Environmental Friendly Materials Research Articles

Electrospun polylactic acid nanofibers membrane with copper ion-loaded clay nanotubes for fresh-keeping packaging

The plastics derived from fossil fuels for food packaging results in serious environmental problems. Developing environment-friendly materials for food packaging is urgent and essential. In this study, polylactic acid (PLA) composite nanofibers membranes were prepared with good biocompatibility and antibacterial property. Cu2+ loaded in the natural halloysite nanotubes (HNTs) was used for the antibacterial agent. Cu2+ was loaded in the HNTs and was confirmed by the X-ray photoelectron spectroscopy (XPS). PLA nanofibers with different HNTs-Cu content were continuous nanofibers with the nanoscale range. HNTs-Cu entered into the nanofiber successfully. Thermal analysis results showed composite nanofibers had good thermal stability. Composite nanofiber membranes had the good hydrophobic property. HNTs-Cu improved the mechanical property of composite nanofibers than pure PLA nanofibers. Tensile strength and elasticity modulus of composite nanofibers with 4 % HNTs-Cu content were the most outstanding. L929 cells were cultured on the nanofiber membranes for biocompatibility evaluation. Cell viability of nanofiber membranes was above the 90 %. Cell live/dead staining results showed L929 cells was seldom dead on the nanofiber membranes. PLA/HNTs-Cu nanofiber membranes exhibited excellent antibacterial effects on S. aureus and E. coli. The inhibitory rates against S. aureus and E. coli were 98.31 % and 97.80 % respectively. The fresh-keeping effects of nanofiber membranes were evaluated by the strawberry preservation. Strawberries covered by nanofiber membranes exhibited better appearance, lower weight loss and higher firmness than control, PLA and PLA/HNTs groups. It promised that PLA/HNTs-Cu composite nanofiber membranes have the significant potential application for active food packaging.

Biochar from sugarcane bagasse: Synthesis, characterization, and application in an electrochemical sensor for copper (II) determination

Biochar (BC) is a carbonaceous material obtained from the thermal decomposition of organic matter under limited oxygen supply that plays an attractive role in waste management. In this study, biochar was prepared from sugarcane bagasse, using pyrolysis temperatures from 300 to 700 °C, and chemically activated with HNO3. Structural characterizations showed that degradation increased as pyrolysis temperature increased. Furthermore, a higher number of functional groups were observed for the materials produced under the lowest temperatures. Chemical activation resulted in oxidation and nitration of carbonaceous structure, increasing the number of functional groups on the materials. All materials were evaluated for the construction of electrochemical sensors towards Cu2+ ions voltammetric determination. The material produced at 400 °C pyrolysis temperature and activated (BCA400) provided the most intense response, which can be related to the presence of one of the highest numbers of surface groups, such as oxygen groups, on it. A method for Cu2+ determination was successfully developed based on differential pulse adsorptive stripping voltammetry (DPAdSV). A linear dynamic range (LDR) from 1.0 to 15.0 μmol L−1 was achieved, with limit of detection (LOD) of 0.36 μmol L−1, and limit of quantification (LOQ) of 1.09 μmol L−1. The method was also adequate in terms of accuracy and precision, as well as selective against most cationic species commonly found in tap water. The analyte was determined in tap water samples, in natura and spiked with the maximum concentration allowed by Brazilian legislation, and successful recovery values were obtained. Therefore, biochar from sugarcane bagasse, an environmentally-friendly material, was successfully used to construct an electrochemical sensor and determining an environmental and health interest analyte.

Superhydrophobic eggshell for fabrication of hydrophobic barrier of paper-based analytical device for colorimetric determination of ammonium ion in water

