Crystallization Of Polylactide Research Articles

Structural features of polylactide and natural rubber films produced by solution casting

Composite film samples of polylactide-natural rubber with a rubber content of 5, 10 and 15 wt. % were obtained by the solution method. The study of morphology showed the presence of rubber inclusions in the form of drops in the polylactide matrix. Thermophysical characteristics were determined by differential scanning calorimetry. It was determined that when rubber was added, the peak of cold crystallization of polylactide disappears on melting thermograms, the melting temperature decreases by 1–4°C compared to 100% polylactide. The structure of the obtained compositions was studied by nuclear magnetic resonance, electron paramagnetic resonance, and X-ray diffraction. The diffraction patterns of the samples contain reflections characteristic of the crystalline α-form of polylactide.

Tensile properties and deformation by different compatibilizers in bio-based polylactide/poly(4-hydroxybutyrate) blends

Blending chemically synthesized poly(4-hydroxybutyrate) (P4HB) with polylactide (PLLA) can overcome PLLA's brittleness, offering fully biobased blends. However, due to low compatibility between PLLA and P4HB, the influence of compatibilizers on the morphology, structure and tensile deformation of PLLA/P4HB blends remains to be unresolved. This article introduces reactive poly(methyl methacrylate-co-styrene-glycidyl methacrylate) (MSG) and non-reactive polyformaldehyde (POM) compatibilizers to improve the compatibility between P4HB and PLLA, achieving the maximal elongation at break exceeding 300 % at 2 wt% MSG or 3 wt% POM. MSG inhibits PLLA crystallization, extending stress stability in the silver streak stage, while POM enhances crystallization, prolonging the strain-hardening stage. Small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) analysis show that pristine PLLA forms voids before fracture, and PLLA/P4HB blends cavitate at the yield point and develop crazes in the silver streak stage. MSG effectively transmits stress and delays cavitation, extending the silver streak stage, whereas POM forms a microcrystalline network, lowering the energy barrier for stretching-induced recrystallization. These findings could provide theoretical guidelines on selecting compatibilizers for different PLLA based blends.

Enhanced rheological, crystallization, mechanical, and heat resistance performance of poly(L‐lactide)/basalt fibers composites via in situ formation of stereocomplex polylactide crystals

AbstractDue to its favorable mechanical strength, transparency, and biocompatibility, polylactic acid (PLA) has considerable potential as a biodegradable material. Nevertheless, developing high‐performance PLA composites through environmentally friendly and cost‐effective methods remains a significant challenge. In this study, the composites comprising poly(L‐lactide) (PLLA), basalt fibers (BFs), and poly(D‐lactide) (PDLA) are prepared through facile melt blending. The in situ formed stereocomplex polylactide (SC‐PLA) crystals improve the crystallization ability and rheological behavior of PLLA/BF/PDLA composites. Upon adding 5 wt% PDLA, BFs are nicely dispersed in PLLA matrix because of increased shear intensity. The synergistic effect of BFs and SC‐PLA crystals enhances the mechanical, thermomechanical, and heat resistance properties of PLLA. In particular, PLLA/BF/10%PDLA composites exhibit a Vicat Softening Temperature (VST) of 155.5°C, increasing by approximately 100°C over neat PLLA. Annealing treatment increases the Young's modulus, thermomechanical properties, and VST of samples while reducing their tensile strength. Interestingly, the tensile strength of the annealed PLLA/BF/10%PDLA composites is 50.2 MPa, twice that of the annealed neat PLLA due to the introduction of SC‐PLA crystals. Simultaneously improving the rheological, mechanical, and heat resistance performance of PLLA opens possibilities for expanding its potential applications in the industrial field.

