Such uniqueness has drawn considerable attention over the past decade. The current review focuses on the recent progress in the design and development of cyclic polymer with an emphasis on its synthesis and bio-related properties and applications. Two primary synthetic strategies towards cyclic polymers, that is, ring-expansion polymerization and ring-closure reaction are summarized. The bioproperties and biomedical applications of cyclic polymers are then highlighted. In the end, the future directions of this rapidly developing research field are discussed. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1447–1458

82 citations


Journal ArticleDOI
TL;DR: In this article, the first use of iron complexes (FeC) as potential photocatalysts for controlled radical photopolymerization reactions (CRP2) was reported, and three compounds were designed and investigated.
Abstract: This article reports on the presumably first use of iron complexes (FeC) as potential photocatalysts for controlled radical photopolymerization reactions (CRP2). Three compounds were designed and investigated. Good linear evolutions of the molecular weight (Mn) with the conversion were observed. A comparison was provided with a reference iridium (III) complex [Ir(ppy)3 where ppy stands for 2-phenylpyridine]. The on/off photopolymerization experiments highlight the presence of dormant species and a re-initiation on demand upon irradiation. This unique re-initiation property was used for the modification of surfaces (hydrophilic/hydrophobic properties) and surface patterning as well as the synthesis of a block co-polymer (PMMA-b-PBA). A comparative analysis of the behavior of these iron complexes in thermally and photochemically activated polymerization was provided. The chemical mechanisms were studied by steady state photolysis, laser flash photolysis, cyclic voltammetry, luminescence quenching, and electron spin resonance experiments. A catalytic cycle was proposed with two steps: (i) the oxidation of the FeC excited state by an alkyl halide and (ii) the reduction by the oxidized form (FeC°+) by an amine or the macroradicals leading to the regeneration of the catalyst.

62 citations


Journal ArticleDOI
TL;DR: In this article, allyl ether functional polycarbonates, synthesized by organocatalytic ring-opening polymerization of the six-membered cyclic carbonate monomer 2-allyloxymethyl-2-ethyltrimethylene carbonate, were used to prepare non-polyether polymer electrolytes.
Abstract: Allyl ether-functional polycarbonates, synthesized by organocatalytic ring-opening polymerization of the six-membered cyclic carbonate monomer 2-allyloxymethyl-2-ethyltrimethylene carbonate, were used to prepare non-polyether polymer electrolytes. UV-crosslinking of the allyl side groups provided mechanically stable electrolytes with improved molecular flexibility—Tg below −20 °C—and higher ionic conductivity—up to 4.3 × 10−7 S/cm at 25 °C and 5.2 × 10−6 S/cm at 60 °C—due to the plasticizing properties of the allyl ether side groups. The electrolyte function was additionally demonstrated in thin-film Li battery cells. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2128–2135

56 citations


Journal ArticleDOI
TL;DR: A diamine monomer 1, 4,4'-(9H-fluorene-9,9-diyl)-bis(2-tert-butylaniline) was synthesized from 9-fluoresnone and 2-TERT-butyliline by the condensation reaction as mentioned in this paper.
Abstract: A novel diamine monomer 1, 4,4'-(9H-fluorene-9,9-diyl)-bis(2-tert-butylaniline), was synthesized from 9-fluorenone and 2-tert-butylaniline by the condensation reaction. Then it was polymerized with several commercial aromatic dianhydrides, respectively, to produce polyimides (PIs) by the one-pot method. The number-averaged molecular weights of the resulting PIs are in the range of (4.54–8.82) × 104 with polydispersity indices from 2.51 to 4.33 by gel permeation chromatography measurement. They are soluble in many organic solvents and can form transparent and tough films by solution-casting. The cut-off wavelengths of UV–vis absorption for the PI films are below 360 nm, which are much lower than that of Kapton film. The light transparency of them is above 90% in the visible light range from 400 to 760 nm. They also display relatively low dielectric constants (from 2.79 to 3.00), low water absorption rates ( 50 MPa). Their excellent solubility and transparency can be attributed to the incorporation of tert-butyl groups and fluorene units into the rigid backbones of PIs. Simultaneously, they still maintain the high thermal stability (the 5% weight loss temperature in the range from 526 to 539 °C in nitrogen) and the high glass transition temperatures (Tg > 340 °C). © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 976–984

