Melt Compounding Research Articles

Microstructural, Mechanical, and Tribological Performances of Composites Prepared via Melt Compounding of Polyamide 6, Basalt Fibers, and Styrene-Ethylene-Butylene-Styrene Copolymer.

Basalt fibers (BFs) are environmentally friendly materials characterized by high strength and good wear resistance, and thus are popular candidates for reinforcing polymers. Herein, polyamide 6 (PA 6), BFs, and the styrene-ethylene-butylene-styrene (SEBS) copolymer were melt compounded sequentially to prepare fiber-reinforced PA 6-based composites. The results showed improved mechanical and tribological performances via the incorporation of BFs and SEBS into PA 6. Compared to neat PA 6, an average 83% increase in notched impact strength was achieved for the PA 6/SEBS/BF composites, which is mainly due to the good miscibility between SEBS and PA 6. The tensile strength of the composites, however, was only increased moderately, since the weak interfacial adhesion was not sufficiently efficient to transfer the load from the PA 6 matrix to the BFs. Interestingly, the wear rates of both the PA 6/SEBS blend and the PA 6/SEBS/BF composites were obviously lower than those of the neat PA 6. The PA 6/SEBS/BF composite with 10 wt.% of the BFs exhibited the lowest wear rate of 2.7 × 10-5 mm3/N·m, which was decreased by 95% compared to that of the neat PA 6. The facilitation of forming tribo-film with SEBS and the naturally good wear resistance of the BFs were responsible for the largely decreased wear rate. Moreover, the incorporation of SEBS and BFs into the PA 6 matrix transformed the wear mechanism from adhesive wear to abrasive wear.

Assessment of Melt Compounding with Zeolites as an Effective Deodorization Strategy for Mixed Plastic Wastes and Comparison with Degassing.

The emission of off-odors from mechanically recycled plastics severely limits their re-introduction into the market for the production of new objects, for the same use or even for less demanding applications, thus hindering the implementation of an effective circular economy for plastics. The addition of adsorbing agents during the extrusion of polymers represents one of the most promising strategy to reduce the odorous emissions of plastics, due to its characteristics of cost-effectiveness, flexibility and low energy consumption. The novelty of this work lies in the assessment of zeolites as VOC adsorbents during the extrusion of recycled plastics. They appear more suitable than other types of adsorbents, due to their ability to capture and "hold" the adsorbed substances at the high temperatures of the extrusion process. Moreover, the effectiveness of this deodorization strategy was compared with the traditional degassing technique. Two types of mixed polyolefin wastes, coming from completely different collection and recycling processes, were tested: Fil-S (Film-Small), deriving from post-consumer flexible films of small size, and PW (pulper waste), which is the residual plastic waste obtained from the paper recycling process. The melt compounding of the recycled materials with two micrometric zeolites (zeolite 13X and Z310) resulted as more effective in the off-odors removal with respect to degassing. In particular, the highest reduction (-45%) of the Average Odor Intensity (AOI) was measured for both PW/Z310 and Fil-S/13X systems at 4 wt% of the zeolites' amount, compared with the corresponding untreated recyclates. Finally, by combining degassing and melt compounding with zeolites, the best result was obtained for the composite Fil-S/13X, whose Average Odor Intensity resulted as quite close (+22%) to the one of the virgin LDPE.

Cross-Linking, Morphology, and Physico-Mechanical Properties of GTR/SBS Blends: Dicumyl Peroxide vs. Sulfur System.

