Polybutene-1 Research Articles

Regulating Porous Structure of Dual-Percolation Polybutene-1 (PB)/Poly(ethylene-co-octene) (POE)/Carbon Nanotube (CNT) Composites for Enhanced Electrical Conductivity and Electromagnetic Interference Shielding Performance

Regulating Porous Structure of Dual-Percolation Polybutene-1 (PB)/Poly(ethylene-<i>co</i>-octene) (POE)/Carbon Nanotube (CNT) Composites for Enhanced Electrical Conductivity and Electromagnetic Interference Shielding Performance

Study on interfacial compatibilizing effect of PB grafts on PB/GNP thermally conductive composites

AbstractUsing polymer‐grafts to improve the interfacial compatibilization of composites is by far the most common and effective strategy. However, although polybutene‐1 (PB) resin enjoys the reputation of “gold plastic” in the field of industry, there are few studies on its grafting and functional modification. In this work, PB‐grafts were prepared by melt grafting method with maleic anhydride (MAH) and styrene (St) as the functional monomers. The effect of two PB‐grafts (PB‐g‐MAH and PB‐g‐MAH‐co‐St) on the interfacial compatibilization of PB/GNP (Graphene nanosheet) thermally conductive composites was compared and the corresponding compatibilizing mechanism is discussed. Results indicate that PB‐g‐MAH‐co‐St has better compatibizing effect than that of PB‐g‐MAH because the cooperation of St with MAH enhanced the grafting degree of functional monomers on PB, and increased the surface energy of PB‐g‐MAH‐co‐St, which reduced the interface energy between PB and GNP and improved its interfacial adhesion. A better compatibilization effect has achieved when the compatibilizer and filler at the mass ratio of 1:4. Under this ratio, when the content of GNP is 30 wt%, the thermal conductivity and electrical conductivity of PB/GNP/ PB‐g‐MAH‐co‐St composite achieved 1.82 W·m−1·K−1 and 8.44 × 10−8 S·cm−1, which are 857.89% and 9 orders of magnitude higher than that of neat PB, respectively. Moreover, the composite has good mechanical properties and processability, which is beneficial to industrialization.Highlights PB‐g‐MAH‐co‐St has higher grafting ratio than that of PB‐g‐MAH. The surface energy of PB/GNP composites is reduced by use of PB‐g‐MAH‐co‐St. There is a suitable mass ratio between compatibilizer and filler. The composite of PB/GNP/PB‐g‐MAH‐co‐St achieved high thermal conductivity. The PB/GNP/PB‐g‐MAH‐co‐St composites have good melting processability.

Accelerated crystallization and crystal-crystal transition of PB induced by PP with optimized content

Isotactic polybutene-1 (PB)/isotactic polypropylene (PP) blends, typical crystalline/crystalline polymer blends with low-melting-temperature (Tm) PB and high-Tm PP, exhibit complicated interactions between their components in both molten and solid states. However, the intrinsic influences of PP component on crystallization of PB form II, form II-I transformation, and the dependence of these phase transitions on PP content are unclear. In this work, the influences of PP content ranged from 5 wt% to 40 wt% on PB crystallization were investigated. It was found that the content of PP played significant roles on the phase morphologies of the blends in molten state and then the subsequent crystallization of PB whatever in form II or form I. The PP components with ≤20 wt% addition acting as heterogeneous nucleation sites promoted crystallization nucleation, increased the crystallinity and lamellar thickness of PB, accelerated PB form II-I transformation and increased transformation degree with the increase in PP content. Whereas, the PP components with ≥30 wt% incorporation reduced the crystallinity and lamellar thickness of PB, retarded PB form II-I transformation and transformation degree with the increase in PP content. Interestingly, the PB/PP (80/20) blend presented the fastest II-I transformation rate as well as the highest transformation degree of PB. The dependence of crystallization and crystal structures of PB form II, form I, and form II-I transformation kinetics on PP concentration was discussed. PB form I′ was not observed in the present study. This work provides a theoretical and practical guide for the preparation of novel PB materials with desired structures and excellent performance, especially with anxiously accelerated crystal-crystal transition and transition degree of PB.