Miscibility, crystallization and morphology in the novel polylactide/poly(4-hydroxybutyrate) blends

The novel marine degradable poly (4-hydroxybutyrate) (P4HB) synthesized by chemical technique could obviously improve the brittleness of polylactide (PLLA) via physical blending. However, the miscibility, crystallization and morphology in PLLA/P4HB blends are still unexplored. In this article, the PLLA/P4HB blends with different weight ratios were prepared by the solution casting method, followed by the melting crystallization treatment. The PLLA and P4HB were demonstrated to be miscible near the melting temperature of PLLA as revealed by the Flory-Huggins interaction parameter calculating by melting point depression method. Anyway, PLLA and P4HB are supposed to be immiscible at room temperature according to the interfacial tension, fourier transform infrared spectroscopy (FTIR) analysis and scanning electron microscopy (SEM) observation. Both of PLLA and P4HB could form the highly crystalline crystals as casting from solution. The existence of P4HB could significantly induce the cold crystallization of PLLA on the second heating curves characterized by differential scanning calorimetry (DSC), showing of a sharp reduction in peak temperature of about 40 °C lower than that of pristine PLLA. The polarized optical microscopy (POM) and atomic force microscopy (AFM) observation revealed that the P4HB phase could penetrate into the region between fibrous crystals of PLLA spherulites during the isothermal crystallization at 130 °C, and the P4HB fragmented crystals will form after cooling to room temperature, leading to the formation of vertical phase separation in PLLA/P4HB blends associating with the surface tension data. The findings will provide theoretical guidance to understand the miscibility in PLLA based fully biodegradable blends, modulating the morphology and properties of the blends.

Influence of Processing Parameters on Mechanical Properties and Degree of Crystallization of Polylactide.

This work attempts to assess the influence of process parameters on the change of mechanical properties and the degree of crystallinity of polylactide (PLA). PLA is a biodegradable material that has been widely used in various areas-from packaging, through medicine, to 3D printing, where it is used to produce prototypes. The method of processing is important, because the technological process and its parameters have a significant impact on the quality of the finished product. Their appropriate selection depends on quality and mechanical properties. The process parameters have an impact on the structure of PLA, specifically on the share of the crystalline phase, which is also important from the point of view of the functional properties of the finished product. This work assessed the impact of the technological parameters of the injection process on the final properties of the obtained samples. The obtained results of static tensile strength, hardness and differential scanning calorimetry (DSC) analysis confirm that changing these parameters affects the material properties.

Improvement of the properties of poly (L-lactide)/ethylene-ethyl acrylate-glyceryl methacrylate terpolymer (EGA) by the introduction of stereocomplex polylactide crystals

Ternary blends comprising poly(L-lactide) (PLLA), ethylene-ethyl acrylate-glyceryl methacrylate terpolymer (EGA), and poly(D-lactide) (PDLA) were melt blended using low-temperature method to obtain blends with balanced properties. The formation of stereocomplex polylactide (SC-PLA) crystals was verified by torque changes and differential scanning calorimetry (DSC) results. The SC-PLA crystals formed a percolating network in the PLLA matrix at a concentration of 2 wt% PDLA, and blend melt presented solid-like rheological behavior. Attributing to the increased viscosity ratio between PLLA and EGA, the size of dispersed EGA phase increased. The crystallization of PLLA was significantly promoted because of the nucleation effect of SC-PLA crystals. The PLLA/EGA/2 %PDLA ternary blends with elongation at break of 138 % and impact strength of 72.3 kJ/m2 exhibited excellent toughness. These ternary blends demonstrated exceptional crystallization ability and tailored rheological and mechanical properties, opening a new path for developing high-performance PLLA-based materials in packaging industry.