This work demonstrates the first application of the superhydrophobic eggshell as an environmental-friendly material for fabricating the hydrophobic barrier of a paper-based analytical device (PAD). The eggshell surface was modified by mixing the pulverized chicken eggshell biowaste with stearic acid and a polystyrene binder to accomplish superhydrophobicity. The PAD (10 × 10 mm2) is comprised of the circular-shaped hydrophilic reservoir (Ø 5 mm). The liquid barrier was fabricated by painting both the topside and the underside of the filter paper with the dispersed superhydrophobic eggshell solution. The SEM images revealed that the microsized superhydrophobic eggshell particles absorbed onto the porous surface of the cellulose fibril. A coated surface with a water contact angle of 155.39° ± 1.02° (n = 10) on the paper substrate was achieved, and this indicated superhydrophobicity. The eggshell barrier enabled excellent water and chemical resistance. The fabricated PAD was applied for the colorimetric determination of ammonium cations (NH4+), based on the modified Berthelot reaction. Samples and chromogenic solutions were aliquoted onto the hydrophilic reservoir, with subsequent capture of the optical image of the stable, green-colored product by a smart phone under a light-controlled studio. The green color intensities were evaluated by ImageJ™ and plotted against the standard NH4+ concentrations. A wide linear calibration range 5.0 to 100 mg N/L was achieved with good linearity (r2 > 0.99). The PAD confirmed satisfied analytical recovery (Mean ± SD: 100.6 % ± 0.97, n = 11 samples) and high precision (RSD = 0.85 %: 10-PAD replicate measurements of 1.0 mg N/L). The limit of detection (3 SD of blank/slope) of 1.05 mg N/L was found sensitive enough to monitor the NH4+ contents in freshwater. The results, determined by the developed PAD and ion chromatography, showed no significant difference under the statistical paired t-test at 95 % confidence (tstat = -1.80, tcri = 2.57, n = 6 samples).

Recycling and detoxification process of waste tire ash via acid leaching and neutralization

The possibility of a novel process of recycling and detoxification for waste tire ash, which contains hazardous Zn and Al, using acid leaching and neutralization was investigated. The waste tire ash mainly contains Zn, Al, Fe, Ca and Si. The leached contents of Zn, Al, and Fe with 1 mol/L of sulphuric acid (H2SO4) and hydrochloric acid (HCl) are almost same and the highest, while those of Ca with HCl is high and with H2SO4 is almost zero due to the formation of gypsum (CaSO4·2H2O). The optimum leaching condition is that waste tire ash was treated with 1 M H2SO4 for 1 h at 60 °C (solid-liquid ratio is 125 g/L). The elution of Zn and Al from the residue via H2SO4 leaching are 0.7 mg/L and 0.15 mg/L, respectively, which are lower than Japanese elution standard (Zn: 1 mg/L, Al: 0.2 mg/L), while those from raw ash are 3.3 mg/L and 1.4 mg/L. Zn-type layered double hydroxide (Zn-LDH) can be synthesized from leached liquor at 40 °C for 1 h by neutralization at pH 7. These results suggested that detoxified ash and environmental friendly material can be obtained from waste tire ash using H2SO4 acid leaching and neutralization.

Preparation of cellulose-paraffin composite foams by an emulsion–gelation method using aqueous inorganic salt solution for thermal energy regulation

Leakage of paraffin phase-change materials during phase transitions limits their application. Cellulose is an environment-friendly material that has the potential to resolve leakage problems. In this study, large-scale, firm, and no leakage cellulose-paraffin composite foams were fabricated via an emulsion–gelation method using a cellulose/LiBr solution. Spherical paraffin particles were embedded into the three-dimensional nanofibrillar network structure of the regenerated cellulose, with no chemical interaction between the paraffin and cellulose. This cellulose-paraffin foam exhibited excellent mechanical properties, with a maximum elastic modulus value of 7.08 MPa. No leakage was observed at 80 °C even when the paraffin content was 80 %. During phase change, the maximum latent heat was 173.2 J g−1. The thermal conductivity was relatively low (46.5–77.2 mW m−1); this represented 23–38 % of the thermal conductivity of pure paraffin. Therefore, foams are promising materials for efficient and reliable thermal energy storage applications.

Enhanced dielectrics, ferroelectric and optical properties of lithium niobate for high temperature applications using potassium oxide (K2O) additive

Dielectrics, Ferroelectric and Optical properties of Lithium Niobate has been examined using Potassium Oxide (K2O) as an additive on the samples prepared by solid state reaction method using high energy ball milling. The crystal structure analysis by Rietveld structure refinement confirms that the LiNbO3 (LN) with K2O additive also exhibit the rhombohedral structure with R3c space group. The SEM characterization of the microstructure reveals that the samples sintered at a temperature of 1050 °C, have regular and uniform grain morphology and better density. The average grain size decreases for the K2O added compositions in the beginning and increases later for higher concentration of additive. Thermal study with TGA suggests that as the activation energy is decreases, the polarization is enhanced and the LN composition with 2.72 wt% K2O additive shows the best thermal stability. The frequency and temperature dependent dielectric properties were investigated in a wide range of frequency and a substantial enhancement in the dielectric constant of LN is obtained by K2O addition. A useful enhancement in permittivity is obtained with increase of temperature. The band gap values for direct and indirect band gaps for the various compositions are also determined. The least direct band gap is discovered to be 2.36 eV for the composition with 2.72 wt% K2O additive. The composition-dependent photoluminescence (PL) emission studies reveal that the emission spectra for both the pure LiNbO3 and K2O added LiNbO3 compositions lies in the UV–visible region. All the investigated compositions exhibit distinct green, yellow, and red emission peaks. The LN with 2.72 wt% K2O additive shows the best dielectric, thermal stability and polarization response with maximum polarization Ps ∼1.16 μC/cm2. The present investigations suggest that properties of LN can be significantly improved by using K2O additive for sustainable, low cost, environmental friendly energy storage material for high temperature applications.

