Fast Crystallization Kinetics Research Articles

Controlling Crystallization: A Key Factor during 3D Printing with the Advanced Semicrystalline Polymeric Materials PEEK, PEKK 6002, and PEKK 7002

AbstractControlling the crystallization of advanced, high‐performance polymeric materials during 3D printing is critical to ensure that the resulting structures have appropriate mechanical properties. In this work, two grades of polyetherketoneketone (PEKK 6002 and PEKK 7002) are used to print 3D specimens via a fused filament fabrication process. The samples are compared with polyetheretherketone printed under the same conditions. Two approaches for controlling the crystallization process are undertaken. The first involves adjustment of the chamber temperature between room temperature and 190 °C to create two regions where crystallization is governed by the slow diffusion process and elevated by limiting the nucleation process. The second approach involves selection of PEKK materials with varying crystallization kinetics, namely. Application of this method into 3D‐printing process allows for printing semicrystalline materials with tailored mechanical, thermal, and chemical properties as either amorphous or in situ crystallized products. The studies undertaken here provide the basis to eliminate expensive and time‐consuming post‐processing of 3D fabricated parts. In particular, solutions for the avoidance of poor adhesion to the building plate and weak interlayer adhesion that can lead to warping are described. The materials are divided into three groups, slow, moderate, and too fast crystallization kinetics.

Facile one-pot synthesis of Fe-UZM-35 catalysts for ammonia selective catalytic reduction

Owing to the narrow crystallization field, the synthesis of the large-pore zeolite UZM-35 with MSE topology starting from amorphous reagents in the presence of dimethyldipropylammonium ions as an organic structure-directing agent is often non-reproducible. Here we report the synthesis of UZM-35 via an interzeolite conversion route using USY zeolites, as the sole source of Al and Si, and a small amount of previously synthesized UZM-35 as seed crystals. We also present the one-pot synthesis of Fe-UZM-35 with the best low-temperature NH3-SCR activity among the iron-exchanged zeolites reported so far. These synthesis routes showed high reproducibility, together with considerably faster crystallization kinetics (≤1.5 vs 7 days) compared to conventional UZM-35 synthesis. When the Fe loading level was properly adjusted, the NH3-SCR activity of one-pot-synthesized Fe-UZM-35 was found to be essentially the same as that of post-synthetically exchanged Fe-UZM-35 due to the similarity in the nature of their iron active sites.

Tailoring the Hydroxyl Density of Glass Surface for Anionic Ring-Opening Polymerization of Polyamide 6 to Manufacture Thermoplastic Composites.

Reactive thermoplastics matrices offer ease of processing using well-known molding techniques (such as Resin Transfer Molding) due to their initially low viscosity. For Polyamide 6 (PA6)/glass composites, the hydroxyl groups on the glass surface slow down the anionic ring-opening polymerization (AROP) reaction, and can ultimately inhibit it. This work aims to thoroughly control the hydroxyl groups and the surface chemistry of glass particulates to facilitate in situ AROP-an aspect that has been barely explored until now. A model system composed of a PA6 matrix synthesized by AROP is reinforced with calcinated and silanized glass microparticles. We systematically quantify, by TGA and FTIR, the complete particle surface modification sequence, from the dehydration, dehydroxylation and rehydroxylation processes, to the silanization step. Finally, the impact of the particle surface chemistry on the polymerization and crystallization of the PA6/glass composites was quantified by DSC. The results confirm that a careful balance is required between the dehydroxylation process, the simultaneous rehydroxylation and silane grafting, and the residual hydroxyl groups, in order to maintain fast polymerization and crystallization kinetics and to prevent reaction inhibition. Specifically, a hydroxyl concentration above 0.2 mmol OH·g−1 leads to a slowdown of the PA6 polymerization reaction. This reaction can be completely inhibited when the hydroxyl concentration reaches 0.77 mmol OH·g−1 as in the case of fully rehydroxylated particles or pristine raw particles. Furthermore, both the rehydroxylation and silanization processes can be realized simultaneously without any negative impact on the polymerization. This can be achieved with a silanization time of 2 h under the treatment conditions of the study. In this case, the silane agent gradually replaces the regenerated hydroxyls. This work provides a roadmap for the preparation of reinforced reactive thermoplastic materials.

