High-performance Polymeric Materials Research Articles

Last developments in polymers for wearable energy storage devices

Last developments in polymers for wearable energy storage devices

Structure and Properties of PVDF/PA6 Blends Compatibilized by Ionic Liquid-Grafted PA6.

Compatibilization of immiscible blends is critically important for developing high-performance polymer materials. In this work, an ionic liquid, 1-vinyl-3-butyl imidazole chloride, grafted polyamide 6 (PA6-g-IL(Cl)) with a quasi-block structure was used as a compatibilizer for an immiscible poly(vinylidene fluoride) (PVDF)/PA6 blend. The effects of two PA6-g-IL(Cl)s (E-2%-50K and E-8%-50K) on the morphology, crystallization behavior, mechanical properties, and surface resistance of the PVDF/PA6 blend were investigated systematically. It was found that the two types of PA6-g-IL(Cl)s had a favorable compatibilization effect on the PVDF/PA6 blend. Specifically, the morphology of the PVDF/PA6 = 60/40 blend transformed from a typical sea-island into a bicontinuous structure after incorporating E-8%-50K with a high degree of grafting (DG). In addition, the tensile strength of the PVDF/PA6/E-8%-50K blend reached 66 MPa, which is higher than that of PVDF, PA6 and the PVDF/PA6 blend. Moreover, the PVDF/PA6/E-8%-50K blend exhibited surface conductivity due to the conductive path offered by the bicontinuous structure and conductive ions offered by grafted IL(Cl). Differential scanning calorimetry (DSC) and wide-angle X-ray diffractometry (WAXD) results revealed that PA6-g-IL(Cl) exhibits different effects on the crystallization behavior of PVDF and PA6. The compatibilization mechanism was concluded to be based on the fact that the nongrafted PA6 blocks entangled with the PA6 chains, while the ionic liquid-grafted PA6 blocks interacted with the PVDF chains. This work offers a new strategy for the compatibilization of immiscible polymer blends.

Influence of Specific Structure on the Dielectric and Thermal Performance of Bulk Polymers: Atomistic Molecular Dynamics Simulations of XNBR

In this work, we investigate the influence of the molecular structure of carboxylated acrylonitrile-butadiene rubber (XNBR) on the dielectric properties through non-equilibrium molecular dynamics (NEMD) simulations. The NEMD simulations are performed for calculating the permittivity (ε) of XNBR under different alternating electric field strength (Ei), alternating electric field frequency (Ef), and temperature. The simulation results show a similar change trend with the reported experimental consequence of dielectric elastomer. Interestingly, a critical alternating Ei at which the dielectric properties of XNBR with different acrylonitrile contents change seriously is found. Moreover, a deep insight into the mechanisms of the dielectric and thermal performance of XNBR is explored through the analysis from the atomistic level, including intermolecular interaction, fractional free volume, molecular chain migration ability, hydrogen bonds breaking and re-formation, dipole autocorrelation function, phonon vibration power spectrum, and kinetic energy. The research results will inspire the design of polymer structures to obtain high-performance polymer materials. This article is protected by copyright. All rights reserved

Synthesis of an aromatic amine derived from biomass and its use as a feedstock for versatile epoxy thermoset

Innovative bio-based monomers and polymers are required as substitutes for limited fossil resources. Aromatic amines as an important class of chemicals are currently mostly formulated from petroleum. In this paper, a guaiacol derivative aromatic amine (5-aminoguaiacol) was designed and successfully synthesized, which was employed together with vanillin to build a high bio-based bisphenol compound. Following by glycidylation and cross-linking with 4,4′-diaminodiphenyl methane (DDM), we presented an epoxy resin network (GV-EP/DDM) bearing dynamic Schiff base bonds with high glass transition temperature of 220 °C, char yield (in N2 at 800 °C) of 44.9%, storage modulus at 30 °C of 3602 MPa, and Young’s modulus of 4489 MPa, which was 33 °C, 2.5-fold, 38% and 28% higher than those of bisphenol A epoxy resin, respectively. Furthermore, the introduction of Schiff base structure endowed the GV-EP/DDM system with shape memory, degradability, reprocessability at 230 °C under 10 MPa, as well as satisfactory antibacterial property. Notably, the higher crosslinking density made GV-EP/DDM have stronger acid resistance than the other epoxy resins with Schiff base bonds. This work provides a feasible toolbox for production of bio-based aromatic amine compounds, and a strategy to construct high performance and versatile bio-based polymer materials.

