Influence of polyamide acid coating reaction on the properties of aramid fibre
This study provides a feasible method for interfacial modification in AF-reinforced epoxy resin composites and may be applicable to rubber composite systems.Graphical abstract (Source: Polymer)
Source: Polymer - June 22, 2019 Category: Chemistry Source Type: research

Preparation and shape memory properties of rigid-flexible integrated epoxy resins via tunable micro-phase separation structures
Publication date: Available online 21 June 2019Source: PolymerAuthor(s): Yazhou Tian, Qiong Wang, Yujing Hu, Hao Sun, Zhichao Cui, Liangliang Kou, Jue Cheng, Junying ZhangAbstractIn this work, two types of rigid-flexible integrated epoxy resins, diglycidyl ether of eugenol-2-mercaptoethanol (DGEEM) and diglycidyl ether of vanillic alcohol (DGEVA), which possess similar rigid methoxy-substituted aromatic structures and different soft aliphatic chains in length, were prepared. Micro-morphology structures were tested by AFM, AFM nanomechanical mapping, and AFM-IR. Macro-properties were respectively characterized by tensile te...
Source: Polymer - June 22, 2019 Category: Chemistry Source Type: research

Microgel/silica hybrid colloids: Bioinspired synthesis and controlled release application
Publication date: Available online 22 June 2019Source: PolymerAuthor(s): Garima Agrawal, Sangram K. Samal, Sushanta K. Sethi, Gaurav Manik, Rahul AgrawalAbstractIn the present work, we demonstrate that polymer based functional microgels can be used as autocatalytic template for the bioinspired deposition of silica nanoparticles inside the microgel network under ambient conditions. Temperature responsive poly(N-vinyl caprolactam) based microgels were synthesized by precipitation polymerization using glycidyl methacrylate as a comonomer. These microgels were further reacted with aminoethanthiol to develop amine functional gr...
Source: Polymer - June 22, 2019 Category: Chemistry Source Type: research

Curing cycloaliphatic epoxy resin with 4-methylhexahydrophthalic anhydride: Catalyzed vs. uncatalyzed reaction
Publication date: Available online 20 June 2019Source: PolymerAuthor(s): Anna I. Barabanova, Boris V. Lokshin, Elena P. Kharitonova, Egor S. Afanasyev, Andrey A. Askadskii, Olga E. PhilippovaAbstractIn this article, a comparative study of the curing of commercial epoxy monomer 4-epoxycyclohexylmethyl-3,4-epoxycyclohexane-carboxylate ERL-4221 with 4-methylhexahydrophthalic anhydride in the presence and in the absence of catalyst N,N-dimethylbenzylamine was performed by Fourier-transform infrared spectroscopy and differential scanning calorimetry. The properties of the resulting material were examined by thermomechanical and...
Source: Polymer - June 21, 2019 Category: Chemistry Source Type: research

Studies on the use of filter-based IR detector for short-chain branching characterization of polyolefin copolymers with high temperature size exclusion chromatography
Publication date: Available online 21 June 2019Source: PolymerAuthor(s): Tiny Frijns-Bruls, Alberto Ortin, Jos Weusten, Erik GeladéAbstractEven though polyolefins are simple polymers from chemical structure point of view, their full characterization in practice is still an intriguing task. Basic macromolecular characteristics of polyethylene or polypropylene like molar mass moments and their distributions (MMD) but also chain conformation and thus information on long-chain branching, can be addressed with high-temperature size-exclusion chromatography (HT-SEC). Hyphenation of infrared detection to size-exclusion chr...
Source: Polymer - June 21, 2019 Category: Chemistry Source Type: research

Fabrication of Robust Honeycomb Patterned Porous Films by Thermochemical Cross-linking of Polyimide
Publication date: Available online 21 June 2019Source: PolymerAuthor(s): Umashankar Male, Do Sung HuhAbstractRobust honeycomb patterned porous (HCP) polymer films resistant to a wide range of organic solvents were obtained using polyimide (PI) by thermochemical cross-linking. For the robust PI HCP film, PI HCP film was fabricated via breath figure method, treated by aq. KOH to induce imide ring cleavage, and followed by re-imidization using heat treatment at 120 °C. The robust PI HCP film was resistant to common organic solvents such as chloroform, etc. over than 20 h, while the pristine PI HCP film solubilized immedia...
Source: Polymer - June 21, 2019 Category: Chemistry Source Type: research

Electroactive six arm star poly(2,2,6,6-tetramethylpiperidinyloxy methacrylate): Synthesis and application as cathode material for rechargeable Li-ion batteries
In this report, we described organic radical batteries (ORBs) based on a newly synthesized star polymer. Six arm star polymer in which the polymer chains radiating from an electroactive triphenylamine core and the chains containing 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) pendant groups was designed and synthesized via core first method using ATRP technique. The molecular weight (Mn) and polydispersity index of the star poly(2,2,6,6-tetramethylpiperidinyloxy methacrylate) (star PTMA) obtained was 6.8 × 104 g mol−1 and 1.08 respectively. The cathode composite materials comprised of star PTMA with SP ...
Source: Polymer - June 21, 2019 Category: Chemistry Source Type: research

