Miscibility Characteristics Research Articles

A Temperature-Transferable Coarse-Grained Model for Poly(lactic Acid) Melts.

We present a temperature-transferable coarse-grained (CG) model for poly(lactic acid) (PLA), specifically designed to replicate its volumetric properties and solubility parameter in the molten state. The CG-bonded potentials were derived by using the iterative Boltzmann inversion (IBI) optimization method to match structural properties from detailed atomistic models. A parametrization workflow was employed to determine nonbonded interaction parameters with temperature-dependent corrections that provide agreement with the target properties across the melting temperature range. The CG model successfully replicates key features of the PLA melt. It satisfactory reproduces the density and solubility parameter, maintains the dependence of chain conformation on molecular weight, and captures the dynamic behavior through agreement in scaled mean squared displacement and diffusion coefficients with the atomistic model. Additionally, the CG model offers much faster equilibration compared with the atomistic model. The proposed model is expected to be particularly useful for investigating the miscibility characteristics of PLA in various blends and composites that remain challenging to explore using fully atomistic simulations or experiments.

Research on Component Variation and Factors Affecting Minimum Miscible Pressure in Low Viscosity Oil Miscibility Process.

Miscible gas flooding is an important approach for enhancing the recovery of unconventional oil reservoirs. The injected gas and crude oil components has a significant impact on the minimum miscible pressure. In order to clarify the miscibility characteristics and factors influencing the minimum miscibility pressure, combining PVT and slim tube experiments, the minimum miscibility pressure between Tuha low viscosity oil and different injected gas was measured. Additionally, chromatography experiments were conducted to study the composition changes of produced oil. The results indicate that when the injection pressure is higher than the minimum miscible pressure, the extraction effect of injected gas on heavy fraction (C16+) in crude oil is enhanced and the extraction effect on light alkanes (C1-C6) is reduced. The increase in the content of light alkanes (C1-C6) and middle distillates (C7-C15) in crude oil reduces the minimum miscibility pressure between crude oil and injected gas. Pipeline gas can effectively extract heavy fraction from crude oil, but its breakthrough time is early. Under the same pressure, earlier breakthrough time of injected gas makes it more difficult for the crude oil and injected gas to miscible. Through the analysis of experimental results, the following main conclusions are drawn: Immiscible flooding causes heavy fraction (C16+) in crude oil to remain, which might affect the physical properties of the reservoir, increasing the difficulty of subsequent development. Gas fingering phenomenon significantly influences the miscibility of injected gas and crude oil, and the viscosity ratio of injected gas and crude oil under high-pressure conditions can be used as an important criterion for screening injected gas.

Impact of water on miscibility characteristics of the CO2/n-hexadecane system using the pendant drop shape analysis method

Miscible CO2 flooding has shown bright prospects for improving oil recovery from unconventional reservoirs as well as for storing greenhouse gas in underground formations. Although the favorable water presence effect has been reported in the near miscible CO2 flooding practices, there is still a lack of target research works on the impact of water on the miscibility characteristics of the oil/gas systems. Therefore in this paper, the effect of water presence on the Minimum Miscibility Pressure (MMP) of the CO2/n-Hexadecane (n-C16H34) system is experimentally investigated based on the Oil Droplet Volume Measurement (ODVM) method. By pre-saturating CO2 with water in the high-pressure high-temperature cell, the water component is introduced at the CO2/oil interface. Measurement results show the water presence could result in lower MMPs of the CO2/oil system. Under five temperature levels of 40 °C, 51 °C, 61 °C, 72 °C, and 82 °C, the water presence decreases the MMPs of the CO2/n-C16H34 system from 8.2 to 7.8 MPa, from 9.6 to 8.8 MPa, from 11.6 to 10.2 MPa, from 13.0 MPa to 12.2 MPa and from 14.6 MPa to 13.2 MPa respectively. Thermodynamic calculations provide consistent results as the experimental observations, indicating the main mechanism behind the lower MMPs of the water presence CO2/oil system could be the decreased CO2 molar fraction in the water presence system. This research is expected to provide an innovative viewpoint to understand the water presence effect in the CO2 flooding processes.

