Read by QxMD icon Read

Macromolecular Rapid Communications

Steffen Eggers, Volker Abetz
Herein, a reversible addition-fragmentation chain transfer (RAFT) polymerization is introduced for reactive monomers like N-acryloylpyrrolidine or N,N-dimethylacrylamide working without a conventional radical initiator. As a very straightforward proof of principle, the method takes advantage of the usually inconvenient radical-generating hydroperoxide contaminations in cyclic ethers like tetrahydrofuran or 1,4-dioxane, which are very common solvents in polymer sciences. The polymerizations are surprisingly well controlled and the polymers can be extended with a second block, indicating their high livingness...
January 15, 2018: Macromolecular Rapid Communications
Mohamed Naguib, Tara L Schiller, Daniel J Keddie
The synthesis of a range of alkyl esters (methyl, n-butyl, and n-decyl) prepared via Steglich esterification of the thermodynamically controlled exo, exo Diels-Alder adduct of furfuryl alcohol and maleic anhydride is reported. Subsequent ring-opening metathesis polymerization of these bio-derivable tricyclic oxanorbornene analogs delivers polymers with targeted molar mass and low molar mass dispersity. The polymerizations are rapid with complete monomer conversion achieved within 15 min. Significantly, the presence of the cyclic lactone at the bridgehead of these monomers leads to polymers with high regioregularity (>85% head-to-tail) and high stereoregularity (>75% trans)...
January 15, 2018: Macromolecular Rapid Communications
Emily R Draper, Bart Dietrich, Christopher Brasnett, Stephen Sproules, Tom O McDonald, Annela M Seddon, Dave J Adams
As the use of low-molecular-weight gelators (LMWGs) as components in single and multicomponent systems for optoelectronic and solar cell applications increases, so does the need for more functional gelators. There are relatively few examples of p-type gelators that can be used in such systems. Here, the synthesis and characterization of three amino-acid-functionalized p-type gelators based on terthiophene, tetrathiafulvalene, and oligo(phenylenevinylene) are described. The cores of these molecules are already used as electron donors in optoelectronic applications...
January 15, 2018: Macromolecular Rapid Communications
Anthony Ndiripo, Andreas Albrecht, Benjamin Monrabal, Jingbo Wang, Harald Pasch
Olefin plastomers/elastomers are typically copolymers with high comonomer contents and low crystallinities. Therefore, the fractionation of these materials with crystallization-based methods is not feasible. On the other hand, solvent and temperature gradient interaction chromatography (SGIC and TGIC, respectively) are suitable techniques for the separation of olefin copolymers with regard to their chemical composition. In this study, the application ranges of both techniques are investigated and compared for ethylene-propylene (EP) copolymers...
January 15, 2018: Macromolecular Rapid Communications
Timo Stukenkemper, Xavier Paquez, M W G M Verhoeven, Emiel J M Hensen, Aylvin A Dias, Dermot F Brougham, Andreas Heise
Silicon wafers are decorated with photoamine generator 4,5-dimethoxy-2-nitrobenzyl 3-(triethoxysilyl)propyl carbamate. UV-irradiation in the presence of benzyl-l-glutamate N-carboxyanhydride is carried out, resulting in the release of the surface-bound primary amines, making them viable N-carboxyanhydride (NCA) polymerization initiators. Successful polypeptide grafting is confirmed by water contact angle measurements as well as by ellipsometry, revealing a poly(benzyl-l-glutamate) (PBLG) layer of ≈3 nm. X-ray photoelectron spectroscopy confirms the presence of amide groups in the grafted PBLG while time-of-flight secondary ion mass spectroscopy provides additional evidence for the presence of PBLG on the surface...
January 15, 2018: Macromolecular Rapid Communications
Rong Wang, Yikun Guo, Di Zhang, Huiqiong Zhou, Dahui Zhao, Yuan Zhang
Attaining control on charge injection properties is significant for meaningful applications of organic field-effect transistors (OFETs). Here, molecular electron-doping is applied with an air-stable dimer dopant for n-type OFETs based on (naphthalene diimide-diketopyrrolopyrrole) polymer hosts. Through investigating the doping effect on contact and transport properties, it is found that the electron transport increases in n-doped OFETs at low doping regime with remaining large on/off ratios. These favorable meliorations are reconciled by the mitigated impacts of contact resistance and interfacial traps, as well as the surface morphology exhibiting features of increased ordering...
