PET Composites Research Articles

Tensile strength of glass fiber-reinforced waste PET and Kenauf hybrid composites

Increasing the amount of plastic waste from year to year is inevitable due to the increased use of plastics by people in the World. This study aims to evaluate the mechanical behavior, in this case, the tensile strength of a hybrid composite between kenaf natural fibers, PET plastic waste and glass fibers for wallboard. This research takes the form of experimental tests in the laboratory. The composite material to be made is a mixture of plastic, kenaf fiber with glass fiber with polyester reinforcement. Both kenaf and glass fiber is made in sheet form. The hypothesis developed in this laboratory study from previous research found that kenaf and glass fiber hybrid material can be used for partition material. Results showed that hybridization with glass fiber enhanced performance properties. A value of 48,5 MPa for tensile strength is achieved from waste PET glass kenaf hybrid composite without immersion.

Preparation of a novel phosphorus‐containing organosilicon and its effect on the flame retardant and smoke suppression of polyethylene terephthalate

A novel phosphorus‐containing silicone flame retardant (PDPSI) was prepared by Mannish reaction, and a series of PDPSI/PET composites were prepared by melt blending method. The nuclear magnetic resonance (1H NMR), Fourier transformation infrared (FTIR), and the thermogravimetric analyzer (TGA) results indicated that PDPSI showed network structure and owned good thermal stability, with the char residue of 62.2% at 800°C. The flame retardancy of PDPSI/PET composites was characterized by limiting oxygen index (LOI), vertical burning tests (UL‐94), and cone calorimeter (CCT). The results revealed that the addition amount of PDPSI was 5%, the LOI value of PDPSI/PET composites increased to 27.3%, and UL‐94 test passed V‐0 rating. When the PDPSI loading was 3%, PET composites showed excellent flame retardancy and smoke suppression, with a decrease in the peak heat release rate (PHRR) by 71.19% and the total smoke release (TSP) reduced from 14.4 to 11.1m2. The scanning electron microscopy (SEM) and FTIR results of char residue demonstrated that the flame‐retardant mechanism of PDPSI was solid phase flame retardant. PDPSI catalyzed the aromatization reaction of PET to promote the formation of a dense and continuous carbon layer, finally improving the flame retardancy and smoke suppression properties of PET.

Physical Properties of Composites Manufactured with Two Wastes from Food-Processing Industry

The sheer amount of waste being produced nowadays by the food processing industry makes it imperative to identify alternative procedures to recycle them. This paper describes an innovative use of protein waste with consumed plastic bottles within composite materials for building applications. The aim of this study was to investigate this two wastes association on the lightening of the composites. The effect of the protein waste introduction on the physical properties of the concrete manufactured with PET aggregates in the hardened state is studied: total and surface porosity, mechanical strengths, dynamic elasticity modulus and thermal conductivity. The optimal formulation of the basic composite, with PET aggregates, is: S/C = 2.8, W/C = 0.45 and a volume percentage of PET aggregates equal to 35%. The hemoglobin powder was introduced after water in the optimal PET composite. Various H/C mass ratios were used: 0.5, 1 and 2%. The influence of the mixing time after hemoglobin addition was also studied. Relative changes in composites properties due to protein introduction are experimentally investigated. For example a decrease in mechanical strengths and in thermal conductivity was observed. The results obtained allowed the elaborated composites to be functionally classified. So they show that the simultaneous valorization of two kinds of waste of the food process industry may be technically feasible and very interesting for the environment.

Study of braiding commingled self-reinforced PET composites

This work examines the flexural and impact behavior of self-reinforced poly(ethylene terephthalate) (srPET) composites, which were produced by film stacking from fabrics composed of braiding commingled yarns with high-tenacity PET (serving as the reinforcements) and copolymerized PET (mPET) (serving as the matrix). The influence of the hybrid yarns, fabric architectures, and processing conditions on the mechanical properties of srPETs were studied.