Determination of the minimum miscibility pressure of the CO2/oil system based on quantification of the oil droplet volume reduction behavior

CO2 miscible flooding is one of the most ideal scenarios in oil recovery practices. Accurate prediction of the minimum miscible pressure (MMP) of the CO2/oil system is essential for CO2 Enhanced Oil Recovery (CO2-EOR) and carbon geological storage applications. In this paper, a novel method based on quantification of the oil droplet volume shrinkage behavior is proposed and demonstrated in the determination of the MMP of the CO2/n-hexadecane (n-C16H34) system and the CO2/n-octadecane (n-C18H38) system. Based on the specific quantitative criterion of the oil droplet volume reduction rate, the MMPs of the CO2/oil system under different temperature levels were determined. The accuracy of the measurement results has been validated with the corresponding thermodynamic phase equilibrium calculation results. To show the application potential of the proposed method, detailed discussions have been provided based on comparisons with the Vanishing Interfacial Tension (VIT) method. It is expected the proposed Oil Droplet Volume Measurement (ODVM) method could act as a robust supplementary for studying the miscibility characteristics of the CO2/oil system.

Miscibility characteristics of the CO2/n-hexadecane system with presence of water component based on the phase equilibrium calculation on the interface region

In correspondence to the bright prospects of CO2 EOR technology on greenhouse gas geological storage as well as oil recovery enhancement practices, the phase equilibrium characteristics of CO2/oil/water system was investigated in this paper. n-Hexadecane (n-C16H34) is employed as the oil component and water is introduced into the two phase system as the dissolved component in CO2. PR-EOS with modified alpha functions and Binary Interaction Parameters (BIPs) is employed to calculate the Minimum Miscibility Pressure (MMPs) of the CO2/n-C16H34 system with or without water presence at three temperatures of 40.3 ℃, 55.4 ℃ and 70 ℃. Calculation model and the employed parameters were validated through comparison with corresponding measurements, including the observation on decreased MMPs of the CO2/H2O/n-C16H34 system in comparison with the CO2/n-C16H34 system. Parameter studies were carried out for the CO2/n-C16H34 system with or without water presence at different molar ratios. It is found the existence of water component could reduce the MMP values of the CO2/n-C16H34 system and the degree of the MMP reduction was related to the molar ratio of CO2 in the system. Higher CO2 molar ratio could result in larger MMP deviation between CO2/C16H34 system and CO2/H2O/C16H34 system.

Insights into the miscibility characteristics of plastic-mimetic polypeptide with hydroxypropylmethylcellulose: Investigation of thermal degradability and intermolecular interactions

In this investigation, we integrated the parent recurring sequence of the plastic-derived polypeptide, poly[0.8(AVGVP),0.2(AEGVP)] (A, V, G, P, and E represents Alanine, Valine, Glycine, Proline, and Glutamic acid respectively) followed by characterization with inverse transition temperature, 13C, and 1H-NMR spectroscopy. The miscibility attributes of poly[0.8(AVGVP),0.2(AEGVP)] with Hydroxypropylmethylcellulose was examined both in aqueous and solid-phase. The Huggins’ co-efficient [KH], the intrinsic viscosity [η], the interaction parameters ΔB and μ suggested by Chee, ΔK and β recommended by Jiang and Han, α by Sun, Δ[η]m by Garcia showed that the polypeptide was miscible with HPMC in all proportions. DSC studies revealed single Tg values, and TGA manifested the enhanced thermal stability for all the proportions compared with their individuals. Further, verified the results by SEM and XRD. The FTIR evidenced existence of intermolecular hydrogen bonding between the two constituent polymers that caused the miscible blend system.

A New Era in Engineering Plastics: Compatibility and Perspectives of Sustainable Alipharomatic Poly(ethylene terephthalate)/Poly(ethylene 2,5-furandicarboxylate) Blends.

The industrialisation of poly(ethylene 2,5-furandicarboxylate) for total replacement of poly(ethylene terephthalate) in the polyester market is under question. Preparation of high-performing polymer blends is a well-established strategy for tuning the properties of certain homopolymers and create tailor-made materials to meet the demands for a number of applications. In this work, the structure, thermal properties and the miscibility of a series of poly(ethylene terephthalate)/poly(ethylene 2,5-furandicarboxylate) (PET/PEF) blends have been studied. A number of thermal treatments were followed in order to examine the thermal transitions, their dynamic state and the miscibility characteristics for each blend composition. Based on their glass transition temperatures and melting behaviour the PET/PEF blends are miscible at high and low poly(ethylene terephthalate) (PET) contents, while partial miscibility was observed at intermediate compositions. The multiple melting was studied and their melting point depression was analysed with the Flory-Huggins theory. In an attempt to further improve miscibility, reactive blending was also investigated.