January 15, 2018: Macromolecular Rapid Communications
Felix N Behrendt, Helmut Schlaad
Metal-free entropy-driven disulfide metathesis polymerization of unsaturated l-cystine based macrocycles produces high-molar-mass heterofunctional poly(disulfide)s, i.e., poly(ester-disulfide-alkene) and poly(amide-disulfide-alkene); Mwapp = 44-60 kDa, Ð > 1.7. The polymerization is fast and reaches equilibrium within 1-5 minutes (monomer conversion 70-90%) in polar aprotic solvents such as N,N-dimethylacetamide, dimethylsulfoxide, or γ-valerolactone. Thiol-terminated polymers are stable in bulk or when dissolved in weakly polar solvents, but rapidly depolymerize in dilute polar solution...
January 5, 2018: Macromolecular Rapid Communications
Xiao-Yan Tu, Chao Meng, Yun-Fei Wang, Li-Wei Ma, Bao-Yan Wang, Jin-Lin He, Pei-Hong Ni, Xiang-Ling Ji, Ming-Zhu Liu, Hua Wei
Adaptation of cyclic brush polymer for drug delivery applications remains largely unexplored. Herein, cyclic brush copolymer of poly(2-hydroxyethyl methacrylate-g-poly(N-isopropylacrylamide-st-N-hydroxyethylacrylamide)) (cb-P(HEMA-g-P(NIPAAm-st-HEAAm))), comprising a cyclic core of PHEMA and thermosensitive brushes of statistical copolymer of P(NIPAAm-st-HEAAm), is designed and synthesized successfully via a graft-from approach using atom transfer free radical polymerization from a cyclic multimacroinitiator...
January 4, 2018: Macromolecular Rapid Communications
Yuli Yin, Yong Zhang, Liancheng Zhao
Polymer solar cells have received considerable attention due to the advantages of low material cost, tunable band gaps, ultralight weight, and high flexible properties, and they have been a promising organic photovoltaic technology for alternative non-renewable fossil fuels for the past decade. Inspired by these merits, numerous state-of-the-art organic photovoltaic materials have been constructed. Among them, indaceno-based polymer materials have made an impact in obtaining an impressive power conversion efficiency of more than 11%, which shows the momentous potential of this class of materials for commercial applications...
January 4, 2018: Macromolecular Rapid Communications
Guohui Hou, Fengle Wang, Zhe Qu, Zhiqiang Cheng, Yingchao Zhang, Shisheng Cai, Tao Xie, Xue Feng
A semicrystalline polymer actuator, which is responsive to solvent vapor with fast and large scale locomotion, is described. The thermoset semicrystalline polymer can be easily synthesized from crystallizable polyester segment poly (ε-caprolactone) and isophorone diisocyanate trimer. Organic solvent vapor is used to induce the reversible swelling-crystallization conversion of the crystallizable polyester segment, resulting in its expansion/shrinkage. The contraction of the polymer actuator (1 mm thick) needs only ≈4 s in room temperature...
January 4, 2018: Macromolecular Rapid Communications
Jianwen Hou, Lele Cui, Runhai Chen, Xiaodong Xu, Jiayue Chen, Ligang Yin, Jingchuan Liu, Qiang Shi, Jinghua Yin
A versatile platform allowing capture and detection of normal and dysfunctional cells on the same patterned surface is important for accessing the cellular mechanism, developing diagnostic assays, and implementing therapy. Here, an original and effective method for fabricating binary polymer brushes pattern is developed for controlled cell adhesion. The binary polymer brushes pattern, composed of poly(N-isopropylacrylamide) (PNIPAAm) and poly[poly(ethylene glycol) methyl ether methacrylate] (POEGMA) chains, is simply obtained via a combination of surface-initiated photopolymerization and surface-activated free radical polymerization...
January 4, 2018: Macromolecular Rapid Communications
Zhenhua Wang, Chuan Xie, Changjiang Yu, Guoxia Fei, Zhanhua Wang, Hesheng Xia
A metal-ligand crosslinked internal self-healing polyurethane is developed using low-cost and commercially available compounds. The mechanical, photoluminescent, and self-healing properties can be governed by incorporating multiple metal-ligand crosslinks with weak and strong coordination bonds and varying the metal ion. In-situ attenuated total reflectance Fourier transform infrared spectroscopy reveals that the metal-ligand bond is cleaved during the damage process while metal ion is still coordinated with the ligand by stronger metal-pyridyl interaction...
January 4, 2018: Macromolecular Rapid Communications
Cheng Wang, Li Yang, Guanjun Chang
Crosslinked high-performance polymers have many industrial applications, but are difficult to recycle or rework. A novel class of recyclable crosslinking Cu(II)-metallo-supramolecular coordination polymers are successfully prepared, which possess outstanding thermal stability and mechanical property. More importantly, the Cu2+ coordination interactions can be further removed via external pyrophosphate to recover the linear polymers, which endow the crosslinking polymers with recyclability.
