Addition Of Compatibilizer Research Articles

Investigation of mechanical properties of compatibilized polyvinyl chloride/polylactic acid nanocomposites

AbstractPolymer alloying is particularly important due to the possibility of choosing a wide range of materials and the ability to design a product with desired properties. In case of incompatibility between the components, the resulting alloy cannot meet the set of desired properties and shows poor performance. In this research, alloys of polyvinyl chloride and polylactic acid were prepared in an internal mixer and nanoclay and maleic anhydride‐grafted styrene‐ethylene/butylene‐styrene (SEBS‐g‐MAH) compatibilizer were used to improve the properties. In order to investigate the morphology and phase distribution of polylactic acid, scanning electron microscope images were taken. Tensile and dynamic mechanical thermal analysis tests were performed to evaluate the properties of the samples. The scanning electron microscope test images show the improvement of system uniformity by adding compatibilizer to the alloy. Adding nanoclay to the alloy increased the storage modulus and uniformity of the system. An increase in glass transition temperature and storage modulus was observed in the samples containing compatibilizer, and the uniformity of the system was also improved. The tensile test results showed that by adding nanoclay up to 3 % by weight, the tensile strength and Young′s modulus increase. Addition of compatibilizer up to 5 % by weight increased the physical and mechanical properties.

Analysis of the effect of boric acid and compatibilizer addition to polylactic acid/basalt fiber composites

AbstractThe objective of this study is to improve the properties of polylactic acid (PLA), a biopolymer produced from renewable resources, without compromising its environmentally friendly “natural composite” properties. The aim was to expand the application range of PLA by making it suitable for the production of high performance composites. With this in mind, it was decided to use inorganic and environmentally friendly materials such as basalt fiber (BF) and boric acid (BA) as reinforcements. Adhesive wear and tensile tests were used to investigate the tribological and mechanical performance of the composites. Differential scanning calorimetry (DSC) and dimensional stability analysis (DSA) methods were used to investigate the thermal properties. Scanning electron microscopy analysis was also used to investigate the morphological properties of the samples. In addition, a matrix modification process using Joncryl®, an epoxy‐based chain extender chemical, was applied to enhance the interfacial interaction between the composite components and improve the composite properties by improving the dispersion of reinforcing materials. As a result of the characterization tests, it was observed that a significant improvement in the properties of the material type containing 10 wt% BF, 0.25 wt% BA and 2 wt% Joncryl® was achieved. A 19% increase in tensile strength of this type of material was observed compared with unreinforced PLA, while the sharp peak increase in the coefficient of friction (COF) curve was shifted from 20 m to 60 m. As a result, it has been presented that environmentally friendly and inorganic materials such as BF and BA can be used to produce composite materials that will serve sectors where the need and use of high performance materials is intense, especially in the automotive, aerospace and aviation sectors.Highlights The properties of PLA matrix composites were improved by the simultaneous use of BF and BA and the addition of Joncryl®. The structural properties of PLA, an environmentally friendly polymer, have been improved without compromising this characteristic. PLA matrix natural composites with performance that can be used in the automotive, aerospace and aviation sectors have been developed.

Mechanical and thermal characterization of elastomer modified polypropylene hybrid composites reinforced with hazelnut shell and wollastonite fillers

AbstractThe demand for sustainable and recyclable materials in industrial applications has led to a surge in interest in green composites, particularly those incorporating natural fillers derived from agro‐food industry waste. This study investigates the mechanical and thermal properties of polypropylene (PP) hybrid composites filled with hazelnut shell and wollastonite, along with the effect of styrene‐ethylene/butylene‐styrene (SEBS) and SEBS‐g‐maleic anhydride (SEBS‐g‐MA) compatibilizers. Various characterization techniques, including tensile, flexural, and impact tests, as well as differential scanning calorimetry (DSC), thermogravimetry (TGA), and scanning electron microscopy (SEM) analyses, were employed to evaluate the composites. Results demonstrate that the addition of wollastonite significantly improves mechanical properties, while hazelnut shell filler affects thermal behavior and stability. SEBS and SEBS‐g‐MA compatibilizers enhance impact resistance; however, they lead to a decrease in other mechanical properties. DSC and TGA analyses demonstrate changes in crystallization behavior and thermal stability due to filler and compatibilizer incorporation. SEM microstructure images show the distribution of SEBS and SEBS‐g‐MA within the composite structure, affecting mechanical and thermal properties. Overall, this study highlights the importance of filler selection, compatibilizer addition, and their distribution in attaining desired properties for industrial applications. Future research should focus on optimizing formulations for specific uses and assessing long‐term performance under real‐world conditions.