Role of the plasticizers on the crystallization of PLA and its composites with mesoporous MCM-41

Several materials were prepared by melt extrusion, based on an L-rich polylactide (PLA), as polymeric matrix, acetyl tri-n-butyl citrate (ATBC) or trioctyl trimellitate (TOTM), as plasticizer, and mesoporous MCM-41 particles, playing a nucleant role. Influence of the addition of these nucleating particles, together with the comparative effect of the two plasticizers, has been thoroughly evaluated on the features of the several phase transitions existing in the PLA polymeric matrix (glass transition, cold crystallization, α′ to α transition, melting processes and melt crystallization) as well as on the rate of PLA crystallization. The window where this ordering process can take place is shifted down to lower temperatures for these binary and ternary systems and the range of temperatures at which the α′ and α polymorphs crystallize under isothermal crystallization from the glassy state significantly changes in the materials containing ATBC as plasticizer, either the binary or ternary ones. Type of the major crystalline lattice developed at 85 and 110 °C has been confirmed, additionally to the DSC experiments, by FTIR spectroscopy.Graphical abstract

Enhancing mechanical and shape memory properties of polylactide/polyamide elastomer blends via reactive blending with a chain extender

AbstractThe structure and properties of incompatible polylactide (PLA)/polyamide elastomer (PAE) blends were tailored by a chain extender specifically the styrene–glycidyl acrylate copolymer Joncryl ADR4368 (ADR). Various PLA/PAE/ADR blends with different compositions were prepared by melt blending, and their morphology, crystallization behavior, and mechanical and the shape memory properties were systematically investigated. The results showed a uniform dispersion of PAE particles in the PLA matrix for the PLA blends with a reduction in particle size upon the addition of ADR. The crystallization of PLA was retarded, which was confirmed by a decrease in the melt crystallization temperature and an increase in cold crystallization temperature in the PLA/PAE/ADR blends. Rheological analysis showed an improvement in the melt elasticity of the PLA/PAE binary blend due to the presence of ADR, possibly attributed to the formation of long‐chain‐branched copolymers at the interface. Notably, the PLA/PAE/ADR blend exhibited superior toughness, featuring an elongation at break of 288% and a notched impact strength of 37 kJ·m−2, along with a high shape memory fixation rate and recovery rate when the ADR content was 1 wt%. Furthermore, the underlying toughening mechanism was elucidated. This work may offer an industrially scalable relevant model to fabricate high‐performance PLA materials.

Supertoughened Polylactide via the Addition of Low Content Poly(ε-caprolactone) and Tensile Deformation above the Glass Transition Temperature

Polylactide (PLA) is considered as an ideal alternative of petroleum-based plastics due to its high tensile strength and biodegradability. However, the low impact strength limits its extensive application in the engineering field. In this work, a supertough binary PLA blend was fabricated through pre-stretching above the glass transition temperature to a certain pre-strain. The biodegradable and biocompatible poly(ε-caprolactone) (PCL) was used as a toughening modifier for the PLA/PCL 95/5 (wt/wt) blend. It was found that the impact strength increased with the increase in pre-strain. The highest notched Izod impact strength reached 251 kJ/m2 at the pre-strain of 400%, nearly 132 times of that for neat PLA (1.9 kJ/m2). To our knowledge, such fabulous impact toughness has not been referred in literature. Even at the pre-strain of 150%, the blend exhibited a sufficiently high notched Izod impact strength of 149 kJ/m2. Small-angle X-ray scattering demonstrated a typical structural feature of combination of PLA shish-kebabs and oriented PCL lamellar stacks due to strain-induced crystallization. The wide-angle X-ray diffraction indicated that PLA crystals had high orientation at the pre-strain of 200% and above. The crystallinity of the PLA matrix increased with the increase in pre-strain, which was consistent with the increasing trend of impact strength. The high orientation of shish-kebabs and increased crystallinity of PLA matrix were the key factors for drastically toughening PLA. This work provides a feasible and effective method to manufacture competitive PLA materials, which can be extended to improve impact toughness of other brittle glassy polymers.

