Melt Mixing Method Research Articles

Development of multifunctional nylon 6,6-based nanocomposites with high electrical and thermal conductivities by scalable melt and dry blending methods for automotive applications

With the advent of intelligent automobile technology, the demand for multifunctional composites with higher electrical and thermal conductivities is increasing. We have herein reported for the first time the effect of polyolester on the dispersion of carbon nanotube (CNT) in the short-carbon fiber (CF)/nylon 6,6 (PA66) composite using a scalable melt-mixing and dry-blending method and its subsequent improvement in electrical and thermal conductivities. Masterbatches were prepared with a higher concentration of CNT (both untreated and polyolester-treated) followed by dry blended with reference composite (30 wt% CF and 10 wt% mineral fiber filled PA66) before making coupons via injection molding. A 500 % and 63 % improvements in electrical (3.14 S cm−1) and thermal conductivities (in-plane) (1.99 W m−1 K−1) conductivities were observed by adding 1.5 wt% treated CNT compared to the reference composite. The improvements were even higher than that of untreated CNT due to better dispersion. Furthermore, the electromagnetic shielding effectiveness reached 61 dB for 1.5 wt% treated CNT-filled composite (39 % enhancement). These results are significant in imparting multiple functionalities to the automotive composite parts.

Effect of the sorbitol to glycerol weight ratio and sugarcane bagasse concentration on the physicomechanical properties of wheat starch-based biocomposite

This study involved fabricating thermoplastic wheat starch–sugarcane bagasse biocomposites through melt mixing method. The effect of sugarcane bagasse concentration at 3 levels of 0 wt.%, 7.5 wt.% and 15 wt.% of wheat starch and sorbitol:glycerol weight ratio at 4 levels of 0:4, 1:4, 2:4 and 4:4 on their physicomechanical properties was evaluated. The results indicated that increasing both of the weight ratio of sorbitol to glycerol and the concentration of bagasse generally led to a significant increase in tensile strength and modulus, but a decrease in elongation at break and equilibrium moisture content. The biocomposite containing the weight ratio of sorbitol:glycerol of 0:4 and bagasse concentration of zero, had the lowest tensile strength (0.22 MPa) and tensile modulus (0.23 MPa), and the highest elongation at break (103.1%) and equilibrium moisture content (30.6%) and conversely The biocomposite containing the weight ratio of sorbitol:glycerol of 4:4 and bagasse concentration of 15, had the highest tensile strength (5.3 MPa) and tensile modulus (371.5 MPa), and the lowest elongation at break (1.5%) and equilibrium moisture content (20.6%). Moisture absorption was also studied using the Peleg model, which showed that samples with lower weight ratios of sorbitol to glycerol and lower bagasse concentrations had higher initial moisture absorption rates and greater moisture absorption capacity. The investigation of thermal behavior of the biocomposites by TGA analysis showed improved thermal stability of the biocomposites by increasing both of the sorbitol:glycerol weight ratio and the bagasse concentration. Finally, the FTIR spectrum revealed an increase in hydrogen and polar bonds in the biocomposites compared to pure starch.Graphical

Unzipped multiwalled carbon nanotube oxide / PEG based phase change composite for latent heat energy storage

Polyethylene glycol (PEG) as a phase change material (PCM) is being explored for latent heat energy storage systems due to its high thermal storage capacity. In the current study, PCM composites were synthesized with different mass fractions of unzipped multiwalled carbon nanotube oxides (UMCNOs) in PEG by melt mixing method. The influence of UMCNOs loading on the thermal conductivity (TC), phase change properties such as temperatures and latent heats of melting and solidifying, thermal energy storage and release rates were investigated. At a loading of 6 mass% of UMCNOs, the TC of the prepared PCM composite increased by 2.1 times as compared to that of pure PEG (0.21 W/m-K). Differential scanning calorimetry analysis showed that as the concentration of UMCNOs increased, there was a slight decrease in the melting temperature. Additionally, the latent heats of melting were found to be reduced by 1.11–9.46 % with the addition of 0.5–6 mass% UMCNOs. Further, the thermal energy storage and release rates were improved with the addition of UMCNOs in PCM composites. In addition, there was negligible change in phase change properties after 100 melting and solidifying cycles of PCM composite, indicating the great prospects for the latent heat energy storage application.

