Isothermal Crystallization Temperature Research Articles

The shear-accelerated II-I phase transition of isotactic poly(1-butene).

The II-I phase transition of isotactic poly(1-butene) (iPBu) leads to improved mechanical performance. However, this will take several weeks and increase storage and processing costs. In this work, shear forces were introduced into the supercooled iPBu melt, and the effects of isothermal crystallization temperature (Tc) and shear temperature (Tshear) on crystallization and phase transition were explored. Shear-induced transcrystalline morphology of Form II with a significantly shortened crystallization induction period can be observed at relatively high Tc (105°C). Besides, the shear-induced Form II can transit to Form I faster than the unsheared one. In addition, the phase transition rate increases as the Tshear decreases, with the fastest rate occurring at Tshear of 120°C. The half transition time (t1/2) is measured as 6.3 hours, much shorter than the 20.7 hours required for unsheared samples. The accelerated phase transition of iPBu can be attributed to the stretching of molecular chains resulting from shear treatment. This study provides a quantitative analysis of the influence of the shear treatment and the Tshear on the II-I phase transition rate. And it also presents a cost-effective and straightforward approach for expediting the phase transition process. This article is protected by copyright. All rights reserved.

An efficient β-nucleating agent with high lattice matching rate for plate-like crystallization of polypropylene random copolymer.

It is challenging to naturally produce large amounts of β-crystals by directly adding a commercial β-nucleating agent (β-NA) into polypropylene random copolymer (PPR) at present. In this work, a novel rare earth β-NA WBN-28 was directly introduced into PPR to prepare β-PPR with high β-crystal conversion. The results of differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) indicated that it is an efficient β-NA for PPR. The β-conversion rate (β-CR) could surpass 85% when the nucleating agent content was mere 0.05%. With the further increment of nucleating agent, the β-CR increased gradually, which could reach 89.5% and 86.9% respectively calculated by DSC and WAXD when the addition amount was 0.4%. The incredible high β-CR delayed the βα-recrystallization in isothermal crystallization. The fusion peak of α-crystal was unobserved below the isothermal crystallization temperature of 122 °C when the addition amount was more than 0.2%. Furthermore, there was a highly ordered structure in WBN-28 with the periodicity of 12.89 Å, which was approximately twice of the unit cell parameter in the c direction of β-PP, indicating a high lattice matching rate between them. Intuitively observed by polarizing optical microscope (POM), the crystal grains of the blends with β-NA were more refined and finally crystallized in a plate-like shape. The forming process of the plate-like β crystalline regions were proposed by scanning electron microscope (SEM) and POM.

Isothermal crystallization kinetics of pure and surface‐modified silica/high‐density polyethylene nanocomposites

AbstractThe isothermal crystallization kinetics of high‐density polyethylene (HDPE) nanocomposites containing 0, 0.5, 0.75, and 2 wt% of pure and surface‐modified silica were evaluated at three crystallization temperatures (Tc) of 120°C, 121°C, and 122°C using differential scanning calorimetry (DSC) and applying Avrami, Tobin, and Malkin equations. According to Hoffman‐Weeks theory, the values of the equilibrium melting point () of the nanocomposites decreased with increasing nanoparticle content and were higher in the samples containing AMS nanoparticles, owing to the larger crystal. The results of all three models offered the same trend according to which the change in the crystallization temperature influenced the nucleation mechanism and the crystallization rate. It was found that a greater number of spherulites can be formed via increasing Tc from 120°C to 122°C which also decreased the crystallization rate of the nanocomposites. At the crystallization temperature of 122°C, the lowest melting temperature was recorded for the samples, attributed to the formation of more crystals with a lower thickness. Moreover, in HDPE/AMS nanocomposites, the crystallization rate was higher than that of HDPE/PSN, ascribed to the positive effect of surface modification on nanoparticles.Highlights Increased polymer/particle compatibility and isothermal crystallization. Evaluating the nucleation and crystallization using different models. The impact of isothermal crystallization temperature on crystallinity. Variation of equilibrium melting point with the nanoparticle content.