Examination of miscibility characteristics of the synthetic plastic-mimetic peptide with polyacrylamide: development of nonwoven mats by electrospinning

ABSTRACT The polypeptide, poly(AVGVP), a prominent member of the synthetic polypeptides (PLP), exhibiting plastic properties for biomedical applications. Their miscibility characteristics with polyacrylamide (PAM) were scrutinized in different weight proportions manipulating viscometry in the aqueous phase. The interaction parameters confirmed that the two polymers are miscible up to 20/80 weight portion of PLP/PAM. Further, the outcomes were supported by Fourier transform infrared (FTIR) spectroscopy, and differential scanning calorimetry (DSC), XRD, and SEM individually. Moreover, blends resulted in nanofibers (75 ± 25 nm) at 26 kV by the electrospinning method, and they may be the potential alternatives for prospective biomedical applications.

Research on miscibility performances of refrigerants with mineral lubricating oils

In order to investigate the performances of environment-friendly refrigerants with lubricating oil in refrigeration system, the miscibility should be well understood firstly. The miscibility characteristics of refrigerants (R1234ze(E), RE170, R22, R142b, R152a, R161, and R227ea) with three kinds of mineral oils (SUNOCO 3GS, OMO-1, and OMO-2) were measured and analyzed by a homemade experimental system at temperature ranging from −70 °C to 40 °C. Five typical statuses of the miscibility of pure refrigerants with mineral oils were revealed in visualization. Meanwhile, some special cases for the miscible performances of R22, R142b, R152a, and R161 were discussed in detail. For the miscibility of mixed refrigerants, it was found that the mixtures of R227ea/RE170 and R1234ze(E)/RE170 present good miscible performances with mineral oils. Furthermore, a theoretical method of a new evaluation index was proposed to predict the miscibility of refrigerants with mineral oils with satisfactory accuracy.

Exploring Next-Generation Engineering Bioplastics: Poly(alkylene furanoate)/Poly(alkylene terephthalate) (PAF/PAT) Blends.

Polymers from renewable resources and especially strong engineering partially aromatic biobased polyesters are of special importance for the evolution of bioeconomy. The fabrication of polymer blends is a creative method for the production of tailor-made materials for advanced applications that are able to combine functionalities from both components. In this study, poly(alkylene furanoate)/poly(alkylene terephthalate) blends with different compositions were prepared by solution blending in a mixture of trifluoroacetic acid and chloroform. Three different types of blends were initially prepared, namely, poly(ethylene furanoate)/poly(ethylene terephthalate) (PEF/PET), poly(propylene furanoate)/poly(propylene terephthalate) (PPF/PPT), and poly(1,4-cyclohenedimethylene furanoate)/poly(1,4-cycloxehane terephthalate) (PCHDMF/PCHDMT). These blends’ miscibility characteristics were evaluated by examining the glass transition temperature of each blend. Moreover, reactive blending was utilized for the enhancement of miscibility and dynamic homogeneity and the formation of copolymers through transesterification reactions at high temperatures. PEF–PET and PPF–PPT blends formed a copolymer at relatively low reactive blending times. Finally, poly(ethylene terephthalate-co-ethylene furanoate) (PETF) random copolymers were successfully introduced as compatibilizers for the PEF/PET immiscible blends, which resulted in enhanced miscibility.

The impacts of gas impurities on the minimum miscibility pressure of injected CO2-rich gas\u2013crude oil systems and enhanced oil recovery potential

An effective parameter in the miscible-CO2 enhanced oil recovery procedure is the minimum miscibility pressure (MMP) defined as the lowest pressure that the oil in place and the injected gas into reservoir achieve miscibility at a given temperature. Flue gases released from power plants can provide an available source of CO2, which would otherwise be emitted to the atmosphere, for injection into a reservoir. However, the costs related to gas extraction from flue gases is potentially high. Hence, greater understanding the role of impurities in miscibility characteristics between CO2 and reservoir fluids helps to establish which impurities are tolerable and which are not. In this study, we simulate the effects of the impurities nitrogen (N2), methane (C1), ethane (C2) and propane (C3) on CO2 MMP. The simulation results reveal that, as an impurity, nitrogen increases CO2–oil MMP more so than methane. On the other hand, increasing the propane (C3) content can lead to a significant decrease in CO2 MMP, whereas varying the concentrations of ethane (C2) does not have a significant effect on the minimum miscibility pressure of reservoir crude oil and CO2 gas. The novel relationships established are particularly valuable in circumstances where MMP experimental data are not available.