Identifying a Mesomorphic Boundary Zone within Polybutene-1 Single Crystals Emerging During a Crystal–Crystal Transformation

We present experimental evidence that the transformation from one solid phase to another solid phase within a faceted polymer single crystal passes through a transient mesomorphic phase. This phase exists in the boundary zone separating the two crystalline phases of isotactic polybutene-1 (PB-1), i.e., Form II and Form I of PB-1. Employing real-time atomic force microscopy in tapping mode (TM-AFM), we followed the crystal–crystal transformation in time. TM-AFM measurements performed at about 20 °C under a nitrogen atmosphere with high humidity have allowed through differences in viscoelastic properties and associated changes in thickness to distinguish the two crystalline phases as well as the boundary zone. Measurements at an elevated temperature of 90 °C (which was far below the melting temperatures of both Form II and Form I crystals) further revealed that this boundary zone shows a transient and diffuse character and a distinctly increased thickness. Using high-resolution phase imaging of TM-AFM, we observed that within this rather extended boundary zone of up to some hundred nanometers at elevated temperatures, Form I crystals with a diameter of around 30 nm were growing in a softer and featureless matrix phase. The boundary zone and so the growth front of the Form I crystal advanced at an almost constant rate, suggesting that chains in the mesomorphic phase were considerably mobile. Our observation of an extended boundary zone probably indicates that compared to a direct crystal–crystal transformation, the corresponding free energy barrier for this transformation is lower within such a zone. Hence, our here presented model study sheds light on the poorly understood and complex pathways involved in a solid–solid transformation within a polymer single crystal.

Diffusion controlled stereoregular polymerization in granule reactors - Reaction kinetic of Pr/Bt sequence polymerization with TiCl4/MgCl2 Ziegler-Natta catalyst

Diffusion controlled stereoregular polymerization was studied to understand the relations between fragmentation and growing of catalyst granules and its catalytic features for olefin polymerizations. In this work, propylene (Pr) polymerization kinetics and Pr/butene-1 (Bt) sequence polymerization kinetics with spherical TiCl4/MgCl2 Ziegler-Natta catalyst were investigated by monitoring catalytic activity (CA), the number of active centers ([C*]/[Ti]) and microstructure of polymers. It was found that the increase in Pr polymerization time benefiting to the catalyst granule fragmentation, had different influences on the [C*]/[Ti] and catalytic efficiency (CE) for Bt-stage polymerization in different stage. Anyway, the isotacticity and weight-average molecular weight (Mw) of isotactic polybutene-1 (iPB) fractions decreased gradually with the increase in Pr polymerization time. It was deduced that the easy solubility of polybutene-1 (PB) brought difficulties in further fragmentation of catalyst particles to expose more active centers, and Bt was more sensitive to the chemical and steric environment around the active species. This work provides further understanding of the catalytic characteristics of granule reactors in the initial polymerization stage, which will guide the novel polyolefin alloy production.

Autoclave foaming and steam-chest molding of polypropylene/polybutene-1 blend bead foams and their crystallization and mechanical properties

Expanded polypropylene (EPP) foams have showed wide applications in our daily life, such as automotive and packaging. Usually, autoclave foaming combined with steam-chest molding is the main artwork to prepare the high-precision EPP foam products. However, the foaming behavior of EPP and the excessive pressure required for molding still need to be further improved, which is great significance for energy saving and cost saving, etc. Herein, this study finds that adding a certain amount of polybutene-1 (PB-1) into the PP can help to reduce the temperature and pressure required for foaming/molding, and to broaden the foaming temperature. For example, in order to make the foam beads bonding well and with the expansion ratio of 20, the molding pressure should be higher than 2.7 bar for Neat PP foams, but just 1.5 bar for PP/PB-1 mixtures. Moreover, the effects of PB-1 content on the crystallization properties and foaming/molding behaviors of the PP/PB-1 bead foams are illustrated, and then the mechanical properties are also studied. Furthermore, the low-pressure foaming strategy presented here is beneficial for reducing the barriers of energy consumption and promoting the development of new bead foam materials.