Effect of particle size distribution on crystallization behavior of glass‐based seals in reversible solid oxide cells

AbstractReversible solid oxide cell (RSOC), integrating solid oxide fuel cell and solid oxide electrolysis cell, usually utilizes a glass material as seals. The particle size distribution of glass has a significant influence on crystallization and sintering behavior in the sealing process during RSOC operation. In this work, the effects of particle size on the non‐isothermal crystallization kinetics of BaO–ZnO–MgO–B2O3–SiO2 glass in RSOC are conducted. The crystallization behavior of glass is experimentally investigated and theoretically analyzed using Kissinger, Augis–Bennett, and Ozawa models. The values of crystallization activation energies are 164.4, 188.4, and 223.2 kJ/mol for 50, 150, and 300 μm (average particle sizes of S1, S2, and S3 glasses, respectively). The Avrami parameter (n) and dimensionality (m) of S1 glass are 0.6 and 0.7, similarly those of S2 glass were 0.9 and 0.7, corresponding to surface crystallization. However, the n and m values of S3 glass are both 1.8, suggesting that crystal growth between 1 (rod like) and 2 (plate like). Coarse glass exhibits better thermal stability and higher sluggishness to crystallize than that of fine glass. The main crystallization phases are characterized as thermally stable structure BaZn2Si2O7. Combined crystallization behavior with sintering behavior of glass, it is indicated that fine glass owns fast crystallization kinetics compared with sintering kinetics, generating a porous structure, whereas glass with larger particles crystallizes more slowly, exhibiting a relatively dense structure in RSOC operation.

Tailored sequencing of highly brominated Poly(ether ether ketone) as a means to preserve crystallizability and enhance Tg

In this report, the bromination of poly(ether ether ketone) (PEEK) using the mild reagent N-bromosuccinimide (NBS) is explored to generate controlled random and blocky microstructures. Bromination proceeded quantitatively in both the solution state and semicrystalline gel-state, and degrees of bromination between 25 and 175 mol% were obtained for both random and blocky BrPEEK. Spectroscopic evidence revealed a higher prevalence of unfunctionalized repeat units for blocky BrPEEK than random BrPEEK at similar degrees of functionality. Furthermore, at similar degrees of bromination, blocky BrPEEK exhibited enhanced glass transition temperatures, greater crystallizability, higher melting temperatures, and faster crystallization kinetics than random BrPEEK, suggesting longer segments of unfunctionalized PEEK in blocky BrPEEK. Overall, this work demonstrates that PEEK can be brominated to very high degrees of substitution in the semicrystalline gel-state while preserving crystallizability and effectively blocking up the functionality.

Probing structure development in Poly(vinylidene Fluoride) during “operando” 3-D printing by small and wide angle X-ray scattering

We have investigated the crystallization of the thermoplastic polymer Poly(vinylidene Fluoride) (PVDF) during “operando” 3D printing Fused Filament Fabrication (FFF). The performance of the 3D printing set-up and the corresponding methodology for performing simultaneous SAXS/WAXS with synchrotron radiation have been discussed. Simultaneous SAXS and WAXS experiments were performed across the printed line with a resolution of 50 μm. The experiments indicate that crystallization is faster at the polymer-air interface than in other points within the printed line. The final crystallinity varies with position being lower at both the interfaces, i.e. polymer-air (13%) and welding zone (11%), while being higher (18%) in the middle part of the printed line. Orientation of the crystalline lamellae is higher at both interfaces, suggesting higher shear rate than in the bulk of the printed line where elongational flow is dominant. The final crystallinity levels in the different locations of the printed line are relatively low, as compared with reported values in melt pressed samples (≈30%), due to the extremely fast crystallization kinetics involved in the solidification of PVDF 3D printed lines. Therefore, it is expected that 3D printed PVDF pieces will exhibit significant structural modifications due to the potential crystallization that eventually will proceed during storage because the glass transition of PVDF is well below room temperature.

Comparison of Differential Scanning Calorimetry, Powder X-ray Diffraction, and Solid-state Nuclear Magnetic Resonance Spectroscopy for Measuring Crystallinity in Amorphous Solid Dispersions - Application to Drug-in-polymer Solubility

The widespread use of amorphous solid dispersions (ASDs) dictates that analytical methods are required to accurately quantify crystallinity and characterize crystals formed in order to help design a stable ASD. Current crystallinity quantitation methods are limited to ASDs of moderate drug loadings, single polymorphs, and fast crystallization kinetics. The ability of multiple differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and solid-state nuclear magnetic resonance (SSNMR) techniques were compared for quantifying crystallinity in ASDs in varying conditions. Determining crystallinity by DSC is limited by its ability to measure Tg or heat of fusion. PXRD was relatively robust in determining crystalline and amorphous ratios for drug-polymer systems in the absence of other excipients. SSNMR provides both quantitative information and reveal how crystal quality changes with crystallization conditions and helps to explain the failure of DSC methods. The results of five different methods using three techniques were directly applied to measure drug-in-polymer solubility with four agreeing well with the literature. PXRD and SSNMR are therefore proposed as alternative methods to quantify crystallinity and predict drug-in-polymer solubility when DSC methods do not work. In-situ and ex-situ annealing was also compared, and equivalent crystallinity data was acquired.

