Polypropylene Phase Research Articles

Effect of antibacterial masterbatches selection on the crystal structure and properties of nanosilver composite materials

AbstractThe distribution of nanosilver in composite materials with two different matrices is related to the selection of antibacterial masterbatches, which has a profound impact on the antibacterial effectiveness of the composite materials. This study utilized ethylene‐vinyl acetate (EVA) and polypropylene (PP) as base materials to fabricate two types of nanosilver composite materials (C1‐EVA/PP and C2‐EVA/PPP) employing varying methods of antimicrobial masterbatches incorporation. Additionally, EVA‐Ag and PP‐Ag nanosilver composite materials were fabricated via melt blending, along with corresponding neat materials and blends (EVA, PP, and C0‐EVA/PP) for comparison. The study results indicate that the addition of nanosilver did not affect the functional groups of either the neat materials and the EVA/PP blends. SEM analysis revealed that nanosilver was dispersed unevenly in the C1‐EVA/PP substrate, while it was more uniformly distributed in the C2‐EVA/PP substrate. In the antibacterial test, the antibacterial rate of C2‐EVA/PP was higher than that of C1‐EVA/PP (56.0% vs. 40.0%). However, all silver‐containing composite materials did not exhibit antibacterial properties in the agar diffusion test. Additionally, nanosilver exhibited an induced crystallization effect on the PP phase of the C2‐EVA/PP composite material, increasing its Tc2 by 0.8°C. Compared with pure PP, the long period of PP‐Ag increased by 0.7 nm, and its impact resistance improved by 13.8%. By comparison, the long period of EVA‐Ag composite materials increased by only 0.2 nm compared to pure EVA. Both C1‐EVA/PP and C2‐EVA/PP composite materials showed 0.3 nm increase in long period compared to C0‐EVA/PP, with their impact resistance improving by 3.1% and 10.3%, respectively, compared to C0‐EVA/PP. The introduction of nanosilver increased the storage modulus, loss modulus, and apparent viscosity of EVA/PP blends. Optical performance analysis shows that nanosilver increases the internal haze of C1‐EVA/PPP by 60% while reducing the transmittance by 0.3%. The effect of nanosilver on the optical properties of C2‐EVA/PPP composites is relatively small. Therefore, this study provides theoretical guidance for the selection of processing methods for dual‐phase antibacterial materials.Highlights Different antibacterial masterbatch impacts silver distribution in composites. The addition of nanosilver can improve the impact performance of materials. Two process methods were used to prepare low‐silver content composite materials. The antibacterial rate of C2‐EVA/PP is higher than C1‐EVA/PP (56% vs. 40%). This study guides the processing methods for dual‐phase antibacterial materials.

The Influence of a Commercial Few-Layer Graphene on Electrical Conductivity, Mechanical Reinforcement and Photodegradation Resistance of Polyolefin Blends

This work demonstrates the potentials of a commercially available few-layer graphene (FLG) in enhancing the electro-dissipative properties, mechanical strength, and UV protection of polyolefin blend composites; interesting features of electronic packaging materials. Polyethylene (PE)/ polypropylene (PP)/ FLG blend composites were prepared following two steps. Firstly, different concentrations of FLG were mixed with either the PE or PP phases. Subsequently, in the second step, this pre-mixture was melt-blended with the other phase of the blend. FLG-filled composites were characterized in terms of electrical conductivity, morphological evolution upon shear-induced deformation, mechanical properties, and UV stability of polyolefin blend composites. Premixing of FLG with the PP phase has been observed to be a better mixing strategy to attain higher electrical conductivity in PE/PP/FLG blend composite. This observation is attributed to the influential effect of FLG migration from a thermodynamically less favourable PP phase to a favourable PE phase via the PE/PP interface. Interestingly, the addition of 4 wt.% (~2 vol.%) and 5 wt.% (~2.5 vol.%) of FLG increased an electrical conductivity of ~10 orders of magnitude in PE/PP—60/40 (1.87 × 10−5 S/cm) and PE/PP—20/80 (1.25 × 10−5 S/cm) blends, respectively. Furthermore, shear-induced deformation did not alter the electrical conductivity of the FLG-filled composite, indicating that the conductive FLG network within the composite is resilient to such deformation. In addition, 1 wt.% FLG was observed to be sufficient to retain the original mechanical properties in UV-exposed polyolefin composites. FLG exhibited pronounced UV stabilizing effects, particularly in PE-rich blends, mitigating surface cracking and preserving ductility.

