Combined effect of isophthalic acid and polyethylene glycol in polyethylene terephthalate polymer on thermal,mechanical, and gas transport properties

The objective of this article is to study the combined effect of isophthalic acid (IPA) and polyethylene glycol (PEG‐400) in PET polymer and film on thermal, mechanical, and gas transport properties. The purpose of developing this material is to reduce the melting point, improve mechanical, thermal, and gas barrier properties. The chosen raw materials, namely, IPA and PEG for copolyester synthesis will replace partially the acid and diol monomers of PET. The molar concentration of comonomers (IPA and PEG‐400) were varied from 2 to 50% and the result shows that the gas barrier properties (namely O₂, CO₂, N₂, and water vapor transmission rate), mechanical, and thermal properties were lesser than that of PET polymer. On improving the crystallinity of PET‐isophthalate‐PEG (PET‐IP) copolymer, barrier properties are improved than that of PET polymer. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Ultrahigh molecular weight polyethylene/polypropylene/organo‐montmorillonite nanocomposites: Phase morphology,rheological, and mechanical properties

Phase morphology, rheological, and mechanical properties of ultrahigh molecular weight polyethylene (UHMWPE)/PP/organo‐montmorillonite nanocomposites were investigated in this work. The results of TEM and XRD indicated that the organo‐montmorillonite PMM prepared with the complex intercalator [2‐methacryloyloxyethyldodecyldimethylammonium bromide/poly(ethylene glycol)] were exfoliated and dispersed into UHMWPE matrix, and the synergistic effect of the complex intercalator on the exfoliation and intercalation for montmorillonite occurred. Besides, the presence of PMM in UHMWPE matrix was found able to lead to a significant reduction of melt viscosity and enhancement in tensile strength and elongation at break of UHMWPE, except that izod‐notched impact strength was without much obvious change. The dispersed PMM particles exhibited a comparatively large two‐dimensional aspect ratio (L_clay/d_clay = 35.5), which played an important role in determining the enhancement of mechanical properties of UHMWPE nanocomposites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Characterization and mechanical properties of exfoliated graphite nanoplatelets reinforced polyethylene terephthalate/polypropylene composites

Recently, graphene and its derivatives have been used to develop polymer composites with improved or multifunctional properties. Exfoliated graphite nanoplatelets (GNP) reinforced composite materials based on blend of polyethylene terephthalate (PET), and polypropylene (PP) compatibilized with styrene–ethylene–butylene–styrene‐g‐maleic anhydride is prepared by melt extrusion followed by injection molding. Characterization of the composites' microstructure and morphology was conducted using field emission scanning electron microscopy, transmission electron microscopy (TEM), X‐ray diffraction analysis (XRD), and Fourier transform infrared spectroscopy (FTIR). Tensile and impact strengths of test specimens were evaluated and the results showed maximum values at 3phr GNP in both the cases. Morphological studies showed that the GNPs were uniformly dispersed within the matrix. Results from XRD analysis showed uniformly dispersed GNPs, which may not have been substantially exfoliated. FTIR spectroscopy did not show any significant change in the peak positions to suggest definitive chemical interaction between GNP and the matrix. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40582.     

Influence of soapstone waste on the mechanical and rheological properties of high-density polyethylene

Soapstone is an abundant mineral in Ouro Preto - Minas Gerais, Brazil and its main destination is in the production of craftsmanship. Rock recovery in those activities is low and the waste disposal is done with little control, which can be hazardous to the environment. This work proposes an alternative use of such potentially harmful waste as reinforcement in a novel polymer matrix composite, which can be particularly attractive to the automotive industry and of which very little information is available elsewhere in the literature. Firstly, the characterization of the waste was performed. Particle size and shape parameters were determined by automated image analysis and the mineralogical composition was determined by X-ray diffraction, infrared, and Raman spectroscopy. High-density polyethylene was used as matrix and the composites were made in three matrix/filler ratios: 90/10, 80/20, and 70/30 by weight. Tensile and rheological properties were measured in order to determine the influence of the particles on the polymer mechanical behavior and processing conditions. The materials showed a pseudoplastic behavior and the filler's influence was more pronounced in the 70/30 composites, which showed higher viscosities than the neat polymer. The addition of particles resulted in more brittle and rigid composites, with higher values of tensile strength.     

