Melt Spinning Research Articles

Washing Resistant Antibacterial PET Composite Fibers Fabricated by Melt Spinning

Washing Resistant Antibacterial PET Composite Fibers Fabricated by Melt Spinning

Microstructural optimization of lignin‐based carbon fiber: Effects of purification and high‐temperature heat treatment

AbstractLignin is a renewable biomass polymer with a carbon content of more than 60% and has been extensively studied for making lignin‐based carbon fibers (CFs). However, impurities and high carbohydrate content in lignin materials severely limit their molding in melt spinning, and pre‐oxidation and carbonization processes also affect the subsequent preparation of CFs. This paper presents a detailed study of lignin‐based carbon fiber preparation. Pretreatment increased lignin's decomposition temperature to 302.1°C and enabled melt‐spun fiber preparation. Then, pre‐oxidation and carbonization of lignin fibers were further discussed. The pre‐oxidized fibers prepared at 280°C and 0.4°C min−1 have high thermal stability and excellent carbonization performance. The lignin‐based carbon fibers (LCFs) prepared at 1100°C and 3°C min−1 have the highest degree of graphitization, and the surface is smooth without obvious holes. Under these conditions, LCFs have a graphitization degree of 1.50 and conductivity of 62.50 S cm−1, making them suitable for sensors and capacitors.Highlights Effects of pretreatment on lignin structure and properties have been studied. Effects of pre‐oxidation and carbonization on the lignin fibers were studied. Lignin‐based carbon fibers with high conductivity were obtained.

Optimization of Planar Flow Melt Spinning Process for Producing Thin, Wide, and Continuous Amorphous Ribbons of Fe73.5Si13.5B9Nb3Cu1 Alloys

Optimization of Planar Flow Melt Spinning Process for Producing Thin, Wide, and Continuous Amorphous Ribbons of Fe73.5Si13.5B9Nb3Cu1 Alloys

Investigation of the degradation behaviour of poly-L-lactic acid braided stents under real-time and accelerated conditions

Degradation tests are a key step in the development of a bioresorbable stent. The present study focused on the degradation of bioresorbable stents made from PLLA filaments, and examined the variation of the physical, thermal, and mechanical properties of the material and the devices under both real-time and accelerated degradation conditions. Results showed that the undegraded filaments were highly crystalline and composed by both α and α′ crystalline phases, induced by both the melt spinning and heat treatment processes. The latter was shown to have an important influence on the further formation of α crystalline phase and therefore crystalline structure perfectioning. Real-time degradation tests showed that the devices maintained structural stability for up to a year, meeting the required 6-month degradation period for vascular stents. Degradation was shown to primarily affect the crystalline regions, and to cause a gradual loss of material ductility before any mass loss or decrease in crystallinity. In turn, a constant decrease of molecular weight was observed, with stent failure occurring around day 389 due to a drop in molecular weight below 10,000 g/mol. Accelerated degradation tests mirrored real-time results until mass loss began. Subsequently a slower molecular weight decrease was observed, with an increase and subsequent decrease of material crystallinity. The consistency of the data obtained between real-time and accelerated degradation before mass loss confirmed the possibility to gain insights into real-time degradation through an accelerated protocol. However, attention must be paid to the initial molecular weight of the material, which has been shown to highly influence the acceleration rate. This study provides a wide range of experimental data both on the real-time and thermally accelerated degradation behaviour of PLLA braided stents that can be used as benchmark for further studies in the field.

Structural and magnetic properties of rapidly solidified and Bi-bonded hot compacted Mn[formula omitted]Al45C1.7Ti[formula omitted] magnets

This study examines the impact of Ti doping on the phase formation and magnetic properties of Mn-Al-C alloys. Using melt spinning, we synthesized Mn53.3−xAl45C1.7Tix alloys (x values ranging from 0 to 1.5) producing high purity ϵ-phase ribbons. The optimal annealing treatment for the formation of ferromagnetic τ-phase is 20 min at 550 °C for all compositions. However, Ti-doped samples showed the formation of β-phase due to partial phase decomposition, and TiC precipitates were present at high Ti concentrations. Upon doping, the Curie temperature was increased from 557K (Ti free sample) to 600K. To improve the coercivity, a combination of ball milling and hot compaction, introducing Bi as a metallic binder, have resulted in increased coercivity from 0.18 T to 0.33 T. Bi addition lead to formation of a grain boundary phase aiding densification. We demonstrate how modifying composition and processing can improve the magnetic properties of Mn-Al based magnets.