Melt pre-shear induced orientation crystallization of PB and PB/HMwPB blend

Shear flow is important to understand the relationship between processing and properties of polymer products. In this work, the influences of shearing and high-molecular-weight polybutene-1 (HMwPB) on the evolution of oriented crystal's morphologies of isotactic polybutene-1 (PB) were investigated by shearing at a temperature slightly above the nominal melting temperature under different shear rate and shear duration. The shear thickening presented in primary normal stress revealed the presence of a gel-like network of shish-precursors, in which a birefringence region was observed in polarized optical microscopy (POM) images after crystallization in both PB and PB/HMwPB blend. Those shish-precursors enhanced the crystallization temperature and directly influenced the crystal structures of PB form II, and these crystal structures could be preserved from the form Ⅱ to form Ⅰ. The rheological, one-dimensional scattering, and DSC data reach a plateau with the shear duration, indicating that all the PB chains achieve their ultimate oriented state. The addition of a small amount of HMwPB caused the earlier formation of shish-precursors, the higher crystallization temperature of PB form Ⅱ, thicker lamellae, higher melting temperature, and degree of orientation of PB form Ⅰ. • Shear conditions for different crystal structures formation were given. • Shish-precursors formation and oriented crystal evolution were investigated using rheology methods combining optical microscopy and scattering technology. • The effect of HMwPB on shish-precursors formation and oriented crystal evolution was investigated.

Melt-state dynamic pressure engineered Polybutene-1 with form I crystals

Controlling the crystalline structure of semi-crystalline polymers is a primary topic for the entire polymer society. Among all investigations in this area, polybutene-1(PB-1) attracts an avalanche of attentions due to its essential feature of conventionally crystallizing into the kinetically favored metastable form II from melts, and then slowly transforms into the thermodynamically stable form I. Although enormous reports studied how to accelerate the transformation of PB-1 from form II to form I, it is still unable to directly obtain high-content form I crystals from pure PB-1 melts, which leads to unavoidable volume shrinkage issue. Herein, we report a novel dynamic pressure engineering (DPE) technique, which can directly induce predominated form I crystals formation from pure PB-1 melts. The initial form I proportion of DPE-processed samples surpasses 60% by FTIR, which is the first report of obtaining PB-1 with predominated form I crystals from pure PB-1 melts. Based on experimental investigations, the novel dynamic pressure induced form I PB-1 formation mechanism has been proposed, which is closely related to the relaxation time of the loose packed (11/3) conformation. Ultimately, this work not only provides a novel technique that can fabricate PB-1 with predominated form I crystals in a simple, highly efficient and low-cost way, but also reveals the essential role of melt-state pressure on the controlled crystallization of polymers.

Constructions of special network structure in natural rubber composites for improved anti-fatigue resistance

Nature rubber (NR) as the most widely used rubber material with excellent comprehensive properties suffers the poor fatigue resistance, which seriously affects the serving life of NR products. Blending crystalline components with NR could improve the fatigue properties of NR. However, the desired structures constructed by the crystalline component in the NR based composites were not clear. Herein, three crystalline polymers including isotactic polybutene-1 (PB), trans-1,4-polyisoprene (TPI) and trans-1,4-poly(butadiene-co-isoprene) copolymer rubber (TBIR) with varied crystallinity and crosslinking ability were selected to blend with NR for various network structure construction. The influences of unvulcanized PB and crosslinkable TPI and TBIR on the polymer network structures, filler network structures and then properties of the final composites were studied. It was found, although the modulus and hardness of both filled and unfilled NR/PB (90/10) vulcanizate improved, while the dynamic properties like heat built-up and fatigue resistance decreased greatly when compared with that of NR vulcanizate. While, NR/TBIR (90/10) vulcanizate showed the highest fatigue life. The structures of unfilled and filled NR/TBIR vulcanizates were analyzed to acquire the desired structure for satisfied fatigue properties of NR based composites. The more homogeneous rubber matrix enhanced with nano-scale crystalline lamellar structures and having co-vulcanization crosslinking bonds between NR and TBIR contributed to the greatly improved fatigue resistance, as well as satisfied other mechanical properties.

Retarded Crystallization and Promoted Phase Transition of Freeze-Dried Polybutene-1: Direct Evidence for the Critical Role of Chain Entanglement

Polymorphism and crystal transition are common phenomena of semicrystalline polymers. These two behaviors are known to be controlled by the nucleation and chain mobility of polymers, both of which are constrained by the chain entanglement at the molecular level. However, the role of chain entanglement in polymorphic crystallization and crystal phase transition of polymers has not been well understood. Herein, we use isotactic polybutene-1 (PB-1) as a model polymorphic polymer and present the crucial role of chain entanglement in the polymorphic crystallization kinetics and solid-solid phase transition. A series of less-entangled PB-1 with different entanglement degrees were successfully prepared by freeze-drying the polymer dilute solution. Compared to the bulk sample and re-entangled one, chain disentangling of PB-1 suppressed the crystallization kinetics of form II but significantly increased the phase transition rate and final transition degree from form II to form I. The disentangling-promoted II-I phase transition originated from the reduced nucleation barrier and enhanced chain mobility. This work would advance the in-depth understanding on the formation and transition mechanisms of polymorphic polymer crystals at the molecular level.