51 citations



Journal ArticleDOI
TL;DR: In this article, a multifunctional polymer unimolecular micelles, which are used as templates to fabricate stable gold nanoparticles (GNPs) in one-step without external reductant, have been designed and prepared.
Abstract: Multifunctional polymer unimolecular micelles, which are used as templates to fabricate stable gold nanoparticles (GNPs) in one-step without external reductant, have been designed and prepared. Amphiphilic 21-arm star-like block copolymers β-cyclodextrin-{poly(lactide)-poly(2-(dimethylamino) ethyl methacrylate)-poly[oligo(2-ethyl-2-oxazoline)methacrylate]}21 [β-CD-(PLA-PDMAEMA-PEtOxMA)21] and the precursors are synthesized by the combination of ring-opening polymerization (ROP) and activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP). The tertiary amine groups of PDMAEMA block reduce the AuCl4− counterion to zerovalent gold in situ, and these gold atoms combine mutually to form final GNPs. GNPs with relatively small size and narrow size distribution can be obtained in longer DMAEMA block copolymer, larger molar ratio of DMAEMA to HAuCl4 and smaller absolute concentrations of both polymer and HAuCl4. These results showed that the unimolecular micelles can be used as templates for preparing and stabilizing GNPs in situ without any external reducing agents and organic solvents, suggesting that the nanocomposite systems are latent nanocarriers for further biomedical application. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 186–196

Journal ArticleDOI
TL;DR: In this paper, a phenomenological mean-field approach with a model that specifically includes bridging of the polyelectrolyte chains by the multiple charges on the multivalent counter-ions was proposed.
Abstract: Polyelectrolyte brushes are essential in many aspects of surface functionality, particularly for colloidal stabilization and lubrication in biological and materials science applications. It has been shown experimentally that the brushes undergo an abrupt shrinkage in the presence of multivalent counter-ions. This transition is studied here using a phenomenological mean-field approach with a model that specifically includes bridging of the polyelectrolyte chains by the multiple charges on the multivalent counter-ions. Using an energy balance represented by the sum of electrostatic, polymeric and entropic mean-field terms, additional parameterized phenomenological terms are introduced for counter-ion condensation and for the attractive interaction between adjacent polyelectrolyte chains to account for the bridging effect. The free energy is minimized with respect to the counter-ion populations and the brush height. In agreement with experimental observations, increasing the concentration of multivalent ions leads to a sharp collapse of the polyelectrolyte brush height. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 284–291


Journal ArticleDOI
TL;DR: Open-shell macromolecular polymers as discussed by the authors have shown great potential in magnetic, energy storage, and biomedical applications, and the progress regarding the syntheses of open-shell containing polymers are reviewed in two distinct subclasses.
Abstract: Tailor-made polymers containing specific chemical functionalities have ushered in a number of emerging fields in polymer science. In most of these next-generation applications the focus of the community has centered upon closed-shell macromolecules. Conversely, macromolecules containing stable radical sites have been less studied despite the promise of this evolving class of polymers. In particular, radical-containing macromolecules have shown great potential in magnetic, energy storage, and biomedical applications. Here, the progress regarding the syntheses of open-shell containing polymers are reviewed in two distinct subclasses. In the first, the syntheses of radical polymers (i.e., materials composed of non-conjugated macromolecular backbones and with open-shell units present on the polymer pendant sites) are described. In the second, polyradical (i.e., macromolecules containing stabilized radical sites either within the macromolecular backbone or those containing radical sites that are stabilized through a large degree of conjugation) synthetic schemes are presented. Thus, the state-of-the-art in open-shell macromolecular syntheses will be reported and future means by which to advance the current archetype will be discussed. By detailing the synthetic pathways possible for, and the inherent synthetic limitations of, the creation of these functional polymers, the community will be able to extend the bounds of the radical-containing macromolecular paradigm. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1875–1894