Synergistic thermo-oxidative maleation of PA11 as compatibilization strategy for PA6 and PBT blend
Publication date: Available online 19 June 2019Source: PolymerAuthor(s): Dylan Jubinville, Boon Peng Chang, Jean-Mathieu Pin, Amar K. Mohanty, Manjusri MisraAbstractThe compatibilization of polyamide (PA) 6 and poly(butylene terephthalate) (PBT) blends has been successively achieved by the design of a compatibilizer made from renewable biobased PA 11, named PA11C. The synergistic action of maleation coupled with thermo-oxidation of the PA11 backbone allows both improvements of hydrophilic/hydrophobic balance and availability of functional groups that able to react during the reactive extrusion. The nature of the functional...
Source: Polymer - June 20, 2019 Category: Chemistry Source Type: research

Chloroethoxy-terminated perfluoropolyether electrolytes with high lithium ion transference number for lithium battery applications
Publication date: Available online 20 June 2019Source: PolymerAuthor(s): Yuzhi Feng, Xiaoting Chen, Huige Wei, Yibo Pei, Xudong TangAbstractThis paper reported the synthesis of an organic solvent, chloroethoxy-terminated perfluoropolyether (PFPECH2CH2Cl), which was obtained by reacting hydroxyethoxy-terminated perfluoropolyether with thionyl chloride. Liquid polymer electrolytes were then prepared by solving bis(trifluoromethane)sulfonimide lithium salt in PFPECH2CH2Cl for lithium ion battery applications. The electrolyte exhibits higher lithium-ion transference number (t+ = 0.87), lower glass transition temperature (T...
Source: Polymer - June 20, 2019 Category: Chemistry Source Type: research

A green cascade polymerization method for the facile synthesis of sustainable poly(butylene-co-decylene terephthalate) copolymers
Publication date: Available online 17 June 2019Source: PolymerAuthor(s): Siyuan Xu, Feng Wu, Zhikai Li, Xiang Zhu, Xiaohong Li, Lian Wang, Yongjin Li, Yingfeng TuAbstractTypical semicrystalline aromatic polyesters are synthesized via the condensation polymerization of aromatic diacids with excess diols in vacuum. We demonstrate here a green cascade polycondensation-coupling ring-opening polymerization (PROP) method for the facile incorporation of diols into polyesters in N2, utilizing cyclic oligo(butylene terephthlate)s as monomer and bio-based 1,10-decanediol as initiator. Poly(butylene-co-decylene terephthalate) (PBDT) ...
Source: Polymer - June 18, 2019 Category: Chemistry Source Type: research

Curing behavior and microstructure of epoxy-POSS modified novolac phenolic resin with different substitution degree
Publication date: Available online 18 June 2019Source: PolymerAuthor(s): Zixuan Lei, Jingru Ji, Qianqiu Wu, Junjie Zhang, Yixun Wang, Xinli Jing, Yuhong LiuAbstractEasily oxidized group and rigid structure of phenolic resin (PR) network can result in brittleness and low char yield at high temperatures, which limits the widespread applications of PR in harsh environment. Whilst organic-inorganic hybrid material, such as POSS-containing material was introduced to enhance PR, the microstructure and the thermo-mechanical properties of the hybrid material modified PR are not well understood. Therefore, in the work, a novel orga...
Source: Polymer - June 18, 2019 Category: Chemistry Source Type: research

Deformation mechanism of hard elastic polyethylene film during uniaxial stretching: Effect of stretching speed
Publication date: Available online 18 June 2019Source: PolymerAuthor(s): Yuanfei Lin, Xueyu Li, Xiaowei Chen, Minfang An, Qianlei Zhang, Daoliang Wang, Wei Chen, Panchao Yin, Lingpu Meng, Liangbin LiAbstractThe effects of stretching speed on the structural evolutions and mechanical behaviors of hard-elastic polyethylene films are studied with in-situ and ex-situ small-angle X-ray scattering (SAXS), scanning electronic microscope (SEM) and tensile tests in a wide stretching speed range (0.04–4 mm/s). Based on the evolutions of structural parameters extracted from SAXS results and the surface morphologies from SEM ex...
Source: Polymer - June 18, 2019 Category: Chemistry Source Type: research

Understanding the effect of chain entanglement state on melt crystallization of the polymer freeze-extracted from solution: The role of critical overlap concentration
Publication date: Available online 18 June 2019Source: PolymerAuthor(s): Yingxiong Wang, Jiaxin Fu, Mingjin Liu, Qiang Fu, Jie ZhangAbstractFreeze-drying of dilute polymer solution is a widely accepted method to yield disentangled polymer. By this method, it has been pointed out that samples recovered from dilute solution possess a better crystallization ability than the bulk polymer. Here, the important role of the critical overlap concentration c* in polymer solution is firstly stressed to give a more quantitative understanding in the relation between entanglement state and melt crystallization behavior. Crystallization ...
Source: Polymer - June 18, 2019 Category: Chemistry Source Type: research