In this work, ground tire rubber and styrene-butadiene block copolymer (GTR/SBS) blends at the ratio of 50/50 wt%, with the application of four different SBS copolymer grades (linear and radial) and two types of cross-linking agent (a sulfur-based system and dicumyl peroxide), were prepared by melt compounding. The rheological and cross-linking behavior, physico-mechanical parameters (i.e., tensile properties, abrasion resistance, hardness, swelling degree, and density), thermal stability, and morphology of the prepared materials were characterized. The results showed that the selected SBS copolymers improved the processability of the GTR/SBS blends without any noticeable effects on their cross-linking behavior-which, in turn, was influenced by the type of cross-linking agent used. On the other hand, it was observed that the tensile strength, elongation at break, and abrasion resistance of the GTR/SBS blends cured with the sulfur system (6.1-8.4 MPa, 184-283%, and 235-303 mm3, respectively) were better than those cross-linked by dicumyl peroxide (4.0-7.8 MPa, 80-165%, and 351-414 mm3, respectively). Furthermore, it was found that the SBS copolymers improved the thermal stability of GTR, while the increasing viscosity of the used SBS copolymer also enhanced the interfacial adhesion between the GTR and SBS copolymers, as confirmed by microstructure evaluation.

Quasi block copolymers noncovalent bonded by stereocomplex crystals

Self-assembly of block copolymers (BCPs) yields unparalleled opportunities to integrate exquisite characteristics for preparation of advanced nanotechnology materials. The high-yield manufacturing of BCP is extremely desired, yet rarely exploited. Herein, we displayed that stereocomplex crystals (sc) of poly lactide (PLA) enantiomers, acting as pseudo linkage between adjacent polymer chains, enable formation of quasi-block copolymer (qBCPs) by straightforward melt compounding. Identical content of poly (D-lactide) (PDLA) and poly (L-lactide) (PLLA) were pre-grafted onto the backbones of poly styrene (PS) and poly (methyl methacrylate) (PMMA), respectively. Due to the complementary multiple hydrobonding interactions between PDLA and PLLA grafted moieties, PS-“block”-PMMA connected by cocrystallized sc was induced during the subsequent melt processing of PDLA-g-PS/PLLA-g-PMMA, thus allowing local segregation of PS-“block” and PMMA-“block” with nanometer size. The refined morphology, which was resembled with micro-phase separation of classical BCP, can be facilely tuned by varying the length and ratio of enantiomeric PDLA/PLLA grafts. More interestingly, the PS-“block”-PMMA typed qBCPs demonstrated superiority in compatibilizing immiscible PS/PMMA polymer blends, as compared with the classical compatibilizer (PS-block-PMMA) via reactive blending. Overall, our strategy represents a general method to construct noncovalent linked di-block copolymer via industrially relevant melt processing, which is quite challenging to achieve by existing synthetic technologies.

Designing Antioxidant and Antimicrobial Polyethylene Films with Bioactive Compounds/Clay Nanohybrids for Potential Packaging Applications

In the present work, direct incorporation of bioactive compounds onto the surface and interlayer of nanoclays before their incorporation into the final polymeric film was conducted, based on a green methodology developed by our group that is compatible with food packaging. This will lead to the higher thermal stability and the significant reduction of the loss of activity of the active ingredients during packaging configuration. On this basis, the essential oil (EO) components carvacrol (C), thymol (T) as well as olive leaf extract (OLE), which is used for the first time, were incorporated onto organo-modified montmorillonite (O) or inorganic bentonite (B) through the evaporation/adsorption method. The prepared bioactive nanocarriers were further mixed with low-density polyethylene (LDPE), via melt compounding, in order to prepare films for potential use as fresh fruit and vegetable packaging material. Characterization of the bioactive nanocarriers and films were performed through XRD, TGA, tensile, antimicrobial and antioxidant tests. Films with organically modified montmorillonite loaded with carvacrol (OC), thymol (OT) and olive leaf extract (OOLE) at 5% wt. showed better results in terms of mechanical properties. The films with polyethylene and organically modified montmorillonite loaded with carvacrol or thymol at 20% wt. (PE_OC20 and PE_OT20), as well as with olive leaf extract at 5 or 10 %wt., clay:bioactive substance ratio 1:0.5 and 10% compatibilizer (PE_OOLE5_MA10 and PE_OOLE10_MA10) exhibited the highest antioxidant activity. The resulting films displayed outstanding antimicrobial properties against Gram-negative Escherichia coli (E. coli) with the best results appearing in the films with 10% OC and OT.