Thermal transitions and molecular mobility in polymeric blends based on polylactide (PLA) and poly(3,3-ethylene dithiodipropionate) (PEDPA)

A series of polymer blends based on poly(lactic acid), PLA, and poly(3,3-ethylene dithiodipropionate) PEDPA, varying in the PLA/PEDPA ratio from 90/10 to 50/50, are studied in this work. The said systems are envisaged for transdermal drug carrier systems, moreover, to be prepared using the method of electrospinning and exhibiting self-healing capabilities. The study involves calorimetry, for glass transition and crystallization, and dielectric spectroscopy, for molecular dynamics, as the main investigation tools, supplemented by X-ray diffraction, polarized light and Fourier transform infrared spectroscopies. For comparison, we study neat PLA and PEDPA. Actually, for PEDPA, the local and segmental molecular mobility map is shown here for the first time. The two phases were found to affect each other's mobility, at a moderate extent. We conclude to the partial miscibility of the two polymers, resulting in systems with PLA matrices and PEDPA/PLA entities (drops) well dispersed throughout the matrix. The segmental dynamics of PLA accelerates in the blends, while the chain fragility (cooperativity) is suppressed, the effects indicating together a plasticization effect. On the other hand, the opposite results are recorded for the mobility of PEDPA at the presence of PLA, namely, deceleration and slight increase in fragility. Based on the ionic conductivity recordings, the PEDPA phase does not seem continuous throughout the blends' volume at any case of PEDPA fraction. In general, the crystallization of PLA is suppressed in the blends, in both the nucleation and crystalline fraction, and, subsequently, the melting point drops. Serious changes in the semicrystalline morphology are observed within the blends, in terms of smaller spherulites and of smaller density. Overall, the results suggest that the PLA/PEDPA blends offer potentials for tuning the macroscopic materials' performance, while the said combination of experimental techniques is able to provide useful information and indirect evidence regarding the polymers' topology.

The Role of the Interface of PLA with Thermoplastic Starch in the Nonisothermal Crystallization Behavior of PLA in PLA/Thermoplastic Starch/SiO2 Composites

Corn starch was plasticized by glycerol suspension in a twin-screw extruder, in which the glycerol suspension was the pre-dispersion mixture of glycerol with nano-SiO2. Polylactide (PLA)/thermoplastic starch/SiO2 composites were obtained through melt-blending of PLA with thermoplastic starch/SiO2 in a twin-screw extruder. The nonisothermal crystallization behavior of PLA in the composites was investigated by differential scanning calorimetry. An interface of PLA with thermoplastic starch was proven to exist in the composites, and its interfacial bonding characteristics were analyzed. The interfacial binding energy stemming from PLA with thermoplastic starch exerts a significant influence on the segmental mobility of PLA at the interface. The segmental mobility of PLA is gradually improved by increasing interfacial binding energy, and consequently, the relative crystallinity on the interface exhibits progressive promotion. The Jeziorny model could well describe the primary crystallization of PLA in the composites. The extracted Avrami exponents based on the Jeziorny model indicate that the primary crystallization of PLA follows heterogeneous nucleation and three-dimensional growth. This study has revealed the intrinsic effect of the interfacial segmental mobility on the nonisothermal crystallization behavior of PLA in composites, which is of technological significance for its blow molding.

Combined Effects from Dual Incorporation of ATBC as Plasticizer and Mesoporous MCM-41 as Nucleating Agent on the PLA Isothermal Crystallization in Environmentally-Friendly Ternary Composite Systems.

Different materials, based on an L-rich polylactide (PLA) as matrix, acetyl tri-n-butyl citrate (ATBC) as plasticizer, and mesoporous Mobile Crystalline Material.41 (MCM-41) particles as nucleating agent, were attained by melt extrusion. These materials are constituted by (a) binary blends of PLA and ATBC with different contents of the latest; (b) a dual compound of PLA and a given amount of MCM-41 silica (5 wt.%); and (c) ternary composites that include PLA, ATBC at several compositions and mesoporous MCM-41 at 5 wt.%. Influence of the incorporation of the plasticizer and nucleating particles has been comprehensively analyzed on the different phase transitions: glass transition, cold crystallization, melt crystallization and melting processes. Presence of both additives moves down the temperature at which PLA phase transitions take place, while allowing the PLA crystallization from the melt at 10 °C/min in the composites. This tridimensional ordering is not noticeable in the pristine PLA matrix and, accordingly, PLA crystallization rate is considerably increased under dynamic conditions and also after isothermal crystallization from either the melt or the glassy state. An important synergistic effect of dual action of ATBC and MCM-41 has been, therefore, found.