Rheological, Structural and Melt Spinnability Study on Thermo-plastic Starch/PLA Blend Biopolymers and Tensile, Thermal and Structural Characteristics of Melt Spun Fibers

Rheological, Structural and Melt Spinnability Study on Thermo-plastic Starch/PLA Blend Biopolymers and Tensile, Thermal and Structural Characteristics of Melt Spun Fibers

Reducing the annealing heating rate sensitivity of Fe83.5Si3B10P2Cu1.5 soft magnetic nanocrystalline alloy by adjusting the melt spinning cooling rate

Reducing the annealing heating rate sensitivity of Fe83.5Si3B10P2Cu1.5 soft magnetic nanocrystalline alloy by adjusting the melt spinning cooling rate

Main-Chain Azobenzene Poly(ether ester) Multiblock Copolymers for Strong and Tough Light-Driven Actuators.

The stimulus-responsive polymeric materials have attracted great research interest, especially those remotely manipulated materials with potential applications in actuators and soft robotics. Here we report a photoresponsive main-chain actuator based on azobenzene poly(ether ester) multiblock copolymer (mBCP) thermoplastic elastomers, (PTAD-b-PTMO-b-PTAD)n, which were synthesized by a cascade polycondensation-coupling ring-opening polymerization method using poly(tetramethylene oxide) (PTMO) and azobenzene-containing cyclic oligoesters (COTADs) as monomers. The thermal, mechanical, and microphase separation behaviors of mBCPs could be flexibly tuned by altering the ratios of soft-to-hard segments and block number (n). The oriented azobenzene mBCP fibers were prepared by melt spinning, showing reversible photoresponsive properties with remarkably high strength (∼1000 MPa) and high elongation at break comparable to spider silks. Fast photoinduced bending and contraction were successfully achieved in these fibers with high work and power densities and energy conversion efficiency, enabling it to lift up about 250 times of its own weight. Moreover, it can take out materials inside the tube by UV-light control. These fibers could be applied in light-driven actuators or telecontrolled robot arms.

Tunning Pr to achieve ultra-high magnetic properties of anisotropic nanocrystalline (Sm,Pr)Co5 magnets

In this study, we reported on the bulk anisotropic nanocrystalline Sm1-xPrxCo5 (x = 0.2–0.6) magnets aimed at achieving excellent energy products. Through a combination of advanced processing techniques, including melt spinning, hot pressing, and hot deformation process, bulk magnets with a fine nanocrystalline structure were successfully synthesized. The results revealed that the substitution of Pr strengthened the c-axis texture and the saturation magnetization, facilitating the enhancement of remanence (Mr) and maximum magnetic energy product [(BH)max]. However, Pr substitution decreased the coercivity (Hci) due to the reduced magnetocrystalline anisotropy field. Excellent magnetic properties are obtained for Sm0.4Pr0.6Co5 magnets with the (BH)max of 23.2 MGOe and Hci of 11.8 kOe. The prepared (Sm,Pr)Co5 magnets with different Pr contents have essentially the same microstructure with RECo5 main phase grains of about 400 nm in diameter and fine dispersed rare earth-rich nanoprecipitates. Our findings can provide reliable reference for manufacturing nanocrystalline permanent magnet materials and promote the development of rare earth permanent magnet new materials.

Enhancing phase change fiber composites with double shell capsules: Magnetic response and photothermal conversion studies

Phase change fibers (PCFs) with temperature-regulating ability have received more and more attention due to their great potential in various advanced applications. However, the preparation of PCFs by electrospinning or wet spinning will release a lot of organic solvents, and it is difficult to solve the leakage problems during thermal cycling and single functionality. Herein, we propose an environmentally friendly and efficient melt spinning strategy to prepare multifunctional magnetic PCFs (MPCFs). Initially, a double shell composed by SiO2–Fe3O4 was constructed of Si–O–Si bond, which not only endowed the prepared phase change capsules with sensitive magnetic responsiveness (18.22 emu/g), but also improved their thermal stability (∼20.0 °C), thus it can be applied in melt spinning. Then the MPCFs prepared by melt spinning exhibited a range of desirable properties inherited from the phase change capsules, including pronounced thermal regulation (Hm = 23.8 J/g), which is higher than most of the PCFs based on phase change capsules. As well as good cycle stability (120 times), sensitive magnetic responsiveness (Ms = 2.68 emu/g), and efficient photothermal conversion ability (66.1 %). Therefore, this study sheds new insight into the preparation of multifunction MPCFs by melting spinning.

