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Macromolecular Rapid Communications

Wei Yuan, Weiwen Chi, Ruimin Liu, Hongkun Li, Yongfang Li, Ben Zhong Tang
Two soluble poly(phenyltriazolylcarboxylate)s (PPTCs) with high molecular weights (M w up to 26 800) are synthesized by the metal-free 1,3-dipolar polycycloadditions of 4,4'-isopropylidenediphenyl diphenylpropiolate (1) and tetraphenylethene-containing diazides (2) in dimethylformamide at 150 °C for 12 h in high yields (up to 93%). The resultant polymers are soluble in common organic solvents and are thermally stable with 5% weight loss temperatures higher than 375 °C. The PPTCs are nonemissive in solutions, but become highly luminescent upon aggregation, showing a phenomenon of aggregation-induced emission...
January 20, 2017: Macromolecular Rapid Communications
Yu-Jing Chiu, Hsiao-Fan Tseng, Yu-Ching Lo, Bo-Hao Wu, Jiun-Tai Chen
Electrospun core-shell fibers have great potentials in many areas, such as tissue engineering, drug delivery, and organic solar cells. Although many core-shell fibers have been prepared and studied, the morphology transformation of core-shell fibers have been rarely studied. In this work, the morphology evolution of electrospun core-shell polymer fibers driven by the Plateau-Rayleigh instability is investigated. Polystyrene/poly(methyl methacrylate) (PS/PMMA) core-shell fibers are first prepared by using blend solutions and a single axial electrospinning setup...
January 20, 2017: Macromolecular Rapid Communications
Chih-Chia Cheng, Wei-Tsung Chuang, Duu-Jong Lee, Zhong Xin, Chih-Wei Chiu
A novel application of supramolecular interactions within semicrystalline polymers, capable of self-assembling into supramolecular polymer networks via self-complementary multiple hydrogen-bonded complexes, is demonstrated for efficient construction of highly controlled self-organizing hierarchical structures to offer a direct, efficient nucleation pathway resulting in superior crystallization performance. Herein, a novel functionalized poly(ε-caprolactone) containing self-complementary sextuple hydrogen-bonded uracil-diamidopyridine (U-DPy) moieties is successfully developed and demonstrated excellent thermal and viscoelastic properties as well as high dynamic structural stability in the bulk state due to physical cross-linking created by reversible sextuple hydrogen bonding between U-DPy units...
January 20, 2017: Macromolecular Rapid Communications
Xiaodong Chi, Xiaofan Ji, Li Shao, Feihe Huang
Herein, for rate-tunable controlled release, the authors report a new facile method to prepare multiresponsive amphiphilic supramolecular diblock copolymers via the cooperative complexation between a water-soluble pillar[10]arene and paraquat-containing polymers in water. This supramolecular diblock copolymer can self-assemble into multiresponsive polymeric micelles at room temperature in water. The resultant micelles can be further used in the controlled release of small molecules with tunable release rates depending on the type of single stimulus and the combination of various stimuli...
January 3, 2017: Macromolecular Rapid Communications
Georg R J Artus, Sandro Olveira, Debabrata Patra, Stefan Seeger
Chemical composition and shape determine the basic properties of any object. Commonly, chemical synthesis and shaping follow each other in a sequence, although their combination into a single process would be an elegant simplification. Here, a pathway of simultaneous synthesis and shaping as applied to polysiloxanes on the micro- and nanoscale is presented. Complex structures such as stars, chalices, helices, volcanoes, rods, or combinations thereof are obtained. Varying the shape-controlling reaction parameters including temperature, water saturation, and the type of substrate allows to direct the reaction toward specific structures...
January 3, 2017: Macromolecular Rapid Communications
Yongwei Wu, Benzhao He, Jia Wang, Rongrong Hu, Zujin Zhao, Fei Huang, Anjun Qin, Ben Zhong Tang
The transition-metal catalyzed and metal-free click polymerizations have been developed as powerful tools for the construction of functional polymers with linear and hyperbranched structures. The latter provides a thorough solution for the completely removing metallic residues from the products encountered in the former. Compared to the activated alkyne-azide metal-free click polymerization, the activated azide-alkyne one is rarely studied. In this Communication, a perfluorophenyl-activated azide of hexane-1,6-diyl-bis(4-azido-2,3,5,6-tetrafluorobenzoate) is rationally designed and facilely prepared...
January 3, 2017: Macromolecular Rapid Communications
Shi-Lei Dong, Lu Han, Cai-Xia Du, Xiao-Yu Wang, Lu-Hai Li, Yen Wei
Electroactive hydrogel scaffolds are fabricated by the 3D-printing technique using composites of 30% Pluronic F127 and aniline tetramer-grafted-polyethylenimine (AT-PEI) copolymers with various contents from 2.5% to 10%. The synthesized AT-PEI copolymers can self-assemble into nanoparticles with the diameter of ≈50 nm and display excellent electroactivity due to AT conjugation. The copolymers are then homogeneously distributed into 30% Pluronic F127 solution by virtue of the thermosensitivity of F127, denoted as F/AT-PEI composites...