Tailoring and Long-Term Preservation of the Properties of PLA Composites with "Green" Plasticizers.

Concerning new polylactide (PLA) applications, the study investigates the toughening of PLA-CaSO4 β-anhydrite II (AII) composites with bio-sourced tributyl citrate (TBC). The effects of 5-20 wt.% TBC were evaluated in terms of morphology, mechanical and thermal properties, focusing on the enhancement of PLA crystallization and modification of glass transition temperature (Tg). Due to the strong plasticizing effects of TBC (even at 10%), the plasticized composites are characterized by significant decrease of Tg and rigidity, increase of ductility and impact resistance. Correlated with the amounts of plasticizer, a dramatic drop in melt viscosity is also revealed. Therefore, for applications requiring increased viscosity and enhanced melt strength (extrusion, thermoforming), the reactive modification, with up to 1% epoxy functional styrene-acrylic oligomers, was explored to enhance their rheology. Moreover, larger quantities of products were obtained by reactive extrusion (REX) and characterized to evidence their lower stiffness, enhanced ductility, and toughness. In current prospects, selected samples were tested for the extrusion of tubes (straws) and films. The migration of plasticizer was not noted (at 10% TBC), whereas the mechanical and thermal characterizations of films after two years of aging evidenced a surprising preservation of properties.

New opportunities for sustainable bioplastic development: Tailorable polymorphic and three-phase crystallization of stereocomplex polylactide by layered double hydroxide

Stereocomplexation between enantiomeric poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) is a promising sustainable approach and gaining momentum to overcome the shortcomings of polylactide (PLA) for its use as a replacement for fossil-based plastics. Filler addition in tailoring the crystallization of stereocomplex PLA (SC-PLA) has attracted extensive attention; however, research has primarily focused on the heterogeneous nucleation effect of filler. The impact of filler on the chain behavior of SC-PLA during crystallization has not been exclusively discussed, and the rigid amorphous fraction (RAF) development remains unknown. In this study, the crystallization of PLLA/PDLA blends was modified by low loading of layered double hydroxide (LDH) (≤ 1 wt%) with the proposed local effect of such filler, and additional RAF development was incurred. In the early stage of crystallization, LDH facilitates the pairing of PLLA and PDLA and arrests the ordered SC pairs during the dynamic balance between the separation and pairing of racemic segments. This explains the severely suppressed homochiral (HC) crystallization, promoted SC crystallization, and additional RAF formation driven by the nucleation-induced chain ordering. This work, for the first time, highlights the role of LDH in creating SC-PLA with tailorable polymorphism and RAF, where the mechanism can be extended to other filler-type nucleator systems.

Effect of the structural features of biobased linear polyester plasticizers on the crystallization of polylactides