Properties of GdSF and phase diagram of the GdF3 - Gd2S3 system

The objectives of this study were to refine the phase diagram of the GdF3-Gd2S3 system and to calculate their liquidus, and to synthesize GdSF and to study their properties. The GdSF compound (ST PbFCl, P4/nmm, a (Å) 3.83006(17), c (Å) 6.8529(3), has an optical band gap for a direct interband transition of 2.56 ​eV and is characterized by a pronounced increase in the Kubelka-Munk function in the region of this transition. Direct optical bandgap of GdSF is measured to be equal to 2.77 ​eV. Two indirect bandgaps are detected to be 1.54 and 2.4 ​eV. Meta-GGA simulations of band structure predicting 1.481 ​eV direct bandgap of GdSF are in good agreement with these features of the experimental absorption spectrum. To explain this complicated case, we argue that formally direct optical transitions to highly dispersive subbands contribute not to direct but to indirect bandgaps measured by Tauc analysis. The GdSF compound melts incongruently with the formation of a melt and γ-Gd2S3 compound at t ​= ​1280 ​± ​2°С, ΔН ​= ​40.6 ​± ​2.8 ​kJ/mol, ΔS ​= ​26.1 ​± ​1.8 ​J/mol∗K. The eutectic has a composition of 13 ​mol.% Gd2S3 (0.74 GdF3 ​+ ​0.26 GdSF), the melting characteristics of the eutectic are 1182 ​± ​2°С, ΔН ​= ​36.2 ​± ​2.5 ​kJ/mol, ΔS ​= ​24.9 ​± ​1.7 ​J/mol∗K. In the system GdF3 - Gd2S3 the balance equations for five phase transformations recorded by the DSC method were compiled. Convergence was achieved in the liquidus of the system constructed according to DSC data and calculated with the use of the Redlich-Kister equation.

Predicting and optimizing the physical and spectroscopic properties of phosphate laser glasses using a phase diagram approach

AbstractDespite the significant technological applications of laser glasses, the quantitative prediction and optimization of their properties, particularly the spectroscopic properties, remain challenging. Here we address this problem by regarding the nearest‐neighboring congruently melting compounds as the “component and structural motifs” based on the phase diagram approach. The composition–structure–property (CSP) relationships of Nd3+‐doped ternary phosphate glasses are investigated. Spectroscopic properties are quantitatively predicted with an error of less than 10% compared to the experimental results. In particular, the fluorescence lifetime (τm) can be accurately calculated using the phase diagram approach, which is difficult to be predicted previously. Furthermore, the CSP databases with over 1000 compositions are established for the optimization of commercial laser glasses. This study enriches the CSP database of traditional laser glass and provides guiding significance for future research.

Effect of molecular chain mobility on the electrothermal stability of polyethylene/multi-walled carbon nanotube electrothermal composites

In this study, we pay close attention to the structure design of high-temperature electrothermal composites. Two kinds of high density polyethylene-based electrothermal composites filled with multi-walled carbon nanotubes (5960G1/MWCNTs and 5000 S/MWCNTs) prepared by melt compounding is employed as examples. The relationship between molecular weight of matrix and electrothermal properties of composites are studied through the investigation of the changes of microstructure and conductive network in the composites during heating-cooling cycles. Benefiting from the increased high-molecular-weight component and decrease of molecular chain mobility, 5960G1/MWCNTs composites shows excellent electrothermal stability with the surface temperature stabilized at about 120 °C within 10 h (applied voltage of 18 V). In addition, owing to the protection of internal conductive network from low molecular chain mobility of the 5960G1, a reduced disruption of conductive network from the thermal expansion of 5960G1/MWCNTs composite can be ensured by the low deformation of matrix with high molecular weight chains, in turn, 5960G1/MWCNTs composite exhibits good electrothermal repeatability at sequent heating-cool cycles. Thus, high molecular weight polyethylene as a matrix favors high temperature use of electrothermal materials and is expected to be applied in the field of commercial high-temperature electrical heating cables.