Parameter effects and process modelling of Polyamide 12 3D-printed parts strength and toughness

ABSTRACT Polyamide 12 (PA12) is a high-performance polymeric material adopted by various industries for its thermal, electrical, and mechanical properties. In this work, a comprehensive examination of the impact of three 3D printing (3DP) parameters, i.e., Nozzle Temperature (NT), Layer Height (LH), and raster Deposition Angle (DA), on the mechanical strength and toughness of Fused Filament Fabrication (FFF) 3DP PA12 polymer is studied. The general full factorial experimental methodology is followed. The 3DP parameters’ effects were analyzed using descriptive and analytic statistical tools, such as Box plots, interaction charts, and ANOVA analysis. The experimental data depicted different spreads and median values for each parameter level regarding the utilized responses, concluding that the modeling process is vital for the process control and the parameters’ optimization. Two predictive models, a Quadratic Regression Model (QRM) and an Artificial Neural Network (ANN) are fitted on the median values of the experimental data responses predictions, i.e. static mechanical strength (σb), elastic modulus (E), and toughness (T). The ANN performance was proven to be better than the QRM, providing better Mean Absolute Percentage Error (MAPE) values. NT and LH increase σb and T medians and spreads, while zero raster DA optimizes the σb and T.

Phosphorous-Nitrogen flame retardants engineering MXene towards highly fire safe thermoplastic polyurethane

Developing high-performance polymeric materials with highly effective flame retardancy and the generation of ultra-low toxic fumes in a fire remains an intractable challenge. In this work, a novel titanium carbide-polyphenyl phosphate ester amide hybrid (Ti3C2Tx-PPPA) was synthesized via the esterification and hydrogen bonding induced assembly for fabrication of thermoplastic polyurethane (TPU) nanocomposites. The Ti3C2Tx-PPPA displayed strong interface interaction with TPU matrix. The cone calorimetry results indicated that the total heat release, total smoke release and total carbon monoxide yield of the TPU nanocomposite with 1.0 wt% Ti3C2Tx-PPPA were dramatically decreased by 32.6%, 54.4% and 36.8%, respectively, compared to those of pristine TPU. Besides, TPU/Ti3C2Tx-PPPA-1.0 showed the highest Flame Retardancy Index (1.76) among all the specimens. The improved fire safety of TPU was ascribed to the catalytic charring, the chemical transformation and the barrier effect of the Ti3C2Tx nanosheets and PPPA trapping free radicals. This work provides a promising strategy for significantly improving the fire-resistance of TPU and further widening its industrial application.

Additively manufactured high-performance polymeric materials and their potential use in the oil and gas industry.

The oil and gas industry has been tagged as among the largest revenue-generating sectors in the world. High-performance polymers (HPPs), on the other hand, are among the most useful industrial materials, while the utility of 3D printing technologies has evolved and transitioned from rapid prototyping of composite materials to manufacturing of functional parts. In this prospective, we highlight the potential uses and industrial applications of 3D-printed HPP materials in the oil and gas sector, including the challenges and opportunities present.Graphical abstract

Bio-based poly (butylene succinate): Recent progress, challenges and future opportunities

• PBS is intensively studied as biodegradable alternative to polyolefins. • Production, synthesis, physico-chemical and mechanical properties of PBS are covered. • Studies on blend and composite applications are comprehensively reviewed. • Challenges, state-of-the-art and future opportunities critically assessed. Rising energy concerns, rapid infrastructure development, and greater environmental awareness have fueled the demand for sustainable materials. In this direction, sustainable bio-based polymer generated from different resources through several operations can meet most of the annual synthetic plastics demand at least in Europe. The advancement of sustainable technologies for the effective utilization of sustainable materials for bioplastic and biomaterials production can afford a novel biorenewable source of sustainable products and biofuel as well as address the rising environmental concerns. Poly(butylene succinate) is one biopolymer that has enormous potential to be used in a wide range of applications. There is currently no extensive review on the PBS based polymer covering the advanced technologies for the development of high-value material. This article covers the advanced state of synthesis, process integrating biological and thermochemical conversion to produce bioplastics (PBS), physico-chemical and mechanical properties, and the recent applications. We have also provided a structural perspective on how PBS can be adopted via appropriate engineering/ modification to its properties. Different changes in the precursors of polymer materials and composites enable a various range of applications, including but not limited to the manufacturing of high-performance polymer materials to composites.