Synthesis and characterization of new continuous phosphate glass fibers intended for structural engineering applications: Structure/property relationships

Nowadays, phosphate glass fibers (PGF) are considered quite competitive respective to conventional glass fibers. This work focus on the development of PGF fibers intended for structural engineering applications such as composite reinforcement for building and automotive fields. For this purpose, two series of phosphate glasses based on 52P2O5-24CaO-13MgO-(11-(X+Y+Z)) K2O-XAL2O3-YF2O3-ZTiO2; (X=1; 3; 5, Y=0; 5, Z=0; 1 mol %) were processed and transformed into phosphate glass fibers by melt spinning. The resulting fibers were characterized. XRD analysis confirmed the non-crystalline nature of phosphate glasses. In addition, the substitution of K2O by Al2O3 and by the combination of Al2O3, Fe2O3 and TiO2 in the composition of phosphate glass could lead to a significant increase in fiber density from 2,16 g/cm3 to 2,80 g/cm3. The stability of the produced phosphate glass fibers was examined using two methods: weight loss at 37°C and dissolution kinetics under different pH levels (4, 7, and 12). The results showed that the chemical resistance of the PGF fibers was improved with up to 99% increase respective to the original formulation. In addition, the mechanical properties of the spinnable phosphate glass manufactured by replacing K2O oxide by Al2O3 oxide were improved, such a substitution led to a maximum tensile strength and modulus of 2668 MPa and 140 GPa, respectively. Therefore, the tensile proprieties were improved by 75% compared to the original formulation. This comparative study between phosphate glass fibers (PGF) and traditional fibers highlight similar tensile strength but combined to notable enhancements in chemical stability through cation addition, expanding their potential use in composite and biomedical materials. Finally, a correlation analysis of mechanical performances was carried out. It was observed that the results obtained using the statistical methods were consistent with the experimental data.

Revisiting Rare Earth Permanent Magnetic Alloys of Nd-Fe-C

Nd-Fe-C alloys have been reported as hard magnetic materials with a potential higher coercivity than Nd-Fe-B alloys. However, it has been seldom studied since its intrinsic properties were investigated in the last century. Here, we revisited the structure, phase precipitation and magnetic properties of rapidly quenched ternary Nd-Fe-C alloys for further understanding their composition-microstructure-property relationships. The Nd10+xFe84−xC6 (x = −2, 0, 2, 3, 4, 5) alloys with various compositions were prepared by melt spinning. The results show that the hard magnetic Nd2Fe14C phase can be hardly formed in the as-spun alloys. Instead, the alloys are composed of soft magnetic α-Fe phase and planar anisotropic Nd2Fe17Cx phase. After annealing above 650 °C, the Nd2Fe14C phase is precipitated by the peritectoid reaction. All optimally annealed alloys contain Nd2Fe14C and Nd2Fe17Cx phases, while the presence and content of α-Fe phase are determined by the alloy composition. The crystallization degree of the as-spun alloys has an effect on their magnetic properties after annealing. After the annealing treatment, partly crystallized as-spun alloys exhibit better magnetic properties than the amorphous alloys. The intrinsic coercivity Hcj = 847 kA/m, remanence Jr = 0.69 T, and maximum energy product (BH)max = 64.3 kJ/m3 were obtained in the Nd14Fe80C6 alloy annealed at 725 °C. The formation of the Nd2Fe14C and Nd2Fe17Cx phases with the Nd2O3 phase precipitated at the triangular grain boundaries is responsible for its relatively good properties. Although the magnetic properties of Nd-Fe-C alloys obtained in this work are inferior to those of Nd-Fe-B, the present results help us to further understand the magnetic behavior of Nd-Fe-C alloys.

Continuous fibers featuring high phase change enthalpy fabricated by melt spinning for thermal management

High performance continuous phase change fibers are of great significance to promote the development and application of functional fibers. But, it is still a challenge to fabricate continuous phase change fibers with high phase transition enthalpy. Herein, a kind of continuous polyurethane phase change fibers (PUPCFs) was first reported which was prepared through melt spinning from the synthesized polyurethane phase change materials (PUPCMs). PUPCFs not only overcomes the leakage problem of phase change materials, but also exhibits high latent heat (110.54 J/g), superior mechanical properties (maximum strain, ∼141.83 %), outstanding fatigue resistance, and good thermal cycle stability. Furthermore, a phase change thermoregulation textile (PUPCT/PDMS) with high enthalpy, hydrophobicity and breathability can be obtained by weaving PUPCFs and then coating with polydimethylsiloxane (PDMS). This work can provide a new idea for efficient and economical production of continuous phase change fibers and opens up opportunities for wearable thermal management textiles.