Isothermal crystallization behavior of poly-ether-ether-ketone/bioactive glass composites and its correlation with scaffold warpage in laser powder bed fusion process

The preparation of poly-ether-ether-ketone/bioactive glass (PEEK/BG) composite scaffolds using laser powder bed fusion (LPBF) has enormous clinical potential. However, ensuring the desired accuracy and reproducibility of composite scaffolds during the LPBF process remains a significant challenge. Therefore, a thorough understanding of the relationship between the crystallization behaviors and the scaffold warpage during the LPBF process is crucial. To address this challenge, this study systematically investigates the isothermal crystallization kinetics of PEEK/BG composites and their relationship with scaffold warpage. The results reveal that the crystallization rates of pure PEEK and PEEK/BG composites decrease as isothermal crystallization temperature increases. Additionally, BG significantly suppresses the isothermal crystallization kinetics of PEEK, resulting in a 250% increase in the half-crystallization time (t1/2) of PEEK/25 wt% BG at 316 °C relative to pure PEEK. Extrapolating the t1/2 using the Hoffman-Lauritzen model can obtain the optimal powder bed temperature (Tb) for each powder in LPBF. Pure PEEK and PEEK/25 wt% BG Diamond scaffolds are printed at the respective inferred Tb (330 °C and 323 °C) and their warpage degrees are compared to that of the pure PEEK scaffold printed at 323 °C. The results demonstrate that raising Tb from 323 °C to 330 °C and adding 25 wt% BG are both effective methods to reduce the scaffold warpage by slowing down the crystallization kinetics of PEEK, resulting in reductions of 57.8% and 50.6% in warpage degree respectively. Furthermore, the incorporation of BG successfully tackles the challenge of simultaneously preventing warpage and secondary sintering in pure PEEK printing. Overall, this study offers a deep comprehension regarding the relationship between crystallization kinetics and scaffold warpage, which is crucial for achieving the reproducibility with desired accuracy of LPBF-printed biological scaffolds for clinical applications.

A study on the crystallization and melting of PLA nanocomposites with cellulose nanocrystals by DSC

AbstractPoly(lactic acid) (PLA)/cellulose nanocrystal (CNC) nanocomposites with 1 or 3 phr of CNC were prepared by melt mixing and compression molding then their % crystallinities as well as crystallization and melting behavior during the first heating/cooling/second heating process were investigated by differential scanning calorimetry (DSC). Isothermal crystallization at 80–130°C for 5 min was performed during the cooling process to see how the isothermal crystallization affects % crystallinity at 25°C. The % crystallinity at 25°C as well as the crystallization rate of the nanocomposite increased with CNC content and showed a maximum at the isothermal crystallization temperature of 105°C regardless of CNC content. The bimodal DSC melting peaks observed during the second heating process were considered due to the crystals with many defects (α′) and the crystals with more perfect structure (α), respectively. Isothermal crystallization kinetic analysis by Avrami equation showed that the Avrami exponents of the nanocomposites were about 1, meaning a rod‐ or disc‐shaped crystal growth mechanism. Improving the mechanical properties of the PLA/CNC nanocomposite would be possible because the % crystallinity at 25°C could be effectively increased by changing CNC content and cooling history.Highlights PLA/CNC nanocomposites. Crystallization and melting behavior analysis of the nanocomposites by DSC. Isothermal crystallization at 80–130°C for 5 min during cooling by DSC. Crystallization degree was maximum for the isothermal crystallization at 105°C. Isothermal crystallization kinetic analysis by Avrami equation.

Controllable cell structures of poly(ether-block-amide) foams via isothermal melt crystallization-foaming in supercritical CO2

A simple isothermal melt crystallization-foaming method was proposed to regulate the crystallinity (Xc) of PEBA to prepare poly(ether-block-amide) (PEBA) foams with uniform or bimodal cell structures by supercritical CO2. PEBA with different Xc values was obtained by controlling the isothermal crystallization temperature (Tiso) and time (tiso). The rheological and DSC results showed that the viscoelasticity and Xc of the samples increased with decreasing Tiso and increasing tiso. PEBA foams with Xc above 1.1% exhibited a distinct bimodal cell structure. The increased crystals acted as heterogeneous nucleation sites to increase the cell density from 6.8 × 106 cells/cm3 to 3.58 × 1010 cells/cm3. The size of large cells decreased from 206.4 µm to 48.0 µm, and the number ratio of small to large cells increased from 2.34 to 65 times. Finally, a mechanism to explain the cell structure variation in PEBA foams was proposed, providing a new strategy for regulating the cell structure of polymeric foams.