Electrical properties of MAH-g-PP modified PP/SEBS matrix semi-conductive composite materials

Polypropylene (PP) becomes a superior candidate material for new environmental-friendly cable insulation layer with its excellent heat resistance, electrical properties and degradability. At present, most of studies focus on the insulation layer of PP cable. However, there are few studies on semi-conductive shielding layer of PP cable which match its insulation layer. In this paper, polypropylene (PP)/styrene ethylene butylene styrene (SEBS) is adopted as matrix of PP cable semi-conductive layer to matching its insulation layer. Meanwhile, Maleic anhydride grafted polypropylene (MAH-g-PP) is used to cooperatively improve the compatibility between PP and SEBS. The physicochemical properties, space charge injection properties and compatibility of semi-conductive composites with different CB and MAH-g-PP contents is studied by combining experiment and simulation methods. The experimental results show that the surface roughness of the semi-conductive layer and the space charge inside the insulation layer decrease first and then increase with the increase of CB addition. Among them, the two parameters of 25 phr CB semi-conductive layer is the lowest, respectively 13.98 nm and 2.25 × 10−8C. These two parameters are significantly reduced after the addition of compatibilizer MAH-g-PP, which decreased by 29.47 % and 62.22 %, respectively. The simulation results show that the Flory-Huggins interaction parameters (χ) of MAH-g-PP with PP and SEBS are −73.3 and −45.2, respectively, which are 236.24 % and 107.34 % lower than those of PP/SEBS. The χ value of MAH-g-PP/CB is 8.20, which is 33.27 % and 9.59 % lower than CB/PP and CB/SEBS, respectively. It shows that MAH-g-PP can effectively improve the compatibility of matrix and filler. This work has important guiding significance for the research of semi-conductive layer formulation of PP cable.

Analysis on Isotropic and Anisotropic Samples of Polypropylene/Polyethyleneterephthalate Blend/Graphene Nanoplatelets Nanocomposites: Effects of a Rubbery Compatibilizer.

Over the past few years, polymer nanocomposites have garnered a significant amount of interest from both the scientific community and industry due to their remarkable versatility and wide range of potential uses in various fields, including automotive, electronics, medicine, textiles and environmental applications. In this regard, this study focuses on the influence of a compatibilizer rubber on a nanocomposite incorporating graphene nanoparticles (GNPs), with a polymer matrix based on a blend of polypropylene (PP) and polyethylene terephthalate (PET). This effect has been investigated on both isotropic samples and on anisotropic/spun fiber samples. The influence of the compatibilizer rubber on morphological, rheological and mechanical properties was analysed and discussed. Mechanical and morphological properties were evaluated on both isotropic samples obtained by compression moulding and melt-spun fibers. The addition of the rubbery compatibilizer increased the viscosity, improving interfacial adhesion, and the same effect was observed for the melt strength and breaking stretching ratios. Mechanical properties, including the elastic modulus, tensile strength and elongation at break, improved in both types of samples but more significantly in the fibers. These improvements were attributed to the orientation of the matrix, the formation of PET microfibrils, and the reduction in the size of graphene nanoparticles due to the action of the elongational flow. This reduction, facilitated by the elongation flow and the action of the compatibilizer, improved matrix-nanofiller adhesion due to the increased contact area between the two polymeric phases and between the filler and matrix. Finally, a transition from brittle to ductile behaviour was observed, particularly in the system with the compatibilizer, attributed to defect reduction and improved stress transmission.