The comparative study of PP-b-PE block copolymer and ethylene-octene block copolymer on crystallization, structure and mechanical property of high-density polyethylene/polypropylene blends

Olefin block copolymers can improve the compatibility between polyethylene (PE) and polypropylene (PP). The work studied the impact of ethylene-propylene multiblock copolymer (PP-b-PE) and ethylene-octene block copolymer (OBC) on the crystallization behavior, mechanical properties, phase structure, and interfacial interactions of HDPE/PP blends. The result showed that PP-b-PE promotes the crystallization temperature and rate of both HDPE and PP, while OBC primarily affects the crystallization behavior of HDPE. The addition of PP-b-PE, as evidenced by small angle X-ray scattering (SAXS), further weakened the interface region between HDPE and PP compared to OBC, indicating enhanced compatibility between HDPE and PP, further confirmed by the stronger adhesion of PP-b-PE to PP and HDPE compared to OBC in peel test. Surface morphology and surface energy analysis demonstrated that PP-b-PE can form a core-shell structure with PP by encapsulating PP, similar to OBC-PP core-shell structure, reducing the interfacial tension between HDPE and PP that effectively transfers stress to the PP phase. The improved compatibility of HDPE/PP resulted in higher elongation at break and equivalent impact strength to HDPE.

Analysis and identification of degradation products in gas, particle, and liquid phases of polypropylene and polyethyleneterephthalate microplastics aging through non-thermal plasma simulation.

Plastic aging can cause alterations in the physical and chemical characteristics of plastics, as well as their behavior in the environment. Due to the extremely slow natural aging process, laboratory simulated aging methods have to be used. In this study, non-thermal plasma (NTP) was adopted to investigate the aging process of polypropylene (PP) and polyethylene terephthalate (PET) microplastics. Various analytical instruments, including proton transfer reaction mass spectrometry and single-particle aerosol mass spectrometry, were employed to examine and identify the organic constituents of the gas, liquid, and particle phase degradation products, as well as to monitor the degradation process. The results showed that after 90min of aging, both PP and PET surfaces showed yellowing, and the carbonyl index of PP increased while that of PET decreased, with an increase in crystallinity. The organic components of reaction products, such as ketones, esters, acids, and alcohols, increased with longer aging times. Gas products mainly contain aromatic hydrocarbons, while particles from aged PET contain compounds with benzene rings and metal elements. Liquid products from aged PP show a significant presence of branched alkanes. Based on this analysis, degradation mechanisms of PP and PET by NTP were proposed. This investigation represents the initial systematically exploration of the release of organic substances during the degradation of microplastics mediated by NTP. It provides significant insights into the detrimental organic compounds emitted during this process, thereby offering valuable information for understanding the environmental and human health implications of natural microplastic degradation. Furthermore, it addressed the requirements for increased attention to the potential environmental risks associated with these harmful components.

Enhancing Mechanical Performance of High-Lignin-Filled Polypropylene via Reactive Extrusion.