Journal ArticleDOI
TL;DR: In this article, a series of novel iron complexes have been synthesized and utilized to initiate the free radical promoted cationic polymerization of epoxides or to polymerize acrylates through photoredox catalysis processes upon exposure to near UV or visible violet (405 nm) light emitting diodes (LEDs).
Abstract: The development of iron complexes for the photoredox catalysis is a huge challenge. Indeed, Iron complexes can be ideal candidates due to their potential visible light absorption and redox properties but also because they are less toxic, inexpensive and environmentally friendly compared to other catalysts. In the present paper, a series of novel iron complexes have been synthesized and utilized to initiate the free radical promoted cationic polymerization of epoxides or the free radical polymerization of acrylates through photoredox catalysis processes upon exposure to near UV (385 nm) or visible violet (405 nm) light emitting diodes (LEDs). When combined with an iodonium salt and N-vinylcarbazole, the iron complex-based photoinitiating systems are able to generate radicals, cations, and radical cations. The initiation efficiency is investigated through real-time Fourier transform infrared spectroscopy and a satisfactory initiating ability is found. The mechanisms for the generation of the reactive initiating species through photoredox catalysis are studied by different methods (steady state photolysis, cyclic voltammetry and electron spin resonance spin trapping techniques) and discussed in detail

Journal ArticleDOI
TL;DR: The cyclic peptide chain transfer agent was able to mediate polymerization as efficiently as a traditional RAFT agent, reaching high conversion in the same time scale while maintaining excellent control over the molecular weight distribution.
Abstract: A systematic comparison between the grafting-to (convergent) and grafting-from (divergent) synthetic routes leading to cyclic peptide–polymer conjugates is described. The reversible addition–fragmentation chain transfer (RAFT) process was used to control the polymerizations and the couplings between cyclic peptide and polymer or RAFT agent were performed using N-hydroxysuccinimide (NHS) active ester ligation. The kinetics of polymerization and polymer conjugation to cyclic peptides were studied for both grafting-to and grafting-from synthetic routes, using N-acryloyl morpholine as a model monomer. The cyclic peptide chain transfer agent was able to mediate polymerization as efficiently as a traditional RAFT agent, reaching high conversion in the same time scale while maintaining excellent control over the molecular weight distribution. The conjugation of polymers to cyclic peptides proceeded to high conversion, and the nature of the carbon at the α-position to the NHS group was found to play a crucial role in the reaction kinetics. The study was extended to a wider range of monomers, including hydrophilic and temperature responsive acrylamides, hydrophilic and hydrophobic acrylates, and hydrophobic and pH responsive methacrylates. Both approaches lead to similar peptide–polymer conjugates in most cases, while some exceptions highlight the advantages of one or the other method, thereby demonstrating their complementarity. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015

Journal ArticleDOI
TL;DR: In this article, six different complexes containing bis(salphen) ligands were synthesized and characterized by various spectroscopic techniques and elemental analysis, and the polymerization followed first-order kinetics as revealed by kinetic experiments.
Abstract: Six different complexes containing bis(salphen) [salphen = N,N'-phenylenebis(salicylideneimine)] ligands were synthesized and characterized by various spectroscopic techniques and elemental analysis. In the presence of benzyl alcohol as an initiator, all the complexes catalyze the ring-opening polymerization of lactide and e-caprolactone, generating high molecular weight (Mn) polymers in a controlled fashion. The linear relationship between the % conversion and Mn proved the control over the polymerization process. The presence of OBn group as an end group was confirmed by MALDI-TOF and 1H NMR spectral analysis of low Mn oligomers. The polymerization followed first-order kinetics as revealed by kinetic experiments. All the complexes were good precatalysts for the polymerization of ethylene. The effect of temperature and time on the yield and activity toward the polymerization of ethylene were widely investigated. In addition, in the presence of tetrabutylammonium bromide as cocatalyst, the formation of degradable polycarbonate with moderate Mn value and narrow molecular weight distributions was observed by the copolymerization of cyclohexene oxide with CO2. The effect of initiator structure, temperature, CO2 pressure, catalyst/cocatalyst loading on the activity, and selectivity toward copolymerization were systematically examined. The thermal properties of the copolymer synthesized were explored using differential scanning calorimetric and thermogravimetric analysis. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015