Development of lead-free metal carbides and ceramic decorated HDPE composites for low energy X-ray shielding applications

Materials with high atomic numbers are effective for shielding ionizing radiation. However, some, such as lead, are toxic, and their disposal causes environmental damage. Polymer composites are a good choice for radiation shielding because they are environmentally friendly, lightweight and non-toxic. This study investigated the possibility of using high-density polyethylenhe (HDPE) composites doped with three different materials comprising the carbide (such as tungsten carbide, and molybdenum carbide) and ceramic (silicon carbide) as a kilo-voltage radiation shield. The linear attenuation coefficients of the composites ranged from 0.21 to 2.82cm−1. The measured results are in good agreement with XCOM with an average error of 13.82%. Through meticulous empirical analysis, including the assessment of linear and mass attenuation coefficients, half-value layer (HVL), and mean free path (MFP), our findings suggest that HDPE composites doped with 15% MoC present the most promising configuration for low-energy X-ray shielding (30–50 keV). This work concludes that HDPE composites decorated with MoC and W could be used as an alternative and environment-friendly material for shielding of kilo-voltage X-rays in medical diagnostics and research environments.

The effects of different electrode materials on the electric field-assisted co-composting system for the soil remediation of heavy metal pollution

The electric field-assisted composting system (EACS) is an emerging technology that can enhance composting efficiency, but little attention has been given to electrode materials. Herein, an EACS was established to investigate the effects of electrode materials on humic substance formation and heavy metal speciation. Excitation-emission matrix analysis showed that carbon-felt and stainless-steel electrodes increased humic acid (HA) by 48.57 % and 47.53 %, respectively. In the EACS with the carbon-felt electrode, the bioavailability factors (BF) of Cu and Cr decreased by 18.00 % and 7.61 %, respectively. Despite that the stainless-steel electrodes decreased the BF of As by 11.26 %, the leaching of Cr, Ni, Cu, and Fe from the electrode itself is an inevitable concern. Microbial community analyses indicated that the electric field increased the abundance of Actinobacteria and stimulated the multiplication of heavy metal-tolerant bacteria. Redundancy analysis indicates that OM, pH, and current significantly affect the evolution of heavy metal speciation in the EACS. This study first evaluated the metal leaching risk of stainless-steel electrode, and confirmed that carbon-felt electrode is environment-friendly material with high performance and low risk in future research with EACS.

Poly(Propylene Carbonate)-Based Biodegradable and Environment-Friendly Materials for Biomedical Applications.

Poly(propylene carbonate) (PPC) is an emerging "carbon fixation" polymer that holds the potential to become a "biomaterial of choice" in healthcare owing to its good biocompatibility, tunable biodegradability and safe degradation products. However, the commercialization and wide application of PPC as a biomedical material are still hindered by its narrow processing temperature range, poor mechanical properties and hydrophobic nature. Over recent decades, several physical, chemical and biological modifications of PPC have been achieved by introducing biocompatible polymers, inorganic ions or small molecules, which can endow PPC with better cytocompatibility and desirable biodegradability, and thus enable various applications. Indeed, a variety of PPC-based degradable materials have been used in medical applications including medical masks, surgical gowns, drug carriers, wound dressings, implants and scaffolds. In this review, the molecular structure, catalysts for synthesis, properties and modifications of PPC are discussed. Recent biomedical applications of PPC-based biomaterials are highlighted and summarized.