Polypropylene (PP) is one of the most extensively used commodity plastics. In terms of eco-friendliness, it is worth considering preparing high-lignin-filled PP. This study explores the incorporation of high lignin content, derived from acetic acid lignin (AAL) and Kraft lignin (KL), into PP through twin-screw extrusion and injection molding. The challenge lies in maintaining mechanical performance. A compatibilizer-specifically, maleic anhydride-grafted polypropylene (MAPP)-is employed to enhance lignin-PP compatibility by chemically bonding with lignin and physically associating with the PP phase. Results indicate that KL maintains better dispersity than AAL. Compatibilizers with a high maleic anhydride (MA) level (≥0.8 wt.%) and moderate melt flow index (MFI) in the range of 60-100 g 10 min⁻¹ prove favorable in constructing a reinforced PP/KL network. Optimizing with 40 wt.% lignin content and 10 parts per hundred (pph) of compatibilizer yields blends with mechanical performance comparable to neat PP, exhibiting a notable increase in modulus and heat deflection temperature (HDT). Furthermore, utilizing PP/lignin blends can lead to a 20% reduction in expenses and approximately 40% reduction in PP-induced greenhouse gas (GHG) emissions. This approach not only reduces PP costs but also adds value to lignin utilization in a sustainable and cost-effective manner.

Thermal oxidation of blends of polypropylene and polyamide 6/66. Effect of inhibition

The thermal oxidation of the blends of isotactic polypropylene (PP) and mixed copolyamide PA6/66 has been studied in a wide range of compositions: 0, 5, 10, 20, 30, 40, 50 and 100 wt % PA6/66. Data obtained by differential scanning calorimetry (DSC) and FTIR indicate the immiscibility of two polymer phases in the blends. The melting enthalpy of mixtures is increased during oxidation that is explained by chemi-crystallization of PP under PP oxidation. PA6/66 component is found to retard the growth of PP enthalpy during PP oxidation. According to DSC data on the PP/PA6/66 blends in air, PA6/66 phase greatly enhances the oxidation onset temperature of the PP/PA6/66 blends thus indicating the improved thermal stability of new material. The oxygen consumption of the PP/PA6/66 blends at 130°C proceeds with a large oxidation induction time (OIT) which is increased with increase in PA6/66 content. After OIT is ended, a constant oxidation rate is established, which is characteristic of the autoxidation mechanism. Kinetic analysis of the thermal oxidation of the PP/PA6/66 blends was carried out on the base of two models of polyolefin autooxidation with hydroperoxide decomposition via the 1st or the 2nd order reaction. The both models were found to describe the experimental kinetic curves of the oxygen consumption. Two possible explanations of the inhibition of PP oxidation by PA6/66 phase are discussed. The migration of active radicals from the PP phase to the PA6/66 phase with their transformation into low-active PA6/66 radicals may be responsible for inhibition and an increase in OIT of PP. Another mechanism of OIT increase may be related with a change in the structure of the PP/PA6/66 blends depending on PA6/66 content.

Functionalized sepiolite intercalated graphene nanostructure reinforced polypropylene composites

The present work developed hybrid polypropylene (PP) ternary composites using PP with different contents of amine-functionalized sepiolite intercalated graphene (f-Sep-Gr) nanofillers through the melt blending method. The amine functionalization on sepiolite intercalated graphene (Sep-Gr) nanostructure was carried out using 3-amino propyl triethoxyl silane. Fourier Transform-Infra Red (FT-IR), X-ray Photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) analysis confirmed the successful functionalization of the amine group into Sep-Gr. Transmission Electron Microscopy (TEM) analysis also confirmed that the amine functionalization didn’t disturb the Sep-Gr morphology. Maleic anhydride graft polypropylene (PP-g-MA) was employed as an interfacial compatibilizer to enhance the dispersion of f-Sep-Gr into the continuous PP phase via a perfect covalent bond interaction. X-ray diffraction (XRD) analysis showed a complete distribution of f-Sep-Gr into the PP/PP-g-MA blend matrix, and the intercalated structure of f-Sep-Gr was not adversely disturbed in the composite. Melt rheological analysis revealed that the composite consisting of the lower content of f-Sep-Gr (0.5 wt%), resulting in a viscous behavior, and a further increase in the content of f-Sep-Gr into the PP/PP-g-MA blend showed viscoelastic solid-like behavior. Differential scanning calorimetry (DSC) analysis revealed that the f-Sep-Gr did not accelerate the melt-crystallization process of PP. In addition, thermogravimetry analysis (TGA) showed that the thermal stability of PP/PP-g-MA/f-Sep-Gr composites improved as a function of f-Sep-Gr content. A small amount of f-Sep-Gr (0.5 wt%) increased Young’s modulus and impact strength of the PP matrix, which is about 123% and 266%, respectively, compared to pure PP. TEM analysis ensured the incorporation of a small fraction of f-Sep-Gr into the blend matrix, forming a three-dimensional network structure in the composite.