Journal ArticleDOI
TL;DR: In this article, a partially aliphatic polyimide based on HPMDA and DDPM was synthesized at 40 °C and showed good flexibility, solubility and thermal stability.
Abstract: Conventional synthesis of polyimides includes high-temperature (160–350 °C) imidization of poly(amic acid)s. In the present work, imidization has been carried out at much lower temperatures (40–160 °C). 1,2,4,5,-cyclohexanetetracarboxylic dianhydride (HPMDA) or pyromellitic dianhydride (PMDA) was polymerized with an aromatic diamine, 4,4′-diaminodiphenylmethane (DDPM), to give poly(amic acid)s, which were then imidized chemically. Imidization was more than 90% complete even at the very low imidization temperature of 40 °C. It was found that the imidization occurs in two steps: an initial rapid cyclization and a subsequent slower cyclization. The activation energy for the rapid process was determined to be 4.3 kJ/mol, and that of the slower process, 4.8 kJ/mol. As the imidization temperature decreases, the transmittance of the resulting polyimides tends to gradually increase, the cutoff wavelength decreases and the color becomes pale. A partially aliphatic polyimide based on HPMDA and DDPM prepared at 40 °C yielded thin films that were highly transparent and colorless, and had good flexibility, solubility and thermal stability. The polyimide films prepared in this study may be good candidates for flexible, transparent plastic substrates in the display industry. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015

Journal ArticleDOI
TL;DR: In this paper, a bisphenol-A diglycidylether (BADGE) based system was introduced to allow the bubble-free photocuring of this widely used epoxy resin.
Abstract: Radical induced cationic frontal polymerization (RICFP) is an extremely powerful and elegant alternative curing technique that allows cationic bulk curing of epoxy resins with very little energy consumption, as well as curing in compartments that are not readily accessible. We recently introduced a bisphenol-A diglycidylether (BADGE) based system that allows the bubble-free photocuring of this widely used epoxy resin. In this article, we describe the high storage stability and possibilities to influence the curing speed via the initiator concentrations of different formulations. These properties allow the adjustment of the frontal polymerization to ones need. We also show that the (thermo)mechanical and electrical properties of frontal cured epoxy polymers compares favorably with those of state of the art material. Finally, different strategies to overcome the challenges on producing epoxy resin based mica composites via RICFP are presented. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3751–3759

Journal ArticleDOI
TL;DR: In this paper, four aminal-linked porous organic polymers (NAPOPs) were synthesized through the reaction of 1,4-Bis(4,6-diamino-s-triazin-2-yl) benzene (BATB) with four kinds of aldehydes substituted with different N-heterocyclic groups.
Abstract: Aiming at tuning the adsorption and fluorescence properties of targeted porous organic polymer, four new aminal-linked porous organic polymers (NAPOPs) were synthesized through the reaction of 1,4-Bis(4,6-diamino-s-triazin-2-yl) benzene (BATB) with four kinds of aldehydes substituted with different N-heterocyclic groups. Among the polymers, NAPOP-3 decorated with 5-phenyl-tetrazole group shows the largest CO2 adsorption capacity (2.52 mmol g−1 at 273 K and 100 kPa) because of its relative large surface area, while NAPOP-1 decorated with piperazine groups shows relative large CO2/N2 adsorption selectivity (77 at 273 K and 100 kPa), attributable to its large CO2 adsorption heats and cabined pore ( 240 wt %). In addition, different luminescence emissions were also observed for NAPOPs, indicating different intramolecular charger transfer occurred inside polymer networks. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1724–1730