Fast synthesis of thin SSZ-13 membranes by a hot-dipping method

Among zeolite membranes with CHA structure, SSZ-13 membrane has certain advantages over all-silica CHA and SAPO-34 membranes, like easy synthesis, good stability and insensitivity to moisture, however, its separation performance is not satisfactory. In this study, SSZ-13 membranes were prepared by a hot-dipping method, where the hot contact of seeded support and mother liquor at synthesis temperature resulted into fast crystallization kinetics and thin membranes. The obtained sub-micron SSZ-13 membranes exhibited outstanding CO2–CH4 mixture separation performance, CO2 permeance ~28 × 10−7 mol/(m2 s Pa) and CO2–CH4 selectivity ~180 at 0.14 MPa and room temperature. The hot-dipping method achieved the complete separation of seeding and crystallization (or membrane growth) by preventing the contact of mother liquor and seeded support before reaching synthesis temperature. This treatment avoids any undesirable change of the seed layer before membrane growth, which may help us to correlate the membrane performance with the properties of seed layer, like seed density, thickness and seed size. On the contrary, the CHA seed layer might be dissolved partially by mother liquor during the heating process of conventional membrane synthesis, which led to thick membranes due to unsatisfactory seeding. This method could be used for the synthesis of other zeolite membranes.

Polarization-oriented LiNbO3 nanocrystals by femtosecond laser irradiation in LiO2–Nb2O5–SiO2–B2O3 glasses

This work investigates the role of a B2O3 addition (up to 21 mole %) into a lithium niobium silicate glass matrix, focusing on the orientational dependency of second harmonic generation (SHG), induced after femtosecond laser irradiation. We detected the sharp emission of light at 515 nm, characteristic of SHG, in both static and scanning configurations, using pulse energy, repetition rate, and laser polarization as varying parameters. Among the results to highlight, the SHG signature appears within a few seconds in highly doped B2O3 glass, i.e., one order of magnitude smaller than in B2O3-free glass. Additionally, we found that the orientability of the polar axis of LiNbO3 nanocrystals by writing laser polarization can be obtained in glasses when SiO2 is substituted with B2O3. These preliminary results open the door to the fabrication of crystal / glass based photonic devices with lower laser power deposited and much faster crystallization kinetics.

Advances in peroxide‐initiated graft modification of thermoplastic biopolyesters by reactive extrusion

AbstractWe report recent advances in the solvent‐free reactive extrusion of thermoplastic biopolyesters, in the presence of peroxide initiators and tri‐functional cross‐linking/ chain extending agents. The resulting compounds have improved processability and properties compared to the starting materials, including higher melt strength due to long‐chain branching, higher crystallinity, faster crystallization kinetics, and improved mechanical properties. We demonstrate that these strategies are effective in thermoplastic biopolyesters, such as poly(lactide) (PLA) and various poly(hydroxyalkanoates) (PHAs), including poly(hydroxybutyrate) (PHB), and medium‐chain length PHAs. In addition to the improvements in properties, this approach has significant benefits in polymer processing operations, including blend compatibilization, and foaming. We also demonstrate that crosslinked PLA particles prepared by reactive extrusion using peroxide and a tri‐functional coagent, serve as very effective nucleating additives, resulting in crystallization half‐times as low as 1 min, and heat deflection temperature as high as 140°C. These modifications do not have adverse effects on the hydrolytic degradation characteristics of PLA.

Effect of 3D Printing Temperature Profile on Polymer Materials Behavior.