Synthesis, Recycling and High‐Throughput Reprocessing of Phase‐Separated Vitrimer‐Thermoplastic Blends

AbstractPhase‐separated polymer blends including a transesterification vitrimer and polypropylene are synthesized from widely available precursors through reactive processing. It is shown that proper formulation during the process including a viscosity modifier of the vitrimer precursors and a reactive interface compatibilizer yields well‐dispersed vitrimer phases with fractions up to 75 wt.% in the polypropylene phase. These vitrimer blends can be easily reprocessed by multiple shredding‐injection cycles and processed in high‐shear conditions through capillary rheometry. Rheological analyses reveal that a percolating dynamic network is formed across the vitrimer domains. It breaks apart during high shear reprocessing of the material and dynamically reforms after thermal annealing of the blends. It therefore ideally combines the mechanical and high‐throughput (re)processing properties of the thermoplastic matrix minor phase with the chemical, thermomechanical, and dynamic properties of the vitrimer major phase. This work illustrates the decoupling of processing at high shear rates enabled by the polypropylene processing aid from the kinetics of dynamic exchanges of the vitrimer phase and thermomechanical properties at the service temperature of the blends.

Regulation of dual-scale structure of polypropylene/poly(ethylene-co-vinyl alcohol) hollow fiber membranes with bimodal pore base on lamellae optimization during annealing

Solvent-free manufacturing process of high performance polymer hollow fiber membranes has always been a desirable direction. Therefore, maleic anhydride grafted polypropylene (PP-g-MAH) as compatibilize, the polypropylene (PP)/poly(ethylene-co-vinyl alcohol) (EVOH) hollow fiber membranes (PMEHFMs) with bimodal pore were manufactured via melt-spinning and stretching. Bimodal pore structure was constructed for improving the porosity and retaining the rejection performance. Based on the effect of EVOH on nucleation behavior and crystal growth of PP phase, the effect of annealing temperature on microscopic lamellar structure of hollow fibers with adding EVOH was investigated in detail, and the results were expected to guide the regulation of dual-scale structure of bimodal pore. With rising annealing temperature, long period of crystal (L) gradually increased, but thickness of lamellae (Lc) and rigid amorphous (Ltr) firstly increased and then decreased when annealing temperature increased to 160 °C, and optimum values were obtained when annealing temperature was 150 °C. The optimum crystallinity and lamellar orientation of annealed hollow fiber annealed at 150 °C were 48.48% and 0.863, respectively. As the annealing temperature increased, the most probable pore size of small scale pores in PMEHFMs increased firstly and then stabilized at 183 nm, which was correspond to the change of lamellar thickness in annealed hollow fibers. Whereas, the most probable pore size of large scale pores did not show a significant change trend. The porosity increased firstly and then decreased with the increase of annealing temperature, which was also correspond to the change of pure water fluxes of PMEHFMs. The porosity and pure water flux of PMEHFM reached the maximum when the annealing temperature was 150 °C.