2-D elemental mapping of an extreme ultraviolet-irradiated PET with a compact near edge X-ray fine structure spectromicroscopy

We present a near edge X-ray fine structure (NEXAFS) spectromicroscopy, that was developed based on a compact laboratory laser-plasma soft X-ray light source. The presented approach to spectromicroscopy is different from the usual synchrotron-based one when the series of full-field microscopy images are obtained at different energies. Herein, spatially localized NEXAFS spectra are obtained using a broad-band SXR emission, and the microscopic image is obtained by a raster scanning. The plasma is formed by the interaction of nanosecond laser pulses with a double stream gas puff target. The laser plasma source was optimized for efficient soft X-ray emission from a krypton plasma in the range ~2 nm to 5 nm wavelength radiation (energy of ~250 eV – 620 eV). This emission is used to acquire simultaneously emission and absorption spectra of soft X-ray light from the source and from the investigated sample. The spectra were acquired from a small area of PET polymer ~30 × 30 μm2 in size. A raster scanning was implemented to obtain 2-D elemental composition maps. A chemical (elemental) composition of EUV-irradiated PET was investigated. The data are in agreement with the reference measurements and the theoretical values. EUV irradiated PET spectra are showing hydrogen decrease in the PET structure due to the EUV irradiation. In the paper, a detailed information about the source, the system, the spectral measurements and the results are presented and discussed.

Solvent-free in situ synthesis of flexible BiVO4/Bi2WO6: MWCNT, PET composites with superior mineralization potential for photocatalytic degradation of organic pollutants

The flexible BiVO4/Bi2WO6: MWCNT, PET composites were facilely prepared by a simple hydrothermal and impregnation method. The morphologies and structures of the as-prepared products were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The visible-light-response photocatalytic performances were investigated by photo-degradation of reactive blue 19 (RB-19) dye. The results showed that the favorable photocatalytic activity of the PET-supported composites can be attributed to the improved separation efficiency of photo-generated electron-hole pairs, and the primary active species in the photo-degradation process were h+ and O2−. The photocatalysts using PET as a matrix material made them much easier to be recycled than powder composites.

Damage behavior of low velocity impact test on glass fiber reinforced poly (ethylene terephthalate) composites

In this study, to enhance the properties of recycled poly (ethylene terephthalate) (r-PET), the direct fiber feeding injection molding (DFFIM) process with un-modified and modified check ring designs were used to fabricate glass fiber reinforced recycled PET (GF/r-PET) composites. The new generated GF/r-PET composites were performed and compared with commercial GF/PET composites to extensive study on the impact properties. The results indicate that the distributional fiber length in the range of 0-800 μm of conventional injection molding process lead to the brittle fracture behavior and low absorbed energy. More existing fiber length in the range of 1000-3800 μm of DFFIM un-modified check ring develops the impact properties as more ductile behavior and energy absorption especially in the initial damage stage. Meanwhile, 3800-8000 μm remaining fiber length provided a small increase in the initial internal damage stage compared to those of 0-3800 μm but it efficiently improves the absorbed energy at the damage propagation energy stage.

Effect of temperature and morphology on the electrical properties of PET/conductive nanofillers composites

Abstract Poly(ethylene terephthalate) (PET) composites were loaded with four different carbon-based fillers: functionalized carbon nanotubes (CNT), exfoliated graphite (EG), and hybrid materials such as Mg(OH)2, which is primarily used as a flame retardant additive in plastics, dispersed over functionalized CNT and EG. The technology used to mix the different phases was high energy ball milling in dry conditions and at ambient temperature. Morphological organization, thermal and electrical properties of composites were evaluated and correlated with the type of filler. The electrical properties were analyzed over a wide temperature range, from 25 °C to 150 °C, and correlated to the starting structural organization of the composites and the morphological transformations occurred during the thermal heating. The addition of EG and CNTs to PET did not have influence on the amorphous arrangement of unfilled PET, while the loading of Mg(OH)2/EG and Mg(OH)2/CNT fillers favoured the PET crystallization. The crystallization inducted by temperature allowed an increasing in electrical conductivity of the starting amorphous samples. On the other hand, it was found a conductivity independent of temperature for semicrystalline samples (filled with Mg(OH)2/EG and Mg(OH)2/CNT). The charge transport, for the analyzed PET composites, is favoured by the higher degree of crystallinity.