This article presents the effect analysis of the printing time sequences on the mechanical properties in correlation with the crystallization kinetics and rheological behavior. For this purpose, two printing order of 3D printed samples (printed simultaneously or in sequence) were chosen. In addition, two different infill patterns (line and gyroid) and building directions (horizontal and vertical) have been used. Concerning the polymer filaments, two commercial polylactic acid (PLA 3D870 and PLA 3D850) having different crystallization kinetics were used. The effect of the printing time delay between each layer on the temperature profile and the crystallization evolution was studied using a finite element analysis method simulation. The simulation results show a greater thermal excursion for longer delay times between the layers and with a crystallization degree evolution characterized by a step pattern. Moreover, a major density of crystals appears in the center of the final part. A new approach was adapted to measure the volumetric contraction of the material as a function of the temperature; it was performed with a gap test using a rotational rheometer under static conditions (without external deformation). The normal force measured from the test has shown a faster and higher increase of the contraction for the material with faster crystallization kinetics and with a higher degree of crystallinity. The results concerning the tensile properties show better rigidity for the samples printed in sequence due to the minor time of delay between the deposited layers. The mesostructure of the printed parts was analyzed with an X-ray tomography and a scanning electron microscope. The highest difference is presented from the PLA 3D870 characterized by the highest rate of crystallization resulting in more microvoids compared with the PLA 3D850, due to the less welding cohesion between the layers.

Influence of the Solidification Process on the Mechanical Properties of Solid-State Drawn PCL/Sepiolite Nanocomposite Tapes

In this research, poly(ε-caprolactone) (PCL) was melt-mixed with sepiolite nanoclays in a twin-screw extruder. In a subsequent step, the extruded films were drawn in the solid state to highly oriented nanocomposite films or tapes. A twin-screw extruder equipped with a Sultzer mixer for improved mixing in combination with a bench top drawing unit was used to prepare oriented nanocomposite tapes of different sepiolite loading and draw ratios. In order to study the influence of the solidification step on the drawability of the materials, different cooling procedures were applied prior to drawing. Optical microscopy images showed that slow or fast solidification using different chill rolls settings (open or closed) for the cast films resulted in different morphological conditions for subsequent drawing. The addition of sepiolite nanofillers led to nucleation and faster crystallization kinetics and oriented tapes which deformed by homogenous deformation rather than necking. The addition of sepiolite significantly improved the mechanical properties of both undrawn and drawn PCL tapes and Young’s modulus (1.5 GPa) and tensile strength (360 MPa) for composites based on 4 wt% sepiolite were among the highest ever reported for PCL nanocomposites. Interestingly, samples cooled with open chill rolls (slow crystallization) showed the highest modulus while solidification with closed rolls (fast crystallization) showed the highest tensile strength after drawing.

Crystal Contact Engineering Enables Efficient Capture and Purification of an Oxidoreductase by Technical Crystallization.

Technical crystallization is an attractive method to purify recombinant proteins. However, it is rarely applied due to the limited crystallizability of many proteins. To overcome this limitation, single amino acid exchanges are rationally introduced to enhance intermolecular interactions at the crystal contacts of the industrially relevant biocatalyst Lactobacillus brevis alcohol dehydrogenase (LbADH). The wildtype (WT) and the best crystallizing and enzymatically active LbADH mutants K32A, D54F, Q126H, and T102E are produced with Escherichia coli and subsequently crystallized from cell lysate in stirred mL-crystallizers. Notwithstanding the high host cell protein (HCP) concentrations in the lysate, all mutants crystallize significantly faster than the WT. Combinations of mutations result in double mutants with faster crystallization kinetics than the respective single mutants, demonstrating a synergetic effect. The almost entire depletion of the soluble LbADH fraction at crystallization equilibrium is observed, proving high yields. The HCP concentration is reduced to below 0.5% after crystal dissolution and recrystallization, and thus a 100-fold HCP reduction is achieved after two successive crystallization steps. The combination of fast kinetics, high yields, and high target protein purity highlights the potential of crystal contact engineering to transform technical crystallization into an efficient protein capture and purification step in biotechnological downstream processes.

Heat-rate-controlled hydrothermal crystallization of high-performance LiMn0.7Fe0.3PO4 cathode material for lithium-ion batteries