Special interface structure and properties for compatible packaging film from biodegradable poly (butylene adipate‐co‐terephthalate)/corn starch composite

AbstractStarch is an environmentally friendly, renewable, green resource and an ideal alternative to polymers from petroleum resources. The preparation of high‐performance poly (butylene adipate‐co‐terephthalate) (PBAT)/corn starch composite materials is of significant importance for saving production costs and expanding the application fields of PBAT plastics. This study employed novel processing techniques such as melt blending and injection molding to fabricate PBAT/corn starch composite materials with polyurethane prepolymer (PCLPU) as a compatibilizer. The impact of varying polyurethane prepolymer concentrations on the composite material's structure, mechanical properties, morphology, thermal behavior, and water absorption was scrutinized. Mechanical performance testing showed that compared to the composite material without PCLPU (P90CS10), adding 5% PCLPU can increase the material's elongation at break from 350.2% to 359.0% and the tensile strength from 12.9 to 19.8 MPa. Scanning electron microscopy, thermogravimetric analysis, and water absorption results indicate that the composite material with the addition of the PCLPU compatibilizer has better compatibility, thermal stability, and water resistance than P90CS10. Additionally, the prepared composite material could be successfully blown into a thin film, further enriching the application of the composite material.Highlights A special interface structure was prepared to increase the compatibility of the poly (butylene adipate‐co‐terephthalate)/corn starch composite. Both the strength and the flexibility of the composite were successfully improved. The processing method through which modification was conducted in the melt was convenient, green, and effective. The prepared composite material has potential application value, and the processing method of the composite material is easy to transfer to industrial production.

Solvent-free blending of CsPbBr3 and commercial polymer: Interface-visualization, bandgap engineering and improved stability in 3D printing

Metal halide perovskites (MHPs) encapsulated in polymer have enhanced stability and processability. Most of the MHPs/polymer composites are fabricated in organic solvents and the interaction between MHPs and polymer matrix is rarely reported. In this work, solvent-free twin-screw blending is adopted for CsPbBr3@PolymerA/PolymerB (PolymerA = polypropylene (PP), polyethylene (PE) or poly(butylene-adipate-co-terephthalate) (PBAT), PolymerB = polylactic acid (PLA)) composites preparation. Different factors including compatibilizer addition, polymer composition and CsPbBr3 feeding ratio are used to investigate the interaction between MHPs and polymer matrix. According to the wetting coefficient calculation, transmission electron microscope (TEM) and scanning electron microscope (SEM) results, CsPbBr3 is mostly distributed in the interface of PE/PLA blending. As a result, the luminescent CsPbBr3 can be used for interface marker to study the polymer interface morphology. The interpenetration morphology of polymer interface allows CsPbBr3 to show the most efficient green emission and convenient halogen exchange. Thus, the optical emission and absorption can be tuned from blue to red. PE/PLA blending endows CsPbBr3@PE5/PLA5 with 3D printing ability and improved stability against to the water, UV light and heat.

A comprehensive review on polystyrene/waste rubber blends: Effective parameters on mechanical properties

AbstractPolystyrene (PS), as a commercial thermoplastic polymer, suffers from brittleness at low temperatures. Blending with elastomers can resolve this defect. In this regard, waste rubbers from tires, shoes, and other sources are promising candidates for some applications. This approach of waste rubber recycling is an environmental‐friendly and economical method to produce value‐added products. This work aims to comprehensively review all reported cases regarding PS (or high‐impact polystyrene, HIPS, and expanded polystyrene, EPS)/waste rubber blends. The influences of different parameters on the mechanical properties were carefully summarized, including mixing conditions (temperature, mixing time, rotor speed, and mixing sequence), rubber content, rubber particle size, compatibilizer addition, rubber devulcanization, and surface treatment of rubber. Some parameters had a negligible effect on the mechanical properties, such as the rotor speed in the mixing process, while significant influences were observed for some parameters, such as rubber content. The effect of some parameters was remarkable only at low or high rubber loading, such as particle size and solvent‐inducing surface treatment of rubber, respectively. Finally, the effects of aforementioned parameters on tensile and impact strengths were compared and recommendations for future research in this field were suggested.Highlights All reported research regarding PS/waste rubber blends was comprehensively reviewed. All different factors influencing mechanical properties were carefully summarized. The effects of different factors on tensile and impact strengths were compared.

