Polyetherketone powder/epoxy blends with low viscosity and high mechanical properties

2020 ◽  
Vol 32 (9) ◽  
pp. 1052-1060
Author(s):  
Hong Li ◽  
Hang Su ◽  
Letian Wang ◽  
Lingyu Sun ◽  
Jiping Yang
Keyword(s):  
High Performance ◽  
Rheological Behaviour ◽  
Complex Viscosity ◽  
High Viscosity ◽  
Diglycidyl Ether ◽  
Forming Process ◽  
Low Viscosity ◽  
Lap Shear ◽  
Epoxy Blends ◽  
Insight Into

The difficult forming process and construction caused by high viscosity has been the main problem restricting the application of high-performance thermoplastic/epoxy blends. In this contribution, low viscous polyetherketone (PEK)/diglycidyl ether of bisphenol A epoxy resin (DGEBA) blends were prepared by mixing the ultrafine PEK powder and DGEBA monomer at ambient temperature. Rheological behaviour shows that complex viscosity of the undissolved blends containing 20 wt% PEK powder is two orders of magnitude lower than that of the dissolved one. Interestingly, diffusion and phase separation of PEK powder in the undissolved PEK/DGEBA/2-methylimidazole/dicyandiamide (M-DICY) blends are affected by the curing processes. Phase-inverted morphology was observed after curing at 120°C/1h + 160°C/0.5 h for the undissolved 20 wt% PEK/DGEBA/M-DICY blends which also exhibited outstanding tensile strength and lap shear strength both at 298 and 77 K. We believe this work should provide a new insight into the preparation of advanced thermoplastic/epoxy blends.

A CASE STUDY OF BIOCOMPOSITE MATERIAL USE IN AUTOMOTIVE APPLICATIONS

2021 ◽  
Author(s):  
DANIEL WALCZYK ◽  
RONALD BUCINELL ◽  
STEVEN FLEISHMAN ◽  
SHARMAD JOSHI
Keyword(s):  
High Performance ◽  
Mechanical Performance ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Maximum Tensile Stress ◽  
High Viscosity ◽  
Flexural Stress ◽  
Fiber Volume ◽  
Low Viscosity ◽  
Biocomposite Material

Interest in biocomposites is growing worldwide as companies that manufacture high-performance products seek out more sustainable material options. Although there is significant research on biocomposite material options and processing found in the literature from at least the last two decades, there are few experimentally based case studies published to help guide product designers and engineers when considering these materials. This paper discusses the use of biocomposites in the seat of an electric bus. Although it is clear that biocomposite material options are quite limited, the authors eventually settled on three natural reinforcements (cellulose, hemp, flax), two epoxies (one low and the other high viscosity) with high biobased carbon content, and one flax precoated with bioepoxy for consideration. Laminate plates with a 4mm nominal thickness are manufactured using VARTM (low viscosity epoxy only), hand layup as a surrogate for prepregging (high viscosity epoxy only), compression molding, and an out-of-autoclave process called the Pressure Focusing Layer (PFL) method. Permeability of the three reinforcements infused with the high viscosity epoxy and fiber volume fractions are determined experimentally to provide insight into VARTM processing and mechanical performance. The tensile modulus, maximum tensile stress, flexural modulus, and maximum flexural stress are measured for all combinations of reinforcement, resin, and processing using tension testing and three-point bending based on ASTM standards. Basic conclusions are drawn about the specific application and more generally about the process of using biocomposites in commercial products.

scholarly journals A Novel Organic–Inorganic Hybrid Admixture for Increasing Flowability and Reducing Viscosity of Ultra-High Performance Paste

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3385 ◽  
Author(s):  
Min Wang ◽  
Hao Yao
Keyword(s):  
Steric Hindrance ◽  
High Performance ◽  
High Performance Concrete ◽  
High Viscosity ◽  
Inorganic Hybrid ◽  
Oh Groups ◽  
Low Viscosity ◽  
Binder Ratio ◽  
The One ◽  
Water Binder Ratio