Enhancing the mechanical,morphological, and rheological behavior of polyethylene/polypropylene blends with maleic anhydride-grafted polyethylene

This is the first study to showcase the use of maleic anhydride-grafted polyethylene (MAPE) to compatibilize polyethylene (PE)-rich blends, where polypropylene (PP) represents the minor phase. By first mixing PP with MAPE, and then adding PE, MAPE was assumed to be localized at the PE/PP interface. Microscopy analysis confirmed that MAPE led to a remarkably fine PE/PP/MAPE morphology, with PP being uniformly dispersed into PE and having an average diameter 267% smaller than that in the PE/PP blend. According to mechanical and rheological tests, this translated into a 14%, 20%, and 14% enhancement of tensile strength, tensile modulus, and tensile toughness, respectively, as well as a 10% and 20% drop in PE/PP viscosity mismatch and interfacial tension, respectively. Finally, PE/PP/MAPE tensile toughness and elongation at break were greater than those of virgin PP, while PE/PP/MAPE strength and stiffness were similar to the ones of neat PP. Therefore, this study provides industries with the possibility to utilize products rich in PE instead of those made of more expensive PP, while still keeping the level of performance high; hence, creating a paradigm shift in the development of advanced lightweight polyolefin materials with tuned functionalities.     

Enhanced mechanical and thermal properties of nanodiamond reinforced low density polyethylene nanocomposites

In this study, the reinforcement effects of low-content hydrophilic nanodiamond (ND) on linear low-density polyethylene (PE) nanocomposites were investigated. ND was incorporated in PE via simple solution blending. The obtained PE/ND nanocomposites were characterized using scanning electron microscopy, ultraviolet–visible spectra, X-ray diffraction, tensile test, thermogravimetry, and differential scanning calorimetry. Generally, PE/ND nanocomposites with poor interfacial interaction cause large agglomerates, resulting in brittle and poor mechanical properties. Owing to the different natures of non-polar PE and polar ND, the higher the ND content, the larger the agglomerates formed in the nanocomposites. However, PE/ND nanocomposites show unique mechanical properties, that is, the Young's modulus, tensile strength, elongation at break, and toughness increased upon the incorporation of ND. The Young's modulus of the PE/ND nanocomposites exceeded the theoretical value calculated using the Halpin–Tsai model. In addition, the toughness increased by 18% at only 0.5 wt% ND loading. Furthermore, there was an increase in the thermal degradation temperature, melting temperature, and crystallization temperature.     

Investigation of rheological,mechanical, and thermal properties of nanocomposites based on nitrile rubber-phenolic resin reinforced with nanographene

In this study, nanocomposites of acrylonitrile butadiene rubber (NBR)/phenolic resin/graphene nanoparticles (GNPs) were prepared using a two-roll mill. According to the results, the addition of GNPs increased the scorch time, vulcanization time, and viscosity of the blends. By adding phenolic resin and in the presence of a higher percentage of acrylonitrile, the modulus and tensile strength increased and the elongation at break decreased. The mechanical properties of the nanocomposites improved with increasing the amount of nanoparticles. The addition of 1.5 phr GNP to the blends containing NBR with 33% and 45% acrylonitrile increased the tensile modulus by 56% and 49%, respectively. The tensile properties of the nanocomposites were also investigated at 50, 25, and 75°C. It was observed that with increasing the amount of nanoparticles, the deterioration of the mechanical properties at elevated temperatures was reduced. Also, thermal stability increased with increasing the amount of nanoparticles in all the samples.     