Biobased composites from agro-industrial wastes and by-products.

The greater awareness of non-renewable natural resources preservation needs has led to the development of more ecological high-performance polymeric materials with new functionalities. In this regard, biobased composites are considered interesting options, especially those obtained from agro-industrial wastes and by-products. These are low-cost raw materials derived from renewable sources, which are mostly biodegradable and would otherwise typically be discarded. In this review, recent and innovative academic studies on composites obtained from biopolymers, natural fillers and active agents, as well as green-synthesized nanoparticles are presented. An in-depth discussion of biobased composites structures, properties, manufacture, and life-cycle assessment (LCA) is provided along with a wide up-to-date overview of the most recent works in the field with appropriate references. Potential uses of biobased composites from agri-food residues such as active and intelligent food packaging, agricultural inputs, tissue engineering, among others are described, considering that the specific characteristics of these materials should match the proposed application.

Simulations on polymer nanocomposite crystallization

Polymer nanocomposites are widely used in industry due to their excellent mechanical properties. Polymer crystallization in polymer nanocomposites can effectively enhance the interfacial interactions between polymer matrix and nanofillers, thereby providing new ideas for preparing high-performance polymer materials. In recent years, molecular simulation has gradually become a powerful research tool for the investigation of polymer materials and physics. In this article, the latest simulation research progress on the crystallization behaviors of polymer nanocomposites under different conditions is reviewed, and the influences of various factors on the crystallization behaviors of homopolymers, copolymers, and oriented polymers filled with nanofillers, as well as polymers grafted on nanofillers are summarized and discussed. It is highly expected that the current review can supply some new insights into the development and design of new nanohybrid structures and then the control of the physical properties of polymer nanocomposites.

Microbial production of megadalton titin yields fibers with advantageous mechanical properties

Manmade high-performance polymers are typically non-biodegradable and derived from petroleum feedstock through energy intensive processes involving toxic solvents and byproducts. While engineered microbes have been used for renewable production of many small molecules, direct microbial synthesis of high-performance polymeric materials remains a major challenge. Here we engineer microbial production of megadalton muscle titin polymers yielding high-performance fibers that not only recapture highly desirable properties of natural titin (i.e., high damping capacity and mechanical recovery) but also exhibit high strength, toughness, and damping energy — outperforming many synthetic and natural polymers. Structural analyses and molecular modeling suggest these properties derive from unique inter-chain crystallization of folded immunoglobulin-like domains that resists inter-chain slippage while permitting intra-chain unfolding. These fibers have potential applications in areas from biomedicine to textiles, and the developed approach, coupled with the structure-function insights, promises to accelerate further innovation in microbial production of high-performance materials.

Retentive Forces of Removable Partial Denture Clasp Assemblies Made from Polyaryletherketone and Cobalt-Chromium: A Comparative Study.

To compare retentive forces of removable partial denture clasps traditionally fabricated with cobalt-chromium (CoCr) material and two computer-aided design and computer-aided manufactured (CAD/CAM) thermoplastic polymers. Forty-eight clasp assemblies (16 CoCr, 16 polyetheretherketone (PEEK) and 16 polyetherketoneketone (PEKK) thermoplastic polymer) were fabricated for 48 mandibular tooth analogs. Individual clasps were inserted and removed on the tooth analogs utilizing a chewing simulator for 15,000 cycles to simulate 10 years of use. Retentive forces were measured utilizing a mechanical load tester at baseline and intervals of 1500 cycles. Data were analyzed with one-way Analysis of Variance, Tukey post-hoc, and paired T tests. Mean retentive forces between all groups were significantly different (p < 0.001). Retentive forces of CoCr clasps were significantly higher than both polymers (p < 0.001). The mean retentive forces for PEEK were not significantly different from PEKK (p = 0.23). A significant increase in retentive forces was observed for all three clasps after the first period of cycling, followed by continual decrease for the remaining cycles. At the endpoint of 15,000 cycles, no clasp assemblies showed lower retentive forces than at initial baseline. Thermoplastic polymer clasps demonstrated lower retentive forces compared to CoCr clasps. All three groups displayed a similar pattern of initial increase, followed by a gradual decrease, of retentive force. Despite this observation, the clasps maintained similar or higher retentive forces than measured at baseline. This resistance to fatigue and ability to fabricate with CAD/CAM technologies provides support for clinical use of these high-performance polymer (HPP) materials.