This work presents, for the first time, a detailed report on how the nucleation and crystallization of polylactide (PLLA) are affected by biobased aliphatic polyesters plasticizers. Three biobased polyesters were synthesized via solvent-free two-stage melt polycondensation of adipic acid (AdA) with three different biobased aliphatic diols and used as plasticizers for poly (L-lactic acid) (PLLA). The molecular structure of the synthesized polyesters was proved using 1H NMR, 13C NMR and Fourier transform infrared (FTIR) spectroscopy. PLLA/AdA-based blends containing 10 wt% of the polyester plasticizers were studied by tensile tests, dynamic mechanical analysis (DMA), wide-angle x-ray scattering (WAXS), differential scanning calorimetry (DSC) and polarized light optical microscopy (PLOM). Adding the plasticizers to PLLA decreased Tg by up to 11 °C and significantly increased the elongation at break by about 8 times compared with neat PLLA. The addition of 10 wt% of any AdA-based plasticizer to PLLA increases the nucleation rate from the glassy state by around 50–110 % depending on the plasticizer. The overall crystallization rate from the glassy state was 2–3 times faster for the plasticized PLLAs than neat PLLA. These results are a consequence of the lower energy barrier for both nucleation and growth processes. The incorporation of AdA-based linear polyesters had an incremental impact on the crystal growth rate (or secondary nucleation) of PLLA spherulites from the melt and glassy states. In conclusion, the AdA-based aliphatic polyesters allowed to enhance PLLA crystallization rates and showed interesting potential for the formulation of fully biobased PLLA blends.

Miscible polymethyl methacrylate/polylactide blend with enhanced foaming behavior and foam mechanical properties

High-performance foams play significant roles in many industries. Microcellular foaming with carbon dioxide as blowing agents is an advanced and environmentally friendly technology to prepare polymeric foams with significantly refined cellular morphology. The manipulation of polymer microstructure and rheological behavior is the key to tailor its foaming behavior. In this study, polymethyl methacrylate (PMMA) was blended with polylactide (PLA) to improve its foaming behavior in one-step batch foaming with carbon dioxide as blowing agents. It was demonstrated that PMMA and PLA are fully miscible in molecular level. The presence of PLA can lead to decreased glass transition temperature of PMMA, and PMMA can suppress the crystallization of PLA. PLA can enhance the melt elasticity of PMMA at low shear oscillation frequencies but decrease the melt elasticity of PMMA at high shear oscillation frequencies. Thanks to the plasticity effect and heterogeneous nucleation effect of PLA, adding an appropriate amount of PLA can significantly broaden the foaming window of PMMA and refine cellular morphology. Microcellular PMMA/PLA foams with cell sizes less than 10 µm and expansion ratio up to 18.4 were fabricated under a foaming pressure of 17.24 MPa with 10 wt% PLA. Nanocellular PMMA/PLA foam can be achieved with the presence of 25 wt% PLA under a foaming pressure of only 6.90 MPa. The PMMA/PLA blend foams show significantly enhanced compression modulus and strength compared with neat PMMA foams. Moreover, reducing cell sizes can significantly enhance the compression modulus and strength of foams.

Enhanced crystallization behavior and stiffness-toughness balance of polylactide/poly(propylene carbonate)/nucleating agent blends

Both poly(propylene carbonate) (PPC) and a hydrazide compound tetramethylenedicarboxylic di(2-hydroxybenzohydrazide) (TMBH) were selected to modify the crystallization behavior and stiffness-toughness balance of polylactide (PLA) simultaneously. For PLA/PPC binary blends, a sea-island phase structure could be observed and transformed to a bi-continuous structure gradually with the increase of PPC concentration. Due to the thermodynamic immiscibility, the addition of PPC had little nucleating effect on PLA during the cooling stage. As a result, tensile properties of PLA/PPC blends declined obviously with increasing PPC loadings. Otherwise, the addition of TMBH effectively enhanced the crystallization ability of PLA. Interestingly, the dimension of both PPC domains and PLA crystals in ternary blends was much smaller than its binary counterparts under the same PPC concentrations due to the addition of TMBH. This contributed to the increase of tensile toughness and the occurrence of brittle-ductile transition as PPC content reached 40 wt%.

Spontaneous formation of hierarchical structures in some polylactide/polysilsesquioxane blends

Evaporative crystallization of polylactide was modulated by functionalized ladder polysilsesquioxanes through conformational changes in the polyester backbone. Atypical spherulites spontaneously formed a hierarchical 3D superstructure.