Bamboo fiber reinforced polypropylene composites and their mechanical,thermal, and morphological properties

Short bamboo fiber reinforced polypropylene composites were prepared by incorporation of various loadings of chemically modified bamboo fibers. Maleic anhydride grafted polypropylene (MA‐g‐PP) was used as compatibilizer to improve fiber–matrix adhesion. The effects of bamboo fiber loading and modification of the resin on the physical, mechanical, thermal, and morphological properties of the bamboo reinforced modified PP composites were studied. Scanning electron microscopy studies of the composites were carried out on the interface and fractured surfaces. Thermogravimetric analysis and IR spectroscopy were also carried out. At 50% volume fraction of the extracted bamboo fiber in the composites, considerable increase in mechanical properties like impact, flexural, tensile, and thermal behavior like heat deflection temperature were observed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

The impact of polymer matrix blends on thermal and mechanical properties of boron nitride composites

To improve mechanical and thermal properties of a hexagonal boron nitride platelet filled polymer composites, maleic anhydride was studied as a coupling agent and compatibilizer. Injection molded blends of acrylonitrile butadiene styrene (ABS), high-density polyethylene (HDPE), and maleic anhydride with boron nitride filler were tested for thermal conductivity and impact strength to determine whether adding maleic anhydride improved interfacial interactions between matrix and filler and between the polymers. Adding both HDPE and maleic anhydride to ABS as the matrix of the composite resulted in a 40% improvement in impact strength without a decrease in thermal conductivity when compared to an ABS matrix. The best combination of thermal conductivity and impact strength was using pure HDPE as the matrix material. The effective medium theory model is used to help explain how strong filler alignment helps achieve high thermal conductivity, greater than 5 W/m K for 60 wt % boron nitride. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48661.     

Preparation and properties of polyethylene terephthalate/polyethylene/near infrared reflective pigment composites

Polyethylene terephthalate/high density polyethylene (PET/HDPE) composites containing a near infrared reflective (NIR, nickel antimony titanium yellow rutile) pigment was prepared using ethylene‐glycidyl methacrylate‐vinyl acetate (EGMA‐VA) as a compatibilizer to increase the infrared reflection of PET/HDPE and limit the thermal heat accumulation in light of environmental and energy conservation concerns. HDPE was premixed with NIR to form N‐HDPE masterbatch. A good interfacial bonding between PET matrix and HDPE dispersed phase with the help of compatibilizer was confirmed through Fourier transform‐infrared spectra, scanning electron microscopy, and torque rheometer. For PET/N‐HDPE composites, the major X‐ray diffraction peaks and melting behaviors remained unchanged, indicating the limited alternation of crystalline structure for the composite systems with or without compatibilizer. The observed increment in the crystallization temperature of PET for the investigated PET/N‐HDPE composites was mainly due to the nucleation role of both inorganic NIR and HDPE. Tensile strength and elongation at break for compatibilized cases at various N‐HDPE contents conferred higher values than those of the corresponding counterparts without compatibilizer. Yet, Young's modulus for compatibilized systems was about 40% lower than that for systems without compatibilizer, attributed to the rubbery nature of EGMA‐VA. With the inclusion of NIR into HDPE to form PET/N‐HDPE composites with or without EGMA‐VA compatibilizer, the values of reflectance increased to a great degree. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40830.     

Effects of filler–filler and polymer–filler interactions on rheological and mechanical properties of HDPE–wood composites

High‐density polyethylene (HDPE)–wood composite samples were prepared using a twin‐screw extruder. Improved filler–filler interaction was achieved by increasing the wood content, whereas improved polymer–filler interaction was obtained by adding the compatibilizer and increasing the melt index of HDPE, respectively. Then, effects of filler–filler and polymer–filler interactions on dynamic rheological and mechanical properties of the composites were investigated. The results demonstrated that enhanced filler–filler interaction induced the agglomeration of wood particles, which increased the storage modulus and complex viscosity of composites and decreased their tensile strength, elongation at break, and notched impact strength because of the stress concentration. Stronger polymer–filler interaction resulted in higher storage modulus and complex viscosity and increased the tensile and impact strengths due to good stress transfer. The main reasons for the results were analyzed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of the filler structure of carbon nanomaterials on the electrical,thermal, and rheological properties of epoxy composites

Carbon nanotubes (CNTs) and graphene nanosheets (GNSs) were used as fillers in epoxy composites with the aim of increasing the electrical and thermal conductivities of the composites. The filling of pristine CNTs produced the highest electrical conductivity (σ), whereas a high CNT functionalization and the two‐dimensional planar structure of GNSs were promising for improving the thermal conductivity. A combination of CNTs and GNSs exploited the advantages of both. When the CNT fraction was larger than 50 wt %, a higher σ was obtained. When a small amount of functionalized CNTs was added to the GNSs, the thermal conductivity was also increased. The rheological measurements revealed the lowest complex viscosity for the GNS filling and showed the exciting advantages of an easy processing. As a result, the mixed filling also exhibited a much lower viscosity than the pure CNT fillings. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Intumescent flame retardant polyurethane/starch composites: Thermal,mechanical, and rheological properties