A comparative study of mechanical and machining performance of polymer hybrid and carbon fiber epoxy composite materials

Fiber-reinforced plastics are known as advanced composite materials thanks to their high strength and lightweight features. Carbon fiber reinforced polymers (CFRPs) are one of the high-performance and high-cost fiber-reinforced polymer (FRPs) materials. They are used in several high-performance engineering applications such as motorsports, marine, aviation, energy and defense industry. The cost of carbon fiber is higher compared to many other materials, more competitive and cost-effective productions will spur the demand for composite parts exponentially. Thus, hybrid laminate composite containing carbon and glass fiber materials were manufactured as an alternative for CFRP materials. Because using glass fiber prepreg instead of carbon fiber prepreg will lead the material to become cheaper. However, machining of the FRP materials is still an important issue. For this reason, the present study is focused on the mechanical and machining performance of the polymer hybrid and carbon fiber epoxy composites.

Recent Progress of High Performance Thermosets Based on Norbornene Functional Benzoxazine Resins

With the growing demand for high performance polymeric materials in industry, several types of thermosets such as bismaleimides, advanced epoxy resins, cyanate esters, and phenolic resins have been widely investigated to improve the performance of thermosetting products. Among them, benzoxazine resins have received wide attention due to their extraordinarily rich molecular design flexibility, which can customize our needs and adapt increasing requirements. To further improve the properties of polybenzoxiazines, researchers have found that the introduction of a norbornene functional group into the benzoxazine moiety can effectively improve the comprehensive performance of polybenzoxazine thermosets. This article focused on reviewing the recent development of high-performance thermosets based on norbornene functional benzoxazine thermosetting resins.

High-performance polymers adapted to facile melt processing through structure design of benzocyclobutene-containing precursors

High-performance polymeric materials with good processability and enhanced performance (higher thermal stability and mechanical strength, higher glass transition temperature (Tg) and lowered thermal expansion) have long been explored by scientists and engineers. The present study demonstrated a new way to fabricate high-performance polymers, such as polyarylamide (traditional polyarylamides can’t be processed by melt processing due to the lack of viscous flow temperature before thermal decomposition), with excellent processability via a facile two-step process, i.e. low-temperature melt processing and a subsequent in-situ thermal curing. Through designing the structure of the BCB-containing precursors, we can well control the melting point and curing temperature, thus adjust the melt processing temperature and curing temperature of the polymers. In our experiments, the temperature difference between precursor melting point and polymerization temperature can be over 200 °C, providing wide processing window and long storage lifetime. Besides, these precursors also possess excellent solubility in organic solvents, which endow them with the possibility of solution or melt processing, as illustrated by the representative precursor, DODA-BCB. The obtained polymer resin films show good thermal stability (Td,5% > 410 °C), high glass transition temperatures (Tg > 240 °C) and good mechanical strength (storage modulus > 1.8 GPa). Further studies on the thermal expansion behavior of the films reveal the thermal contracting feature of p-3,4′-ODA-BCB, the mechanism has been discussed in detail using DFT calculations, VT-FTIR and TMA.

Synergy between Photoluminescence and Charge Transport Achieved by Finely Tuning Polymeric Backbones for Efficient Light-Emitting Transistor.

The lack of design principle for developing high-performance polymer materials displaying strong fluorescence and high ambipolar charge mobilities limited their performance in organic light-emitting transistors (OLETs), electrically pumped organic laser, and other advanced electronic devices. A series of semiladder polymers by copolymerization of weak acceptors (TPTQ or TPTI) and weak donors (fluorene (F) or carbazole (C)) have been developed for luminescent and charge transporting properties. It was found that enhanced planarity, high crystallinity, and a delicate balance in interchain aggregation obtained in the new copolymer, TPTQ-F, contributed to high ambipolar charge mobilities and photoluminescent quantum yield. TPTQ-F showed excellent performance in solution-processed multilayered OLET devices with an external quantum efficiency (EQE) of 5.3%.