Heating aluminum dross: Harmless process and utilization as cement admixture

Phosphogypsum (PG) and aluminum dross (AD) with harmful impurities seriously hinder its large-scale engineering utilization. In this paper, the properties of AD and PG as cement admixture were investigated with the aim of reducing the environmental pollution and landfill stockpiling pressure. The migration and transformation rules under crucial factors were analyzed by different characterization methods while AD was heated at different temperature. Then, the compressive strength, soluble phosphorus and fluorine concentration, hydration heat and expansion rate of specimens prepared with AD, PG, and Portland cement (PC) were evaluated to illustrate the hydration mechanism. Compared to the other experiment sets, the results indicated that AD treated at 900°C not only had a higher nitrogen removal rate, but also maintained hydration activity at a relatively high level. Moreover, Heating AD at 900℃ effectively accelerated the dissolution of gypsum and calcium silicate, resulting in increased formation of ettringite (AFt), calcium silicate hydrates (C-S-H) and calcium aluminium hydrates (C-A-H). When the binder consisted of 14% heated aluminium dross (HAD), 6% PG, and 80% PC, the specimen reached the highest compressive strength value at 25.87 MPa. This work provided a new strategy for synergistic utilization of PG and AD, promoting the development of environment-friendly industrial wastes-based cementitious materials effectively.

Gamma shielding ability of Bismuth-Tungsten oxide (Bi[formula omitted]O[formula omitted]W) nanoparticles

Exposure to high energy radiations like X/gamma rays and neutrons is of serious concern for radiation professionals as they result in several radiation hazards. Shielding plays a prominent role in reducing the radiation exposure. Attempts are being made by several researchers to explore a novel material which can effectively absorb high energy radiations and find a best substitute for lead which is known to be heavy and toxic. In the present study, authors have attempted to synthesize a novel material and investigate the radiation shielding ability and structural properties of Bi2O6W nanomaterial. Bi2O6W nanomaterial has been synthesized for the first time using green synthesis approach in order to have environmental friendly material. SEM, XRD & FTIR techniques were used to investigate the physical & chemical structure and gamma ray spectrometer to study the gamma shielding ability of the said material. The XRD results reveal single crystal structure of the material. The mass attenuation coefficient was found to decrease with increase in photon energy due to the interaction of photons with the nanomaterial. The mass attenuation coefficient is found to be 0.127 ± 0.017, 0.142 ± 0.02, 0.106 ± 0.015,0.090 ± 0.013, 0.089 ± 0.013 and 0.094 ± 0.014 cm2/g for 0.276, 0.365, 0.511, 0.662, 1.173 and 1.332 MeV gamma rays respectively. The radiation protection efficiency is found to be high in lower energy range when compared to higher energy range of gamma photons. Thus, the newly synthesized nanomaterial can be used for shielding of X/Gamma radiations in the radiation environment thus proving its efficiency in low energy shielding applications like medical field.

The use of wood veneer to beautify wood plastic composites

Wood-plastic composites (WPC) can be regarded as environmentally-friendly materials which are mainly manufactured with recycled wood and thermoplastics. However, it is difficult to decorate WPCs with wood veneer using the types of polar adhesives which are commonly used in the woodworking industry due to the nonpolar and nonporous surfaces of WPCs. In the present study, four kinds of abrasive material, including sanding paper, industrial scouring pad, nylon and steel wire wheels were evaluated as a means of promoting adhesion between a wood fiber/high-density polyethylene (WF/HDPE) board and wood veneer using an isocyanate-crosslinking polyvinyl acetate adhesive. Based on the test results of bonding strength and water resistance, it was found that neither the sanding paper commonly used in the woodworking industry, nor steel wire commonly used in the WPC industry were particularly effective, with the scouring pad approach (nylon substrate entangled with silicon carbide) being the best choice. Scanning electron microscopy, Fourier-transform infrared spectroscopy, contact angle measurements, and roughness tests were used to analyze the surface properties of abraded surfaces. Although all four abrasion materials scraped the surface plastic layer off and exposed the wood fibers, they formed significantly different morphologies and affected surface wettability. A combination of suitable surface roughness and enough fiber exposure was found to be necessary for a WF/HDPE composite to build a good glue line. Abrasion with an industrial scouring pad might be a simple and effective method for removing a surface layer and aiding the application of a decorative layer.

An efficient and simple approach to remove Cd(II) in aqueous solution by using rice straw biochar: performance and mechanisms.