The low flowability and high viscosity of ultra-high performance concrete (UHPC), which is mainly caused by the silica fume (SF) agglomeration and low water–binder ratio, is a severe defect in its engineering applications. Herein, a novel organic–inorganic hybrid (OIH) admixture was synthesized by grafting comb-like polycarboxylate ether (PCE) onto the surface of SF. On the one hand, PCE-grafting could effectively prevent SF agglomeration and improve the dispersion of SF core. The reason being the consumption of polar silicon hydroxyl (Si-OH) groups on the surface of SF and the steric hindrance effect generated from PCE arms. On the other hand, OIH admixture could adsorb onto the surface of cement and SF particles by electrostatic interaction, exhibiting stronger steric hindrance effect than traditional comb-like PCE. As a result, UHPC system with this star-like OIH admixture presented high flowability and low viscosity at low water–binder ratio (0.18).

scholarly journals Preparation of a High-Performance Porous Ceramic Membrane by a Two-Step Coating Method and One-Step Sintering

2018 ◽  
Vol 9 (1) ◽  
pp. 52 ◽  
Author(s):  
Zhiwen Hu ◽  
Yulong Yang ◽  
Qibing Chang ◽  
Fengli Liu ◽  
Yongqing Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Ceramic Membrane ◽  
Porous Ceramic ◽  
Ceramic Membranes ◽  
High Viscosity ◽  
Solid Content ◽  
Low Viscosity ◽  
Coating Method ◽  
One Step ◽  
Hole Defects

Hole defects and uneven membrane thicknesses can lead to poor performance, especially in the separation stability of ceramic membranes. This paper uses a one-step sintering method, which avoids hole defects and uneven membrane thicknesses, for the preparation of high-performance and defect-free ceramic membranes. For this purpose, two kinds of ceramic membrane slurry with high or low viscosities were prepared by alumina particles, as raw materials. Both the effects of the two coating process with a one-step coating method for low-viscosity slurry, and the two-step coating method with a high viscosity flush after a low viscosity coating, on the surface properties of a ceramic membrane, were studied in detail. The result shows that the properties of ceramic membranes can be improved by a two-step coating method, with a high viscosity flush after a low viscosity coating, A high-performance and defect-free ceramic membrane was obtained by one-step sintering at 1450 °C for 2 hr with 7 wt % solid content and a coating time of 11 s.

The Structure of Imidazolium-Based Ionic Liquids: Insights From Ion-Pair Interactions

2007 ◽  
Vol 60 (1) ◽  
pp. 9 ◽  
Author(s):  
Patricia A. Hunt ◽  
Ian R. Gould ◽  
Barbara Kirchner
Keyword(s):  
Ionic Liquids ◽  
Melting Point ◽  
Ion Pairs ◽  
Liquid Structure ◽  
High Viscosity ◽  
Ion Pair ◽  
Low Viscosity ◽  
Association Energy ◽  
Dynamics Simulations ◽  
Insight Into

A large number of ab-initio (B3LYP/6–31++G(d,p)) computed ion-pair structures have been examined in order to determine if such calculations are capable of offering insight into the physical properties of the liquid state, particularly viscosity and melting point. Ion pairings based around the 1-butyl-3-methylimidazolium (C4C1im) cations and a range of anions (Cl, BF4, and N(Tf)2 where N(Tf)2 is bis(trifluoromethylsulfonly)imide) were chosen because of the range of viscosities exhibited by the corresponding ionic liquids. We have used these results to build up a ‘picture’ of the ionic liquid structure which is consistent with molecular dynamics simulations and experimental evidence. However, further work is required to established if such an analysis could be predictive. Nevertheless, we establish clear relationships relating ion-pair association energy, a derived ‘connectivity index’, and the diversity of structures with viscosity and melting point. Our calculations indicate that ions in C4C1imCl form a strong, highly connected and regular array thus rationalizing the high viscosity and melting point. In contrast the ion-pairs of C4C1imN(Tf)2 form a weakly interacting, highly disordered, and low connectivity network consistent with the low viscosity and melting point. C4C1imBF4 lies midway between these two extremes.

scholarly journals TRIBOLOGICAL BEHAVIOUR OF THE LOW AND HIGH VISCOSITY PEEK AGAINST STEEL USING DIFFERENTS CONTACT PRESSURES

2013 ◽  
Vol 4 (2) ◽  
Author(s):  
Vanessa Rodriguez ◽  
Jacob Sukumaran ◽  
Yeczain Perez ◽  
Patrick De Baets ◽  
Matyas Ando
Keyword(s):  
High Performance ◽  
Friction And Wear ◽  
Large Scale ◽  
High Viscosity ◽  
Tribological Behaviour ◽  
Wear Performance ◽  
Low Viscosity ◽  
Enhanced Properties ◽  
Semi Solid ◽  
Contact Pressures