January 4, 2018: Macromolecular Rapid Communications
Gaixia Cao, Guo Li, Qi Yang, Zhaotie Liu, Zhongwen Liu, Jinqiang Jiang
A novel hyperbranched lower critical solution temperature (LCST) polymer with sharp temperature and CO2 -responsive behaviors is presented in this study. The target polymer of hyperbranched poly(oligo(ethylene glycol) (HBPOEG) is constructed using POEG as the backbone and tertiary amines as branch points. Phase transition of HBPOEG in aqueous solution is investigated by heating and cooling the system; the results indicate that HBPOEG in aqueous solution has a concentration-dependent phase transition behavior with excellent repeatability...
January 3, 2018: Macromolecular Rapid Communications
Jing Yang, Fan Chen, Huijuan Ran, Jian-Yong Hu, Bo Xiao, Ailing Tang, Xiaochen Wang, Erjun Zhou
A novel n-type polymer of PTDI-T based on asymmetric rylene diimide and thiophene is designed and synthesized. The highest power conversion efficiency of 4.70% is achieved for PTB7-Th:PTDI-T-based devices, which is obviously higher than those of the analogue polymers of PPDI-2T and PDTCDI. When using PBDB-T as a donor, an open-circuit voltage (VOC ) as high as 1.03 V is obtained. The results indicate asymmetric rylene diimide is a kind of promising building block to construct n-type photovoltaic polymers.
January 2, 2018: Macromolecular Rapid Communications
Alexander Eibel, Philipp Marx, Huifei Jin, Ioannis-Alexandros Tsekmes, Inge Mühlbacher, Johan J Smit, Wolfgang Kern, Frank Wiesbrock
Copoly(2-nonyl-2-oxazoline)-stat-poly(2-dec-9'enyl-2-oxazoline)s can be crosslinked by the thiol-ene reaction with glycol dimercaptoacetate. The copoly(2-oxazoline)-stat-copolyester is tested as dielectric for high-voltage applications, either as unfilled resin or as composite with nanoscaled fillers of silica, alumina, and hexagonal boron nitride. During AC voltage tests, all materials have an average breakdown strength of 45-50 kV mm-1 . For DC voltage tests, samples with SiO2 (hBN) have an average breakdown strength of ≈100 (80) kV mm-1 , while the unfilled copoly(2-oxazoline) has an average breakdown strength of ≈60 kV mm-1 ...
January 2, 2018: Macromolecular Rapid Communications
Xingjian Li, Yi Pan, Zhaohui Zheng, Xiaobin Ding
Fabricating a single polymer network with no need to design complex structures to achieve an ideal combination of tunable high-strain multiple-shape memory effects and highly recoverable shape memory property is a great challenge for the real applications of advanced shape memory devices. Here, a facile and general approach to recoverable high-strain multishape shape memory polymers is presented via a random copolymerization of acrylate monomers and a chain-extended multiblock copolymer crosslinker. As-prepared shape memory networks show a large width at the half-peak height of the glass transition, far wider than current classical multishape shape memory polymers...
January 2, 2018: Macromolecular Rapid Communications
Marina González-Burgos, Edurne González, José A Pomposo
In this study the superior stability against degradation induced by ultrasound irradiation of water-soluble single-chain polymer nanoparticles when compared to their parent precursor polymers is reported, and a loop scission mechanism in support of such behavior is suggested.
January 2, 2018: Macromolecular Rapid Communications
Ya-Lan Lin, Jia-Hong Chu, Hao-Jun Lu, Na Liu, Zong-Quan Wu
In this paper, the facile synthesis of hybrid Fe3 O4 magnetic nanoparticles carrying helical poly(phenyl isocyanide) (PPI) arms via both "grafting from" and "grafting onto" strategies is reported. First, alkyne-Pd(II) catalysts are anchored onto the surface of the Fe3 O4 magnetic nanoparticle, which promote the polymerization of enantiopure phenyl isocyanide, affording the expected hybrid magnetic nanoparticle with Fe3 O4 in core and helical PPI as arms. The nanoparticle also exhibits highly optical activity due to the excess of one-handed helicity of the PPI arms...
January 2, 2018: Macromolecular Rapid Communications
Zhengbang Wang, Cong Liang, Haolin Tang, Sylvain Grosjean, Artak Shahnas, Joerg Lahann, Stefan Bräse, Christof Wöll
Achieving high values for proton conductivity in a material critically depends on providing hopping sites arranged in a regular fashion. Record values reported for regular, molecular crystals cannot yet be reached by technologically relevant systems, and the best values measured for polymer membranes suited for integration into devices are almost two orders of magnitude lower. Here, an alternative polymer membrane synthesis strategy based on the chemical modification of surface-mounted, monolithic, crystalline metal-organic framework thin films is demonstrated...
December 18, 2017: Macromolecular Rapid Communications
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"