Component compatibility study of poly(dimethyl siloxane) with poly(vinyl acetate) of varying hydrolysis content: An atomistic and mesoscale simulation approach

Molecular simulations are very promising computational methods to understand miscibility of polymers, surface behavior and bulk properties of materials. In this investigation, such useful computations have been carried out on blends of hydrophobic poly(dimethyl siloxane) (PDMS) with commercially available hydrolyzed grades (0%, 86% and 100% hydrolysis) of poly(vinyl acetate) (PVAc) present in varying weight fractions. The material properties like Flory-Huggins interaction parameter (χ), blend compatibility and thermal transitions have been estimated by atomistic molecular dynamics (MD). The glass transition temperature (Tg) has been estimated for pristine polymers and their blend systems as well, which are found in line with previously reported values. However, some blend systems displayed occurrences of multiple Tg's, thereby, signifying phase separation. χ values have been estimated from atomistic simulations and compared with critical χC. Among different potential energy components, torsional energy plotted against a range of temperature (~90–350 K) showed distinct inflection points near Tg. In addition, morphology has also been predicted using Dissipative Particle Dynamics (DPD) and Mesoscopic dynamics (Mesodyn) simulations in order to visualize phase segregation and results found in accord with χ and Tg studies. Interestingly, while the atomistic MD and mesoscale simulations of short-chain systems (Mw ~2000) predicted limited miscibility, the mesoscale simulations of large chain lengths (Mw ~1,00,000) depict complete immiscibility at all blend contents and all hydrolyzed PVAc grades. The blend compatibility study using atomistic and mesoscale simulations indicates that incompatibility increases with increasing degree of hydrolysis, chain length and PVAc content. Further, simulations help screen 20 wt% PVAc (0% hydrolysis and 86% hydrolysis) or 10 wt% of PVOH (100% hydrolysis) in PDMS as an optimal formulation with improved miscibility characteristics.

Elastin‐based polymer: synthesis, characterization and examination of its miscibility characteristics with poly(vinyl alcohol) and electrospinning of the miscible blends

AbstractMiscibility is an important factor for peptide‐based polymer blends for employment in the pharmaceutical, drug delivery and biomedical fields. The current study presents the synthesis of a repeating sequence of elastin, poly(GVGIP), characterized using1H NMR and13C NMR spectroscopy, and an investigation of its miscibility characteristics with poly(vinyl alcohol) (PVA) over a broad range of composition in solid and solution phase using various analytical techniques. The miscibility behaviour of the blend solutions was established quantitatively by the analysis of various parameters of simple viscometric measurements. The results confirmed the miscibility of the blends containing up to 50% of the polypeptide. Further, Fourier transform infrared spectroscopy indicated the existence of intermolecular hydrogen bonding between the two polymers in the blends. Scanning electron microscopy and X‐ray diffraction revealed the change in surface morphology and crystallinity for blend films. Differential scanning calorimetry demonstrated a single glass transition temperature of the blend films. Interestingly, long, thin nanofibre meshes were also successfully prepared through electrospinning of poly(GVGIP)/PVA blends from aqueous solutions at a very low concentration (5 wt%). © 2018 Society of Chemical Industry

Characterization of catalytic fast pyrolysis oils: The importance of solvent selection for analytical method development