Analysis of X-ray and gamma ray shielding performance of prepared polymer micro-composites

Polymethyl-methacrylate (PMMA) was used as the matrix to prepare micro composites for radiation shielding, with 10%, 20%, 30%, and 40% Bi2O3 filler loadings, by melt mixing method. The mass attenuation coefficients (MAC) of prepared micro composites along with pure PMMA were measured with a NaI (Tl) scintillator detector spanning a wide range of energies (59–1332 keV). Several radioactive point sources, which are commonly used in many industrial and medical applications, namely Co-60 (1173 and 1332 keV), Co-57 (122 keV), Cs-137 (662 keV), Am-241 (59.6 keV), Ba-133 (81 and 356 keV) and Ra-226 (242 keV), were used in the experimental work. The shielding performance increased substantially with increasing Bi2O3 filler loading especially in the low energy range and decreased with increasing energy except at 122 keV due to bismuth K-absorption edge. At higher energies 1173 and 1332 keV, Compton effect is the most dominant effect leading to minor variations as observed. XCOM software was used for comparison, by computing the mass attenuation coefficient for prepared micro composites at all used Bi2O3 loadings including pristine PMMA. In addition, the effective atomic number Zeff, electron density Neff as well as the photoelectric absorption and incoherent scattering contributions to MAC, were evaluated for further analysis. The prepared PMMA-Bi2O3 micro composites shielding materials performed very well in the whole energy range 59–1332 keV of interest to medical and industrial applications, and are excellent at lower energies and higher Bi2O3 loadings. In particular, at 40% loading, the experimental MAC for the Cs-137 gamma line (662 keV) reached 93.4% of that of lead element. Therefore, these composites are much recommended cost effective, light and safe shielding material for x and gamma rays.

Experimental and theoretical investigation of mechanical and rheological properties of compatibilized XNBR/NR/GO nanocomposites

In this research, nanocomposites based on carboxylated nitrile rubber (XNBR)/natural rubber (NR) with different concentrations of graphene oxide (GO) were prepared by melt mixing method. The role of XNBR-grafted maleic anhydride (XNBR-g-GMA) as a compatibilizer and the effect of GO content on the morphological, mechanical, rheological, and vulcanization properties were evaluated. It was observed that with increasing the concentration of GO, the scorch and vulcanization time decreased, while the torque of the samples increased. Morphological studies illustrated that by raising the concentration of GO in the presence of a compatibilizer, the fracture surface of nanocomposites became rougher and the average size of dispersed phase decreased. In addition, the presence of XNBR-g-GMA compatibilizer improved the uniform dispersion of GO within the XNBR/XNBR-g-GMA/NR matrix. The mechanical properties of nanocomposites showed the best results for XNBR/NR with a ratio of 75/25. Theoretical studies on the mechanical and rheological properties of nanocomposites performed by Mori-Tanaka and Carreau-Yasuda models and illustrated a good agreement with experimental data.

The potential use of natural expanded perlite as a flame retardant additive for acrylonitrile‐butadiene‐styrene based composites