Effect of the thermoplastic types and ratios for the 3D printed thermoplastic natural rubber vulcanizates: Mechanical, dynamical, thermal, printed-structural properties

Since the crosslinked natural rubber (NR) products contain chemical crosslinks, the materials have loosened the biodegradable and environmentally friendly properties. Combination of NR and thermoplastic, so called thermoplastic natural rubber (TPNR), can be a proper approach for solving this evident through new technological processing. Therefore, the three-dimensional 3D printing TPNR based on polypropylene (PP) and high-density polyethylene (HDPE) thermoplastics were carried out. Blending ratios of 70:30 and 80:20 have investigated, while the dynamically cured system was applied to the blends. This aims to the NR applications and solves the end-cycled of NR waste which cannot be recycled. Relating the molecular structure of the blends, the crosslinked NR particles are dispersed and distributed in the PP phase, while the superior toughness of HDPE provides high elongation at break and impact strength. However, the high crystallinity of PP combined with its low toughness and high stickiness makes it a more broadly applicable 3D printing material than HDPE. It was found that the complexed 3D printing of PP/NR at 80:20 showed the highest compressive strength relative to pure PP. This indicates the improvement of the intrinsic properties of the blends. This improvement can be advantageous for the NR product platform when it is incorporated in PP and parts are produced by 3D printing.

Effect of Oxidation Temperature on the Crystalline Phase of Polypropylene in Composites with Single-Walled Carbon Nanotubes

Effect of Oxidation Temperature on the Crystalline Phase of Polypropylene in Composites with Single-Walled Carbon Nanotubes

Effect of Oxidation Temperature on the Crystalline Phase of Polypropylene in Composites with Single-Walled Carbon Nanotubes

The effect of thermal oxidation on the crystalline phase of polypropylene in composites with single-walled carbon nanotubes has been studied. The composites are synthesized in propylene bulk using a homogeneous catalytic system rac-Me2Si(2-Me-4PhInd)2ZrCl2, activated by methylaluminoxane. The effect of thermal oxidation on thermophysical characteristics (the heat of melting and the melting temperature) measured by DSC and changes occurring in the polymer investigated by IR spectroscopy is studied. Changes in the structure of PP during thermo-oxidative degradation are studied by DSC at 140 and 170°С, that is, before and after melting of the samples. It is shown that the oxidized PP in the composites possesses a higher degree of crystallinity and a more perfect structure than the pure PP. At 170°С the effect of thermo-oxidative stabilization is observed only at low filling degrees (up to 3 wt %), in agreement with the TGA data. An analysis of IR spectra demonstrates that the presence of nanotubes in PP‑based composites during oxidation slows down the formation of oxygen-containing groups in the polymer. The conclusion is made that carbon nanotubes inhibit the thermal oxidation of polypropylene in the composites.

Mechanism of βα recrystallization in isotactic polypropylene

βα recrystallization refers to a process of melting of the β crystallites followed by a recrystallization into α phase in isotactic polypropylene (iPP). It is normally observed only after cooling down the β-nucleated iPP (β-iPP) from the crystallization temperature to below 100 °C before heating. In this work, several β-iPP with different molecular weights were employed to investigate the βα recrystallization in the heating process starting at the crystallization temperature (Tc). It turned out that the non-cooled β-iPP with a molar mass of about 12 kg/mol (β-iPP12K) showed a βα recrystallization during slowing heating. The extent of the βα recrystallization gradually reduced with the increase of the Tc of the β-iPP12K. This peculiar behavior of β-iPP12K can be assigned to the existence of less stable β-crystallites which are susceptible to βα recrystallization. The β-iPP12K preferred to crystallize into thin β-crystallites with low stability which could be melted at low temperatures to form “amorphous self-nuclei” during slow heating. These local ordered amorphous phase would serve as nucleation-sites for α growth in a favorable temperature range. With respect to the β-iPP with high molar mass, although the “amorphous self-nuclei” could be induced at a certain temperature, this temperature was already beyond the appropriate temperature for α growth.