Molar mass dependent spatial distribution of form II to I transition inside spherulites of disentangled isotactic Polybutene revealed by scanning Confocal Raman microscopy

Form II to I transition in isotactic polybutene-1 (PB-1) is known to depend on the molar mass due to complicated interplays between crystalline phase and the amorphous inter-crystalline links. In general, higher molar mass favored the transition at the early stage as more inter-crystalline links result in more form I nuclei. At the late stage, it was observed that the low molar mass samples possess higher transition rate because of an easy relaxation of the unfavored stress generated during the transition. In this work, form II to I transition at room temperature in spherulites with few inter-crystalline links between adjacent lamellae, which were obtained by isothermally crystallizing two commercial PB-1 of different molar mass at sufficiently high temperature, were investigated using confocal Raman microscope scanning along the radii. Surprisingly, the spherulite of the higher molar mass PB-1 showed a higher gross transition rate at late stage than that of the lower molar mass one. Considering the impacts from the thermal stress, exterior stress, the neighbor effect of form I as well as the coordination of thermal fluctuation driven transition and retarding effect by nearest form I, a detailed analysis of the spatial distribution of the transition within the spherulites revealed that the lamellae inside the higher molar mass sample led to a higher form II to I transition in the late stage through its preponderance of abundant long-chain ends, numerous folding parts and more effective lateral connectivity along the radial arms.

Mechanism of form I′ formation in polybutene-1/polypropylene blends

Isotactic polybutene-1 (PB) can crystallize into form I′ polymorph directly in its blends with isotactic polypropylene (iPP), but the mechanism remains controversial. In this work, by using Fourier-transform infrared spectroscopy (FTIR), wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC), we investigated systematically cold crystallization of PB in its blends with iPP and with atactic polypropylene (aPP), one crystallizable and the other amorphous. It was found that form I′ was produced in both PB/iPP and PB/aPP blends, the higher the PP content, the greater the form I′ fraction, and iPP was found to be more effective in promoting form I'. However, in a PB/iPP blend containing 10 wt% iPP with the iPP fully crystallized at 120 °C, the PB crystallized into form II exclusively in the cold crystallization, at a faster rate than in neat PB. These experimental results indicate that in PB/iPP blends both confined nucleation mechanism and surface nucleation mechanism operate, but the former governs the PB polymorph formed. Under the confinement only the smaller form I′ nuclei are allowed, and the PP crystals then expedite the process via the surface nucleation mechanism.

Covalent crosslinks turn natural Eucommia ulmoides gum/polybutene‐1 composites into multiple shape memory materials

AbstractA series of shape memory natural Eucommia ulmoides gum (EUG)/polybutene‐1 (PB‐1) composites were developed based on polymer blending. It was revealed that covalent crosslinks turned typical “sea‐island” phase morphology in the EUG/PB‐1 blend into a chemical co‐continuous structure, which played a vital role in promoting mechanical performances and fulfilling multiple shape memory effect dominated by the two well‐separated crystalline and melting phase transitions. Although the increase in cross‐linking density was a disadvantage to mechanical performances and shape fixing, the composite with more covalent crosslinks displayed better shape recovery capacity. The EUG/PB‐1 composite crosslinked by 0.4 phr diycumyl peroxide (DCP) displayed the highest shape fixing capacity, while the best shape recovery ability was given by that crosslinked by 1.6 phr DCP. The findings would provide a new technique to develop intelligent materials applied in smart packaging and hot‐shrinkable products.

