Showing papers in "Journal of Applied Polymer Science in 2018"
TL;DR: In this paper, a review summarizes the recent developments on a variety of biodegradable polymer blends compatibilized by melt processing with a main focus of ex situ and in situ compatiblization strategies.
Abstract: The majority of materials used for short-term and disposable packaging application are non-biodegradable which are not satisfying the demands in environmental safety and sustainability. Biodegradable polymers are an alternative for these non-biodegradable materials. The biodegradable polymeric materials can degrade in a reasonable time period without causing environmental problems. However, biodegradable polymers possess some limitations such as comparatively high cost, insufficient mechanical performances, and inferior thermal stability to extend their widespread application in packaging industry. To overcome these limitations, one of the most commonly used strategies is melt blending of dissimilar biodegradable polymers. Unfortunately, most of the biodegradable polymer blends exhibit insufficient performance because they are thermodynamically immiscible as well as exhibit poor compatibility between the blended components. It has been established that the compatibilization is a well-known strategy to improve the performances of the immiscible biodegradable polymer blends by enhancing the adhesion between the phases. As a result, recent studies focus on various compatibilizers to enhance the performances of the resulting biodegradable polymer blends. This review summarizes the recent developments on a variety of biodegradable polymer blends compatibilized by melt processing with a main focus of ex situ and in situ compatibilization strategies. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 45726.
219 citations
201 citations
TL;DR: In this paper, the influence of temperature and relative humidity on the plasticity controlled failure of polyamide 6 was investigated, and the Ree-Eyring equation was employed and modified to include the effect of relative humidity.
Abstract: In this study, the influence of temperature and relative humidity on the plasticity controlled failure of polyamide 6 was investigated. Uniaxial tensile tests were performed at several temperatures, strain rates, and relative humidity; creep tests were performed at different relative humidity and applied load. In order to describe and predict the yield kinetics, the Ree–Eyring equation was employed and modified to include the effect of relative humidity. Subsequently, by the introduction of the concept of critical amount of accumulated plastic strain, the yield kinetics were successfully translated to predictions of time-to-failure. A good agreement between predictions and experimental results is obtained, showing that the model is a suitable and versatile tool to evaluate mechanical performance of a temperature and moisture sensitive material such as polyamide 6. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 45942.
135 citations
TL;DR: In this article, a modified CNCs (b-CNCs) were prepared using benzoic acid as a nontoxic material through a green esterification method in a solvent free technique.
Abstract: Cellulose nanocrystal (CNCs)-reinforced poly(lactic acid) (PLA) nanocomposites were prepared using twin screw extrusion followed by injection molding. Masterbatch approach was used to achieve more efficient dispersion of CNCs in PLA matrix. Modified CNCs (b-CNCs) were prepared using benzoic acid as a nontoxic material through a green esterification method in a solvent-free technique. Transmission electron microscopy images did not exhibit significant differences in the structure of b-CNCs as compared with unmodified CNCs. However, a reduction of 6.6–15.5% in the aspect ratio of b-CNCs was observed. The fracture surface of PLA-b-CNCs nanocomposites exhibited rough and irregular pattern which confirmed the need of more energy for fracture. Pristine CNCs showed a decrease in the thermal stability of nanocomposites, however, b-CNCs nanocomposites exhibited higher thermal stability than pure PLA. The average storage modulus was improved by 38 and 48% by addition of CNCs and b-CNCs in PLA, respectively. The incorporation of b-CNCs increased Young’s modulus, ultimate tensile stress, elongation at break, and impact strength by 27.02, 10.90, 4.20, and 32.77%, respectively, however, CNCs nanocomposites exhibited a slight decrease in ultimate strength and elongation at break. VC 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46468.
125 citations
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114 citations
TL;DR: In this paper, the harmful health effects associated with the exposure to phthalate esters products, explains the usage of oleochemicals resources as a substitute to Phthalate derivatives and describes different approaches for the epoxidation of vegetable oils.
Abstract: Phthalate esters received a considerable attention owing to its various applications and the harmful health effects resulting from phthalate exposure; thus, finding an alternative to phthalate derivatives became a necessity. Phthalate esters are commonly used as plasticizer in polymer formulation; in particular for poly(vinyl chloride) (PVC) formulation. According to the researches in the last 18 years, epoxidized vegetable oils are one of the alternatives that are strongly encouraged to substitute phthalate esters since they were proven to be valid in various applications, eco-friendly and sustainable resource. However, most of the production practices for epoxidized vegetable oil are via conventional epoxidation that concentrates on a catalyst that is homogeneous and non-reusable. This type of catalyst, however, causes several problems later in the process. Therefore, the selective epoxidation of vegetable oils process requires new catalytic systems that are more aligned with the green chemistry principles. This article reviews the harmful health effects associated with the exposure to phthalate esters products, explains the usage of oleochemicals resources as a substitute to phthalate esters and describes different approaches for the epoxidation of vegetable oils. Finally, it draws attention to the usage of epoxy and bio-based compounds as plasticizers in PVC manufacturing. VC 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46270.
94 citations
TL;DR: In this paper, the authors developed and characterized active biodegradable poly(3-hydroxybutyrate-co-3hydroxyvalerate) (PHBV) melt mixed nanocomposites and bilayer structures containing copper oxide (CuO) nanoparticles.