Molecular weight dependence of the physical aging of polycarbonate
Publication date: 12 September 2019Source: Polymer, Volume 178Author(s): Shotaro Nishitsuji, Yuki Watanabe, Hiroshi Ito, Masaru Ishikawa, Takashi Inoue, Mikihito TakenakaAbstractIn our previous paper, we reported that the impact value of polycarbonate (PC) increases with increasing molecular weight and decreases upon annealing [Polymer 2012, 53, 895–896]. To clarify these phenomena, the effects of molecular weight and heat treatment on the fracture of PC are investigated in this study. The results show that the stress for craze nucleation increased as the molecular weight increased but was not affected by annealing. ...
Source: Polymer - June 18, 2019 Category: Chemistry Source Type: research

Effects of electron donating and accepting moieties on electrical memory behaviors of polymers
In this study, three different series of vinyl copolymers bearing electron donating and accepting moieties in various compositions and their homopolymers were synthesized by reversible addition-fragmentation chain transfer polymerizations. They all were soluble in conventional organic solvents and gave good quality nanoscale films via conventional coating and drying processes. They were thermally stable up to 242 °C or higher temperatures. Their optical and electrochemical properties as well as electron densities and mass densities were measured. The nanoscale film morphologies were further examined by synchrotron gr...
Source: Polymer - June 16, 2019 Category: Chemistry Source Type: research

Fuel cell electrolyte membranes based on copolymers of protic ionic liquid [HSO3-BVIm][TfO] with MMA and hPFSVE
Publication date: Available online 15 June 2019Source: PolymerAuthor(s): V.M. Ortiz-Martínez, Alfredo Ortiz, Verónica Fernández-Stefanuto, Emilia Tojo, Maxime Colpaert, Bruno Améduri, Inmaculada OrtizAbstractPolymeric ionic liquids (PILs) have recently been attracting great attention as new types of electrolytes for polymer exchange membrane fuel cells (PEMFCs), clean energy devices, due to their outstanding properties. In this work, the copolymerization of the ionic liquid (IL) 1-(4-sulphobutyl)-3-vinylimidazolium trifluoromethanesulphonate, [HSO3-BVIm][TfO], with methyl methacrylate (MMA) and ...
Source: Polymer - June 16, 2019 Category: Chemistry Source Type: research

Synthesis and self-assembly of Poly(N-octyl benzamide)-μ-poly(ε-caprolactone) miktoarm star copolymers displaying uniform nanofibril morphology
In this study, we employed an efficient strategy by the combinations of chain-growth condensation polymerization (CGCP), styrenics-assisted atom transfer radical coupling (SA ATRC), and ring-opening polymerization (ROP) to synthesize novel miktoarm (μ) star copolymers. Accordingly, poly(N-octyl benzamide) (PBA) and poly(ε-caprolactone) (PCL) arms were conjugated to form μ-(PBA)2(PCL)m star (m = ca. 4; Mn = ca. 13400; Đ = 1.17; abbr.: μ-(PBA)(PCL)). Thermal properties of homopolymers and μ-(PBA)(PCL) were examined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC...
Source: Polymer - June 16, 2019 Category: Chemistry Source Type: research

Enhanced thermal stability and mechanical property of EVA nanocomposites upon addition of organo-intercalated LDH nanoparticles
Publication date: Available online 14 June 2019Source: PolymerAuthor(s): Ji-Hee Lee, Wei Zhang, Hyeon-Ju Ryu, Goeun Choi, J. Yoon Choi, Jin-Ho ChoyAbstractOrgano-intercalated layered double hydroxides (LDHs)/ethylene vinyl acetate (EVA) nanocomposites were synthesized using the solution blending method. Pristine layered double hydroxides are not compatible with hydrophobic polymer matrix due to their hydrophilic property. As an attempt to improve the compatibility of LDHs with hydrophobic EVA, positively charged LDH surface was modified by incorporating various anionic surfactants. Surfactants were selected by considering ...
Source: Polymer - June 16, 2019 Category: Chemistry Source Type: research

A novel liquid imidazole-copper (II) complex as a thermal latent curing agent for epoxy resins
In this study, 1-cyanoethyl-2-ethyl-4-methylimidazole (1C2E4MI) was modified by copper chloride to improve its thermal latency towards epoxy resins. Unexpected complexation between 1C2E4MI and copper chloride was discovered, and two complexes which included a liquid and a solid were generated. The microanalytical results show that the ligand-metal ratios of these two complexes are 7:1 (liquid) and 1:1 (solid), rather than the theoretical 4:1 ratio. The liquid 1C2E4MI-copper (II) complex (Complex-L) exhibits superior miscibility with epoxy resins, and the resulting epoxy systems show distinctly prolonged pot life at 25 and ...
Source: Polymer - June 16, 2019 Category: Chemistry Source Type: research