High supersaturation degree can endow hydrothermal products with small size, high crystallinity, designed morphology and orientation. However, adjusting the hydrothermal supersaturation level in organic-free systems is still a great challenge. In this work, high supersaturation degree is feasibly achieved via a green and efficient strategy just by elevating the hydrothermal heating rate, where cubic-like LiMn0.7Fe0.3PO4 cathode material with improved electrochemical kinetics is obtained. Detailed studies reveal that the elevated heating rate could improve the critical dissolved temperature of the precursor and lead to shortened time window for nucleation, and finally give rise to high supersaturation level and fast crystallization kinetics. By this heating-rate-controlled hydrothermal strategy, cuboid-like LiMn0.7Fe0.3PO4 particles with average length of 373 nm are successfully synthesized at the optimal heating rate of 5 °C/min. After coated with conductive carbon, the LiMn0.7Fe0.3PO4/C electrode possesses enhanced conductivity for both electron and Li+, which delivers superior electrochemical properties of 166.5 mAh·g−1 and 87.3 mAh·g−1 at the rates of 0.1 C and 10 C, respectively. We believe this work provides new perspectives for the synthesis of properties-controlled nanocrystals in the hydrothermal system.

Thermal Analysis of Crystallization and Phase Transition in Novel Polyethylene Glycol Grafted Butene-1 Copolymers.

Copolymerization is an effective strategy to regulate the molecular structure and tune crystalline structures. In this work, novel butene-1 copolymers with different polyethylene glycol (PEG) grafts (number-average molecular weight Mn = 750, 2000, and 4000 g/mol) were synthesized, for the first time introducing long-chain grafts to the polybutene-1 main chain. For these PEG-grafted copolymers, crystallization, melting, and phase transition behaviors were explored using differential scanning calorimetry. With respect to the linear homopolymer, the incorporation of a trimethylsilyl group decreases the cooling crystallization temperature (Tc), whereas the presence of the long PEG grafts unexpectedly elevates Tc. For isothermal crystallization, a critical temperature was found at 70 °C, below which all polyethylene glycol-grafted butene-1 (PB-PEG) copolymers have faster crystallization kinetics than polybutene-1 (PB). The subsequent melting process shows that for the identical crystallization temperature, generated PB-PEG crystallites always have lower melting temperatures than that of PB. Moreover, the II-I phase transition behavior of copolymers is also dependent on the length of PEG grafts. When form II, obtained from isothermal crystallization at 60 °C, was annealed at 25 °C, PB-PEG-750, with the shortest PEG grafts of Mn = 750 g/mol, could have the faster transition rate than PB. However, PB-PEG-750 exhibits a negative correlation between transition rate and crystallization temperature. Differently, in PB-PEG copolymers with PEG grafts Mn = 2000 and 4000 g/mol, transition rates rise with elevating crystallization temperature, which is similar with homopolymer PB. Therefore, the grafting of the PEG side chain provides the available method to tune phase transition without sacrificing crystallization capability in butene-1 copolymers.

Optimizing film morphology and crystal orientation of perovskite for efficient planar-heterojunction solar cells by slowing crystallization process

Abstract The morphology of perovskite film plays a key role in determining photoabsorption, carrier transport and ambient stability in perovskite solar cells. However, due to the fast crystallization kinetics, the perovskite film fabricated by solution-processing technique usually suffers from low crystallinity and poor orientation. Here, both the morphology and the ambient stability of perovskite films were improved through regulating crystallization rate and enhancing intermolecular interaction by adding α, ω-diamino poly (ethylene glycol) (PEG-NH2) into precursor solution (mixture of CH3NH3I and PbCl2). The PEG-NH2 and Pb2+ tended to form a new chelated compound Pb2+-PEG-NH2. The stable multidentate chelation between Pb2+ and PEG-NH2 retarded the crystal growth rate to half of the one of the film without PEG-NH2, which is determined by the in situ UV–vis absorption spectra and in situ two-dimensional detection capability. The slow crystallization process is beneficial for realizing an uniform perovskite film with enhanced crystallinity almost 3 times of the pristine film, and increased crystal size from smaller than 100 nm to larger than 300 nm. In addition, the content of perovskite crystals adopted (h 0 0) orientation increased from 9.59% to 20.70% due to the flexible PEG-NH2 chains. Moreover, the ambient stability of perovskite films was also enhanced because the Pb-halogen bond in perovskite crystals became stronger as well as the film became defect-free. As a result, the device fabricated with PEG-NH2 attained a high efficiency of 15.6% with remarkably prolonged ambient stability without encapsulation. This work demonstrates that introducing the polymer that can coordinate to Pb2+ is a feasible way to simultaneously enhance both efficiency and stability of perovskite solar cells.

Understanding the fast crystallization kinetics of In–Sb–Te by using ultrafast calorimetry

The crystal growth rates of supercooled liquids In–Sb–Te can be well characterized by ultrafast DSC, and it benefits to the optimization for phase-change materials.