Tailoring the crystallization and melting behavior of 3D protein-polymer biocomposite materials: A study of pressure-induced silk fibroin/poly(L-lactic acid) foams

Crystallization and melting behavior of 3-D composite materials is critical in the field of biopolymer materials, because the crystal structure and crystallization kinetics of the materials will affect the performance of the biocomposite materials and their fabrication process. In this study, thermal analysis combined with structural analysis such as X-ray diffraction (XRD) were used to study the melting behavior of silk fibroin/polylactic acid (SF/PLA) composite foam materials prepared under a pressure of 0–6 MPa, and the mechanism of their isothermal crystallization kinetics was discussed. The results showed that both α and α'-type crystals exist in the composite material, and their contents can be tuned by isothermal crystallization temperature. When the isothermal crystallization temperature is around 105 °C, the crystallization time is the shortest and the crystallization rate is the fastest. Besides, silk fibroin can shorten the crystallization half-life of the composite foam and improve the crystallinity of the material. However, the high isothermal temperature will facilitate the interaction between SF and PLA segments to slow down the diffusion, folding and crystallization of the PLA segments. Using Avrami analysis, it is found that the crystal growth in 3-D composites follows a non-three-dimensional truncated spherical direction. This study provides a deeper understanding of the crystallization behavior of protein-synthetic polymer biocomposite materials and offers experimental and theoretical guideline for the regulation and utilization of their structure and properties for the design of new biocomposite materials.

Impact of polymer chain packing and crystallization on the emission behavior of curcumin-embedded poly(L-lactide)s.

The development of biodegradable and biocompatible fluorescent materials with tunable emission in the solid state has become increasingly relevant for smart packaging and biomedical applications. Molecular packing and conformations play a critical role in tuning the solid-state photophysical properties of fluorescent materials. In this work, tunable emission of bioactive curcumin was achieved through the manipulation of the crystallization conditions and the polymorphic form of covalently linked poly(L-lactide) in the curcumin-embedded poly(L-lactide) (curcumin-PLLA). In the melt-crystallized curcumin-PLLA, with the increase in the isothermal crystallization temperature, a bathochromic shift in the fluorescence of curcumin-PLLA was observed due to the change in the intramolecular conjugation length of curcumin. The change in the isothermal crystallization temperature of curcumin-PLLA resulted in the rotation of the terminal phenyl rings of curcumin with respect to the central keto-enol group due to the covalently linked helical PLLA chains. In addition, solvent-induced single crystals and a gel of curcumin-PLLA were prepared and the influence of the polymorphic form of PLLA on the emission behavior of curcumin-PLLA was investigated. The results suggest that the polymer chain packing, crystallization conditions, morphology, and polymorphic form could play an influential role in dictating the fluorescence properties of fluorophore-embedded polymers.

A feasible strategy to balance the performance of stereo-complexed polylactide by incorporating poly(butylene adipate-co-terephthalate)

The raw material of polylactide (PLA) is lactic acid obtained by biological fermentation. PLA is the most promising degradable polymer to replace traditional plastics to address the pollution problems caused by their non-degradability. However, the application of PLA is hindered by its low softening temperature, easy hydrolysis, and poor toughness. Herein, the ternary composites with PLLA, PDLA and Poly (butylene adipate-co-terephthalate) (PBAT) were prepared by melt blending to balance its thermal stability, hydrolysis, and toughness. The effects of PBAT content (3 %, 6 %, 9 % and 12 %) and isothermal crystallization temperature on composite properties were fully investigated. The results show that the composite of stereo-complexed PLA (sc-PLA) with 6 % PBAT crystallized at 110 °C exhibits good comprehensive properties. Its vicat softening temperature (VST), mass loss rate under alkaline (pH = 12) and breaking elongation are 166 °C, 21.6 % and 4.40 %, respectively. Compared with the pure PLLA sample crystallized at same condition, the VST, mass loss rate and breaking elongation are 159 °C, 24.7 % and 3.76 % respectively, which increased by nearly 5 %, 13 % and 20 %. This indicates that this strategy is feasible to balance the heat resistance, hydrolysis resistance and toughness of PLA, while it sacrifices the tensile strength a little. This work provides a new way to modify and improve the PLA properties. Nonetheless, it is also necessary to coordinate the compatibility of PLA and PBAT.

Improving the order of crystalline regions of poly(3-hexylthiophene) by crystallization from the self-nucleation domains

To obtain well-defined crystalline structures starting from an isotropic melt state, we crystallized poly(3-hexlylthiophene) isothermally at high temperatures, using various multi-step thermal protocols and profiting from a self-nucleation process. We explored the possible impact of self-nuclei from the melt memory domain and of remaining crystalline seeds from the self-seeding domain on isothermal crystallization at high temperatures. Depending on the thermal protocol, self-seeding allowed to obtain crystals grown from nuclei formed at the isothermal crystallization temperature and from crystalline seeds remaining after annealing at the self-nucleation temperature. Isothermal annealing of samples crystallized by rapid cooling from the isotropic melt allowed to significantly improve their crystallinity but to a lesser extent enhanced the crystalline quality, characterized by the value of the melting temperature.