Processing and Characterization of PET Composites Reinforced With Geopolymer Concrete Waste

In the present study, poly (ethylene terephthalate)-based composites were produced and characterized. These composites were composed by poly (ethylene terephthalate) (PET) reinforced with geopolymer concrete waste (GCW). Both untreated (U-GCW) and treated with oleic acid (OA) geopolymer concrete waste (T-GCW) were used in the production of the composites. The PET/GCW ratios used for either treated or untreated GCW bodies were 80/20 (wt%), 60/40 (wt%) and 50/50 (wt%). Chemical compositions were assessed by X-ray fluorescence spectroscopy (XRF), crystallinity by differential scanning calorimetry (DSC), thermal stability by thermogravimetry (TGA), microstructure by field emission gun scanning electron microscopy (FEG-SEM) with energy dispersive X-ray spectroscopy (EDS), and mechanical properties were assessed by compression tests. Fourier transform infrared spectroscopy (FT-IR) was used to check the efficiency of the treatment with OA, as well as the interaction between PET and GCW. The T-GCW PET composites showed better thermal, physical, and mechanical properties, for non-structural applications, when compared to U-GCW.

Synthesis and characterisation of hybrid polyethylene terephthalate matrix composites reinforced with Entada Mannii fibre particles and almond shell particles

Development of ecofriendly biocomposites to replace non-biodegradable synthetic fibre composites for optimum performances is the main objective of this study. To highlight biocomposites as suitable replacements, polyethylene terephthalate matrix composites reinforced with blended water retted and surface alkali treated Entada Mannii fibre particulates and carbonised tropical almond shell ash (TASA) were synthesized by mould casting. The efficacy of water retting as a means of extracting fibres from Entada Mannii plant and fibre modification using NaOH of varying concentration on the mechanical properties of Entada Mannii fibre particulates – PET composites were investigated. Mercerization enhanced the surface properties of Entada Mannii fibres and thus led to better bonding between it and the matrix. Hybrid composites from untreated Entada Mannii fibre particulates and tropical almond shell exhibited the highest hardness of 41.09 BHN. 4% NaOH treated fibre particulate hybrid composites exhibited tensile strength (4.795MPa), flexural strength of 6.09MPa, hardness value of 37.63 BHN, and impact energy of 21.49J compared to the 6% NaOH treated fibre particulate hybrid composites.

Crystallization derivation of amine functionalized T12 polyhedral oligomeric silsesquioxane-conjugated poly(ethylene terephthalate)

Most inorganic nucleating agents for poly(ethylene terephthalate) (PET) have limited nucleating ability due to poor compatibility with PET. Polyhedral oligomeric silsesquioxanes (POSS) is a type of cage-shaped organic/inorganic hybrid nanoparticles with three different particle sizes: octameric (T8), decameric (T10), and dodecameric (T12). POSS is considered as a promising nucleating agent for PET because the inorganic moieties contribute to high thermal stability and nucleation and the organic moieties can be tethered to PET chains. In contrast to T8 POSS, the nucleation ability of T12 POSS for PET has been poorly reported. In this study, our newly synthesized aminopropyl functionalized T12 POSS (A-POSS) is proposed as a potential nucleating agent for PET. The amine group of A-POSS is able to be chemically conjugated to PET chains, thereby giving a more homogeneous dispersion of T12 POSS in PET than non-functional T12 Phenyl POSS (N-POSS). Its PET composites gave a ∼1.2 fold higher crystallization temperature and ∼2.7 fold higher shear-induced crystallization rate over pristine PET. Such nucleating effects for PET is more effective than those of non-functional T12 POSS and the more widely studied T8 POSS. This strategy is potentially beneficial for the high-shear melt processes of PET such as spinning and film extrusion.

Coating magnesium hydroxide on surface of carbon microspheres and interface binding with poly (ethylene terephthalate) matrix

In this account, magnesium hydroxide (MH) employed as a capsule wall was firstly coated on the surface of carbon microspheres (CMSs) to obtain MH@CMSs using liquid phase deposition, then was modified by 3-Aminopropyltriethoxysilane (APTS) to form FMH@CMSs. To investigate the interface binding forces, a series of PET composites was prepared by melt compounding with MH@CMSs or FMH@CMSs. Field-emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), Fourier-transform Infrared spectrometry (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to characterize the morphology, chemical structure, and effect of functionalization of CMSs. The coating degree and thermal stability were investigated by thermogravimetry analysis. The results showed that CMSs were coated by an inorganic shell layer of MH as a capsule wall. On the other hand, MH@CMSs were coated with an organic layer of APTS. When compared to MH@CMSs, the interface binding forces between FMH@CMSs and PET matrix were significantly improved, and the tensile strength of FMH@CMSs/PET was higher than that of MH@CMSs/PET. At 1wt% mass fraction of FMH@CMSs, the limiting oxygen index (LOI) value of PET composites increased from 21% to 27.6% following a V-0 rating. The tensile strength of FMH@CMSs/PET increased by 66.2% to reach 47.20MPa, a value nearly similar to that of PET. Overall, the formed two layers provided the FMH@CMSs/PET with good mechanical and flame-retardant properties, which would broaden their scope of application.