  In the market of polymers for tribological applications polyetheretherketone (PEEK) are often used for satisfying requests coming from industry regarding enhanced properties such as, thermal stability, friction and wear resistance. These properties promote the material to be used in so called high performance tribological applications. However, fundamental mechanisms governing friction and wear are not yet fully understood and neither is the influence of composition parameters. An important parameter is PEEK’s viscosity during manufacturing process which is heated up to semi-solid state, between its glass transition and melting temperature. This paper studies the friction and wear performance of low and high viscosity PEEK and pure PEEK under dry reciprocating sliding contact. The tests were performed in large scale specimens under flat-on-flat configuration to determine the transitions in tribological behaviour at different contact pressures. Tests were carried out at controlled atmosphere with 25 °C and a relative humidity of 50%. Contact pressures parameters were 4, 8 and 10 MPa used at a sliding speed of 20 mm/s. Post mortem analyses were carried out by means of 2-D surface topography and optical microscopy. The results show that the pure PEEK exhibits low coefficient of friction and wear rate when the contact pressure increase and similar behave for high and low viscosity PEEK.

scholarly journals Study on strong spinning preparation method and mechanism of the industrial pure titanium ultrafine crystallization

2019 ◽  
Vol 14 ◽  
pp. 155892501989525
Author(s):  
Yu Yang ◽  
Yanyan Jia
Keyword(s):  
Heat Treatment ◽  
High Performance ◽  
Pure Titanium ◽  
Grain Structure ◽  
Theoretical Research ◽  
Ultrafine Grain ◽  
Forming Process ◽  
Spinning Process ◽  
And Performance ◽  
Material Utilization

Ultrafine crystallization of industrial pure titanium allowed for higher tensile strength, corrosion resistance, and thermal stability and is therefore widely used in medical instrumentation, aerospace, and passenger vehicle manufacturing. However, the ultrafine crystallizing batch preparation of tubular industrial pure titanium is limited by the development of the spinning process and has remained at the theoretical research stage. In this article, the tubular TA2 industrial pure titanium was taken as the research object, and the ultrafine crystal forming process based on “5-pass strong spin-heat treatment-3 pass-spreading-heat treatment” was proposed. Based on the spinning process test, the ultimate thinning rate of the method is explored and the evolution of the surface microstructure was analyzed by metallographic microscope. The research suggests that the multi-pass, medium–small, and thinning amount of spinning causes the grain structure to be elongated in the axial and tangential directions, and then refined, and the axial fiber uniformity is improved. The research results have certain scientific significance for reducing the consumption of high-performance metals improving material utilization and performance, which also promote the development of ultrafine-grain metals’ preparation technology.

Insight into the structure-capacity relationship in biomass derived carbon for high-performance sodium-ion batteries

2021 ◽  
Vol 62 ◽  
pp. 497-504
Author(s):  
Jianguo Sun ◽  
Yao Sun ◽  
Jin An Sam Oh ◽  
Qilin Gu ◽  
Weidong Zheng ◽  
...  
Keyword(s):  
High Performance ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
Insight Into

scholarly journals 3D Printing of High Viscosity Reinforced Silicone Elastomers

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2239
Author(s):  
Nicholas Rodriguez ◽  
Samantha Ruelas ◽  
Jean-Baptiste Forien ◽  
Nikola Dudukovic ◽  
Josh DeOtte ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
New Technologies ◽  
Three Dimensional ◽  
High Viscosity ◽  
Layer By Layer ◽  
Silicone Elastomers ◽  
Uv Curable ◽  
Octet Truss ◽  
Tunable Mechanical Properties

Recent advances in additive manufacturing, specifically direct ink writing (DIW) and ink-jetting, have enabled the production of elastomeric silicone parts with deterministic control over the structure, shape, and mechanical properties. These new technologies offer rapid prototyping advantages and find applications in various fields, including biomedical devices, prosthetics, metamaterials, and soft robotics. Stereolithography (SLA) is a complementary approach with the ability to print with finer features and potentially higher throughput. However, all high-performance silicone elastomers are composites of polysiloxane networks reinforced with particulate filler, and consequently, silicone resins tend to have high viscosities (gel- or paste-like), which complicates or completely inhibits the layer-by-layer recoating process central to most SLA technologies. Herein, the design and build of a digital light projection SLA printer suitable for handling high-viscosity resins is demonstrated. Further, a series of UV-curable silicone resins with thiol-ene crosslinking and reinforced by a combination of fumed silica and MQ resins are also described. The resulting silicone elastomers are shown to have tunable mechanical properties, with 100–350% elongation and ultimate tensile strength from 1 to 2.5 MPa. Three-dimensional printed features of 0.4 mm were achieved, and complexity is demonstrated by octet-truss lattices that display negative stiffness.