Impact of thermomechanical reprocessing conditions on polypropylene composites made from automotive waste parts: A path to a circular economy

AbstractThis work focused studying waste car bumper samples and their processing by re‐extrusion‐injection. Car bumpers are composed of crystalline phases of polypropylene (PP), talc, and amorphous ethylene propylene diene monomer (EPDM). The recycled material's thermal, mechanical, and structural properties depend strongly on the process used for extrusion and injection and the crystalline phases formed during the heating process. The FWHM of the x‐ray diffraction patterns was used to study the recrystallization phenomenon in PP, and the result was in direct correlation with the Differential Scanning Calorimetry (DSC) results. The remaining micro paint particles from the bumpers involved in the recycled extrusion‐injection process affect the mechanical properties, and their size and toughness could affect the injection. Removing these particles could improve the mechanical properties of the recycled PP. Car parts based on polypropylene can be recycled for the automotive industry to produce the same type of products and even for other areas. A methodology and metrology can be developed to understand the chemical composition and its relationship with the properties of PP‐based materials. This could lead to finding new applications in different fields and promote the development of a circular economy.

Influence of Molecular Weight on the Nucleation and Growth of Different Crystal Forms in Isotactic Polypropylene: In Situ Synchrotron Microfocus X-Ray Scattering Combined with Fast-Scanning Chip Calorimetry Investigations

The molecular weight (Mw)-dependent formation of mesophase and the α phase of isotactic polypropylene (iPP) was explored by utilizing in situ synchrotron microfocus X-ray scattering measurements combined with a portable fast-scanning chip calorimetry (FSC) technique. A phase diagram illustrating the relationship between the lamellar long spacing (dac) and crystallization as well as melting temperatures of three iPP samples with different molecular weights suggests that a common crystallization line was shared by the mesophase of all three samples, whereas three different crystallization lines were observed for these iPP samples. Furthermore, unlike in the case of the α phase where the melting lines were significantly different from their crystallization lines, the melting line of the mesophase was found to overlap with its crystallization line. The results indicate that the crystallization of the α phase satisfied the multistage crystallization model in which an intermediate layer is suggested to be generated prior to the formation of native crystallites. The Mw-independent formation of the mesophase demonstrated that the nucleus size did not rely on the Mw of iPP because the final sizes of the mesophase were close to the initial nuclei sizes. The larger difference of the lamellar long spacing presented in the α phase of iPP with different Mw indicated that the growth from nuclei to crystallites was significantly influenced by the Mw.

Prediction of comprehensive mechanical properties of thermoplastic vulcanizate (TPV) with various composition ratios based on a micromechanical method

In the field of thermoplastic vulcanizate (TPV), experimental methods cannot quantify the relationship between the internal structure and performance of TPV, and are not conducive to the accurate design of TPV structure and performance, which is one of the problems to be solved in this field. In this study, a simple and effective two-dimensional micromechanical model was established based on the real microstructure of TPV by using the micromechanical method and the mechanical properties of TPV with different ethylene propylene diene monomer (EPDM) mass fractions were studied. The results show that with the increase of EPDM content, the maximum stress distribution area of TPV would change, the elastic modulus of TPV would gradually decrease, while the maximum stress of polypropylene (PP) phase would first decrease and then increase and strain corresponding to elastic–plastic change would also increase. The resilience of TPV increases with the increase of EPDM content and decreases with the increase of strain load. When the EPDM content is higher than 70%, the “S” bending deformation would occur at the thinnest part of PP matrix ligament.

Topography and electrostatic interactions of electret fibres in N95 facemasks

Facemasks have been a critical line of defense in the Covid-19 pandemic and have been used for decades to reduce the inhalation of sub-micron aerosols, including bacteria, viruses and nano-materials. These facemasks leverage electrostatic charge properties of non-woven electret fibre mats to remove sub-micron aerosols. However, the topographical and electrostatic properties of these mats have not been well characterized at the nano-scale. In this study, we use atomic force microscopy (AFM) to examine the surface topography of the electret fibres within a commercial respirator fibre mat, use electrostatic force microscopy to map the electrostatic interactions emanating from these fibres, and use synchrotron X-ray scattering to probe polymer morphology. We find that within these mats the fibres exhibit significant heterogeneity in surface topography, electrostatic interactions and polypropylene phase composition. The surface topographies ranged from nano-smooth surfaces to ordered spherulitic structures. The electrostatic interactions varied across fibre length and circumference, and are only weakly correlated with surface topographical features. Finally, we use AFM to characterize fibres after filtering a NaCl aerosol and find that the deposited particles are heterogeneous in size and distributed over the fibre surfaces.