Enhanced flame retardancy, smoke suppression, and acid resistance of polypropylene/magnesium hydroxide composite by expandable graphite and microencapsulated red phosphorus

AbstractLow flame retardant efficiency and poor acid resistance of filled polymer composites are two main drawbacks of magnesium hydroxide (MH) as a flame retardant (FR). To solve these problems, expandable graphite (EG) and microencapsulated red phosphorus (MRP) were introduced into polypropylene/magnesium hydroxide (PP/MH) composite by melt compounding. The obtained PP/MH/EG/MRP quadruple composite was studied regarding its fire behavior as well as acid resistance. Obvious flame retardant synergism among MH, EG, and MRP is found in PP, which diminishes the loading of FR from 63.0 to 37.5 wt% to obtain V‐0 rating in UL‐94 test and low smoke release. Compact intumescent char with high thermo‐oxidative stability was generated on composite surface, which plays a vital role in flame retardancy. The removal of MH by acid erosion on PP/MH/EG/MRP composite surface does not affect production of intumescent char and fire behavior of this composite. The composite displays good fire retardancy, smoke inhibition, and acid resistivity concurrently. This article renders an easy and cheap route to overcome the main faults of MH.

Evaluation of the Physical and Shape Memory Properties of Fully Biodegradable Poly(lactic acid) (PLA)/Poly(butylene adipate terephthalate) (PBAT) Blends.

Biodegradable polymers have recently become popular; in particular, blends of poly(lactic acid) (PLA) and poly(butylene adipate terephthalate) (PBAT) have recently attracted significant attention due to their potential application in the packaging field. However, there is little information about the thermomechanical properties of these blends and especially the effect induced by the addition of PBAT on the shape memory properties of PLA. This work, therefore, aims at producing and investigating the microstructural, thermomechanical and shape memory properties of PLA/PBAT blends prepared by melt compounding. More specifically, PLA and PBAT were melt-blended in a wide range of relative concentrations (from 85/15 to 25/75 wt%). A microstructural investigation was carried out, evidencing the immiscibility and the low interfacial adhesion between the PLA and PBAT phases. The immiscibility was also confirmed by differential scanning calorimetry (DSC). A thermogravimetric analysis (TGA) revealed that the addition of PBAT slightly improved the thermal stability of PLA. The stiffness and strength of the blends decreased with the PBAT amount, while the elongation at break remained comparable to that of neat PLA up to a PBAT content of 45 wt%, while a significant increment in ductility was observed only for higher PBAT concentrations. The shape memory performance of PLA was impaired by the addition of PBAT, probably due to the low interfacial adhesion observed in the blends. These results constitute a basis for future research on these innovative biodegradable polymer blends, and their physical properties might be further enhanced by adding suitable compatibilizers.

Improvement of Poly(lactide) Ductile Properties by Plasticization with Biobased Tartaric Acid Ester

AbstractDiethyl l‐tartrate (DET) is used as a biobased plasticizer for poly(lactide) (PLA) formulations with improved ductile properties without compromising biodegradation. Different weight percentages (wt.%) of DET in the 0–50 wt.% range are added to PLA by melt compounding and subsequently processed by injection molding. The effect of wt.% DET on mechanical, thermal, thermo‐mechanical, morphology, biodegradation, and crystallinity is studied. Addition of 20 wt.% DET leads to a noticeable increase in elongation at break up to values of 567%, which is quite an interesting result considering the extreme brittleness of PLA. These results are verified by field emission scanning electron microscopy (FESEM) images, where filament‐like structures are observed, indicative of an effective plasticization. Differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) show that the glass transition temperature of PLA is drastically decreased down to values of 23 °C for the sample with the highest amount of DET (50 wt.%), thus increasing its ductility and processability. Fourier‐transformed infrared spectroscopy (FTIR) spectra show that there exists chemical interactions between PLA and DET. Finally, the biodegradability analysis proves that the developed blends are fully biodegradable, achieving complete disintegration after 49 days. It is observed that DET enhanced the disintegration rate of PLA.