Physics of Directional Polymer Crystallization.

It has been proposed that the nonisothermal directional crystallization of a polymer driven by a moving sink has an exact analogy to an equivalent isothermal crystallization protocol. We show that this is substantially true because polymers are poor thermal conductors; thus, polymer crystallization occurs over a relatively narrow spatial regime, while the thermal gradients created by this freezing occur over a much broader scale. This separation of scales allows us to replace the crystallization process, which is spatially distributed, with an equivalent step. The temperature at this step, which corresponds to the desired equivalent isothermal crystallization temperature, scales linearly with sink velocity. However, a few metrics, such as the Avrami exponent characterizing the kinetics of crystallization are very different in the two cases. These findings provide new insights into the physics of these spatially varying crystallization protocols and should inspire new experiments to probe the underlying equivalences more deeply.

Effect of Tm of blend components on the isothermal melt-crystallization process of PHB/PLLA blends investigated using spectroscopic imaging and DSC

The understanding of morphology and crystallization in biopolymer blends offers the ability to tune these properties for specific uses. In this study, the isothermal melt-crystallization process of poly (3-hydroxybutyrate) (PHB)/poly ( l -lactic acid) (PLLA) blends with different weight loadings and molecular weights was investigated using in-situ attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopic imaging and differential scanning calorimetry (DSC). When the isothermal crystallization temperature is constant, increasing the fraction of blend component with a lower T m results in the decreasing T m of both blend components, which is indicated in DSC thermograms. The reduced T m delays the crystallization of both blend components and then the restrained crystallization leads to a greater extent of phase separation, which is shown in ATR-FTIR spectroscopic images. Likewise, at a constant isothermal crystallization temperature, with the decreasing molecular weights of blend components, the miscibility of polymer blend should be enhanced because of the shift of the phase boundary in phase diagram to lower temperatures. However, the decreasing overall crystallization rate and the delay of crystallization indicated in the integrated absorbance profiles and the decreasing T m indicated in the DSC thermograms can be used to explain the greater extent of phase separation in the PHB/PLLA blend shown in the spectroscopic images. A phase diagram was prepared to show the effect of polymer molecular weight on the miscibility of PHB/PLLA blends. Thus, increasing the fraction of the blend component with a higher T m , choosing polymers with a higher molecular weight and decreasing the isothermal crystallization temperature have been demonstrated to be effective methods to promote the miscibility of upper critical solution temperature (UCST) crystallizable polymer blends. Moreover, it was concluded that in-situ ATR-FTIR spectroscopic imaging can be combined with integrated absorbance profiles and DSC thermograms to deepen the understanding of multicomponent polymer systems. • A phase diagram was prepared to show the effect of M w on the miscibility of PHB/PLLA blends. • Effective methods are found to promote the miscibility of UCST polymer blends during isothermal crystallization process. • Spectroscopic imaging can be combined with DSC thermograms to deepen the understanding of multicomponent polymer systems.

Crystallization Behavior of Isotactic Polybutene Blended with Polyethylene.

In this work, the melt crystallization behavior and the solid phase transition of isotactic polybutene (PB) were studied in the polybutene/high-density polyethylene (PB/PE) blends covering the whole composition range. For the dynamic cooling crystallization, PE exhibits almost the same crystallization temperature in all blends, whereas PB exhibits a distinct non-monotonic dependence on the composition ratio. Combining the ex situ X-ray diffraction and in situ Fourier transform infrared spectroscope, it was demonstrated that during cooling at 10 °C/min, the presence of at least 70 wt% PE can induce the formation of form I′ directly from the amorphous melt. The detailed relations of polymorphism with temperature were systematically investigated for the PB/PE blends. Different from the formation of the sole tetragonal phase with ≤50 wt% PE, the trigonal form I′ could crystallize directly from amorphous melt with ≥60 wt% PE, which can be further enhanced by elevating the temperature of isothermal crystallization. Interestingly, the critical lowest temperature of obtaining pure form I′ was 85 °C with 70 wt% PE and decreased to 80 °C as the PE fraction was increased to 80 wt%. On the other hand, the spontaneous phase transition from the kinetically favored form II into the thermodynamically stable form I was also explored with X-ray diffraction methods. It was found that at the room temperature, phase transition kinetics can be significantly accelerated by blending at least 70 wt% PE.