Melt-Processable Semicrystalline Polyimides Based on 1,4-Bis(3,4-dicarboxyphenoxy)benzene Dianhydride (HQDPA): Synthesis, Crystallization, and Melting Behavior.

It is a great challenge to develop semicrystalline polyimides exhibited significant recrystallization ability and fast crystallization kinetics from the melt. A series of semicrystalline polyimides based on 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride (HQDPA) and different diamines, including 1,3-bis(4-aminophenoxy)benzene (TPER), 1,4-bis(4-aminophenoxy)benzene (TPEQ), 4,4′-oxydianiline (4,4′-ODA) and 4,4′-bis(4-aminophenoxy)biphenyl (BAPB), end capped with phthalic anhydride were synthesized. Crystallization and melting behaviors were investigated by differential scanning calorimetry (DSC). The polyimide derived from HQDPA/TPER (PI-1) exhibited a glass transition temperature (Tg) at 190 °C and double melting temperatures (Tms) at 331 °C and 350 °C, and the polyimide derived from HQDPA/TPEQ (PI-2) displayed a Tg at 214 °C and a Tm at 388 °C. PI-1 and PI-2 showed significant recrystallization ability from melt and high crystallization rate by isothermal crystallization kinetics study, while polyimides based on 4,4′-ODA and BAPB lost crystallizability once taken to the melt. These polyimides also exhibited excellent thermo-oxidative stability with 5% weight loss temperature higher than 500 °C and good mechanical properties with tensile moduli of 2.0–3.3 GPa, tensile strengths of 85–105 MPa and elongations at break of 5–18%. PI-1 also possessed outstanding melt flowability with less than 300 Pa·s around 370 °C by rheological measurements.

Glass formation adjacent to the intermetallic compounds in Cu-Zr binary system

On the contrary to the common belief that glass formation is unfeasible near terminal intermetallic compound due to fast crystallization kinetics, here we present our findings that bulk metallic glasses are readily formed near intermetallic compounds, far away from the traditional region of glass forming near eutectics. While the intermetallic compounds themselves are not possible glass formers, bulk metallic glasses can be quenched compositionally neighboring the intermetallic compounds as close as 0.5 at.%. Taking binary Cu-Zr as a model system, the phenomenon of two optimum glass forming compositions sandwiching the corresponding intermetallic compounds (Cu51Zr14, Cu10Zr7, CuZr, CuZr2 and Cu8Zr3) is observed consistently. This new scenario of “intermetallic glass” is verified by the thermodynamic principle that the alloy liquids neighboring the intermetallic compounds possess lower Gibbs free energy than that of the compounds themselves. Furthermore, the sluggish crystallization behavior of these liquids provides an additional kinetic explanation.

Thermal and kinetic behaviors and microscopic characteristics of diacylglycerol‐enriched palm‐based oils blends

This study aimed to investigate how mixtures of diacylglycerol‐enriched oils affected the phase behavior, thermal characteristics, crystallization properties, and the microstructure in a solid fat system. diacylglycerol‐enriched palm oil (PO‐DAGE) was mixed with diacylglycerol‐enriched palm stearin (PS‐DAGE) in various concentrations. On the basis of iso‐solid diagram and phase diagram, PO‐DAGE/PS‐DAGE blends exhibited a better compatibility compared to their corresponding original blends. DSC thermal profiles showed that the melting and crystallization properties of PO‐DAGE/PS‐DAGE were obviously different from their original blends. Crystallization kinetics revealed that PO‐DAGE/PS‐DAGE blends showed rather high crystallization rates and displayed no spherulitic crystal growth at all examined supercoolings. From the results of polarized light micrographs, PO‐DAGE/PS‐DAGE showed more dense structures with very small needle‐like. X‐ray diffraction evaluation exhibited when above 30% PS‐DAGE was added to PO‐DAGE, β‐polymorph crystals dominated.Practical applications: The results demonstrate that DAG‐enriched blends based from palm oil and palm stearin exhibited rather fast crystallization kinetics, which could provide a feasible solution to the annoying problems with palm‐based oils in terms of slow crystallization. DAG‐enriched blends have flatter SFC profiles and better compatibility as well as the fine microstructure compared to their corresponding original blends. These properties will be conducive to the development of DAG‐enriched plastic fats in the future, which exhibits the functionality to reduce postprandial lipid levels and to treat obesity.Compared the melting properties of DAG‐enriched blends based from palm stearin and palm oil with their corresponding original blends.