AbstractThis study aimed to reveal the effect of expanded perlite (EP) additive as a flame retardant for acrylonitrile‐butadiene‐styrene (ABS) copolymer based composites. Before composite preparation, fine powdered EP was characterized by Fourier transform infrared spectroscopy, x‐ray diffraction, thermogravimetric analysis, and scanning electron microscopic analyses. Also, maleic anhydride grafted ABS (MAH‐g‐ABS) with a grafting degree of 3.9 wt% was synthesized and used as a polymeric compatibilizer. ABS/EP composites with different ratios of EP were prepared by a continuous one‐step melt mixing method. Thermogravimetric and morphological analysis, tensile tests, limiting oxygen index (LOI) and UL‐94 vertical burning tests of the composite materials were investigated. EP significantly decreased the decomposition rate of ABS and promoted char formation. EP provided a UL‐94 V‐1 flammability rating with great fire resistance and self‐extinguishing properties to the ABS matrix without any melt dripping. The LOI of ABS was greatly improved, reaching a value of 28.5% by adding only 5 phr EP. Zinc borate (ZB) also played a significant role in enhancing thermal stability and flame retardancy by creating a good synergism with EP. The composite containing 5 phr ZB showed a flame retardant grade of UL‐94 V‐0 and an LOI value of 27.5%.Highlights Flame retardant ABS/EP composites were successfully prepared by melt mixing. The EP ratio of 10 phr provided the highest resistance to flammability. ZB showed good synergy with EP in enhancing the flame retardancy of ABS. ABS/EP10/ZB‐5 composite had a UL‐94 V‐0 rating with an LOI value of 27.0%. This study proved the potential use of natural EP as a flame retardant filler.

Synergistic Effect of Nano-Silica and Intumescent Flame Retardant on the Fire Reaction Properties of Polypropylene Composites.

Silica nanoparticles (nano-silica) were used as synergistic agents with ammonium polyphosphate (APP) and pentaerythritol (PER) to enhance flame retardancy of polypropylene (PP) in this research. The composites were prepared using a melt-mixing method. The influences of nano-silica on the fire performance of composites were thoroughly discussed, which promotes understanding of nano-silica on the flame-retardant performance of polypropylene composite. Scanning electron microscope (SEM) and energy-dispersive spectrometer (EDS) results indicated that the nano-silica with a diameter of about 95 ± 3.9 nm were dispersed favorably in the composite matrix, which might elevate its synergistic effect with intumescent flame retardant and improve the flame retardancy of polypropylene composite. The synergistic effects between nano-silica and intumescent flame retardant on PP composites were studied using the limiting oxygen index (LOI), UL-94 test, and cone calorimeter test (CCT). The total amount of flame retardant was maintained at 30%. When the dosage of nano-silica was 1 wt.%, the LOI value of PP/IFR/Si1.0 composite reached 27.3% and its UL-94 classification reached V-1. Based on the parameters of the CCT, the introduction of nano-silica induced composites with depressed heat release rate (HRR) and peak heat release rate (PHRR). The PHRR of PP/IFR/Si0.5 was only 295.8 kW/m2, which was 17% lower than that of PP/IFR. Moreover, the time to PHRR of PP/IFR/Si0.5 was delayed to 396 s, which was about 36 s later than that without nano-silica. EDS was used to quantitatively analyze the distribution of silica in charred residue. The EDS results indicated that the silica tended to accumulate on the surface during the fire. The surface accumulation characteristic of silica endows it with the enhanced flame-retardant properties of polypropylene composite at a very small dosage (as low as 1 wt.%).

Mechanical, electrical, and adhesive synergies in melt-processed hybrid bio-based TPU nanocomposites

Hybrid nanocomposites (NCs) based on a bio-based thermoplastic polyurethane (TPU) with multi-walled carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) as nanofillers, were obtained using a simple melt-mixing method. The effects of a) the GNP:CNT ratio, b) the total nanofiller content, and c) the aspect ratio of the CNTs on both the nanostructure and the thermal, electrical, mechanical, and adhesive properties of the NCs were studied in depth. Synergies were observed in the mechanical and electrical properties of the hybrid NCs when compared to the corresponding binary TPU/GNP and TPU/CNT NCs, regardless of either the GNP:CNT ratio or the aspect ratio of the CNTs. This was attributed to the enhanced dispersion of the GNPs in the presence of CNTs, caused by the intercalation of the two-dimensional graphene nanoplatelets among the one-dimensional carbon nanotubes. Consequently, the resulting conductive network was more efficient, and the reinforcing efficiency of the single nanofillers was improved. The findings of our study show that electrically conductive NCs with improved mechanical properties were achieved when part of the CNTs in the formulation was replaced by cheaper GNPs. Furthermore, a synergy was also observed in the adhesive properties of the hybrid NCs through their significantly higher lap shear strength than that of the pure TPU or binary reference NCs. In other words, by replacing part of the CNTs with GNPs, we were able to obtain hybrid TPU NCs which were cheaper, more effective, and higher performing than binary TPU/CNT and TPU/GNP NCs, pointing to their potential use as electrically conductive hot-melt adhesives.