Journal ArticleDOI
TL;DR: In this paper, the authors report ten DArP protocols across the three major classes of DARP to generate poly[(2,5-bis(2-hexyldecyloxy)phenylene)-alt-(4,7-di(thiophen-2-yl)benzo[c][1,2-5]thiadiazole)] (PPDTBT).
Abstract: Despite the emergence of direct arylation polymerization (DArP) as an alternative method to traditional cross-coupling routes like Stille polymerization, the exploration of DArP polymers in practical applications like polymer solar cells (PSCs) is limited. DArP polymers tend to have a reputation for being marginally inferior to Stille counterparts due to the increased presence of defects that result from unwanted side reactions in direct arylation, such as unselective C-H bond activation and homocoupling. We report ten DArP protocols across the three major classes of DArP to generate poly[(2,5-bis(2-hexyldecyloxy)phenylene)-alt-(4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole)] (PPDTBT). Through evaluation of the method and resulting photophysical and electronic properties, we show not all DArP methods are suitable for generating device-quality alternating copolymers. When DArP PPDTBT was synthesized in superheated THF with Cs2CO3, neodecanoic acid, and P(o-anisyl)3, it generated polymers of exceptional quality that performed comparably to Stille counterparts in both roll coated ITO-free and spin-coated ITO devices. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2907–2918

Journal ArticleDOI
TL;DR: In this article, a scalable and controlled synthesis of a library of pH and temperature-sensitive 2-n-propyl-2-oxazoline P(nPropOx) based copolymers containing amine and carboxylic acid functionalized side chains by cationic ring opening polymerization and postpolymerization functionalization strategies is discussed.
Abstract: Polymers that possess lower critical solution temperature behavior such as poly(2-alkyl-2-oxazoline)s (PAOx) are interesting for their application as stimulus-responsive materials, for example in the biomedical field. In this work, we discuss the scalable and controlled synthesis of a library of pH- and temperature-sensitive 2-n-propyl-2-oxazoline P(nPropOx) based copolymers containing amine and carboxylic acid functionalized side chains by cationic ring opening polymerization and postpolymerization functionalization strategies. Using turbidimetry, we found that the cloud point temperature (CP) is strongly dependent on both the polymer concentration and the polymer charge (as a function of pH). Furthermore, we observed that the CP decreased with increasing salt concentration, whereas the CP increased linearly with increasing amount of carboxylic acid groups. Finally, turbidimetry studies in PBS-buffer indicate that CPs of these polymers are close to body temperature at biologically relevant polymer concentrations, which demonstrates the potential of P(nPropOx) as stimulus-responsive polymeric systems in, for example, drug delivery applications. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015

Journal ArticleDOI
TL;DR: In this article, a series of homo-, bi-, and mononuclear Ni(II)-based catalysts (BNCn n n/1/4, MNC4) were used for ethylene polymerization.
Abstract: A novel series of homo-, bi-, and mononuclear Ni(II)-based catalysts (BNCn n = 1–4, MNC4) were used for ethylene polymerization. The optimum conditions for the catalyst BNC4 (the highest catalytic activity) was obtained at [Al]/[Ni]=2000/1, Tp = 42 °C, and tp = 20 min that was 1073 g PE/mmol Ni h. In theoretical study, steric and electronic effects of substituents and diimine backbone led to prominent influence on the catalyst behavior. The highest MV was resulted from polymerization using BNC4; however, the highest unsaturation content was obtained from BNC1. GPC analysis showed a broad MWD (PDI = 17.8). BNC1 and BNC2 in similar structures showed broad peaks in DSC thermogram, while BNC3 and BNC4 with more electronic effects showed a peak along with a wide shoulder. Monomer pressure increasing showed enhancing in activity of the BNC4, meanwhile a peak with shoulder to a single peak in DSC thermogram and uniformity in morphology of the resulted polymer were observed. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016