Two catalytic fast pyrolysis (CFP) oils (bottom/heavy fraction) were analyzed in various solvents that are used in common analytical methods (nuclear magnetic resonance – NMR, gas chromatography – GC, gel permeation chromatography – GPC, thermogravimetric analysis – TGA) for oil characterization and speciation. A more accurate analysis of the CFP oils can be obtained by identification and exploitation of solvent miscibility characteristics. Acetone and tetrahydrofuran can be used to completely solubilize CFP oils for analysis by GC and tetrahydrofuran can be used for traditional organic GPC analysis of the oils. DMSO-d6 can be used to solubilize CFP oils for analysis by 13C NMR. The fractionation of oils into solvents that did not completely solubilize the whole oils showed that miscibility can be related to the oil properties. This allows for solvent selection based on physico-chemical properties of the oils. However, based on semi-quantitative comparisons of the GC chromatograms, the organic solvent fractionation schemes did not speciate the oils based on specific analyte type. On the other hand, chlorinated solvents did fractionate the oils based on analyte size to a certain degree. Unfortunately, like raw pyrolysis oil, the matrix of the CFP oils is complicated and is not amenable to simple liquid–liquid extraction (LLE) or solvent fractionation to separate the oils based on the chemical and/or physical properties of individual components. For reliable analyses, for each analytical method used, it is critical that the bio-oil sample is both completely soluble and also not likely to react with the chosen solvent. The adoption of the standardized solvent selection protocols presented here will allow for greater reproducibility of analysis across different users and facilities.

Preparation of Poly (vinyl chloride) / Poly(methyl methacrylate) Recycled Blends: Effect of Varied Concentration of PVC and PMMA in Stability of PVC Phase on the Recycled Blends

The present work deals with the effective utilization of plastics generated from E-waste stream. Polyvinyl chloride (PVC) collected from the data cable waste and Poly(methyl methacrylate) (PMMA) waste materials from the light guidance panels used in the LED screens of computers are used as raw materials in the present investigation. Recycled blend of PVC/PMMA was prepared using mechanical recycling techniques at different compositions via melt blending techniques. The blends were characterized by mechanical, thermal, and morphological studies. The molecular interactions that have taken place between the polymeric materials in the recycled blend have been evaluated using FTIR analysis. The flammability characteristics of the blends were studied by determining rate of burning. The miscibility characteristics in the blends have been studied scanning electron microscopy. Overall stability of the recycled blend improved as compared with its parent recycled materials..

Preparation and characterization of recycled blends using poly (vinyl chloride) and poly(methyl methacrylate) recovered from waste electrical and electronic equipments

The current investigation deals with the effective utilization of plastics generated from electronic waste. In this study two different polymers: Poly (vinyl chloride) (PVC) collected from the data cables and Poly(methyl methacrylate) (PMMA) recovered from the liquid crystal display (LCD) panels used in computers were used to prepare the PVC/PMMA recycled blends using mechanical recycling technique at different compositions. The blends were characterized for various physico-mechanical, thermal, processability and morphological studies. Higher impact strength and elongation at break was observed for recycled blend with higher weight percentage of recycled PVC. The blend prepared at 70:30 wt ratio of recycled PVC (r-PVC): recycled PMMA (r-PMMA) in recycled blend exhibited better impact strength and elongation at break than the other blends. The thermal degradation of the recycled blend investigated using thermogravimetric analysis (TGA) suggested enhanced thermal stability of recycled blend than its individual recycled materials. The miscibility characteristics of the blends have been studied employing differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Both results show partial miscibility of r-PVC and r-PMMA in the recycled blend.

Effects of hydrolyzed PIM-1 in polyimide-based membranes on C2–C4 alcohols dehydration via pervaporation

Polymers of intrinsic microporosity, specifically PIM-1, have attracted significant attention for gas separation due to its relatively high permeability and reasonably good selectivity. Although few studies evaluated the potential of PIM-1 in pervaporation, their dehydration performance was not impressive because of low selectivity. In this work, we aim to develop a simple but effective approach to enhance the selectivity of PIM-1 while preserving its high permeability for pervaporation dehydration through blending it with different polyimides. The miscibility characteristics of the newly developed membranes in terms of free energy of mixing are examined by molecular simulation while the degrees of swelling in solvents and the changes in interstitial space are characterized by sorption analyses and X-ray diffraction (XRD), respectively. By optimizing the blend ratio, a simultaneously good flux and separation factor have been achieved. For example, the Matrimid membrane containing 20wt% hydrolyzed PIM-1 (hPIM-1) possesses a high flux of exceeding 47.8g/m2h and a separation factor of more than 5000 for the dehydration of 1-butanol. This work may provide an inspiration of exploring the potential of gas separation membranes for pervaporation applications.