A study on microwave absorption properties of polyaniline/nitrile rubber/graphene/Fe3O4 composites with a thickness of 0.7 mm and high flexibility

AbstractThe genotoxic effect of microwave radiation on humans is one of the leading causes of some diseases like cancer. Despite many reported materials for microwave absorption, there is still a demand for a super‐thin and flexible microwave absorber. In the present work, we synthesized Fe3O4/graphene/polyaniline/nitrile butadiene rubber composites with a thickness of 0.7 mm using a melt mixing method. Then, we comprehensively studied the electromagnetic and microwave absorption properties of the composites from 8 to 12 GHz. The composite with 38 wt% Fe3O4 and 6 wt% graphene exhibited the highest microwave absorption of more than 8 dB in the entire range of 8–12 GHz, with a minimum reflection loss of −14 dB at 10.3 GHz. By increasing the weight content of Fe3O4 and graphene, the imaginary part of dielectric permeability and magnetic permeability initially went up and then declined, resulting in poor impedance matching. Hence, we precisely controlled the weight content of the fillers to reach the highest impedance matching and attenuation constant. Consequently, this work opened up a unique way for developing super‐thin, lightweight, flexible microwave‐absorbing materials.

QATLAMLI SILIKATLAR VA IZOTAKTIK POLIPROPILEN ASOSIDAGI KOMPOZITLARNING MEXANIK VA TERMIK XUSUSIYATLARI

In this work, polymer composite materials based on polypropylene (PP) and layered silicates were obtained by melt mixing method. The research looked into the effect of the amount of compatibilizer on thermal and mechanical properties of composites based on two types of layered silicates with modifiers of different interlayer densities, with maleic anhydride grafted polypropylene (MA-p-PP), which was used as a compatibilizer. The compatibilizer was changed to 3, 6, 9 and 12 % while the amount of filler in the composite remained at 3 %. Cloisite15A, a layered silicate with a higher modifier density, produced intercalated structures, while Cloisite20A, with a relatively lower modifier density, produced mostly exfoliated nanocomposites. Forming of the nanostructure led to a significant increase in thermal stability (50 % weight loss was observed at temperatures of 360 and 430 °C for polypropylene and its based nano-composites, respectively). The analysis of the mechanical properties of nanocomposites showed that the elastic modulus increases by 15–20 %, and this effect is more expressive for exfoliated structures, however, the yield stress remains practically unchanged, and a significant decrease in elastic deformation is observed.

Effects of interfacial interactions on structural, optical, thermal degradation properties and photocatalytic activity of low-density polyethylene/BaTiO3 nanocomposite

Barium titanate (BaTiO3) filled low density polyethylene (LDPE), (LDPE)100−x/(BaTiO3)x (where x = 0, 2, 4, 6 and 10) nanocomposites are prepared via a solvent-free melt-mixing method. The effects of nano-sized BaTiO3 (nBT) on the structural, optical and thermal degradation properties of LDPE are investigated to address the qualitative interfacial interaction effects due to the spatial distribution of nBT particles in the LDPE matrix. X-ray diffraction (XRD) results confirm the uniform dispersion of nBT nano-fillers in the LDPE polymer matrix. The crystallite size of LDPE increases with increasing the nBT content. Fourier transform infrared spectroscopy (FTIR) results indicate the enhancement in interfacial physical interactions between the polymer and nano-fillers with increasing nano-filler content. The band gap energy of the nanocomposites decreases with increasing nano-filler content, which suggests chemical imperfections close to the interfaces. DSC results depict higher Tm values for the composites which is attributed to the heterogeneous nucleating effects of the nBT particles. Thermo-gravimetric analysis (TGA) results indicate an increase in the decomposition temperature (TD), thermal stability and good dispersibility probability of nBT with increasing nBT. The photocatalytic decomposition of MB is highest (73.52%) for the 10% nBT incorporated LDPE nanocomposite sample. These results correlate with the effect of the interfacial interactions between the nBT fillers and the LDPE polymer matrix.