Extrusion foaming behavior of polybutene‐1. Toward single‐material multifunctional sandwich structures

AbstractPolymeric foams are a key element of many multifunctional sandwich structures. The most commonly used polymeric foam, polyurethane, presents environmental drawbacks, related to poor recyclability and the use of toxic diisocyanates for their manufacturing. The separation of layers in sandwich structures is a further unresolved hurdle toward the recyclability of these elements. There is a need for broadening the spectrum of polymeric foams. In this context, the foamability of polybutene‐1 (PB‐1) is studied through extrusion foaming experiments. From the application side, foaming PB‐1 would allow the manufacturing of district heating pre‐insulated pipes out of one single material, bringing circular product design to the energy sector. From the scientific side, there is a knowledge gap in the foaming of polymers in the rubbery state at room temperature, such as PB‐1, due to difficulties in the cell stabilization step. This supports the need for research in the foaming of this polymer. In this study, four commercial grades of PB‐1 were evaluated, covering different chain structures, molecular weights, and crystallinity degrees. Very different foaming behaviors were found. Dimensionally stable foams were achieved with the two homopolymers tested, demonstrating the foamability of this polymer.

Regulation of alkoxysilane on stereoregular polymerization of Butene-1 catalyzed by TiCl4/MgCl2 Ziegler-Natta catalysts

External electron donors (ED) as one of the components in traditional Ziegler-Natta (Z-N) catalysts play important roles in determining the activity, stereoregularity of the active species for ɑ-olefin polymerization. Alkoxysilanes with different size and different electron-donating alkyl substituents were investigated to study the stereoregular polymerization of butene-1 catalyzed by TiCl4/MgCl2 Z-N catalysts. The obtained polybutene-1 (PB) was fractionated into three components including high isotactic PB (HiPB), medium isotactic PB (MiPB) and atactic PB (aPB) and the number of active centers ([C*]/[Ti]) of each component were measured accordingly. The mmmm sequence concentration, weight-average molecular weight (Mw), molecular weight distribution (MWD), and crystallizability of PB were studied by carbon-13 nuclear magnetic resonance spectrometry (13C-NMR), gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). The addition of dimethyldimethoxysilane (D1) with 120.1 Å3 volume and 0.6802 a.u. electron density had little influence on the stereoregular polymerization of butene-1. The incorporation of diphenyldimethoxysilane (D3) with higher steric hindrance (231.2 Å3 volume), stronger electro-donating ability (0.6969 a.u. electron density) produced PB with higher HiPB component, higher mmmm sequence concentration, accompanying by the reduced catalytic activity and [C*]/[Ti]. The probably active center models absorbing different ED were proposed to explain the catalytic behaviors for butene-1 polymerization and formation of PB with different components.

Crystallization kinetics, crystalline structures and properties of PB/PP blends regulated by poly(butene-block-propylene) copolymers

Blending isotactic polybutene-1 (PB) with isotactic polypropylene (PP) is a facial strategy to improve the mechanical properties and promote polymorphous transformation of PB. As the immiscible polymer pairs with strong crystallizability, the interactions between PP and PB in the melt state influence the subsequent processes like phase separation and crystallization, and then determine the crystalline structures and properties of the blends. Herein, two kinds of poly(butene-block-propylene) (PB-b-PP) copolymers with different sequence structures fractionated from PB/PP in-reactor alloy using temperature rising elution fractionation were utilized to compatibilize the PB/PP (80/20) blend. The phase morphologies, crystallization kinetics of PP and PB phases, and crystalline structures in PB/PP/PB-b-PP blends were characterized by phase contrast optical microscopy (PCOM), differential scanning calorimeter (DSC), and small-angle X-ray scattering (SAXS). The PB-b-PP copolymer with longer PP blocks (A) showed more satisfied compatibilization for PB/PP blends and PB/PP/PB-b-PP-2.5 blend with 2.5 wt% copolymer as compatibilizer exhibited the most stable phase morphology with the smallest PP domains in melt state at 200 °C. During isothermal crystallization processes of the PB/PP/PB-b-PP blends at 135 °C for PP crystallization and then 90 °C for PB crystallization, the crystallization rate including nucleation rate and nucleation density, and crystallinity of PP and PB (form II) increased, and achieved the largest when the copolymer concentration was 2.5 wt% in PB/PP/PB-b-PP blend. The copolymer A significantly accelerated crystallization rate of PP compared with that of copolymer B. The PB/PP/A-2.5 blend with the largest lamellae thickness and highest crystallinity of PB form I, combined with the smallest spherulites, exhibited the highest modulus, tensile strength and toughness. The compatibilizing mechanism and roles of PB-b-PP copolymers for PB/PP blends were discussed to understand the physical and mechanical behaviors of the blends.