Thermal insulation Behavior of Functionally Graded Aerogel: The Role of Novolac Molecular-Weight
Publication date: Available online 15 June 2019Source: PolymerAuthor(s): Mina Noroozi, Mahyar Panahi-Sarmad, Ahmad Reza BahramianAbstractIn this research, a novel aerogel with a functionally-graded (FG) structure as a thermal insulator has been fabricated without interfaces through sol-gel polymerization. The effects of molecular-weight (Mw) and initial-solvent concentration as decisive parameters in the microstructure of phenol-formaldehyde aerogels are systematically studied. The results show that a broad spectrum of Mw created via the precise control of the cross-linking (CL) process of the resin. Moreover, the sol-size...
Source: Polymer - June 16, 2019 Category: Chemistry Source Type: research

Application of mean-field theory to the spin casting of polystyrene and poly(methyl methacrylate) blend films from toluene
Publication date: Available online 13 June 2019Source: PolymerAuthor(s): Youmna Mouhamad, Parvaneh Mokarian-Tabari, Richard.A.L. Jones, Mark GeogheganAbstractThe Flory-Huggins free energy of mixing is shown to be appropriate for the analysis of the temporal evolution of a ternary blend of polystyrene and poly(methyl methacrylate) during spin-coating from toluene using an in-situ light scattering technique. For the range of concentrations studied, both the onset of film instability and the observation of a scattering ring occur at the same toluene volume fraction. The success of Flory-Huggins theory indicates that polymer c...
Source: Polymer - June 15, 2019 Category: Chemistry Source Type: research

Synthesis of medium bandgap copolymers based on benzotriazole for non-fullerene organic solar cells
Publication date: Available online 14 June 2019Source: PolymerAuthor(s): Shanshan Ma, Yu Song, Zhenfeng Wang, Baitian He, Xiye Yang, Li Li, Baomin Xu, Jie Zhang, Fei Huang, Yong CaoAbstractThree new copolymer donors based on DCN-alt FTAZ PT-68, PT-810-H, and PT-810-L were synthesized by adjusting the alkyl chains and molecular weight. The copolymers showed deep highest occupied molecular orbital (HOMO) levels of about −5.50 eV due to introducing fluorine atoms and cyano electron-withdrawing groups. Therefore, devices based on the copolymers as donors and ITIC as acceptors had high open-circuit voltages (VOC) exceed...
Source: Polymer - June 15, 2019 Category: Chemistry Source Type: research

Mixed-matrix membranes based on 6FDA-ODA polyimide and Silicalite-1 with homogeneous spatial distribution of particles
We report an experimental procedure leading to defect-free mixed-matrix membranes with a homogeneous spatial distribution of filler particles, volume fractions of which are within the interval [0.10, 0.35]. A polyimide matrix was synthetized from 4,4´-(hexafluoroisopropylidene) diphtalic anhydride and 4,4′-oxydianiline in the solution with N,N-dimethylformamide. (3-aminopropyl) triethoxysilane was used as a linker to improve the phase contact between silicalite-1 particles and the polyimide matrix. We found that a homogeneous spatial distribution of particles in the resulting membrane was achieved if kinematic ...
Source: Polymer - June 15, 2019 Category: Chemistry Source Type: research

Preparation and characterization of boronic acid- functionalized halloysite Nanotube/Poly(vinyl alcohol) nanocomposites
Publication date: Available online 14 June 2019Source: PolymerAuthor(s): Masaru Mukai, Wei Ma, Keiko Ideta, Atsushi TakaharaAbstractOrganic-inorganic nanocomposite films consisting of surface functionalized halloysite nanotube (HNT) and poly (vinyl alcohol) (PVA) with improved mechanical and thermal properties were prepared. The surface of HNT was modified with boronic acid by two different methods. In the first method, a boronic acid group bearing a triethoxysilane was synthesized and used to modify HNT directly. In the second method, HNT was modified by 3-aminopropyltriethoxysilane (APTES) and 4-formylphenylboronic acid ...
Source: Polymer - June 15, 2019 Category: Chemistry Source Type: research

All-atom molecular dynamics study of impact fracture of glassy polymers. I: Molecular mechanism of brittleness of PMMA and ductility of PC
Publication date: Available online 14 June 2019Source: PolymerAuthor(s): Kazushi Fujimoto, Zhiye Tang, Wataru Shinoda, Susumu OkazakiAbstractMolecular mechanism of brittle and ductile impact fractures of glassy polymers has been investigated. We performed atomistic molecular dynamics (MD) calculations for two glassy polymers, brittle poly(methyl methacrylate) (PMMA) and ductile polycarbonate (PC) using the dissociative force fields. The systems were prepared as realistic as possible such that they reproduced the experimental molecular weight distribution, tacticity, radius of gyration, and entanglement density. The calcula...
Source: Polymer - June 15, 2019 Category: Chemistry Source Type: research