Journal ArticleDOI
TL;DR: Froimowicz et al. as mentioned in this paper, Pablo, Pablo, and Isabela, studied at the Instituto de Tecnologia En Polimeros y Nanotecnologias (ITEN) in Argentina.
Abstract: Fil: Froimowicz, Pablo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Tecnologia En Polimeros y Nanotecnologia. Universidad de Buenos Aires. Facultad de Ingenieria. Instituto de Tecnologia En Polimeros y Nanotecnologia; Argentina. Case Western Reserve University; Estados Unidos

Journal ArticleDOI
TL;DR: In this article, the ultraviolet crosslinkable macromonomer poly(2-methyl-2-oxazoline) dimethylacrylate was synthesized by cationic ring-opening polymerization in a microwave reactor initiated by 1,4-dibromobutane.
Abstract: Molecular design, fabrication, and properties of thin-film coatings based on poly(2-methyl-2-oxazoline) (PMOX) and its copolymers were investigated to tackle problem of marine and bacterial fouling prevention. The ultraviolet crosslinkable macromonomer poly(2-methyl-2-oxazoline) dimethylacrylate was synthesized by cationic ring-opening polymerization in a microwave reactor initiated by 1,4-dibromobutane. In order to study the charge effect of the PMOX coatings on the adhesion of fouling organisms, PMOX surfaces with negative, neutral, and positive ζ-potential values were prepared by copolymerization with the positively charged monomer [2-(methacryloyloxy)-ethyl]trimethylammonium chloride. The coatings were stable in sea water for at least 1 month without significant reduction in the film thickness. The marine antifouling activity was evaluated against barnacle cyprids Amphibalanus amphitrite and algae Amphora coffeaeformis. Results showed that PMOX coatings provide effective reduction of the settlement regardless of the molar mass and surface charge of the polymer. Bacterial adhesion test showed that PMOX coatings effectively reduce Staphylococcus aureus and Escherichia coli adhesion. Owing to its good stability and antifouling activity PMOX has a great potential as antifouling coating for marine antifouling applications.

Journal ArticleDOI
TL;DR: In this article, a monofunctional benzoxazine with ortho-methylol functionality has been synthesized and highly purified, and the chemical structure of the synthesized monomer has been confirmed by 1H and 13C NMR, Fourier transform infrared spectroscopy (FT-IR), and elemental analysis.
Abstract: Monofunctional benzoxazine with ortho-methylol functionality has been synthesized and highly purified. The chemical structure of the synthesized monomer has been confirmed by 1H and 13C nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FT-IR) and elemental analysis. One-dimensional (1D) 1H NMR is used with respect to varied concentration of benzoxazines to study the specific nature of hydrogen bonding in both ortho-methylol functional benzoxazine and its para counterpart. The polymerization behavior of benzoxazine monomer has been also studied by in situ FT-IR and differential scanning calorimetry, experimentally supporting the polymerization mechanism of ortho-methylol functional benzoxazine we proposed before. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3635–3642

Journal ArticleDOI
TL;DR: In this paper, a series of pconjugated TIIG-based small molecules and alternating copolymers were synthesized via direct C-H arylation, which enables the efficient synthesis without use of flammable and toxic orgametallic reagents in fewer steps compared Suzuki and Stille coupling.
Abstract: Thienoisoindigo (TIIG) has emerged as an attractive building block for high-performance organic optoelectronic devices. Here we report the first synthesis of a series of pconjugated TIIG-based small molecules and alternating copolymers via direct C–H arylation, which enables the efficient synthesis without use of flammable and toxic orgametallic reagents in fewer steps compared Suzuki and Stille coupling. The direct arylation coupling between TIIG and two respective mono-bromo aryl reactants clearly shows that the a-H is more reactive than the b-H in the thiophene unit of TIIG. The high regioselectivity of TIIG monomer warrants the successful synthesis of high-quality alternating copolymers with minimal structural defects. PTIIG-BT polymer synthesized via direct arylation polymerization (DAP) showed comparable molecular weight and hole mobility than the same polymer previously synthesized via Suzuki coupling. Moreover, the two new polymers (PTIIG-TF and PTIIG-2FBT) synthesized via DAP showed hole mobility up to 10 cm V s in FET devices fabricated and tested under ambient conditions. VC 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2015–2031