Structure and 119Sn Mössbauer-spectroscopic characterization of BaRhSn2

Abstract The stannide BaRhSn2 was synthesized by induction melting of an arc-melted RhSn2 precursor compound with barium in a sealed tantalum ampoule. The structure of BaRhSn2 was refined from single-crystal X-ray diffractometer data: MgCuAl2 type, Cmcm, a = 437.56(4), b = 1242.35(10), c = 767.30(6) pm, wR2 = 0.0845, 469 F 2 values and 16 variables. The rhodium and tin atoms form a two-dimensional [RhSn2] δ− polyanionic network with short Rh–Sn (273–274 pm) and Sn–Sn (303–312 pm) distances. The large barium atoms lead to a substantial orthorhombic distortion of the (lonsdaleite-related) tin substructure, forcing a break of the Sn–Sn bond in b direction. This change in the tin substructure is reflected in the 119Sn Mössbauer spectrum. The tin atoms exhibit a higher s electron density which is expressed in an increased isomer shift of δ = 2.08(1) mm s−1 as compared to the previously reported stannide CaRhSn2 with a three-dimensional [RhSn2] δ− polyanionic network and δ = 1.96(4) mm s−1.

Enhanced thermal conductivity of polyamide nanocomposites involving expanded graphite–carbon nanotube network structure using supercritical CO2

In this study, supercritical carbon dioxide (scCO2) was used to form a network structure of expanded graphite (EG) and multi-walled carbon nanotube (MWCNT) to achieve high thermal conductivity. Continuous processes, such as supercritical drying and rapid expansion of supercritical solutions were applied to pristine graphite and MWCNT. Polyamide 6 (PA6) nanocomposites with scCO2-treated EG and MWCNT were prepared by twin-screw extruder-based melt compounding. In the PA6 nanocomposites, the EG sheets were homogenously dispersed, while the MWCNTs were located between the EG sheets, thereby acting as a bridge for the EG. Subsequently, the 35 wt.% imbedding in PA6 nanocomposite had an effective heat transfer pathway and high thermal conductivity (2.12 W m−1 K−1). It was observed that supercritical fluid processing is a facile and effective strategy to improve the thermal conductivity of polymer nanocomposites.

押出機を用いたプラスチックの溶融混練プロセスの解析と評価

Melt compounding using an extruder is the method for mixing functionalized materials into plastics to add functionality to existing plastics and improve their performance. The performance of the composites depends on the dispersion state of the mixed materials in the composites. Therefore, the analysis and evaluation of the dispersion state of adding materials in the composites are necessary for considering the performance of the composites. In this article, we focus on the melt compounding of composite materials using thermoplastics and outline the analysis and evaluation methods of melt compounding and mixing process of plastics by an extruder, citing the references. First, we explain the concepts of dispersive mixing and distributive one as the basic theory of melt compounding. Next, we introduce the following examples for the analysis and evaluation of melt compounding by an extruder, 1) Dispersion of binary mixtures, 2) Dispersion of functionalized fillers such as nanoclay and vapor-grown carbon fiber, 3) Evaluation by flow simulation of polymer melts in an extruder, 4) Estimation of pigment dispersion and online estimation during melt compounding as the other topics. Finally, we describe future problems and tasks as the conclusion.