A brief review on preparation and application of MWCNT-based polymer nanocomposites

Technological advancementalways seeks new materials with improved functional properties, particularly for smart applications. In this regard, nanotechnology is offering today wide range of novel material designs fabricated by compounding nanofillers into the polymer matrix. Different allotropic forms of carbon can reinforce the properties of polymers for various applications. Reinforcement depends on the dimension, shape, size and compatibility of the nanofiller with the polymer matrix. Chemical modification of filler surfaces and the matrix can selectively localize the filler in the hybrid composites in the desired phase or at the interface by melt mixing or solution casting method, during compounding procedure. In this regard, the conducting nature of the additioin of multiwalled carbon nanotubes (MWCNTs) into a polymer matrix fosters the conductivity into the materials. Such nanocomposites can be used for numerous applications such as conducting materials, super-capacitors, light emitting devices, medical purposes etc,. This review paper focuses on different methods of preparation of MWCNT/polymer nanocomposites, their surface properties, and microbial properties etc,.

EVA/zinc oxide nanocomposites for active food packaging: selected physical, and microbial properties

The melt-mixing method was used to obtain nanocomposites of ethylene vinyl acetate copolymer (EVA) with 1, 3 or 5wt% of hydrophilic zinc oxide (ZnO) nanoparticles. The contact angle, barrier and antimicrobial properties of the obtained composites were investigated. The nanocomposites were characterized by better hydrophilic and barrier properties, as evidenced by, respectively, a smaller contact angle and lower water vapor permeability and water absorption compared to EVA, which can be explained by the formation of hydrogen bonds between EVA and ZnO. In addition, the composites were characterized by greater bactericidal activity against E. coli and S. aureus. The optimal physical and microbial properties were obtained with 3 wt% ZnO content.

A shape-memory, room-temperature flexible phase change material based on PA/TPEE/EG for battery thermal management

The development of conventional battery thermal management (BTM) based on phase change material (PCM) is restricted by its low thermal conductivity, leakage and high rigidity. To solve these problems, the thermally induced flexible phase change materials (FPCMs) have been proposed, but their flexibility only manifests at temperatures above the phase change temperature, which is detrimental to the assembly at room temperature. Herein, using paraffin (PA) as PCM, thermoplastic polyether ester elastomer (TPEE) as flexible support material and expanded graphite (EG) as heat transfer enhancement material, a novel FPCM with shape memory property and wider flexible temperature (−15 to 60 °C) was successfully prepared through melt-mixing method. And then it was skillfully assembled on power batteries at room temperature through flexibility in conjunction with shape memory property. On this basis, the flexibility of FPCM can be utilized to reduce thermal contact resistance during the whole process of battery operation. The results revealed that the measured thermal contact resistance of the above BTM was 0.272 °C/W, lower than that of previous thermally induced FPCM reported. Furthermore, the maximum temperature of the battery module with the passive BTM based on FPCM could be maintained below 55 °C and the temperature difference was within 3 °C under the high discharge rate of 5C and 40 °C ambient temperature.

A study on the synergetic effects of self/induced crystallization and nanoparticles on the mechanical properties of semi-crystalline polymer nanocomposites: experimental and analytical approaches