The Determination of Interfacial Shear Strength in Short Fiber Reinforced Poly Ethylene Terephthalate by Kelly-Tyson Theory

The interfacial shear strength value measuring by the modified Kelly-Tyson equation method was studied the measurement accuracy. The measuring accuracy by using the modified Kelly-Tyson equation method is compared to the nano-indentation testing method. The results and an influential factor are described. An error in the modified Kelly-Tyson equation is verified to avoid the incorrect measurement when the interfacial shear strength was measured by the modified Kelly-Tyson equation. To study the different interfacial shear strength behavior, short fiber reinforced PET composites were fabricated. In this study, an advance fabricating technique for short fiber reinforced composite as direct fiber feeding process is conducted to fabricate GF/recycled PET for studying the interfacial shear strength. The result indicates that the modified Kelly-Tyson equation method accurately provides the accurate interfacial shear strength value, if it is conducted with the sample without a horizontally aligned fiber. So the high fiber loading content sample should be avoided to get the more accuracy result. The large horizontally aligned fiber area into specimens extremely resulted in the incorrect measurement of the interfacial shear strength value by the modified Kelly-Tyson equation method. The fiber agglomeration factor and the sensitively horizontally aligned fiber area must be considered its influence on the measuring for improving the equation effectiveness.

Long-term creep behavior of self-reinforced PET composites

Long-term creep behavior of self-reinforced PET composites

超音波処理ナノクレイ-ポリエチレンテレフタレート系複合材料の動的粘弾性特性

The objective of this study is to investigate the dynamic viscoelastic properties of poly (ethylene terephthalate) (PET) composites with ultrasonicated nanoclay. The nanoclays were ultrasonicated in solvent, and dried in an oven. The dispersion stability of nanoclay/solvent suspensions was observed to evaluate the degree of exfoliation of nanoclays. Morphology of ultrasonicated nanoclays was also examined using a scanning electron microscope (SEM). Specimens of PET composites with ultrasonicated nanoclays were then fabricated by melt blending. Dynamic viscoelastic tests were carried out, and the effects of ultrasonication time and nanoclay volume fraction on the temperature dependence of the storage and loss moduli of the composites were discussed. Morphology of nanoclays in the composites was also examined using a transmission electron microscope (TEM). In addition to conducting experiments, finite element analyses were performed using a three-dimensional unit cell model to predict the elastic properties of nanoclay/PET composites. The effect of nanoclay morphology on the elastic properties of the composites was examined.

Comparison of Mechanical and Interfacial Properties of Carbon Fiber Reinforced Recycled PET Composites with Thermoforming Temperature and Time

Comparison of Mechanical and Interfacial Properties of Carbon Fiber Reinforced Recycled PET Composites with Thermoforming Temperature and Time

Flame retardant performance of a carbon source containing DOPO derivative in PET and epoxy

ABSTRACTThe combination of gas‐phase and condensed‐phase action will contribute to high quality flame retardant. A novel 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO)‐based flame retardant (DOPO‐DOPC), which contains carbon source was synthesized in favor of conducting the effect of gas‐phase as well as promoting the char formation in condensed‐phase. The chemical structure of DOPO‐DOPC was characterized by nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR). DOPO–DOPC was used as an additive in poly(ethylene terephthalate) (PET) and epoxy resin (EP). The flame retardancy of PET/DOPO‐DOPC and EP/DOPO‐DOPC composites were studied by limiting oxygen index (LOI) and UL‐94 test. The results showed that the incorporation of DOPO–DOPC into PET or EP could obviously improve their flame retardancy. The LOI values of modified PET or EP, which contained 10 wt % DOPO‐DOPC reached 42.8 and 31.7%, respectively. The thermogravimetric analysis (TGA) results revealed that DOPO–DOPC enhanced the formation of char residues. The Laser Raman spectroscopy (LRS) was used to investigate the carbon structure of thermal oxidation residues. Because of the combination of the gas phase flame retardant effect of DOPO moiety and the promoting formation of char residues in condensed phase, the PET and EP composites exhibited significant improvement toward flame retardancy. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44639.