Interfacial localization of organoclay enhances the peelability of polyethylene/polybutene-1/organoclay nanocomposite films

Premature failure in polymer blends originates mainly at interfaces between immiscible polymers which is deemed detrimental to mechanical properties in many applications. Here we exploit this phenomenon in developing a peelable film with a very wide peelable seal-temperature window (ΔTp) of over 90 °C. A melt-cast films of low-density polyethylene (PE) containing both 5 wt% isotactic polybutene-1 (PB-1) and 1 phr organoclay shows peel strength well within the peelable region (150–650 N/m), whereas the PE/5 wt% PB-1 blend, and PE/1 phr organoclay nanocomposite films are lock sealed similar to the neat PE film after the sealing process. Furthermore, the characteristic aging of the PE/PB-1 blends is eliminated by the addition of organoclay to the system. The results indicate a synergistic interaction between organoclay and PB-1 that plays a key role in the formation and consistent propagation of cracks throughout the system. The localization of organoclay at the interface of the PE/PB-1 blend significantly reduces the thickness of the fibrillar PB-1 phase more than three times to 60 nm. This suggests an increase in the interfacial area that can facilitate interfacial cracking and failure at the interface. The nanoconfinement induced by the PE matrix and organoclay at the interface also enhance the formation of the thermodynamically stable form I and form III PB-1 crystals rendering a consistent peel performance.

An improved method for the high isotacticity measurement of polybutene-1

High isotactic polybutene-1 (HiPB) plays important roles in presenting outstanding resistance to creep and crack at high temperature. Therefore, rapid and accurate measurement of the HiPB is extremely important for both synthesis and application of polybutene-1 (PB). In this work, solvent extraction fractionation with diethyl ether (DE) and n-hexane (C6) as solvents (DE-C6 method) and an improved fractionation method combining isothermal crystallization and solvent extraction with xylene (Xyl) and n-pentane (C5) as solvents (Xyl-C5 method) were used to fractionate PB samples. The carbon-13 nuclear magnetic resonance spectrometry (13C-NMR), gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) were used to conduct the composition analysis of PB original samples and PB fractions. It was found that the DE-C6 method was greatly depended on the molecular weight of the fractions, while the Xyl-C5 method was biased on the isotacticity of PB fractions and fractionated PB samples into atactic PB (aPB), medium isotactic PB (MiPB) and HiPB, which showed independence on the molecular weight of fractions. Therefore, the Xyl-C5 method is recommended for more accurate measurement and isolation of HiPB fractions from PB samples.

Promotion of Form I′ in the Polymorph Selection of Polybutene-1 during Crystallization under High Gas/Supercritical Fluid Pressure via Enhancing Chain Mobility

Polybutene-1 (PB-1) always crystallizes into its metastable form II when cooled from a molten state because of its lower nucleation barrier, while the stable form I exhibits superior properties com...

How Nanotopography-Induced Conformational Changes of Fibrinogen Affect Platelet Adhesion and Activation.

The conformational state of adsorbed human plasma fibrinogen (HPF) has been recognized as the determinant factor in platelet adhesion and thrombus formation on blood-contacting biomaterials. Studies have highlighted the ability to control the HPF conformation merely by tailoring surface nanotopographical features. However, a clear relationship between the conformational changes of adsorbed HPF and the degree of platelet adhesion and activation achieved with different surface nanotopographies is still unclear. Here, we examined HPF assembly characteristics on nanostructured polybutene-1 (PB-1) surfaces with nanosized lamellar crystals (LCs), needle-like crystals (NLCs), and a nanostructured high-density polyethylene (HDPE) surface with shish-kebab crystals (SKCs), at a biologically relevant HPF concentration. By exposing the nanostructured surfaces with preadsorbed HPF to human platelets, significant differences in platelet response on LCs/SKCs and NLCs were identified. The former presented a uniform monolayer in the advanced stage of activation, whereas the latter exhibited minimal adhesion and the early stage of activation. Distinct platelet response was related to the postadsorption conformational changes in HPF, which were confirmed by topography-dependent shifts of the amide I band in attenuated total reflection-Fourier transform infrared (ATR-FTIR) analysis. Supported by atomic force microscopy (AFM) characterization, we propose that the mechanism behind the nanotopography-induced HPF conformation is driven by the interplay between the aspect ratios of polymeric crystals and HPF. From the biomedical perspective, our work reveals that surface structuring in a nanoscale size regime can provide a fine-tuning mechanism to manipulate HPF conformation, which can be exploited for the design of thromboresistant biomaterials surfaces.