CHARACTERIZATION OF ASPHALT MODIFICATION USING GROUND RUBBER AND REACTIVE RUBBER NR-g-MA AS COMPATIBILIZER

This study aims to improve the quality of asphalt by adding ground tyre rubber (GR) and reactive rubber (NR-g-MA) as compatibilizers of asphalt-rubber mixability. The use of GR has been widely used to improve the performance of asphalt and extend the service life of asphalt. The NR-g-MA used was the product of the copolymerization of SIR-20 rubber grafts with maleic anhydrous (MA) through a melting process in an internal mixer. Mixing of GR in asphalt was carried out in an external mixer with composition of asphalt/GR 95/5 phr at the temperature of 180oC for 90 minutes. The performance of asphalts were measured based on conventional test of penetration and softening point. The rheological properties of asphalt were measured using a Dynamic Shear Rheometer (DSR). Important parameters of the rheological properties measured are complex shear modulus (G*) and phase angle (d). Asphalt resistance to the permanent deformation (rutting) were determined on asphalt that has undergone a short-term aging process in a rolling thin film oven (RTFO) and measured at high temperatures (58-82OC). Fatigue crack resistance was tested on asphalt that has undergone a long-term aging process using the method of pressure aging vessel (PAV) and measured at low temperatures (25-31OC). Asphalt-GR mixtures' chemical, thermal and morphological properties were studied using ATR-FTIR, DSC/TGA, and SEM respectively. The results showed that adding used ground rubber (GR) decreased the penetration value by 9.93 – 18.87% and increased the softening point of asphalt from 5.57 – 11.40%. Rheological analysis showed that the addition of GR and compatibilizer NR-g-MA increase the value of complex shear modulus (G*) and decrease the phase angle (d) of the asphalt. The addition of ground rubber and reactive rubber of NR-g-MA to asphalt improve the performance of asphalt because it has rutting resistance at high temperatures as well as improves asphalt cracking resistance at low-temperature measurements. The addition of NR-g-MA reactive rubber to modified asphalt ground rubber can increase the mixability of asphalt-rubber used tires.

Deformation kinetics of single-fiber polypropylene composites: Adhesion improvement at the expense of toughness

Despite the maturity of the technology, processing of fiber-reinforced thermoplastic materials remains challenging, and difficulties in processability often result in material formulations with high modulus and strength, yet rather poor ductility compared to the pure polymer matrix. To gain fundamental insight into the deformation mechanisms present in such materials, the complexity of the system is step-wise increased; first, the effect of the most commonly applied adhesion enhancement, the addition of MAH-g-PP compatibilizer, on the bulk properties is assessed. The small-strain tensile properties, i.e., modulus and yield stress, appear to be only marginally affected by the addition of such compatibilization agent, however, the strain-at-break is strongly reduced, even before the addition of the fiber reinforcement. Subsequently, using in-situ X-ray characterization methods upon tensile deformation, the time evolution of crystal structure and lamellar morphology is determined, and at first glance the compatibilizer addition appears to better preserve the crystalline structure. The onset of local failure (cavitation) is quantified at the interface of a single glass fiber. By increasing the adhesive interaction between fiber and matrix the stress concentration at the interface is increased, leading to an acceleration in void formation followed by unstable growth, which in turn strongly embrittles the composite. By the addition of various selective nucleating agents, it is demonstrated that the role of local phase composition and morphology on the deformation kinetics and subsequent failure mechanisms is much more pronounced than the increased adhesion between fiber and matrix by compatibilization or sizing effects. These findings may specify a new route towards tougher fiber-reinforced composites with reduced complexity in the material formulation.

Customized compatibilizer to improve the mechanical properties of polylactic acid/lignin composites via enhanced intermolecular interactions for 3D printing

Polylactic Acid (PLA)/lignin composite shows great potential as a 3D printing material due to its eco-friendliness and cost-effectiveness, but the poor compatibility seriously reduces the mechanical properties, which restricts its wide applications. Herein, a new strategy for concurrently enhancing tensile strength, elongation, and toughness of PLA/Lignin (P/L) composites through intermolecular interactions enhancement with a lignin-based compatibilizer was firstly reported. In detail, the lignin-g-maleic anhydride-g-PLA (LMP) compatibilizer was tailor-made by a two-step method. Mechanical testing results indicated that the tensile strength, elongation, and toughness were increased by 22%, 68%, and 114%, respectively in P/L20 (20% lignin) after adding 5 wt% of LMP, which is superior to the addition of commercial compatibilizer, polyethylene glycol. SEM observation, rotational rheometer testing, DSC analysis, and molecular dynamics (MD) simulation remarkably verified that LMP distinctly increased the intermolecular interaction. In particular, the van der Waals energy of lignin-LMP and LMP-PLA was raised by 15.7% and 60.8% and the electrostatic potential energy was boosted by 11.0% and 60.7%, respectively, based on lignin-PLA. Additionally, P/LMP5/L20 achieved excellent antioxidant properties (91% radical scavenging activity rate), which could be a potential candidate to replace traditional materials for medical applications of 3D printing. Overall, this study proposes a novel approach to develop economical biodegradable composites with great mechanical and extraordinary antioxidant performances for 3D printing.