Fracture behavior and damage development in self-reinforced PET composites assessed by located acoustic emission and thermography: Effects of flame retardant and recycled PET

Self-reinforced polyethylene terephthalate (srPET) composites were produced by hot pressing from woven fabrics composed of double covered uncommingled yarns. The mid section of the latter contained recycled PET homopolymer filaments (reinforcement) whereas the covering filaments (overtaking the role of the embedding matrix) were spun from a PET copolymer with and without flame retardant. The fracture of the srPET was studied in tensile loaded notched specimens using located acoustic emission (AE), infrared thermography (IT) and visual inspection in situ. The crack growth was reconstructed by evaluating the located AE and IT results and compared with the observed one. In the knowledge of the crack propagation the J-integral resistance (JR) fracture mechanics concept was followed to characterize the fracture behavior. srPET with fire retardant matrix exhibited lower JR characteristics than the unmodified composite. This was traced to differences in the failure modes considering the amplitude distribution of the AE events and post mortem failure analysis. Size of the damage zone was estimated by considering the located AE (≈20 mm) and IT results (≈15 mm), and the related difference discussed.

Impact of carbon nanotubes addition on electrical, thermal, morphological, and tensile properties of poly (ethylene terephthalate)

In this study, multi-walled carbon nanotubes (MWCNTs) were incorporated into poly (ethylene terephthalate) (PET) matrix in their as-received (A-MWCNTs) and treated (T-MWCNTs) forms. Melt-compounding method was used for the preparation of these carbon nanotubes (CNTs)-reinforced PET composites. The electrical conductivity, thermal stability, morphological, and tensile properties were investigated. For testing and characterization, impedance spectroscopy, thermo-gravimetric analysis, scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy and tensile testing were utilized. The results demonstrates that an incorporation of ~0.25 wt% A-MWCNTs, an electrically conductive polymer nanocomposite (~0.2 S/m), was formed with a low percolation threshold (~0.33 wt%). In contrast, at the same loading of T-MWCNTs or even up 2 wt% did not yield conductive polymer. Presumably, such behavior is attributed to the acid treatment that disrupted the inherent electrical conductivity of the CNTs and also reduced their aspect ratio. Nevertheless, T-MWCNTs showed a better dispersion and distribution into the PET matrix than that of A-MWCNTs counterpart. Moreover, an improved tensile behavior was observed for T-MWCNTs incorporated composites than that of A-MWCNTs counterpart. Improved thermal stability was observed for PET/A-MWCNTs in both the air and nitrogen atmospheres. Whereas, PET/T-MWCNTs exhibited the highest thermal stability in all samples in nitrogen atmosphere. However, poor thermal response was seen in air atmosphere.

Mechanical and open hole tensile properties of self‐reinforced PET composites with recycled PET fiber reinforcement

ABSTRACTThe tensile strength of notched composites is an important factor for composite structural design. However, no literature is available on the notch sensitivity of self‐reinforced polymer composites. In this study, self‐reinforced recycled poly (ethylene terephthalate) (srrPET) composites were produced by film stacking from fabrics composed of double covered uncommingled yarns (DCUY). Composite specimens were subjected to uniaxial tensile, flexural, and Izod impact tests and the related results compared with earlier ones achieved on srPET composites reinforced with nonrecycled technical PET fibers. Effects of open circular holes on the tensile strength of srrPETs were studied at various width‐to‐hole diameter (W/D) ratios of the specimens. In the open hole tensile (OHT) measurements bilinear (yielding followed by post‐yield hardening) stress–strain curves were recorded. The srrPET composites had extremely high yield strength retention (up to 142%) and high breaking strength retention (up to 81%) due to the superior ductile nature of the srrPETs, which induces plastic yielding near the hole thereby reducing the stress concentration effect. The results proved that srrPET composites are tough, ductile notch‐insensitive materials. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43682.