Ultrafine-grained Al-La-Mg-Mn alloy fabricated by melt spinning and hot extrusion with ultrahigh strength and thermal stability

To enhance the mechanical properties of Al–(La, Ce) alloys, melt spinning and hot extrusion were employed to fabricate Al-La-Mg-Mn alloy with an ultrafine-grained structure (∼0.56 μm). The as-extruded alloy exhibits the highest tensile strength of 621 ± 4 MPa among Al–(La, Ce) alloys fabricated by various methods while retaining an appreciable elongation of 6.8 ± 1.1 %. The high strength is mainly ascribed to the ultrafine grains and high-volume intermetallics, conferring robust grain boundary strengthening and Orowan strengthening effects. Additionally, this study delved into the high-temperature (400°C) coarsening behavior of the intermetallic and grain size. The findings unveil an exceptionally low coarsening rate of the intermetallic at 400°C (3.19×10−33 m4 s−1), accompanied by only slight grain coarsening, underscoring the remarkable thermal stability of the ultrafine-grained structure.

Formation, thermal stability and soft magnetic properties of Fe-Co-B-Si amorphous alloys with ultrahigh saturation magnetic induction of 2.0 T

This paper studies the influence of metallic element composition on the formation ability, thermal stability and magnetic properties of melt-spun (Fe1-xCox)B15–19Si1 (x =0.2–0.4) amorphous alloy ribbons. The maximum metal concentration at which an amorphous phase is formed during melt spinning has been determined in conjunction with the metal content dependence of crystallization processes and crystallized phases. The amorphous (Fe0.8Co0.2)84B15Si1 alloy with the highest metal content in an optimally annealed state exhibits an extremely high saturation induction (MS) of 2.0 T, low coercive force of 7.6 A m−1, high effective permeability of 13500 at 1 kHz and low core losses of 5.5 W kg−1 at 100 mT and 19.7 W kg−1 at 200 mT at 10 kHz which have not been simultaneously obtained for all kinds of soft magnetic materials up to date. The replacement of Fe with Co significantly increases the Curie temperature of the amorphous phase, resulting in very high thermal stability of the high MS alloys. The combination of excellent soft magnetic properties with ultrahigh MS value makes them candidates for use in highly loaded high-speed electric motors capable of operating at temperatures up to 473 K.

Preparation of SiO2-IR3535 mosquito repellent nanocapsules and its performance study

The exploration of functional textiles signifies an inexorable path in the future advancement of the textile industry. In this study, sol-gel method was employed to encapsulate IR3535, a mosquito repellent substance, into silica nanocapsules, resulting in the production of silica-ethyl butylacetylaminopropionate (SiO2-IR3535) mosquito repellent nanocapsules with effective mosquito repellency. By manipulating factors such as surfactant dosage, ammonia dosage, wall-to-core ratio, alcohol-to-water ratio, rotational speed, reaction time, and reaction temperature, during the preparation process, the particle size was cpntrolled and optimal conditions for subsequent spining processes was obtained. The prepared SiO2-IR3535 mosquito-repellent nanocapsules exhibited uniform appearance and morphology with consistent size distribution (average particle size: 342 nm). In addition, these nanocapsules exhibited enhanced heat resistance and an oil loading rate of about 13 % as confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), infrared spectroscopy (FTIR), Raman spectroscopic simultaneous thermal analysis (STA), and elemental analyses, and kinetic modeling was performed to fit the release profiles of these capsules. Additionally, SiO2-IR3535 nanocapsules were added into polypropylene fiber by melt spinning method, the prepared polypropylene fiber has been uniformly dispersed both internally and externally within the fiber, thereby it can provide a sustained mosquito-repellent effect to the polypropylene fiber with SiO2-IR3535 nanocapsules.