Effect of Mixing Strategy on the Structure-Properties of the PLA/PBAT Blends Incorporated with CNC

Polylactide (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) blend nanocomposites including 3 wt% of cellulose nanocrystals (CNCs) were prepared by melt compounding method in a twin-screw extruder and an internal mixer. Blend nanocomposites were formulated by diluting three different masterbatches prepared by solution casting method that contained 7 wt% of CNC. These masterbatches were: (m1) PLA/PBAT/CNC masterbatch; (m2) PLA/CNC masterbatch; and (m3) PBAT/CNC masterbatch. These were to explore how different preparation methods affect the dispersion and localization of CNC and hence the properties of PLA/PBAT/CNC blend nanocomposites. Scanning electron microscopy (SEM) was used to study the structural changes of the blends. Rheological properties of PLA/PBAT blends and PLA/PBAT/CNC blend nanocomposites were also investigated. In the samples prepared by internal mixer, the rheological behavior of blend nanocomposite prepared through premixing of CNC particles with PLA showed a transition from liquid-like to a gel-like behavior. According to the rheological results and differential scanning calorimetry (DSC) analysis, it was found that the CNC overall enhanced the viscoelastic properties of blends and improved the PLA crystallization, respectively. Dynamic mechanical analysis (DMA) illustrated that the incorporation of CNC also enhanced the elastic modulus of PLA/PBAT blends specifically above the glass transition temperature of PLA. The expected improvements in mechanical properties did not occur due to the possible existence of residual solvent in the blends.

Tungsten disulfide nanotubes enhance flow-induced crystallization and radio-opacity of polylactide without adversely affecting in vitro toxicity

Treatment of vascular disease, from peripheral ischemia to coronary heart disease (CHD), is poised for transformation with the introduction of transient implants designed to “scaffold” regeneration of blood vessels and ultimately leave nothing behind. Improved materials could expand the use of these devices. Here, we examine one of the leading polymers for bioresorbable scaffolds (BRS), polylactide (PLA), as the matrix of nanocomposites with tungsten disulfide (WS2) nanotubes (WSNT), which may provide mechanical reinforcement and enhance radio-opacity. We evaluate in vitro cytotoxicity using vascular cells, flow-induced crystallization and radio-opacity of PLA-WSNT nanocomposites at low WSNT concentration. A small amount of WSNT (0.1 wt%) can effectively promote oriented crystallization of PLA without compromising molecular weight. And radio-opacity improves significantly: as little as 0.5 to 1 wt% WSNT doubles the radio-opacity of PLA-WSNT relative to PLA at 17 keV. The results suggest that a single component, WSNT, has the potential to increase the strength of BRS to enable thinner devices and increase radio-opacity to improve intraoperative visualization. The in vitro toxicity results indicate that PLA-WSNT nanocomposites are worthy of investigation in vivo. Although substantial further preclinical studies are needed, PLA-WSNT nanocomposites may provide a complement of material properties that may improve BRS and expand the range of lesions that can be treated using transient implants. Statement of significanceBioresorbable Scaffolds (BRSs) support regeneration of arteries without permanent mechanical constraint. Poly-L-lactide (PLLA) is the structural material of the first approved BRS for coronary heart disease (ABSORB BVS), withdrawn due to adverse events in years 1-3. Here, we examine tungsten disulfide (WS2) nanotubes (WSNT) in PLA to address two contributors to early complications: (1) reinforce PLLA (enable thinner BRS), and (2) increase radiopacity (provide intraoperative visibility). For BRS, it is significant that WSNT disperse, remain dispersed, reduce friction and improve mechanical properties without additional chemicals or surface modifications. Like WS2 nanospheres, bare WSNT and PLA-WSNT nanocomposites show low cytotoxicity in vitro. PLA-WSNT show enhanced flow-induced crystallization relative to PLA, motivating future study of the processing behavior and strength of these materials.