Structure and Self-reinforcing Mechanism of Biaxially Oriented Polyethylene Pipes Produced by Solid Phase Die Drawing
Publication date: Available online 12 June 2019Source: PolymerAuthor(s): Chen Kong, Yujie Wang, Lin Ye, Xiaowen ZhaoAbstractBiaxially oriented polyethylene (PE) pipes were prepared through solid phase die drawing technology. Drawing speed presented a prominent effect on the hoop draw ratio (DRhoop) and axial draw ratio (DRaxial) of the pipes. For pipe with DRhoop/DRaxial of 2.465/1.182, the tensile strength was improved significantly along hoop direction as well as axial direction, reaching respectively 1.75 and 1.3 times of the isotropic sample. Through die drawing, more uniform and dense oriented lamellar structure forme...
Source: Polymer - June 13, 2019 Category: Chemistry Source Type: research

Effect of organic anion with multiple hydrophobic sites on gelation and phase separation in aqueous methylcellulose solution: Beyond simple salting-in effect
Publication date: Available online 12 June 2019Source: PolymerAuthor(s): Motoki Shibata, Tsuyoshi Koga, Koji NishidaAbstractWe studied addition effect of sodium tetraphenylborate (NaBPh4), an organic salt with multiple hydrophobic sites, on thermoresponsive behavior of aqueous methylcellulose (MC) solution. By means of simultaneous measurements of viscosity and light transmittance during heating, it was clarified that the concentration of added NaBPh4 determines which of gelation and phase separation occurs first. Aqueous MC solution without NaBPh4 formed gels below the phase separation temperature, and therefore the phase...
Source: Polymer - June 13, 2019 Category: Chemistry Source Type: research

Influence of water content on alkali metal chloride transport in cross-linked Poly(ethylene glycol) Diacrylate.1. Ion sorption
Publication date: Available online 12 June 2019Source: PolymerAuthor(s): Eui-Soung Jang, Jovan Kamcev, Kentaro Kobayashi, Ni Yan, Rahul Sujanani, Theodore J. Dilenschneider, Ho Bum Park, Donald R. Paul, Benny D. FreemanAbstractThe relationship between ion size and sorption properties in water swollen uncharged polymers was investigated as a model system for understanding ion sorption and transport in more complex systems (i.e., charged polymer networks). Alkali metal chloride (e.g., LiCl, NaCl, and KCl) sorption coefficients in a series of cross-linked poly(ethylene glycol) diacrylate (XLPEGDA) polymer membranes were measu...
Source: Polymer - June 13, 2019 Category: Chemistry Source Type: research

High solid content production of environmentally benign ultra-thin lignin-based polyurethane films: Plasticization and degradation
Publication date: Available online 12 June 2019Source: PolymerAuthor(s): Yan Zhang, Jingya Wang, Xiangchen Fang, Jianjun Liao, Xin Zhou, Shumin Zhou, Fudong Bai, Shaozhong PengAbstractHere, an environmentally benign method of minimizing waste creation and production time was proposed to fabricate the ultra-thin polyurethane films (LPUfs). The lignin was used as hard segments and poly(ε-caprolactone) glycol (PCL) served as soft segments through the coupling of hexamethylene diisocyanate (HDI). The modified fabrication method could economize the usage of solvent more than six-fold and reduce the production time withi...
Source: Polymer - June 13, 2019 Category: Chemistry Source Type: research

Glass transition of a polystyrene surface as detected via two-dimensional diffusion of Au atoms during physical vapor deposition
Publication date: Available online 13 June 2019Source: PolymerAuthor(s): Takashi Sasaki, Yuta Ito, Taichiro Sasai, Satoshi IrieAbstractWe investigated two-dimensional diffusion of Au atoms across the surface of a polystyrene (PS) film during physical vapor deposition to determine the surface glass transition temperature (Tg). Deposited Au atoms underwent two-dimensional diffusion on the PS surface until they coalesce with other atoms or aggregated particles. The diffusivity of Au on the PS surface was evaluated from the size and the number density of yielded Au nanoparticles. The diffusion coefficient D of Au was found to ...
Source: Polymer - June 13, 2019 Category: Chemistry Source Type: research

Chain expansion process from knotted globule
Publication date: Available online 13 June 2019Source: PolymerAuthor(s): Mitsuo Nakata, Yoshiki Nakamura, Yasuyuki Maki, Toshiaki DobashiAbstractKnotting in a polymer chain was investigated by observing the chain expansion process from a collapsed chain for the solution of poly(methyl methacrylate)(PMMA) with Mw = 1.22 × 107 in the mixed solvent tert-butyl alcohol + water(2.5 vol%). Because of very slow phase separation in the solution the chain collapse after a temperature drop and chain expansion after a jump were determined by static light scattering. PMMA chain was shown to collapse rapidly...
Source: Polymer - June 13, 2019 Category: Chemistry Source Type: research