Journal ArticleDOI
TL;DR: A pyridine-containing aromatic phthalonitrile monomer, 2,6-bis[4-(3,4-dicyanophenoxy)benzoyl]pyridine (BCBP) was synthesized from the nitro displacement of 4-nitrophthaloniitrile by the phenoxide of BHBP.
Abstract: A novel pyridine-containing aromatic phthalonitrile monomer, 2,6-bis[4-(3,4-dicyanophenoxy)benzoyl]pyridine (BCBP) was synthesized from the nitro displacement of 4-nitrophthalonitrile by the phenoxide of 2,6-bis (4-hydroxybenzoyl)pyridine (BHBP). 4-(Aminophenoxy) phthalonitrile (APPH) was selected to promote the curing reaction, and the curing behavior has been investigated by differential scanning calorimetric (DSC), suggesting a wide processing window about 64 °C. Different curing additive concentrations resulted in polymers with different crosslinking degrees and subsequently influenced the performance of resins. The resulting BCBP polymer exhibited high glass transition temperatures exceeding 400 °C, outstanding thermo-oxidative stability with weight retention of 95% at 530 °C, indicating a significant improvement in thermal properties endowed by pyridine units. Additionally, it also showed a lower overall water absorption after submersion in boiling water for 50 hours. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3819–3825

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TL;DR: The highly tunable properties of PGA reported herein demonstrate a biodegradable polymer platform, ideal for engineering solid dispersions, nanoemulsions, or nanoparticles for healthcare applications.
Abstract: There is an increasing need to develop bio-compatible polymers with an increased range of different physicochemical properties. Poly(glycerol-adipate) (PGA) is a biocompatible, biodegradable amphiphilic polyester routinely produced from divinyl adipate and unprotected glycerol by an enzymatic route, bearing a hydroxyl group that can be further functionalized. Polymers with an average Mn of ∼13 kDa can be synthesized without any post-polymerization deprotection reactions. Acylated polymers with fatty acid chain length of C4, C8, and C18 (PGAB, PGAO, and PGAS, respectively) at different degrees of substitution were prepared. These modifications yield comb-like polymers that modulate the amphiphilic characteristics of PGA. This novel class of biocompatible polymers has been characterized through various techniques such as FT-IR, 1H NMR, surface, thermal analysis, and their ability to self-assemble into colloidal structures was evaluated by using DLS. The highly tunable properties of PGA reported herein demonstrate a biodegradable polymer platform, ideal for engineering solid dispersions, nanoemulsions, or nanoparticles for healthcare applications.

Journal ArticleDOI
TL;DR: In this paper, a liquid-type thermal latent curing agent was proposed to improve the shelf life of one-component epoxy-imidazole compositions, which has superior miscibility toward epoxy resins.
Abstract: Epoxy resins are important thermosetting resins widely employed in industrial fields. Although the epoxy–imidazole curing system has attracted attention because of its reactivity, solidification of a liquid epoxy resin containing imidazoles proceeds gradually even at room temperature. This makes it difficult to use them for one-component epoxy resin materials. Though powder-type latent curing agents have been used for one-component epoxy resin materials, they are difficult to apply for fabrication of fine industrial products due to their poor miscibility. To overcome this situation and to improve the shelf life of epoxy–imidazole compositions, we have developed a liquid-type thermal latent curing agent 1, generating an imidazole with a thermal trigger via a retro-Michael addition reaction. The latent curing agent 1 has superior miscibility toward epoxy resins; in addition, it was confirmed that the epoxy resin composition has both high reactivity at 150 °C, and long-term storage stability at room temperature. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2680–2688