In recent years, cadmium pollution in water environment has become an environmental problem that could not be ignored. As a porous carbon rich solid material, biochar is an environment-friendly new material because of its ultra-high adsorption capacity and strong chemical stability. In this study, rice straw biochar (RS-Biochar) was successfully prepared at different temperatures for removal of Cd(II) from aqueous solution. Through a series of characterization and adsorption experiments, the adsorption principle of Cd(II) by RS-Biochar was deeply studied. The results showed that RS-Biochar prepared at 600 °C (BioC600) has high specific surface area (232.6 m2/g) and shows high Cd(II) removal rate of 91.23% with the maximum Cd(II) adsorption capacity of 8.62 mg/g. The Langmuir model fit well to describe the adsorption process of Cd(II) on the BioC600. The mechanism analysis showed that hydroxyl and carboxyl groups on the biochar surface were concerned in the removal of Cd(II). The formation of CdCO3 in the adsorption process was also be proven. Importantly, RS-Biochar could be conveniently produced with needed scale, displaying a promising approach for remediating Cd(II)-contaminated water environment and a huge application potential.

Advanced strategies for marine antifouling based on nanomaterial-enhanced functional PDMS coatings

Marine biofouling seriously affects human marine exploitation and transportation activities, to which marine antifouling (AF) coatings are considered to be the most cost-effective solution. Since the mid-20th century, human beings have dedicated their efforts on developing AF coatings with long cycle and high performance, leading to a large number of non-target organisms' distortion, death and marine environmental pollution. Polydimethylsiloxane (PDMS), is considered as one of the representative environment-friendly AF materials thanks to its non-toxic, hydrophobic, low surface energy and AF properties. However, PDMS AF coatings are prone to mechanical damage, weak adhesion strength to substrate, and poor static AF effect, which seriously restrict their use in the ocean. The rapid development of various nanomaterials provides an opportunity to enhance and improve the mechanical properties and antifouling properties of PDMS coating by embedding nanomaterials. Based on our research background and the problems faced in our laboratory, this article presents an overview of the current progress in the fields of PDMS composite coatings enhanced by different nanomaterials, with the discussion focused on the advantages and main bottlenecks currently encountered in this field. Finally, we propose an outlook, hoping to provide fundamental guidance for the development of marine AF field.

Effects of pyrolysis bio-oil derived from palm kernel shell on modified bitumen properties

Economical and environmental friendly materials that able to replace petroleum based binder has become an urgent demand in road industry. Bio oil from palm oil waste is relatively more economical and has the potential to used as bitumen replacement as bio asphalt. The performance of bio asphalt derived from different source and process to produce bio oils are varies. Hence, this study aims to investigate the effects of palm kernel shell bio-oil in terms of physical properties, the chemical functional group, and the morphology. The bitumen properties were evaluated by the conventional physical tests, Fourier Transform Infrared Spectroscopy, and Scanning Electron Microscopy. The palm kernel shell bio-oil was added into the bitumen by weight of bitumen at 0%, 2%, 3%, 5%, 10%, 15%, and 20% and blended using mechanical stirrer. From the conventional physical test, it was found that bio-oil modified bitumen increased in penetration and ductility with decreased softening point. This indicate that direct addition of bio oil soften the modified bitumen. The change of the functional group in FTIR is significantly influenced by the increasing content of bio-oil. The morphology of the modified bitumen showed inhomogenous surface with noticeable wrinkles as the bio oil content increase. Based on the physicochemical evaluation, 3% bio oil replacement passed all the physical tests requirement with less changes in FTIR result. Therefore, 3% bio oil content is proposed for further tests for direct inclusion of bio oil into bitumen for local road construction utilization.

Non-equilibrium orbital angular momentum for orbitronics

Efficient manipulation of magnetization by electrical current is a key aim in spintronics. The state-of-the-art theories and experiments in spintronics show that harnessing non-equilibrium orbital angular momentum can significantly enhance the efficiency due to novel torques. Devices are based on environment-friendly materials, which has been difficult to achieve by the mechanisms based on spin only, and this has also kickstarted a new emerging field of research: orbitronics.