Functionalized carbon nanotubes modulate the phase transition behavior of thermoresponsive polymer via hydrophilic-hydrophobic balance
Publication date: Available online 11 June 2019Source: PolymerAuthor(s): Ritu Yadav, Pannuru VenkatesuAbstractThe world of nano-science is getting popularity due to their vast applications in the field of material science, biotechnology and biomedical research. In this context, carbon-nanotubes (CNTs) have provided new horizons because of their use as molecular transporters. Nonetheless, the low solubility in molecular solvents and cytotoxity of CNTs prevent their utility in biological process. Here, we established increasing solubility and dispersion of CNTs by functionalization with –COOH group that overcome these ...
Source: Polymer - June 12, 2019 Category: Chemistry Source Type: research

Regioregularity controlled phase behavior for Poly(3-hexylthiophene): A combined study of simple coarse-grained simulation and experiment
In this study, we developed a simple coarse-grained simulation model framework to investigate the effect of regioregularity (RR) on the crystallization behavior of poly(3-hexylthiophene) (P3HT). To describe the regio-chemistry of P3HT, two different coarse-grained beads were designed to contain either regio-regularly substituted head-to-tail (HT) orientations or regio-irregularly substituted non-HT orientations, and two beads were randomly incorporated in a single polymer where the total RR was tuned from regio-random (RR = 50%) to regio-regular (RR = 100%). Based on our modeling, the crystallization behaviors in b...
Source: Polymer - June 12, 2019 Category: Chemistry Source Type: research

Publishers Note
Publication date: Available online 12 June 2019Source: PolymerAuthor(s): (Source: Polymer)
Source: Polymer - June 12, 2019 Category: Chemistry Source Type: research

The molecular weight dependence on physical aging of Polycarbonate
Publication date: Available online 12 June 2019Source: PolymerAuthor(s): Shotaro Nishitsuji, Yuki Watanabe, Hiroshi Ito, Masaru Ishikawa, Takashi Inoue, Mikihito TakenakaAbstractIn our previous paper, we reported that the impact value of polycarbonate (PC) increases with increasing molecular weight and decreases upon annealing [Polymer 2012, 53, 895–896]. To clarify these phenomena, the effects of molecular weight and heat treatment on the fracture of PC are investigated in this study. The results show that the stress for craze nucleation increased as the molecular weight increased but was not affected by annealing. ...
Source: Polymer - June 12, 2019 Category: Chemistry Source Type: research

Deformation induced void formation and growth in β nucleated isotactic polypropylene
Publication date: Available online 10 June 2019Source: PolymerAuthor(s): Takahiko Kawai, Syota Soeno, Shin-ichi Kuroda, Shunsuke Koido, Tomoyuki Nemoto, Motonori TamadaAbstractIn-situ synchrotron small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) were carried out to investigate the deformation and the void formation behavior of β nucleated isotactic polypropylene during uniaxial stretching at 100 °C. WAXD results indicated that β crystal started to deform after yielding, followed by recrystallization to α-phase. A quasi-quantitative SAXS analysis was attempted to evaluate the ...
Source: Polymer - June 12, 2019 Category: Chemistry Source Type: research

A reactive hydrophobically modified ethoxylated urethane (HEUR) associative polymer bearing benzophenone terminal groups: Synthesis, thickening and photo-initiating reactivity
Publication date: Available online 10 June 2019Source: PolymerAuthor(s): Tao Guan, Zhukang Du, Xueyi Chang, Dongli Zhao, Shurui Yang, Ning Sun, Biye RenAbstractHydrophobically modified ethoxylated urethanes (HEURs), as a representative class of associative polymers, are widely used as rheology modifiers in waterborne systems such as coatings, emulsions, inks etc. due to their unique associative network structure and finite relaxation behavior in solution. However, conventional HEURs are non-reactive and generally stay free in final cured films, which may induce some damages to the performance of the coatings. To solve the ...
Source: Polymer - June 12, 2019 Category: Chemistry Source Type: research

Lamellar structures in blends of amorphous–block–main-chain liquid crystal–block–amorphous copolymers and amorphous homopolymers: Effects of the amorphous homopolymer molecular weight
In this study, the lamellar forming T (5.5-39-5.5) and T (11-39-11) copolymers were blended with homoPEMA (Hz) with Mn of z kDa at a concentration of 20 wt% to give the two series of blends T (5.5-39-5.5)/Hz and T (11-39-11)/Hz. These blends were examined for microdomain morphology as a function of the molecular weight ratio of z/x. T (5.5-39-5.5)/Hz formed lamellar microdomains over the investigated z/x range of 0.6–3.8, whereas T (11-39-11)/Hz formed lamellae over a narrower range of 1.2–2.6. The lamellar spacing and the PEMA and LC lamellar thicknesses (dam and dLC) were constant over z/x and dam was great...
Source: Polymer - June 12, 2019 Category: Chemistry Source Type: research