Synthesis and Characterization of Metallic (Fe‐Ni, Fe‐Ni‐Si) Reference Materials for SIMS 34S/32S Measurements

Secondary ion mass spectrometry (SIMS) is often used to determine the sulfur contents and isotope ratios of metallic alloys in meteorites or high‐pressure experimental samples. However, SIMS analyses involve calibration and the determination of instrumental mass fractionation in reference materials with a matrix composition similar to that of the unknown samples. To provide metallic reference materials adapted to S measurements via SIMS, we synthesised a series of twenty‐eight alloys comprising four FeNi(±Si) compositions (Fe95Ni5, Fe90Ni10, Fe80Ni20, and Fe80Ni15Si5) with S contents varying from 100 μg g−1 to 4 g/100g using the “melt spinning” method, which guarantees that the metal alloys are rapidly quenched at ~ 106 K s−1. Sulfur contents were determined at the Service d'Analyse des Roches et Minéraux at the CRPG and absolute δ34S values were determined by multi‐collector ICP‐MS (MC‐ICP‐MS, ThermoScientific Neptune) and isotope ratio mass spectrometry (Thermoscientific Delta V). A δ34S value of 16.01 ± 0.31‰ was consistently obtained using the MC‐ICP‐MS, which was indistinguishable of the δ34S value of the FeS starting material (15.95 ± 0.08‰). It suggests that S did not undergo isotopic fractionation during the melting process. Of fifteen samples containing ≤ 5000 μg g−1 S, SIMS measurements with 15‐μm‐diameter spots were repeatable to within 10% relative (1 standard deviation, 1s) for S contents and 2‰ for δ34S values. However, samples containing > 5000 μg g−1 S showed FeNi–FeS immiscibility, leading to minor dispersion of the S mass fractions and δ34S values. No matrix effect was observed for Fe‐Ni, Si, or S contents in terms of the calibration curves and instrumental mass fractionation. We ultimately recommend eight samples as reliable reference materials for S isotopic measurements by SIMS, which we can share worldwide with other laboratories.

Unconventionally Large Exchange Bias and Cluster Spin Glass State in Mn2(Ni,Sn) Heusler Alloys Melt Spun Ribbons

Unconventionally Large Exchange Bias and Cluster Spin Glass State in Mn₂(Ni,Sn) Heusler Alloys Melt Spun Ribbons

Numerical Study of Melt-Spinning Dynamic Parameters and Microstructure Development with Ongoing Crystallization.

In response to an investigation on the paths of changes in the crystallization and radial differences during the forming process of nascent fibers, in this study, we conducted numerical simulation and analyzed the changes in crystallization mechanical parameters and tensile properties through a fluid dynamics two-phase model. The model was based on the melt-spinning method focusing on melt spinning, the environment of POLYFLOW, and the method of joint simulation, coupled with Nakamura crystallization kinetics, including the development of process collaborative parameters, stretch-induced crystallization, viscoelasticity, filament cooling, gravity term, inertia, and air resistance. Finally, for nylon 6 BHS and CN9987 resin spinning, the model successfully predicted the distribution changes in temperature, velocity, strain rate tensor, birefringence, and stress tensor along the axial and radial fibers and obtained the variation pattern of fibers' crystallinity along the entire spinning process under different stretching rates. Furthermore, we also explored the effects of spinning conditions, including inlet flow rate, winding speeds, and the extrusion temperature, on the fibers' crystallization process and obtained the influence rules of different spinning conditions on fiber crystallization. Knowing the paths of changes in mechanical performance can provide important guidance and optimization strategies for the future industrial preparation of high-performance fibers.

Toward durable polylactic acid/poly(methyl methacrylate) polyblend fibers with high performance

AbstractPolylactic acid/poly(methyl methacrylate) (PLA/PMMA) composite fibers with high performance were fabricated using melt spinning technique. The crystallization, lamellae orientation and physical properties of composite fibers were investigated systematically. The addition of PMMA (0–20 wt%) has improved the hydrolysis resistance of composite fibers by preventing water molecules from penetrating and diffusing through the fibers, but the strength and heat resistance were reduced at the same time. The stereocomplex crystallites (SC) formed before spinning by introducing poly(D‐lactide) (PDLA) (3 wt%) in poly(L‐lactide) (PLLA) matrix and acted as nucleating agents to enhanced the crystallization and lamellae orientation of PLLA matrix, which improved the physical properties of PLA composite fibers resultful. The tensile strength of PLA fibers with 3 wt% PDLA and 5 wt% PMMA was increased 31% as well as the boiling water shrinkage and the hydrolysis rate were decreased 30% and 33% in relation to PLLA fibers. Finally, the hydrolysis resistance was further enhanced on the basis of realizing high strength and heat resistance, which is of great significance for preparing durable PLA fiber materials and expanding their application.