Type and Size Selectivity of Single-Walled Carbon Nanotubes by Phenylethynyl Terminated Imide Oligomers

Aromatic polyimides are well-known as high-performance polymer materials which have excellent properties such as high thermal stability, strong mechanical strength, and superior chemical resistance. However, rigid backbones of oligomers and strong chain interactions result in lower processibility. Our molecular modeling suggests that the enhancement of nanotube solubilization is attributed to the formation of self-assembled intermolecular structures associated with the inclusion of curing agents, in conformity with experimental findings. On the other hand, isolation of single-walled carbon nanotubes (SWNTs) with specific chirality and diameter is critical for achieving optimum performances of SWNTs in various application. Our studies reveal that phenylethynyl terminated imide (PETi) oligomer selectively enriches metallic and semiconducting (6, 5) SWNT.

3D Cationic Polymeric Network Nanotrap for Efficient Collection of Perrhenate Anion from Wastewater.

Rhenium is one of the most valuable elements found in nature, and its capture and recycle are highly desirable for resource recovery. However, the effective and efficient collection of this material from industrial waste remains quite challenging. Herein, a tetraphenylmethane-based cationic polymeric network (CPN-tpm) nanotrap is designed, synthesized, and evaluated for ReO4- recovery. 3D building units are used to construct imidazolium salt-based polymers with positive charges, which yields a record maximum uptake capacity of 1133mg g-1 for ReO4- collection as well as fast kinetics ReO4- uptake. The sorption equilibrium is reached within 20min and a kd value of 8.5 × 105 mL g-1 is obtained. The sorption capacity of CPN-tpm remains stable over a wide range of pH values and the removal efficiency exceeds 60% for pH levels below 2. Moreover, CPN-tpm exhibits good recyclability for at least five cycles of the sorption-desorption process. This work provides a new route for constructing a kind of new high-performance polymeric material for rhenium recovery and rhenium-contained industrial wastewater treatment.

Effect of surface treatment and manufacturing process on the shear bond strength of veneering composite resin to polyetherketoneketone (PEKK) and polyetheretherketone (PEEK)

Statement of problemPolyaryletherketones (PAEKs) are high-performance polymer materials in which polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) are the most used. Although mechanical and shear bonding strength tests have been performed on the 2 materials, studies on the influence of processing on bonding are scarce. PurposeThe purpose of this in vitro study was to determine the influence of the surface treatment and the manufacturing process on the shear bond strength of veneering composite resin to PEKK and PEEK. Material and methodsThirty pressed PEKK, 30 milled PEKK, and 30 milled PEEK specimens were distributed in 6 groups (n=13) as per the manufacturing process and treatment surface. The specimens were either treated with airborne-particle abrasion with 110-μm aluminum oxide, or no surface treatment was applied. Moreover, the PEKK specimens were grouped regarding their manufacturing process, as either milled or heat-pressed. The specimens were all bonded by using a methyl methacrylate–based adhesive (visio.link), and composite resin (Gradia Revolution 2) was bonded to the specimens. An Instron universal machine was used to calculate the shear bond strength between the PEEK or PEKK and the composite resin. Two specimens from each group had their topography modification assessed with a scanning electron microscope. Statistical analysis was performed by using a 3-way ANOVA for multiple comparisons (α=0.05) ResultsThe groups that were surface treated with 110-μm aluminum oxide (Al2O3) before bonding showed significantly higher shear bond strength (P=.001) than the other groups. However, no statistically significant difference was observed among the groups, regardless of the manufacturing process (milled or heat-pressed) (P=.607). ConclusionsPEEK and PEKK surfaces treated with 110-μm aluminum oxide airborne-particle abrasion displayed better shear bond strength to composite resin. The manufacturing process (milled or heat-pressed) did not significantly affect the bond strength of PEKK when subjected to the same bonding process.

The Influence of Pressure-Induced-Flow Processing on the Morphology, Thermal and Mechanical Properties of Polypropylene Blends

The pressure-induced-flow (PIF) processing can effectively prepare high-performance polymer materials. This paper studies the influence of pressure-induced-flow processing on the morphology, thermodynamic and mechanical properties of polypropylene (PP)/polyamide 6 (PA6) blends, PP/polyolefin elastomer (POE) blends and PP/thermoplastic urethane (TPU) blends. The results show that pressure-induced-flow processing can significantly improve the thermodynamic and mechanical properties of the blends by regulating internal structure. Research shows that the pressure-induced-flow processing can increase the strength and the toughness of the blends, particularly in PP/TPU blends.