Effects of Recycled Polymer on Melt Viscosity and Crystallization Temperature of Polyester Elastomer Blends.

As the world is paying attention to the seriousness of environmental pollution, the need for a resource circulation economy is emerging due to the development of eco-friendly industrial groups. In particular, the recycling of thermoplastic elastomers without cross-link has been highlighted in the plastics field, which has rapidly developed the industry. Growing interests have been directed towards the advancement of thermoplastic polyether-ester elastomer (TPEE) as a material suitable for the circular economy owing to its remarkable recyclability, both in terms of mechanical and chemical processes. Due to its excellent processability, simple mechanical recycling is easy, which is a driving force towards achieving price competitiveness in the process. In molding TPEE resin, it is essential to check the thermal properties of the resin itself because the thermal properties, including the melting and crystallization temperatures of the resin, depend on the design of the polymer. In this study, the thermal and mechanical performances of TPEE blends were evaluated by manufacturing compounds by changing the amount of recycled resin and additives. When the recycled resin was added, the melt flow index (MFI) changed rapidly as the temperature of the melt flow index measurement increased. Rapid changes in MFI make the fiber spinning process uncontrollable and must be controlled by optimizing the addition of compatibilizers. Based on the thermal property results, compatibilizers such as Lotader and Elvaloy series exhibited minimal change in glass transition temperature, even with greater amounts added. This makes them well-suited as compatibilizers for fiber spinning.

A bibliometric analysis and review on the performance of polymer-modified bitumen

The addition of polymer to a base binder has been documented as a successful approach in terms of improving physical and rheological properties of the base bitumen. However, the main drawbacks of polymer-modified bitumen are incompatibility and degradation of polymer due to aging. This article aims to introduce a bibliometric analysis and review on modifying bitumen with polymers. Additionally, this article intent to highlight the significant gaps and recommendations for future work. Furthermore, another objective of this article is to provide a worth attempt regrading reducing the negative impact of polymer’s drawbacks on the performance of polymer-modified base binder. The findings of this article demonstrated that the test of storage stability for polymer-amended bitumen should be modified, in which the softening point of aluminum tube centerpiece should be measured to introduce a better evaluation for the storage stability of polymer-amended bitumen. In addition, the effects of kinetic factors (mixing sequence, viscosity of blend, shear rate, and time of mixing) on the compatibility of polymer-amended bitumen should be investigated. Moreover, the addition of compatibilizers and stabilizers to polymer-modified binder is recommended to improve compatibility and reduce the effect of aging on degradation of polymer.

Mechanical, thermal properties and shape memory behaviors of PLA/PCL/PLA‐g‐GMA blends

AbstractTo improve the toughness of polylactic acid (PLA), in this research, a tough polymer polycaprolactone (PCL) was combined with PLA to prepare blends, and a compatibilizer of glycidyl methacrylate grafted PLA (PLA‐g‐GMA) was produced to enhance the compatibility of PLA/PCL blend. Compared with PLA/PCL blend, the compatibilized blend exhibited a lower melting temperature and greater thermal stability. The tensile test indicates that the addition of compatibilizer greatly improved the toughness of the PLA/PCL blend. Particularly, the elongation at break of PLA/PCL blend with 6 wt% PLA‐g‐GMA increased to 370% and reached about 66 times of neat PLA. In addition, compatibilized blends have good shape memory performance. The research provides a simple and feasible method to overcome the brittleness of PLA, supplying a new strategy to modify PLA.