The effect of isothermal crystallization on mechanical properties of poly(ethylene 2,5-furandicarboxylate)

Abstract The effects of isothermal crystallization temperature/time on mechanical properties of bio-based polyester poly(ethylene 2,5-furandicarboxylate) (PEF) were investigated. The intrinsic viscosity, crystallization properties, thermal properties, and microstructure of PEF were characterized using ubbelohde viscometer, X-ray diffraction, polarizing optical microscope, differential scanning calorimetry, and scanning electron microscopy. The PEF sample isothermal crystallized at various temperatures for various times was denoted as PEF-T-t. The results showed that the isothermal crystallization temperature affected the mechanical properties of PEF-T-30 by simultaneously affecting its crystallization properties and intrinsic viscosity. The isothermal crystallization time only affected the crystallization properties of PEF-110-t. The crystallinity of PEF-110-40 was 17.1%. With small crystal size, poor regularity, and α′-crystal, PEF-110-40 can absorb the energy generated in the tensile process to the maximum extent. Therefore, the best mechanical properties can be obtained for PEF-110-40 with the tensile strength of 43.55 MPa, the tensile modulus of 1,296 MPa, and the elongation at a break of 13.36%.

Fascinating morphology and crystallization behavior of melt miscible binary blends of crystalline homopolymers depicting nearly simultaneous melting transitions

We report on the interesting crystallization behavior of crystalline/crystalline polymer blends, composed of poly(butylene adipate) (PBA) and poly(ethylene oxide) (PEO), with nearly simultaneous melting and crystallization transitions. The miscibility of the two components ensured that the crystallization, on cooling, occurred from the homogenous phase in the melt. The crystalline morphology and structure was investigated using a combination of DSC, PLOM, WAXD and SAXS measurements. The crystalline structure and morphology of the PEO/PBA blends were found to be governed by a strong competition between the faster crystallization kinetics of PEO and relatively much higher nucleation density of PBA. In the PEO-rich blend, the faster crystallization kinetics of the PEO dominated the crystallization morphology development such that the minority component i.e. PBA was found to get entrapped in the interlamellar and interfibrillar regions of PEO spherulites. Interestingly, the resulting crystallization of PBA, within the confined intraspherultic regions of PEO, favored the formation of β phase crystals even at very high isothermal crystallization temperatures. In the symmetric and PBA-rich blends, the higher nucleation density of PBA had a dominant influence on the crystalline morphology development, especially at high degree of supercooling. This resulted in the formation of a variety of interesting morphologies which included interpenetrating spherulites, PEO templated PBA and PBA templated PEO spherulites. Furthermore, the α crystal phase of PBA was found to be more stable in a large supercooling window plausibly due to the dilution effect of PEO. The present study provide novel insight into the competitive role of crystallization rate and nucleation density on the crystallization behavior of crystalline/crystalline blends, with similar melting points, which has been scarcely studied in the past.

Crystallization kinetics, polymorphism fine tuning, and rigid amorphous fraction of poly(vinylidene fluoride) blends

Fast scanning calorimetry (FSC) is used to study crystallization of poly(vinylidene fluoride) (PVDF), and its blends with a random fluorinated copolymer (FCP) of poly(methyl methacrylate) and 1H,1H,2H,2H-perfluorodecyl methacrylate (PMMA-r-PFDMA). By varying the residence time at isothermal melt crystallization temperatures TMC = 80–120°C, the amount of α- and β-phase can be controlled, yielding partial or complete suppression of β-phase for all blends studied. Nonisothermal crystallization kinetics are also studied by FSC and analyzed using the Mo model. Crystallization rates increase when FCP is present. PVDF crystallizes into β-phase when cooled from the melt at rates faster than 3000 K/s giving PVDF crystal fractions of about 0.05–0.16. Only α-phase occurs at cooling rates slower than 2000 K/s yielding larger PVDF crystal fractions of about 0.30–0.43. Cooling rates between those limits result in mixed α- and β-phase. The rigid amorphous fraction (RAF) of PVDF varies with α and β crystal fraction in PVDF/FCP blends. RAF of α-phase PVDF ranges from 0.21 to 0.28 whereas RAF of β-phase PVDF spans a wider range, reaching values from 0.42 to 0.46.