PHASE RELATIONS IN THE Sb2Te2S-Bi2Te2S SYSTEM AND CHARACTERIZATION OF Sb2-xBixTe2S SOLID SOLUTIONS

The phase equilibria of the Sb2Te2S-Bi2Te2S system was studied by powder X-ray diffraction (PXRD), differential thermal analysis (DTA), scanning electron microscope (SEM) and energy dispersive Xray (EDX) microanalysis. It was shown that due to incongruent melting of the Sb2Te2S compound the system is non-quasibinary, but it is stable below the solidus and characterized by the formation of a continuous series of solid solutions with a tetradymite-like hexagonal structure. The lattice parameters were determined from powder diffraction patterns. It was established that the crystal lattice parameters of solid solutions vary linearly with composition

Evaluation of the Degree of Dissociation of A Congruent Compound Fe2Ti across the Bjerrum–Guggenheim Coefficient

This article describes a new quantitative evaluation method for the degree of dissociation of a compound depending on the curvature of the liquidus line curve. The main point of this method was to determine the specific expressions for dissociation parameters according to the mathematical model of the crystallization line of the compound on the phase diagram. This was based on generally accepted thermodynamic relations. Empirically, it has now been established that for many types of phase equilibria, a common feature is the presence of a correlation dependence between the ratios of the real Gibbs energy of the distribution of components to its ideal component. The osmotic coefficient of Bjerrum–Guggenheim was used as a measure of the deviation of the system from ideality. This coefficient can be in an analytical form depending on the temperature and composition of the phases. The obtained correlation dependence of the osmotic coefficient of Bjerrum–Guggenheim on the ratio of the activity of the liquid and solid phase has been used to develop a mathematical apparatus to analytically describe the lines and surfaces of the crystallization phases. Accordingly, a single analytical basis, as a universal dependence of the modified Schröder–Le Chatelier equation, has been applied. Based on this equation, the conditions have been defined to develop an equilibrium method with which to calculate the thermal dissociation of chemical compounds. The principle of this method has been examined based on the two-component iron-titanium system. The numerical results of the degree of dissociation of the congruent Fe2Ti compound have been obtained using the Gibbs energy of the dissociation reaction and the reaction constant. However, it has been found that the degree of dissociation in the compound Fe2Ti was 0.04%. Demonstrative material for the behavior of the osmotic coefficient of Bjerrum–Guggenheim under boundary conditions has been presented as an assessment criterion of melt structures. The diagrams of the Φi function of the crystallizing phases near the melting temperature of congruently melting compounds (Tm.) have been mathematically studied. Thus, this study demonstrates that ΦAmBn′ diagrams tended to zero and approached the melting temperature of the compound Tm,AmBn, i.e., above the melting temperature of this compound ΦAmBn′→∞; then,lnxAmBn→0, and, as a result, xAmBn→1.

Self-Assembled Serpentine Ni3Si2O5(OH)4 Hybrid Sheets with Ammonium Polyphosphate for Fire Safety Enhancement of Polylactide Composites.

Biodegradable polylactide (PLA) has been widely utilized in people's daily lives. In order to improve the fire safety of PLA, ammonium polyphosphate (APP) was self-assembled onto the surface of serpentine Ni3Si2O5(OH)4 through the electrostatic method, followed by mixing with PLA by melt compounding. The APP-modified serpentine (serpentine@APP) dispersed uniformly in the PLA matrix. Compared with pure PLA, the PLA composite with 2 wt% serpentine@APP reduced the peak heat release rate (pHRR) and total heat release (THR) by 43.9% and 16.3%, respectively. The combination of APP and serpentine exhibited suitable synergistic flame-retardant effects on the fire safety enhancement of PLA. In addition, the dynamical rheological tests revealed that the presence of APP and serpentine could reduce the viscosity of PLA composites. The plasticizing effects of APP and serpentine benefited the processing of PLA. The mechanical properties of PLA/serpentine@APP maintained suitable performance as pure PLA. This study provided a feasible way to enhance the fire safety of PLA without sacrificing its mechanical properties.