January 3, 2017: Macromolecular Rapid Communications
Hien The Ho, Maël Le Bohec, Julien Frémaux, Sandie Piogé, Nathalie Casse, Laurent Fontaine, Sagrario Pascual
Copolymers of 2-(N,N-dimethylamino)ethyl acrylate (DMAEA) and 2-(tert-Boc-amino)ethyl acrylate (tBocAEA) are synthesized by reversible addition-fragmentation chain transfer polymerization in a controlled manner with defined molar masses and narrow molar masses distributions (Ð ≤ 1.17). Molar compositions of the P(DMAEA-co-tBocAEA) copolymers are assessed by means of (1) H NMR. A complete screening in molar composition is studied from 0% of DMAEA to 100% of DMAEA. Reactivity ratios of both comonomers are determined by the extended Kelen-Tüdos method (r DMAEA = 0...
January 3, 2017: Macromolecular Rapid Communications
Jennifer A Reeves, Michael L Allegrezza, Dominik Konkolewicz
Vinyl ketone polymers, including phenyl vinyl ketone (PVK), are an important class of polymers due to their ability to degrade upon irradiation with ultraviolet light which makes them useful for a variety of applications. However, traditional radical methods for synthesizing PVK polymers give rise to poor control or are unable to produce block copolymers. This work uses reversible addition-fragmentation chain transfer polymerization (RAFT) and photochemistry to polymerize PVK. When visible blue radiation of 440 ± 10 nm is used as the light source for the photopolymerization, rapid polymerization and well-defined polymers are created...
January 3, 2017: Macromolecular Rapid Communications
Helena Henke, Oliver Brüggemann, Ian Teasdale
This feature article briefly highlights some of the recent advances in polymers in which phosphorus is an integral part of the backbone, with a focus on the preparation of functional, highly branched, soluble polymers. A comparison is made between the related families of materials polyphosphazenes, phosphazene/phosphorus-based dendrimers and polyphosphoesters. The work described herein shows this to be a rich and burgeoning field, rapidly catching up with organic chemistry in terms of the macromolecular synthetic control and variety of available macromolecular architectures, whilst offering unique property combinations not available with carbon backbones, such as tunable degradation rates, high multi-valency and facile post-polymerization functionalization...
January 3, 2017: Macromolecular Rapid Communications
Hui Xie, Xiao-Ying Deng, Chuan-Ying Cheng, Ke-Ke Yang, Yu-Zhong Wang
Multistimuli-responsive shape-memory polymers are highly desirable in various applications, and numerous modes have been developed in recent years. However, most of them need to reprogram before they are ready to respond to another stimulus while one is triggered. Here, a new strategy is developed to achieve dual-stimuli-responsive triple-shape memory with non-overlapping effect in one programming cycle. Here, a series of poly(l-lactide)-poly(tetramethylene oxide) glycol copolymers (PLA-PTMEG-A) is prepared by selected dangling photoresponsive anthracene moieties on the crystalline PTMEG backbone...
January 3, 2017: Macromolecular Rapid Communications
Timo Witt, Manuel Häußler, Stefan Mecking
Starting from readily available oleic and erucic acid, macrocyclic nonadecalactone (C19 ) and tricosalactone (C23 ) can be synthesized in polymerization grade purity in a four-step reaction sequence. Ring-opening polymerization (ROP) of these strainless macrolactones can be performed utilizing an enzyme as a catalyst. Despite the missing ring-strain as key driving force for smaller (strained) lactones, high molar masses (Mn ≈ 10(5) g mol(-1) ) can be accessed in an entropically driven ROP. Polyester-19 and polyester-23 prepared feature melting temperatures well above 100 °C...
January 3, 2017: Macromolecular Rapid Communications
Lifen Xiao, Wen Zhu, Jiqiang Chen, Ke Zhang
Cyclic multiblock polymers with high-order blocks are synthesized via the combination of single-electron transfer living radical polymerization (SET-LRP) and copper-catalyzed azide-alkyne cycloaddition (CuAAC). The linear α,ω-telechelic multiblock copolymer is prepared via SET-LRP by sequential addition of different monomers. The SET-LRP approach allows well control of the block length and sequence as A-B-C-D-E, etc. The CuAAC is then performed to intramolecularly couple the azide and alkyne end groups of the linear copolymer and produce the corresponding cyclic copolymer...