Synthesis of soluble, air-stable fully conjugated ladder polymers
Publication date: Available online 10 June 2019Source: PolymerAuthor(s): Takaaki Hirano, Hitoshi Hanamura, Munenori Inoue, Saori Ueda, Makoto Watanabe, Masao Tanabiki, Koichiro MikamiAbstractHerein, we report the synthesis of soluble, air-stable fully conjugated ladder polymers incorporating a BTBT structure as a repeating unit. The ladder polymers were synthesized through a simple process: A Migita-Kosugi-Stille polycondensation, followed by an intramolecular oxidative C–H annulation (Scholl reaction). Absorption and fluorescence spectrometric analyses, as well as theoretical analysis and model reaction revealed tha...
Source: Polymer - June 10, 2019 Category: Chemistry Source Type: research

Graphene oxide grafted with polyoxazoline as thermoresponsive support for facile catalyst recycling by reversible thermal switching between dispersion and sedimentation
Publication date: Available online 9 June 2019Source: PolymerAuthor(s): Alexander Kozur, Laura Burk, Ralf Thomann, Pierre J. Lutz, Rolf MülhauptAbstractGrafting polyoxazolines exhibiting a cloud point temperature (TCP) in the reaction medium onto graphene oxide (TRGO) prepared by thermal reduction of graphite oxide affords thermoresponsive catalyst supports and enables catalyst recycling by thermal switching between dispersion and sedimentation. In a facile grafting-to process the functional groups of the TRGO react with the cationic oxazolinium end groups, obtained by living cationic ring-opening polymerization of 2-...
Source: Polymer - June 9, 2019 Category: Chemistry Source Type: research

Synthesis of ultrahigh molecular weight bottlebrush block copolymers of ω-end-norbornyl polystyrene and polymethacrylate macromonomers
Publication date: Available online 7 June 2019Source: PolymerAuthor(s): Ho-Bin Seo, Yong-Guen Yu, Chang-Geun Chae, Myung-Jin Kim, Jae-Suk LeeAbstractWell-controlled polystyrene-polymethacrylate bottlebrush block copolymers (BBCPs) of ultrahigh molecular weight using ω-end-norbornyl polystyrene as the macromonomer for the first block were synthesized by combining living anionic polymerization (LAP) and ring-opening metathesis polymerization (ROMP). The ω-end-norbornyl polystyrene (NB-PSt), poly(tert-butyl methacrylate) (NB-PtBMA), poly(methyl methacrylate) (NB-PMMA), and poly(benzyl methacrylate) (NB-PBzMA) macr...
Source: Polymer - June 7, 2019 Category: Chemistry Source Type: research

Non-Enthalpic Enhancement of Spatial Distribution and Orientation of CNTs and GNRs in Polymer Nanofibers
Publication date: Available online 7 June 2019Source: PolymerAuthor(s): Yevgen Zhmayev, George L. Shebert, Shubham Pinge, Prabhleen Kaur, Hongshen Liu, Yong Lak JooAbstract:Multi-wall carbon nanotubes (CNTs) and their unzipped counterparts graphene nanoribbons (GNRs) are promising materials for energy storage applications, due to their unique architecture and properties. However, spatial distribution and orientation in polymer matrices plays a crucial role in determining the charge and mass transfer effectiveness of the nanocomposite. Here, we report a controlled enhancement of dispersion and spatial alignment of CNTs and ...
Source: Polymer - June 7, 2019 Category: Chemistry Source Type: research

Tailoring the Thermal Conductivity of Poly(dimethylsiloxane)/Hexagonal Boron Nitride Composite
Publication date: Available online 7 June 2019Source: PolymerAuthor(s): Ziwei Li, Ke Li, Jun Liu, Shui Hu, Shipeng Wen, Li Liu, Liqun ZhangAbstractMolecular dynamics (MD) simulation was employed to predict the thermal conductivity of poly(dimethylsiloxane) (PDMS)/hexagonal boron (h-BN) composite. Two MD simulation models were constructed. Model one is h-BN monolayer being adsorbed by PDMS chains, which is designed to examine the influence mechanism of polymer molecules on the heat conduction of h-BN. The polymer molecules were divided into several layers along the normal direction of the h-BN, which had different impacts o...
Source: Polymer - June 7, 2019 Category: Chemistry Source Type: research

Single-ion conducting polymer electrolytes with alternating ionic mesogen-like moieties interconnected by poly(ethylene oxide) segments
Publication date: Available online 5 June 2019Source: PolymerAuthor(s): Hannes Nederstedt, Patric JannaschAbstractSolid single-Li+-ion conducting polymer electrolytes are currently explored for safe high-temperature lithium batteries. In the present work we have prepared and studied materials based on alternating mesogen-like naphthalene sulfonate units interconnected by flexible poly(ethylene oxide) (PEO) segments in order to induce microphase separation and physical crosslinking. These segmented polymers were readily prepared in polycondensations of a naphthalene diol sulfonate and chain-end chlorinated PEO. The ionic co...
Source: Polymer - June 6, 2019 Category: Chemistry Source Type: research