Ageing characteristics of polyethylene-modified asphalt binders blended with different compatibilisers

ABSTRACT In this study, virgin low-density polyethylene (LDPE) and recycled polyethylene (RPE) were blended with an asphalt binder in combination with compatibilizers such as styrene-butadiene-styrene (SBS), Elvaloy, sulfur, and polyphosphoric acid (PPA): LDPE, LDPE + SBS + Sulfur, LDPE + Elvaloy, LDPE + Elvaloy + PPA, LDPE + sulfur, RPE, RPE + sulfur, and RPE + PPA. This study aimed to investigate (1) the distribution of PE in asphalt binder, (2) chemical changes in the binder due to the addition of compatibilizers, and (3) the ageing characteristics and their effects on the rheological and performance properties. Micrographs revealed that the LDPE dispersity improved with the addition of Elvaloy. The PE blends with sulfur met the target performance grade of PG76V-10. The PE blends with sulfur exhibited the highest fatigue life at low strain levels and degraded rapidly with an increase in strain level. The LDPE blends with Elvaloy experienced the least degradation in fatigue life with an increased strain level; this low ageing susceptibility was due to the lowest carbonyl (I c =o) and sulfoxide (I s=o) index values.

High-reactive silica nanosheets as compatibilizers for immiscible PLLA/PBAT polymer blends

While nanoparticles were considered to be the most promising compatibilizers for immiscible polymer blends, high-efficient nanoparticle-based compatibilizers were still under development. Herein, a high-reactive silica nanosheet (HRN) compatibilizer with excellent compatibilization effect was synthesized and its compatibilization effect was investigated. The HRN compatibilizer was fabricated by skillfully melt-blending amino functionalized silica hollow spheres (AHS) and the poly(styrene-co-glycidyl methacrylate) (PSGMA) with average ten reactive epoxy groups per chain. During the mixing, the AHS were crushed to nanosheets upon the strong shearing and simultaneously grafted PSGMA chains on nanosheets via the reaction of epoxy and amino groups. The PSGMA with high epoxy groups content endowed the HRN with high reactivity. To demonstrate the compatibilization efficiency of our high-reactive compatibilizer, different amounts of HRN were incorporated into the immiscible polylactic (l-acid)/polybutylene adipate terephthalate (PLLA/PBAT) blend, a blend system widely applied in packing and agricultural films, to investigate and compare the changes in morphologies and mechanical properties. Only 3 wt% addition of HRN compatibilizer could significantly decrease the droplets size and dramatically improve the tensile strength and elongation at break of the blend by 1.4 and 23 times. The present work provided a new idea for the development of nanoparticle-based compatibilizer with high compatibilization efficiency.

Effect of maleic anhydride compatibilizer addition on mechanical properties of polylactic acid (PLA)/cellulose acetate (CA) composites film

Environmental problems caused by the use of undegradable conventional plastics are still the major issue. According to the Badan Pusat Statistik (BPS) in 2021, plastic waste in Indonesia accumulated as much as 66 million tons per year and is expected to raise gradually. PLA and CA, derived from renewable resources, are biodegradable, thermoplastic, resistant to pressure, and are often used as raw materials for the manufacture of composite plastics. PLA is hydrophobic and CA is hydrophilic, so a compatibilizer is needed as a substance that can improve the mechanical properties, compatibility, and homogeneity of the resulting composite film. This research aims to obtain the ratio of PLA/CA and the concentration of maleic anhydride (MA) compatibilizer to produce PLA/CA composites film with good mechanical strength and according to packaging material standards. The method in this research is solvent casting by synthesizing composite films through sample preparation, modification of CA with MA, grafting of PLA/CA and MA, synthesis of composite films of PLA/CA and MA, as well as several characteristic tests. The results showed that the obtained films were identified as having PLA, CA, and MA, had a relatively smooth surface and were degraded at a temperature treatment of 543 o C. The best film was obtained from mass variations of PLA/CA and MA (6:4:1.5 gram) with a tensile strength of 7.38 MPa, and elongation at break reached 18.11% and met the packaging standard values by Japanese Industrial Standard (JIS).