Correlation Between Miscibility and Rheological Characteristics of the Polystyrene (PS) and Poly(styrene-co-acrylonitrile) (PSAN) Blends

Rheological measurement has been an effective technique to characterize the miscibility of polymer blends. This article investigates the viscoelastic behavior of poly(styrene) (PS) and poly(styrene-co-acrylonitrile) (PSAN) binary solutions in tetrahydrofuran (THF) relative to PS/PSAN/THF ternary solutions mainly reporting the findings of the authors involving the correlation between the miscibility and rheological behavior. Rheological properties, such as shear viscosity, and shear stress as a function of shear rate were investigated for different blend compositions. Moreover, complex viscosity, loss and storage moduli were also investigated as functions of both the frequency and blend composition. The criterion of miscibility based on the rule of mixture has been discussed. The present study revealed very small window of miscibility as only composition, 50/50 showed values close to the additivity rule or intermediate to those of the neat polymers, thereby indicating very weak interactions between the blend components. On the basis of various findings during the rheological investigation, the blend under study is classified almost immiscible. Moreover, the obtained results also suggested that the miscibility depends on the blend composition and frequency.

Evaluation of olefinic block copolymer blends with amorphous polyolefins—effect of different unsaturated and saturated hydrocarbon tackifier resins on blend miscibility

ABSTRACTBlends of ethylene–octene based olefinic block copolymer (OBC) with two amorphous polyolefin (APO) polymers [atactic propylene homopolymer (PP) and ethylene–propylene copolymer (PE–PP)] were evaluated at three different ratios. Dynamic mechanical analysis (DMA) and transmission electron microscopy (TEM) evaluations were performed to determine the blend miscibility characteristics. Viscoelastic properties of both OBC blends with PP polymer, and OBC blends with PE–PP copolymer showed incompatibility. Analysis revealed that both blends formed two phase morphologies. The effect of three unsaturated aliphatic hydrocarbon resins with varying aromatic content and two saturated hydrocarbon resins with different chemistries were evaluated as compatibilizing agent for OBC/PP and OBC/PE–PP blends. A 1 : 1 polymer blend ratio of OBC/PP and OBC/PE–PP was selected to better understand the influence of resin addition at three different levels 20, 30, and 40 wt %. The fully aliphatic unsaturated resin seems to improve the miscibility of the OBC/PP blends at higher resin addition levels, but reduced the miscibility as the aromatic content of the resin increases. However, OBC/PE–PP blends showed improved miscibility with increasing aromatic content. A ternary phase morphology was particularly observed for both OBC/PP and OBC/PE–PP blends with highly aromatic (14%) unsaturated hydrocarbon resin, in which OBC formed the continuous phase, and PP, PE–PP, and unsaturated hydrocarbon resins formed the dispersed phase. Interestingly, we did not observe much difference in miscibility characteristics between the two saturated resin chemistries in both blend systems (OBC/PP and OBC/PE–PP). The Harkins spreading coefficient concept was used to better understand the ternary blend dispersed phase morphology. Spreading coefficients indicate that the free hydrocarbon resins (both unsaturated and saturated) were encapsulated by the amorphous PP or amorphous PE–PP polymer in the dispersed phase for the respective blend compositions. Overall OBC–PP and OBC/PE–PP blends showed better miscibility characteristics with both saturated aliphatic hydrocarbon resins, irrespective of the difference in resin chemistries. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2624–2644, 2013

Low-Temperature Processable Degradable Polyesters.

Block copolymers composed of a low-T(g) and high-T(g) block, with suitable pressure miscibility characteristics, can be formed at low-temperature through the application of pressure. Aliphatic block copolyesters composed of poly(ε-caprolactone) derivatives and poly(L-lactide) show room temperature processability under hydraulic pressure of 34.5 MPa without polymer degradation. Mechanism of the pressure-induced flow is investigated by small-angle X-ray scattering. A scattering associated with a lamellae structure observed at ambient conditions decreases with elevating hydrostatic pressures, indicating pressure-induced phase mixing. Traces of the pressure-induced phase transition are studied by differential scanning calorimetry and X-ray diffraction. Tensile test of the block copolymers reveals that the mechanical properties can be readily controlled by changing composition, molecular weight, and chemical structure of the blocks. Among them, the hard segment PLLA fraction is the key factor to characterize the properties. Young's modulus of the block copolyesters is similar to that of polyethylene.