Preparation of cyclodextrin-based porous polymeric membrane by bulk polymerization of ethyl acrylate in the presence of cyclodextrin
Publication date: Available online 6 June 2019Source: PolymerAuthor(s): Yuichiro Kobayashi, Yukie Nakamitsu, Yongtai Zheng, Yoshinori Takashima, Hiroyasu Yamaguchi, Akira HaradaAbstractWe disclose an efficient synthesis to prepare polymeric membranes containing cyclodextrins (CDs). Bulk polymerization of ethyl acrylate containing peracetylated γ-CD (PAcγCD) yields a porous polymeric membrane containing CDs [CD membrane (BP)]. Krypton adsorption measurements reveal that the CD membrane (BP) has a porous structure. The specific surface area of the CD membrane (BP) is 10 times higher than that of a CD-based polyme...
Source: Polymer - June 6, 2019 Category: Chemistry Source Type: research

The role of pH, ionic strength and monomer concentration on the terpolymerization of 2-acrylamido-2-methylpropane sulfonic acid, acrylamide and acrylic acid
Publication date: Available online 5 June 2019Source: PolymerAuthor(s): Alison J. Scott, Thomas A. Duever, Alexander PenlidisAbstractThe current study examines the effects of important factors (namely, pH, ionic strength and monomer concentration) on the terpolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS), acrylamide (AAm) and acrylic acid (AAc). A good understanding of how these factor levels affect terpolymerization reactivity ratios, and terpolymer composition, microstructure and molecular weight paves the way for the synthesis of custom-made polymers for specific applications. For the range of condit...
Source: Polymer - June 5, 2019 Category: Chemistry Source Type: research

Application of iterative reconstruction algorithms to mitigate CT-artefacts when measuring fiber reinforced polymer materials
Publication date: Available online 3 June 2019Source: PolymerAuthor(s): Arnold Wilbers, Ander Biguri, Jennifer Schillings, Joachim LoosAbstractIn general, fiber reinforced polymer materials are being used in case of challenging mechanical requirements. Important parameters determining performance of such polymer composites are properties of the components as well as the quality of the fiber-polymer interface. For example, porosity or voids particularly at the interface will influence the overall performance of the composite negatively. Therefore, it is of importance to know the actual porosity value to e.g. calculate and p...
Source: Polymer - June 5, 2019 Category: Chemistry Source Type: research

Tuning the material properties of a water-soluble ionic polymer using different counterions for material extrusion additive manufacturing
Publication date: Available online 3 June 2019Source: PolymerAuthor(s): Callie E. Zawaski, Emily M. Wilts, Camden A. Chatham, Andre T. Stevenson, Allison M. Pekkanen, Chen Li, Zhiting Tian, Abby R. Whittington, Timothy E. Long, Christopher B. WilliamsAbstractAdditive manufacturing (AM) affords the opportunity to print tailored pharmaceuticals to customize the quantity of medicine, number of medicines, and time and rate of release to be adapted for an individual's needs. A series of sulfonated poly(ethylene glycol) (SPEG) polymers for fused filament fabrication (FFF) that (i) dissolves quickly (
Source: Polymer - June 5, 2019 Category: Chemistry Source Type: research

Rigid nanoparticles promote the softening of rubber phase in filled vulcanizates
Publication date: Available online 3 June 2019Source: PolymerAuthor(s): Yihu Song, Ruiquan Yang, Miao Du, Xinyan Shi, Qiang ZhengAbstractEnhanced mechanical softening accompanying nanoparticles reinforcement of rubber is an important source of energy dissipation and heat buildup of industrially engineered elastomers. Its mechanism previously assigned to damages in the filler network, rubber-filler interface and rubber phase remains controversial in more than 70 years. Through investigating the typical Payne effect of styrene-butadiene rubber gum and its vulcanizates as well as silica filled compounds and vulcanizates and t...
Source: Polymer - June 5, 2019 Category: Chemistry Source Type: research

Rheological and Mechanical Properties of a Novel Polyamide 6 Synthesized by Anionic Polymerization of ε-caprolactam in a Twin-Screw Extruder
In this study, we successfully synthesized a novel polyamide 6 (PA6, nylon 6) with a linking agent (a diepoxide) by in-situ reactive extrusion. In order to vary the physical properties of the polymer, a unique strategy was introduced. The linking agent reacted with growing PA6 chains during the anionic polymerization in the extruder. The extrudates appear to have a different structure (chain branching) without forming a network structure, causing a remarkable enhancement in the rheological properties as well as the mechanical properties of the nylon 6 produced. The molar ratio of linking agent to initiator was optimal at 0...
Source: Polymer - June 5, 2019 Category: Chemistry Source Type: research