scholarly journals A Low-Viscosity BisGMA Derivative for Resin Composites: Synthesis, Characterization, and Evaluation of Its Rheological Properties

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 338
Author(s):  
Ali Alrahlah ◽  
Abdel-Basit Al-Odayni ◽  
Haifa Fahad Al-Mutairi ◽  
Bashaer Mousa Almousa ◽  
Faisal S. Alsubaie ◽  
...  
Keyword(s):  
Substantial Reduction ◽  
Triethylene Glycol ◽  
High Viscosity ◽  
Resin Matrix ◽  
Resonance Spectroscopy ◽  
Dental Resin ◽  
Triethylene Glycol Dimethacrylate ◽  
Oh Groups ◽  
Low Viscosity ◽  
13C Nuclear Magnetic Resonance

This study aimed to synthesize new bisphenol A-glycidyl methacrylate (BisGMA) derivatives, targeting a reduction in its viscosity by substituting one of its OH groups, the leading cause of its high viscosity, with a chlorine atom. Hence, this monochloro-BisGMA (mCl-BisGMA) monomer was synthesized by Appel reaction procedure, and its structure was confirmed using Fourier transform infrared spectroscopy, 1H and 13C-nuclear magnetic resonance spectroscopy, and mass spectroscopy. The viscosity of mCl-BisGMA (8.3 Pa·s) was measured under rheometry conditions, and it was found to be more than 65-fold lower than that of BisGMA (566.1 Pa·s) at 25 °C. For the assessment of the viscosity changes of model resins in the presence of mCl-BisGMA, a series of resin matrices, in which, besides BisGMA, 50 wt % was triethylene glycol dimethacrylate, were prepared and evaluated at 20, 25, and 35 °C. Thus, BisGMA was incrementally replaced by 25% mCl-BisGMA to obtain TBC0, TBC25, TBC50, TBC75, and TBC100 blends. The viscosity decreased with temperature, and the mCl-BisGMA content in the resin mixture increased. The substantial reduction in the viscosity value of mCl-BisGMA compared with that of BisGMA may imply its potential use as a dental resin matrix, either alone or in combination with traditional monomers. However, the various properties of mCl-BisGMA-containing matrices should be evaluated.

scholarly journals A Conceptional Approach of Resin-Transfer-Molding to Rosin-Sourced Epoxy Matrix Green Composites

Aerospace ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 5
Author(s):  
Sicong Yu ◽  
Xufeng Zhang ◽  
Xiaoling Liu ◽  
Chris Rudd ◽  
Xiaosu Yi
Keyword(s):  
Composite Laminates ◽  
Resin Transfer Molding ◽  
High Viscosity ◽  
Ramie Fiber ◽  
Liquid Composite Molding ◽  
Curing Agent ◽  
Molding Process ◽  
Transfer Molding ◽  
Low Viscosity ◽  
Composite Molding

In this concept-proof study, a preform-based RTM (Resin Transfer Molding) process is presented that is characterized by first pre-loading the solid curing agent onto the preform, and then injecting the liquid nonreactive resin with an intrinsically low viscosity into the mold to infiltrate and wet the pre-loaded preform. The separation of resin and hardener helped to process inherently high viscosity resins in a convenient way. Rosin-sourced, anhydrite-cured epoxies that would normally be regarded as unsuited to liquid composite molding, were thus processed. Rheological tests revealed that by separating the anhydrite curing agent from a formulated RTM resin system, the remaining epoxy liquid had its flowtime extended. C-scan and glass transition temperature tests showed that the preform pre-loaded with anhydrite was fully infiltrated and wetted by the liquid epoxy, and the two components were diffused and dissolved with each other, and finally, well reacted and cured. Composite laminates made via this approach exhibited roughly comparable quality and mechanical properties with prepreg controls via autoclave or compression molding, respectively. These findings were verified for both carbon and ramie fiber composites.

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