This work investigates the effects of nanoparticle content, aggregation/agglomeration, polymer/particle interphase, and crystallinity on the mechanical properties of high-density polyethylene (HDPE) nanocomposites. Different samples of HDPE nanocomposites, containing 0.5, 0.75, and 2 wt% of pure and surface-modified silica nanoparticles were prepared by melt-mixing method. The pure silica nanoparticles (PSN) and surface-modified silica nanoparticles with (3-aminopropyl) tri-ethoxy-silane (AMS) were characterized with field emission scanning electron microscopy (FESEM) and Fourier-transform infrared (FTIR) spectra. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used to estimate the crystallinity and crystal size of the nanocomposite samples. Finally, tensile testing was performed on the nanocomposites to establish the relationship between mechanical properties and nanoparticle loading, and surface modification. The results indicate that the crystallinity and elastic modulus of the nanocomposites increased with increasing nanoparticle content. Moreover, the Gutzow–Dobreva theory was applied to approximate the degree of the induced crystallinity in each sample. A mechanical model based on two equivalent box models (EBM) was proposed to determine the crystalline, amorphous phase modulus, thickness and tensile modulus of the polymer/particle interphase region, which showed a decreasing trend with the nanoparticles content and indicated that this region was thicker for the HDPE/AMS relative to HDPE/PSN. Also, it was found that nanoparticles affected both crystalline and amorphous sections, which their effect on the crystals was more significant and presence of the well-dispersed nanoparticles in the amorphous section substantially enhanced their performance against the exerted stress.

Preparation of A Dynamically Vulcanized Nanocomposite Thermoplastic Based on PLA/NR and Cellulose Nanocrystal (CNC)

Dynamically vulcanized nanocomposite thermoplastic based on poly (lactic acid) (PLA)/natural rubber (NR) is prepared through a dynamic curing process. The cross-linked NR phase exhibits a continuous network structure embedded in the PLA phase, which differs from the conventional plastic/rubber system with an "island-sea" morphology in which vulcanized rubber particles are dispersed in the plastic matrix. Its favorable internal interfacial compatibility was confirmed by SEM analysis. Also, CNC has been used as a sustainable additive to improve the mechanical properties of PLA/NR thermoplastic vulcanizate (TPV). To achieve homogeneous dispersion of CNC, the melt mixing method was used. The mechanical properties were considerably enhanced by CNC addition, which increased from 14% of the unfilled TPV to 70% of the sample with CNC (1.5 phr relative to PLA). The "green" raw materials and high mechanical properties of PLA/NR/CNC prepared from the dynamic curing process are expected to open up a wide range of potential applications in the fields of smart medicine.

Preparation of PLA-TPU-Nanoclay composites and characterization of their morphological, mechanical, and shape memory properties

In this study, a combination of polylactic acid polymer and thermoplastic polyurethane with the addition of nano-clay particles was used. The reason for using clay nanoparticles and their strength is the low price and availability of this material. Adding nano-clay particles to the polymer composition improves the mechanical properties of the composite as they will interact with functional groups of the polymer.The results of the FTIR spectroscopy confirmed the presence of three components in the compound indicating that no chemical reactions occurred among the three components during the compounding process. The FE-SEM images taken from the compounds showed that TPU and nano-clay particles were evenly distributed in the PLA matrix. The DMTA results were utilized to determine the transfer temperature of the compounds as well as the storage and loss modulus and the shape memory properties. The XRD spectroscopy was used to determine the crystallinity and exfoliation of the nanoparticles. The mechanical properties of the fabricated polymer compounds were determined. It was found that the sample with 3% by weight of clay nanoparticles had the highest strength, and the sample with 5 wt% of clay nanoparticles had the highest toughness among nanocomposites. According to the hardness measurement, the sample with 5% by weight of clay nanoparticles has the highest hardness amongst all prepared composites. The memory properties of the prepared nanocomposites showed a significant improvement with increasing the amount of nanoparticles.This study showed the suitability and efficiency of PLA, TPU, and clay nanoparticle melt mixing methods in achieving a relatively tough shape memory composite. At the same time, this method is also inexpensive and scalable.