Crystallization and melting behavior of polyvinylidene fluoride in confined space of nanotubes

Homopolymer poly (vinylidene fluoride) (PVDF) thin films were fabricated via high pressure process and then PVDF film was melt into porous anodic aluminum oxide (AAO) templates to form hollow nanotubes and isothermally crystal at a certain temperature. Scanning electron microscopy (SEM) and Transmission Electron Microscope (TEM) is used to observed the microstructure of nanotubes. To explore the influence of nanopores on the crystallization and melting of PVDF, differential scanning calorimetry (DSC) is used. It turns out that crystal phase is restrained in the nanotubes and mainly exists and at high temperature within relatively large nanopores and the bulk. As for phase, the increase of isothermal crystallization temperature results in the increase of melting temperature.

Tuning isothermal crystallization kinetics by minor similar solute element substitution in novel La‐(AlGa)‐C metallic glasses

AbstractIn the present text, the effects of minor similar solute element Ga substitution for Al on the isothermal crystallization kinetics of novel light RE‐based La‐(AlGa)‐C metallic glasses (MGs) were systematically investigated between La60Al26Ga4C10 MG and the precursor La60Al30C10 MG by using phase analysis, Johnson–Mehl–Avrami and Arrhenius using x‐ray diffraction, transmission electron microscopy, and differential scanning calorimetry. The incubation period, the accomplishment time of the whole process, and the diversity of both the precipitated phases and the varying trend of the local Avrami exponent are elevated by minor similar solute element Ga substitution for Al, respectively. Additionally, the Avrami exponent of different isothermal crystallization temperature changes from g n > 2.5 to a combination of values 1.5 < n < 2.5 and a value n > 2.5 given by minor similar solute element Ga substitution for Al, corresponding to the crystallization characteristics changing from crystallization with promoting nucleation rate to a combination of crystallization with a reducing nucleation rate and crystallization with promoting nucleation rate. Moreover, the isothermal crystallization process becomes more difficult after minor similar solute element Ga substitution for Al, due to the reduced Avrami exponent and the intensified local activation energy.

Ring-banded spherulites in polylactide and its blends

In this paper the influence of different aspects of crystallization process on the formation of ring-banded spherulites and the transition between banded and non-banded structures in polylactide was analyzed. Based on the measurements using the differential scanning calorimetry (DSC) and polarized optical microscopy (POM), it was found that the banding phenomenon of spherulites in polylactide and its blends with triethyl citrate (TEC) exclusively depends on the degree of supercooling (ΔT). In the work, for the first time, the equilibrium melting point (Tm0) of polylactide was correlated with the isothermal crystallization temperature (Tic) in the context of banded spherulites formation. To determine the Tm0 of polylactide blends, due to the possibility of modifier migration towards the sample surface, a correction of the methodology was proposed. It has been shown that ΔT necessary to initiate the growth of spherulites with a ring pattern in polylactide ranges from 46 to 56 °C. The inclusion of TEC into polylactide matrix shifts the Tic range in which banded spherulites appear towards lower values, but does not change the required value of supercooling degree. A direct correlation between the band space of the ring-banded spherulites and the degree of supercooling was also demonstrated.

Influence of the amphiphilic molecule on high-density polyethylene crystallization

The influence of organic additives on crystallization of polyolefins has not been paid enough attention due to the low dosage, but it may have a significant impact on the properties of polyolefins. In the paper, the organic amphiphilic molecules were introduced into high-density polyethylene (HDPE) through melt blending, and compared with neat HDPE. It is mainly discussed for the following aspects including analysis of crystal structure and morphology using wide-angle X-ray diffraction (WAXD) and polarized optical microscopy (POM), respectively; analysis of crystallinity, crystal rate, crystal growth and crystallization enthalpy, using the differential scanning calorimetry (DSC). The research indicates that the organic amphiphilic molecules may act as an internal lubricant. On the one hand, HDPE molecular chains are easy to fall off from crystal lattices, resulting in lagging crystallization peak, simultaneously reducing the interaction between HDPE molecules should induce the lower activation energy (ΔEm) to increase the crystallinity of HDPE. On the other hand, the amphiphilic molecules should be exclude from HDPE crystal to the amorphous area due to poor compatibility; thus, the HDPE/amphiphilic molecules blends, similar to neat HDPE, conduct homogeneous nucleation, and the growth of monocrystal performs the tendency of the zero-dimension to the two-dimension with increase in temperature of isothermal crystallization and decreasing cooling rate of non-isothermal crystallization. It is hoped that through these studies, people will pay more attention to the impact of organic additives on the performance of HDPE.