AeMg6Ga6S16 (Ae = Ca, Sr, Ba): The First Double Alkaline‐Earth Metal Chalcogenides with Excellent Performances

AbstractInfrared nonlinear optical (IR NLO) crystals are of quite significance in the development of laser technology, yet rationally designing new IR NLO crystal that can satisfy all the property requirements is still a great challenge owing to the incompatibility between large second harmonic generation (SHG) response and wide band gap. Herein, taking AgGaS2 (AGS) as the template and using highly electropositive alkaline‐earth metal cations substituting Ag+ cations, the first examples of double alkaline‐earth (Ae) metal chalcogenide IR NLO crystals, AeMg6Ga6S16 (Ae = Ca, Sr, Ba), are successfully designed and synthesized. Structurally, they possess stable [Mg/GaS]∞ open frameworks, which can accommodate a wide range of cations from the small size of Ca2+ to large Ba2+ cations and all of the resulting compounds melt congruently. More importantly, these materials achieve the optimal balance among the critical performance parameters, including the strong SHG response (≈0.7–0.8 × AGS) and wide band gap (Eg = 3.50–3.54 eV). Theoretical calculations and structure analysis reveal that their superior NLO properties can be attributed to the synergistic contribution of the polarizable MgS6 and GaS4 groups.

Enhancement of viscoelastic property of MABS processed by melt compounding and injection molding

AbstractThis work is focused on developing a new type of polymer blend to improve the viscoelastic property of methyl methacrylate acrylonitrile butadiene styrene (MABS). A multi‐phase binary polymer blend was prepared by melt mixing in a twin screw extruder with three different weight ratios (10, 20, and 30 wt%) with a dynamically vulcanized alloy consisting mostly of fully cured ethylene propylene diene rubber (EPDM) particles encapsulated in a polypropylene (PP) matrix trade name Santoprene and an engineered styrene based thermoplastic elastomer trade name VDT to enhance the viscoelastic property of the blends. The compatibility and performance of the binary blend were studied by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), Fourier transform infrared (FT‐IR) spectroscopy, nuclear magnetic resonance (NMR), laser microscopy, scanning transmission electron microscopy (STEM) and tensile analysis. The DMA analysis of the samples revealed that the damping performance was significantly increased with the incorporation of the elastomeric phase into the MABS matrix. In addition, the morphological analysis revealed that VDT is more compatible with MABS compared to Santoprene. The NMR and FT‐IR analysis further supported the reason for higher compatibility of VDT and MABS blend. The improvement of the damping properties has been observed with the increased wt % of the VDT and Santoprene in the blends.

Blending PLA with Polyesters Based on 2,5-Furan Dicarboxylic Acid: Evaluation of Physicochemical and Nanomechanical Properties

Poly(lactic acid) (PLA) is a readily available, compostable biobased polyester with high strength and toughness, and it is excellent for 3D printing applications. Polymer blending is an economic and easy way to improve its properties, such as its slow degradation and crystallization rates and its small elongation, and thus, make it more versatile. In this work, the effects of different 2,5-furan dicarboxylic acid (FDCA)-based polyesters on the physicochemical and mechanical properties of PLA were studied. Poly(butylene furan 2,5-dicarboxylate) (PBF) and its copolymers with poly(butylene adipate) (PBAd) were synthesized in various comonomer ratios and were blended with 70 wt% PLA using melt compounding. The thermal, morphological and mechanical properties of the blends are investigated. All blends were immiscible, and the presence of the dispersed phases improved the crystallization ability of PLA. Mechanical testing revealed the plasticization of PLA after blending, and a small but measurable mass loss after burying in soil for 7 months. Reactive blending was evaluated as a compatibilizer-free method to improve miscibility, and it was found that when the thermal stability of the blend components allowed it, some transesterification reactions occurred between the PLA matrix and the FDCA-based dispersed phase after 20 min at 250 °C.