Control of graphene nanoplatelets at the interface of the co-continuous polypropylene/polyamides 6 blend under the elongational flow

Controlling the filler selective distribution at the interface of co-continuous polymer blend is an effective way to fabricate high performance composites. In this work, the graphene nanoplatelets (GNPs) were distributed at the interface of co-continuous polypropylene (PP)/polyamides 6(PA6) blend by melt blending under the elongational flow generated by convergent-divergent channels. And the formation of co-continuous structure and migration mechanism of GNPs in the PP/PA6 blend under the elongational flow were discussed based on the analysis of rheological measurement, scanning electron micrographs, selective etching experiment and thermal conductivity measurement. The results show that both PP and PA6 phase are elongated into fibrous phase structure under the elongational flow. This indeed enlarge the volume ratio range of composites forming co-continuous structure. And GNPs are oriented along the phase interface and stay at the interface during migration under the elongational flow, which can improve its in-plane thermal conductivity. The in-plane thermal conductivity of the PP/PA6/GNPs composites prepared under the elongational flow are all higher than those prepared under the shear flow. Particularly, the composite prepared under the elongational flow with the 65/35 vol ratio of PP/PA6 still kept a co-continuous structure and the GNPs distributed at the interface. Its in-plane thermal conductivity reached a maximum value of 1.13 W/m K.

Jamming carbonaceous nanofiller in the continuous phase and at the blend interface for phenomenal improvement in the overall physico-mechanical properties of compatibilized thermoplastic elastomer

Reduced graphene oxide (RGO) nanosheets have been selectively jammed in the continuous polypropylene (PP) phase and at the blend interface of random terpolymer of ethylene, acrylic ester and maleic anhydride (EAMAT) compatibilized PP and epichlorohydrin rubber (ECH) based thermoplastic elastomer (TPE). The presumptions from the contact angle studies regarding the preferential localization of RGO in the continuous PP phase and at the blend interface of compatibilized PP/ECH/EAMAT/RGO TPE nanocomposite have been analyzed via field emission scanning electron microscopy and atomic force microscopy. The presence of RGO in the continuous PP phase and at the blend interface results in a phenomenal improvement in the mechanical, rheological and viscoelastic properties of the compatibilized PP/ECH/EAMAT/RGO TPE nanocomposites. X-ray diffraction studies of the strained compatibilized PP/ECH/EAMAT/RGO TPE nanocomposite testify that, during straining, the RGO nanosheets help the PP chains to orient and consequently there is a prominent improvement in the overall physico-mechanical properties.

Effect of Compatibilizer on the Properties of Areca-Fiber Reinforced Polypropylene Composites

ABSTRACT Areca fiber reinforced polypropylene (PP) composites were prepared at 20%, 30%, 40%, and 50% loading levels in the presence of compatibilizing agent, MAPP (maleic anhydride grafted polypropylene). The influence of compatibilizing agent and filler concentration on the mechanical properties of the resulting composites was studied. At 50% areca fiber loading, tensile, flexural strength, and modulus of the coupled samples were found to be superior when compared to the uncoupled samples. Coupled composites exhibited effective coupling/interfacial adhesion between the surface of areca fiber and polypropylene phase as evidenced by SEM microphotographs and FTIR spectroscopy. Increase in fiber percentage led to an increase in brittleness and stiffness of composites. A considerable increase in strength was noticed upon the addition of compatibilizing agent, due to proper incorporation of areca fiber into the polypropylene matrix and the efficient transfer of load from matrix to the fiber. Higher moisture absorption in case of composites with higher fiber content was found. Addition of MAPP reduces the percentage of water absorption as a result of encapsulation of areca fiber. Areca fiber can be effectively utilized to develop artificial wood with better properties to replace natural wood as a waste-to-wealth approach.