Intumescent flame retardant polyurethane/starch (IFRPU/starch) composites were prepared by means of melt blending. Microencapsulated ammonium polyphosphate (MCAPP) was added to improve its compatibility with matrix, retardation of reaction between acid and carbon source, and its water resistancy. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of hydrogen bonding and entangled network between IFR system and PU matrix. Further, scanning electron microscopy (SEM) illustrated homogeneity of starch in matrix. By addition of 10 wt % of starch and 20 wt % of IFR, limiting oxygen index (LOI) increased from 22.0 to 40.0 and UL94 V0 rating was achieved. Differential scanning calorimetry (DSC) detected three endothermic transitions and one glass transition (T_g). The temperature of transition III and T_g increased with starch due to crosslinking between PU and starch. The improved thermal stability in the presence of starch was confirmed by thermogravimetric analysis (TGA). Beside the fact that starch was used as a carbonization agent to improve flame retardancy, it also effectively led to enhanced mechanical and viscoelastic properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41158.     

Mechanical and thermal properties of polypropylene/modified basalt fabric composites

Basalt fabric (BF) was first treated with silane coupling agent KH550, modified basalt fabric (MBF) was obtained. Then MBF were molded with polypropylene (PP) matrix, and polypropylene/modified basalt fabrics (PP/MBF) composites were obtained. The influence of concentration and treating time of KH550 on MBF were characterized by hydrophilicity and lipophilicity. The tensile strength and morphology of basalt fabric were tested by single filament strength tester and scanning electron microscopy. The mechanical properties of composites were measured with electronic universal testing machine and impact testing machine, and the thermal properties were tested by thermogravimetric analysis and dynamic mechanical analysis. The results showed that the lipophilicity of MBF is improved significantly by KH550 while the tensile is nearly damaged. The mechanical properties of composites are larger than that of pure PP, among which the impact property was improved the most, showing 194.12% enhancement. The thermal stability and dynamic viscoelasticity were better than pure PP; furthermore, the concentration of KH550 virtually had no effect on the thermal stability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42504.     

Effect of trisilanolphenyl‐POSS on rheological,mechanical, and flame‐retardant properties of poly(ethylene terephthalate)/cyclotriphosphazene systems

Poly(ethylene terephthalate) (PET) chips were coated by trisilanolphenyl–polyhedral oligomeric silsesquioxane (T‐POSS) and hexakis (para‐allyloxyphenoxy) cyclotriphosphazene (PACP) using the predispersed solution method, and PET/PACP/T‐POSS hybrids were further prepared by the melt‐blending method. The influence of T‐POSS on the rheological, thermal, and mechanical properties and flame retardancy of PET/PACP composites were discussed. The results suggest that T‐POSS was homogeneously dispersed in the PET matrix, which reduced the negative effects on polymer rheology and mechanical properties. For the PET/4%PACP/1%T‐POSS sample, the tensile strength at break and T_g increased from 29.67 MPa and 81.7 °C (PET/5%PACP) to 34.8 MPa and 85.8 °C, respectively, but the sample also self‐extinguished within 2 s, and the heat release capacity was reduced by 27.9% in comparison with that of neat PET.© 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45912.     

Rheological behavior and mechanical properties of sawdust/polyethylene composites

We have characterized the melt rheological behavior and the solid tensile properties of sawdust/polyethylene composites prepared in an internal mixer. Various concentrations (from 0 to 60 wt %) and three particle sizes have been tested, in presence of a coupling agent (maleic anhydride grafted polyethylene). In the molten state, for each particle size, a mastercurve of the complex viscosity as function of frequency can be plotted, using a shift factor depending on weight fraction. We show that the shift factors can be described by a Krieger‐Dougherty law, leading to a “universal” viscosity law of the Carreau‐Yasuda type. In the solid state, the presence of sawdust increases Young modulus in uniaxial elongation, mainly for small size particles, but reduces dramatically deformation at break and tensile strength. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Linear low‐density polyethylene/poly(ethylene terephthalate) blends compatibilization prepared by an eccentric rotor extruder: A morphology,mechanical, thermal,and rheological study