Fractal structures of PA6/POE blend nanocomposites and their dynamic properties

We investigate the effect of minor phase rheological properties and compatibilizer on the phase morphology and graphene 3D structure in polyamide-6 (PA6)/polyolefin elastomer (POE) blends. It is revealed that in blends containing low viscosity (LV) POE, graphene is better dispersed facilitating its localization at the interface. In the blend containing high viscosity (HV) POE with poor graphene dispersion, large graphene aggregates are observed inside the POE phase with less interfacial coverage. Interestingly, graphene induces a co-continuous morphology and electrical and rheological percolation in both systems, although at a lower graphene content for the LV system. The LV system exhibits a more interconnected morphology, while in the HV system we observe a compact fractal-like POE structure with a lower degree of interconnectivity. Our morphological observation suggests that co-continuous morphology in the LV system is dominated by sheet formation, while in the HV system it is dominated by coalescence between moderately elongated domains. Fractal analysis of the graphene 3D network (based on the rheological characterization) is correlated with the higher degree of connectivity of the graphene 3D structure in the LV system. The 2D fractal dimension of the POE phase (host phase for graphene) is in line with the fractal dimension of the graphene flocs, indicating that the graphene flocs influence the blend morphology. The addition of compatibilizer to the HV system did not result in improved electrical properties.

Effect of compatibilizer addition on the surface nucleation of dispersed polyethylene droplets in a self-nucleated polypropylene matrix

A significant portion of the global plastics market encompasses the production of polyolefin materials and especially polypropylene (PP) and polyethylene (PE), as commodity polymers with a wide range of applications. However, the increase in the generation of unsustainable plastic waste requires a close technological look-up to address this challenge adequately. In this context, mechanical recycling is part of the strategies expected to contribute to the solution. Nevertheless, the melt blending process presents a challenge due to the immiscibility between PP and PE. Therefore, compatibilization strategies are meant to solve the problem effectively. In this paper, we employ a commercial ethylene-ran-methyl acrylate random copolymer as a compatibilizer for PP/PE blends. With the addition of the compatibilizer, it was possible to obtain a 44% reduction in PE domain size, while ductility increased by around ∼40% with respect to uncompatibilized blends. Interesting results were obtained concerning the crystallization behavior of the blends. The overall isothermal crystallization kinetics of the different blend components was studied, and a synergistic nucleation effect of the PP and the compatibilizer toward the PE phase was found. For the first time, the effect of the compatibilizer on the surface nucleation of PE in a self-nucleated PP matrix phase is reported. An enhancement in the crystallization rate of PE was found when the self-nucleation protocol was applied to the polypropylene matrix phase for neat and compatibilized blends. The nucleation efficiency was in the range of 120–124%, indicating a supernucleation behavior. The induced crystallization at the interface by the self-nucleated polypropylene is the reason for such high nucleation efficiencies. Surprisingly, a higher amount of compatibilizer decreases the overall crystallization rate of PE droplets. The compatibilizer segregates at the interface between both polymers, reducing the surface nucleation of the PE droplets on the PP matrix phase. The results presented in this paper lead the way toward improving the use of post-consumer recycled materials.

Development and Mechano-Chemical Characterization of Polymer Composite Sheets Filled with Silica Microparticles with Potential in Printing Industry.

Polymer composite sheets using a low-cost filler (local natural sand) and polymer (high-density polyethylene, HDPE) as a replacement of the traditionally used wood-fiber-based sheets for paper-based applications were developed. The sand/polymer composite sheets were prepared by melt extrusion in a melt blender followed by compression molding. The effects of varying particle size, concentration, and the use of a compatibilizer (polyethylene-grafted maleic anhydride) was studied on the mechano-chemical performance properties of the composite sheets such as morphology, thermal and mechanical properties, and wettability characteristics used in the printing industry. In terms of thermal stability, filler (sand) or compatibilizer addition did not alter the crystallization, melting, or degradation temperatures significantly, thereby promoting good thermal stability of the prepared sheets. Compatibilization improved anti-wetting property with water. Additionally, for the compatibilized sheets prepared from 25 µm sand particles, at 35 wt%, the contact angle with printing ink decreased from 44° to 38.30°, suggesting improved ink-wetting performance. A decrease in the elastic modulus was also observed with the addition of the compatibilizer, with comparable results to commercial stone paper. Results from this study will be considered as a first step towards understanding compatibility of local natural sand and polymers for paper-based application.