THERMODYNAMIC PROPERTIES OF COMPLEX COPPER CHALCOGENIDES REVIEW

Complex copper-based chalcogenides are a significant environmental-friendly functional material that has great application potential due to their interesting thermoelectric, photoelectric, optical, and other properties, as well as their ionic conductivity. Analysis of numerous studies shows that improving the application characteristics of these compounds is associated with manipulating their structure and composition. An effective solution for optimizing such processes requires their in-depth thermodynamic analysis, which requires reliable data on the fundamental thermodynamic characteristics of the corresponding compounds. This review summarizes the results of researches, including ours works, on the thermodynamic properties of copper chalcogenides with some p1 -p 3 elements. The majority of these works were carried out using various modifications of the electromotive force (EMF) method. Planning of experiments carried out by this equilibrium method of chemical thermodynamics and processing of their data is impossible without the presence of reliable data on phase equilibria. Taking this into account, in addition to thermodynamic data, the work also presents the solid-phase equilibria diagrams for a number of systems studied by the EMF method. The analysis showed that for the Cu-Tl-X, Cu-Ge(Sn)-X (X-S, Se, Te) and Cu-As(Sb, Bi)-S(Se) ternary systems there are mutually consistent data on the phase equilibria and thermodynamic functions of the ternary compounds. For the Cu-Tl-X and Cu-Sn-Se systems, the thermodynamic functions of ternary compounds are obtained by two modifications of the EMF method by determining the partial molar functions of two different components - copper and thallium (tin). The thermodynamic properties of copper chalcogenides with gallium, indium, and silicon have not been extensively researched, and the data that is available is inconsistent.

Integrated microfluidic platforms for heavy metal sensing: a comprehensive review.

Heavy metals are found naturally; however, anthropogenic activities such as mining, inappropriate disposal of industrial waste, and the use of pesticides and fertilizers containing heavy metals can cause their unwanted release into the environment. Conventionally, detection of heavy metals is performed using atomic absorption spectrometry, electrochemical methods and inductively coupled plasma-mass spectrometry; however, they involve expensive and sophisticated instruments and multistep sample preparation that require expertise for accurate results. In contrast, microfluidic devices involve rapid, cost-efficient, simple, and reliable approaches for in-laboratory and real-time monitoring of heavy metals. The use of inexpensive and environment friendly materials for fabrication of microfluidic devices has increased the manufacturing efficiency of the devices. Different types of techniques used in heavy metal detection include colorimetry, absorbance-based, and electrochemical detection. This review provides insight into the detection of toxic heavy metals such as mercury (Hg), cadmium (Cd), lead (Pb), and arsenic (As). Importance is given to colorimetry, optical, and electrochemical techniques applied for the detection of heavy metals using microfluidics and their modifications to improve the limit of detection (LOD).

Sürdürülebilir cephe tasarımının bir bileşeni olarak lamine pencerelerin teknolojik özelliklerinin belirlenmesi

Wood is an environment-friendly, durable and sustainable material which gives spaces a warm and natural look. The construction industry, which uses many types of materials together in terms of its components, focuses on efficiency in building materials in order to offer aesthetic, economical and ergonomic solutions as a result of today's architectural approaches. In the construction sector, the use of wood has become widespread in facade design and window production especially with the increasing importance of environmental awareness and sustainability in the 21st century. In this study, black pine (Pinus nigra subsp. pallasiana) has been used as the wood material. The test samples consist of three layers. Urea-formaldehyde glue was used for bonding the test samples. Following the physical and mechanical experiments conducted during the research process, it was determined that the technological characteristics of the window profile produced from three-layer laminated black pine wood are superior to the technological characteristics of the solid window profile representing its own species. In order to achieve sustainability goals, it can be recommended to use laminated wooden window profiles in buildings.

Synthesis and investigation of sustainable long-chain branched poly(lactic acid-r-malic acid) copolymer as toughening agent for PLA blends

Poly(lactic acid) (PLA) is the most promising candidate for biobased and biodegradable plastic which combines biocompatibility, renewability as well as excellent processability. However, toughening is still needed for PLA as to obtain materials suitable for broader applications. In this work, long-chain branched random copolymers poly(lactic acid-r-malic acid) (PMLA) were synthesized based on bio-resourced lactic acid (LA) and malic acid (MA) through polycondensation as toughening agent for PLA. The chemical structures of PMLA were characterized by 1H NMR and 1H–13C HSQC analysis. In the PLA and PMLA blends, PMLA has apparent effect on the crystallinity of PLA and the blends show a great increase of elongation at break to over 300 % even at low PMLA content of 2%wt. Furthermore, the thermal properties of the blend are characterized through DSC and the micro-structure investigated through Positron annihilation lifetime spectroscopic (PALS) technique. PMLA with long-chain branched topology shows an excellent capability in the toughening of PLA and maintains the total biodegradability of the resultant blend at the same time, that is critical for environment-friendly materials.