In this study, various poly(ethylene terephthalate) (PET) and linear low‐density polyethylene (LLDPE) with maleic anhydride‐grafted LLDPE (LLDPE‐g‐MAH) compatibilizer were melt blended under an elongational flow. A novel extrusion device, eccentric rotor extruder (ERE), was developed to supply such flow during the process. Including morphology, mechanical properties, melting behavior, and rheological behavior were studied. The morphological study showed that the compatibility between LLDPE and PET was greatly improved with LLDPE loading up to 80 wt %. Mechanical tests indicated that LLDPE could toughen PET to some extent. Moreover, a comparison of samples prepared between ERE and conventional extruder was made and demonstrated the sample prepared by ERE can exhibit better mechanical properties. Differential scanning calorimetry results revealed that PET can promote the crystallinity of LLDPE. Rheological behavior indicated that the complex viscosity of the blends exhibited strong shear thinning phenomenon with increasing LLDPE content, particularly in high‐frequency range blend with the LLDPE weight ratio of 80 wt % was more sensitivity to shear rate than neat LLDPE. The G′‐G″ curves of the blends also revealed that the microstructure of the blends changed significantly with the addition of LLDPE which was consistent with the scanning electron micrographs that PET particles became smaller and distributed more uniform with increasing LLDPE content. Furthermore, the blends showed similar stress relaxation mechanism with adding LLDPE content from 60 to 100 wt %. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46489.     

Polycarbonate‐based composites reinforced by in situ polytetrafluoroethylene fibrillation: Preparation,thermal and rheological behavior

Fibrillar reinforced composites of polytetrafluoroethylene (PTFE) and polycarbonate (PC) were prepared by in situ fibrillation of PTFE into PC matrix using twin screw extruder. Different samples were obtained by varying the relative ratio between PC and PTFE. The rheological properties of the PC/PTFE composites were found to depend on concentration of the PTFE fibrils. The melt strength analysis in nonisothermal conditions was also studied. The increase in force and decrease in drawability with increasing the PTFE content are associated with the PTFE fibrils formed in situ during the thermomechanical process in twin screw extruder. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42401.     

Effects of chicken eggshell filler size on the processing,mechanical and thermal properties of PVC matrix composite

The effects of filler particle size of poly(vinyl chloride)/chicken eggshell powder (PVC/ESP) composites on the processing, tensile properties, morphology and thermal degradation were investigated. The mixing of composites was done using Rheomix internal mixer. The processing torque of PVC/ESP composite at a particle of 0.2 μm exhibits lower processing torque compared to that at a particle size of 7 μm due to the dispersive resistance from larger ESP filler particles. Good interfacial adhesion exists between the filler and matrix in composites prepared via a filler particle size of 0.2 μm, which has improved the tensile strength and modulus of PVC/ESP composite compared to a filler particle size of 7 μm as justified from FESEM images on the tensile fracture surface of the composites. Thermogravimetric analysis results show that the filler particle size of 0.2 μm composite exhibits higher thermal stability compared to the filler particle size of 7 μm composite.     

Nielsen thermal conductivity model for single filler carbon/polypropylene composites

In this study, three different carbon fillers (Thermocarb TC‐300 synthetic graphite, Ketjenblack EC‐600 JD carbon black, and Hyperion Catalysis International's FIBRIL? carbon nanotubes) were added to a polypropylene matrix to produce single filler composites with filler concentrations of up to 80 wt % synthetic graphite (61.6 vol %), 15 wt % carbon black (8.1 vol %), and 15 wt % carbon nanotubes (7.4 vol %). The through‐plane thermal conductivity for each formulation was measured. For the synthetic graphite, carbon black, and carbon nanotubes composites, the Nielsen model was applied to the experimental through‐plane thermal conductivity data. The Nielsen Model presented in this work showed very good agreement with experimental data. The model parameters were similar to those used in the literature for these fillers in other polymers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009