January 3, 2017: Macromolecular Rapid Communications
Yi Chen, Liang-Kai Lin, Shu-Jen Chiang, Ying-Ling Liu
In this work, a cocatalytic effect between Meldrum's acid (MA) and benzoxazine (Bz) compounds has been explored to build up a self-promoting curing system. Consequently, the MA/Bz reactive blend exhibits a relatively low reaction temperature compared to the required temperatures for the cross-linking reactions of the pure MA and Bz components. This feature is attractive for energy-saving processing issues. Moreover, the thermosetting resins based on the MA/Bz reactive blends have been prepared. The MA component can generate additional free volume in the resulting resins, so as to trap air in the resin matrix and consequently to bring low dielectric constants to the resins...
December 27, 2016: Macromolecular Rapid Communications
Sergey Vyazovkin
This article surveys the decade of progress accomplished in the application of isoconversional methods to thermally stimulated processes in polymers. The processes of interest include: crystallization and melting of polymers, gelation of polymer solutions and gel melting, denaturation (unfolding) of proteins, glass transition, polymerization and crosslinking (curing), and thermal and thermo-oxidative degradation. Special attention is paid to the kinetics of polymeric nanomaterials. The article discusses basic principles for understanding the variations in the activation energy and emphasizes the possibility of using models for linking such variations to the parameters of individual kinetic steps...
December 23, 2016: Macromolecular Rapid Communications
Hui Li, Xiaodong Fan, Xin Min, Yongchao Qian, Wei Tian
Supramolecular copolymers can not only enrich the diversity of the polymer backbone but also exhibit certain special and improved properties compared with supramolecular homopolymers. However, the synthesis procedure of supramolecular copolymers is relatively complicated and time-consuming. Herein, a simple transformation from an AB2 -based supramolecular hyperbranched homopolymer to an AB2 +CD2 -based supramolecular hyperbranched alternating copolymer by the "competitive self-sorting" strategy is reported...
December 23, 2016: Macromolecular Rapid Communications
Katarína Borská, Daniela Moravčíková, Jaroslav Mosnáček
Well-defined poly(methyl methacrylate) (PMMA) and poly(methyl acrylate) (PMA) are prepared via photochemically induced atom transfer radical polymerization (photoATRP) using ppm amounts of CuBr2 /tris(2-pyridylmethyl)amine and CuBr2 /tris[2-(dimethylamino)ethyl]amine catalyst complexes, respectively, without degassing of polymerization mixture and with no need to introduce an external reducing agent to the system. The effect of ligand to CuBr2 ratio on kinetic and induction period during the polymerization of MMA and MA is investigated...
December 22, 2016: Macromolecular Rapid Communications
Ji Hoon Park, Nuri Han, Ji Eun Song, Eun Chul Cho
A surfactant-free approach is proposed to synthesize nonspherical Janus particles with temperature-dependent wettability on hydrophobic surfaces. Sub-micrometer-sized particles comprising poly(styrene-co-divinylbenzene) core and a thermally responsive poly(N-isopropylacrylamide-co-methacrylic acid) shell are first synthesized to stabilize styrene droplets in water, producing a Pickering emulsion. Upon heating to 80 °C and subsequent addition of initiators to the aqueous phase, styrene droplets are polymerized and combine with the core-shell particles to construct dumbbell-shaped nonspherical particles...
December 22, 2016: Macromolecular Rapid Communications
Mark Billing, Christine Gräfe, Adrian Saal, Philip Biehl, Joachim H Clement, Silvio Dutz, Steffen Weidner, Felix H Schacher
This study presents the synthesis and characterization of zwitterionic core-shell hybrid nanoparticles consisting of a core of iron oxide multicore nanoparticles (MCNPs, γ-Fe2 O3 ) and a shell of sultonated poly(2-vinylpyridine-grad-acrylic acid) copolymers. The gradient copolymers are prepared by reversible addition fragmentation chain transfer polymerization of 2-vinylpyridine (2VP), followed by the addition of tert-butyl acrylate and subsequent hydrolysis. Grafting of P(2VP-grad-AA) onto MCNP results in P(2VP-grad-AA)@MCNP, followed by quaternization using 1,3-propanesultone-leading to P(2VPS -grad-AA)@MCNP with a zwitterionic shell...
December 22, 2016: Macromolecular Rapid Communications
Yuandu Hu, Juan Pérez-Mercader
Ruthenium-functionalized poly(N-isopropyl acrylamide)-based chemically oscillating microgels with diameters between 1 and 6 µm are synthesized by a modified precipitation polymerization approach. It is found that the initial amount of N-isopropyl acrylamide (NIPAAm) can significantly affect the final sizes of the microgels. 2.5 g of initial NIPAAm results in microgels with maximum average diameter of ≈6 ± 0.5 µm. Making use of their fluorescence due to their ruthenium contents and their larger sizes compared to microgels prepared using other traditional methods, the impact of changes in the NaBrO3 concentrations on their microscopic behavior is studied using a combination of fluorescence microscopy and dynamic light scattering techniques...
December 22, 2016: Macromolecular Rapid Communications
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