Studies on dielectric properties of barium titanate-polyetherimide nanocomposite

The electrical properties of nanocomposites based on polyetherimide (PEI) filled with barium titanate nanoparticles (BT) getting (PEI/BT) were studied. The hydrophilicity, porosity, and water uptake capacity of barium titanate clay showed a remarkable improvement with a 3 wt%. dosage, conferring to study. Barium titanate has high cation exchangeability, allowing for the incorporation of a variety of cations. Melt mixing method has used to produce the inorganic/organic hybrid nanocomposite films made of barium titanate clay and poly(ether-imide) (PEI). By adjusting the barium titanate clay concentration, a variety of PEI nanocomposite films have been produced. Nanoscale distribution of barium titanate clay affected the properties of PEI. PEI as electrical conductivity (1 × 10−11 S/cm) with different wt % clay showed enhanced advance in the properties. The combination of barium titanate nanoparticles (BT) as filler materials generates a synergistic effect within the polymeric matrix of the nanocomposite favoring the increase in the electrical conductivity of the system. With increasing additive concentration, SEM analysis showed an increase in macrovoides and surface roughness. Additionally, the penetration rate increased with the addition of barium titanate. All different types of material dielectric experiments have shown the impact of water or other contaminants. Water has the effect of reducing the nanocomposites' dielectric strength.

Zn[B3O4(OH)3] composites fabrication based on PVC pipes scrap via comparing melt mixing and casting procedures under the effect of electron beam irradiation

In several works, scientific researchers targeted the development of polymeric materials with good mechanical and thermal properties and resist heat and fire propagation. In a new approach, this article goals to the usage of waste polyvinyl chloride (WPVC) based polymer composites derived from PVC pipes scrap filled with fixed percent of zinc borate particles (ZnB), which were prepared via two different techniques named melt mixing WPVC/ZnB (M) and casting WPVC/ZnB (C). The fabricated composites by the two methods were irradiated in an electron beam accelerator (EB) at 30 kGy. A comparative study of the thermal and mechanical properties based on stress-strain curves, tensile strength (TS), elongation at break (E %), and tear strength were evaluated. Furthermore, the rate of heat burning (%) for the two methods has been performed. Moreover, differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), Infrared spectroscopy analysis (FTIR), X-ray diffraction (XRD), and the activation energy (Ea) calculation of the prepared samples have been considered. The observed improvements in the mechanical, thermal, and flammability behavior of WPVC were succeeded by incorporating ZnB particles. The irradiated WPVC loaded with zinc borate presented a superior flame propagation fraction when matched with their corresponding unirradiated composites. Also, WPVC composite films prepared via the melt mixing method reveal more excellent properties than those equipped by the casting process for the most investigated factors.

Polypropylene and Graphene Nanocomposites: Effects of Selected 2D-Nanofiller’s Plate Sizes on Fundamental Physicochemical Properties

The authors developed a nanocomposite using polypropylene (PP) and graphene nanoplatelets (GNPs) with a melt mixing method. Virgin PP was filled with three sets of GNPs with a fixed thickness (15 nm) and surface area (50–80 m2/g). The selected H-type GNPs had three different sizes of 5, 15 and 25 µm. The nanocomposites were made by loading GNPs at 1, 2 and 3 wt.%. Mechanical analysis was carried out by performing tensile, flexural and impact strength tests. The crystalline, micro-structural, thermal and dynamic mechanical properties were assessed through XRD, FESEM, PLM, DSC, TGA and DMA tests. It was observed that all three types of GNPs boosted the mechanical strength of the polymer composite. Increasing the nanofiller size decreased the tensile strength and the tensile modulus, increased the flexural strength and flexural modulus, and increased the impact strength. Maximum tensile strength (≈41.18 MPa) resulted for the composite consisting 3 wt.% H5, whereas maximum flexural (≈50.931 MPa) and impact (≈42.88 J/m) strengths were observed for nanocomposite holding 3 wt.% H25. Graphene induced the PP’s crystalline phases and structure. An improvement in thermal stability was seen based on the results of onset degradation (TD) and melting (Tm) temperatures. Graphene increased the crystallization (Tc) temperatures, and acted like a nucleating agent. The experimental analysis indicated that the lateral size of graphene plays an important role for the nanocomposite’s homogeneity. It was noted that the small-sized GNPs improved dispersion and decreased agglomeration. Thus overall, small-sized GNPs are preferable, and increasing the lateral size hardly establishes feasible characteristics in the nanocomposite.