Abstract: Active biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) melt mixed nanocomposites and bilayer structures containing copper oxide (CuO) nanoparticles were developed and characterized. The bilayer structures consisted of a bottom layer of compression molded PHBV3 (3% mol valerate) coated with an active electrospun fibers mat made with CuO nanoparticles and PHBV18 (18% valerate) derived from microbial mixed cultures and cheese whey. The results showed that the water vapor permeability increased with the CuO addition while the oxygen barrier properties were slightly enhanced by the addition of 0.05 wt % CuO nanoparticles to nanocomposite films but a negligible effect was registered for the bilayer structures. However, the mechanical properties were modified by the addition of CuO nanoparticles. Interestingly, by incorporating highly dispersed and distributed CuO nanoparticles in a coating by electrospinning, a lower metal oxide loading was required to exhibit significant bactericidal and virucidal performance against the food-borne pathogens Salmonella enterica, Listeria monocytogenes, and murine norovirus. The biodisintegration tests of the samples under composting conditions showed that even the 0.05% CuO-coated structures biodegraded within 35 days. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45673.
94 citations
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78 citations
TL;DR: Polymer-based nanogenerators (PNGs) have exact features to fulfill the requirements of energy harvesting from objects in motion and data transmission in wearable electronics, sensors, and wireless transmitters.
Abstract: Technologies for energy harvesting from objects in motion are gaining a continuously increasing interest to directly power wearable electronics, sensors, and wireless transmitters. New networks where things will be uniquely identified and interconnected will require key enabling technologies, particularly cheap, flexible generators of renewable energy, conformable to any solid surface, to power independently individual objects and data transmission. Polymer-based nanogenerators (PNGs), capable of converting mechanical energy into electricity, have exact features to fulfill these requirements. This article highlights advances in PNGs with focus on material chemistries and geometrical features, device design strategies, and performances. Representative examples of applications which show large-scale capability are reported. Concluding sections summarize the key challenges and the commercialization perspectives of PNGs for use in real life applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45674.
TL;DR: The inclusion of multiple elevated release temperatures allowed for the application of the Arrhenius model to calculate drug release constants and representative sampling intervals, demonstrating the use of elevated temperatures for accelerated-time drug release studies.
Abstract: Development of injectable, long-lasting, contraceptive drug delivery formulations and implants are highly desired to avoid unplanned pregnancies while improving patient compliance and reducing adverse side effects and treatment costs. The present study reports on the fabrication and characterization of two levonorgestrel (LNG) microsphere injectable formulations. Poly(e-caprolactone) (PCL) with 12.5% and 24% (w/w) LNG were fabricated into microspheres, measuring 300±125 μm, via the oil-in-water (o/w) emulsion solvent evaporation technique. Formulations showed sustained drug release up to 120 days. FTIR, XRD, DSC, and TGA confirmed the absence of LNG chemical interaction with PCL as well as its molecular level distribution. The in vitro release of LNG was calculated to be Fickian diffusion controlled and properly characterized. The inclusion of multiple elevated release temperatures allowed for the application of the Arrhenius model to calculate drug release constants and representative sampling intervals, demonstrating the use of elevated temperatures for accelerated-time drug release studies.
TL;DR: In this paper, activated carbon (AC) was synthesized by chemical activation process from rice husk, with the BET surface area of 2180 m2/g, and the average fiber diameter was found to be 83'±'12.5 nm.
Abstract: In this study, activated carbon (AC) was synthesized by chemical activation process from rice husk, with the BET surface area of 2180 m2/g. Chitosan/poly(ethylene oxide) (PEO)/AC nanofibrous membrane (CPANM) was synthesized by electrospinning process. The average fiber diameter was found to be 83 ± 12.5 nm. Incorporation of AC lead to increase in the surface area of CPANM than chitosan/PEO fiber (CPF) by 371 m2/g. X-ray photoelectron spectroscopy survey and narrow scan analysis further proved the presence of AC in the membrane. CPANM showed higher adsorption capability than CPF. Analysis of the mechanism of heavy metals adsorption by CPANM and CPF hypothesized that, (NH2) is the only active group in CPF, whereas both (NH2) and (COOH) contributed in adsorption for CPANM. Maximum adsorption capacity of CPANM for Cr(VI), Fe(III), Cu(II), Zn(II), and Pb(II) ion was found to be 261.1, 217.4, 195.3, 186.2, and 176.9 mg g−1 respectively. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 45851.
TL;DR: In this article, the incorporation of exfoliated graphene oxide (GO) into nanoscale polyacrylonitrile (PAN) fibers via an electrospinning method leads to the formation of membrane sheets with enhanced mechanical properties.
Abstract: Varying amounts of exfoliated graphene oxide (GO) are systematically incorporated into nanoscale polyacrylonitrile (PAN) fibers via an electrospinning method. Subsequent treatment of the PAN–GO composite nanofibers under a moderate temperature and high pressure leads to the formation of membrane sheets with enhanced mechanical properties. scanning electron microscope, Fourier transform infrared spectroscopy, and contact angle measurements confirm the successful incorporation of the GO into the PAN nanofiber membranes whose diameter, porosity, and pore size are notably influenced by the amount of the GO content. These composite membranes also exhibit a gradual reduction in the water contact angle as a function of the hydrophilic GO content, resulting in a beneficial property for water purification. In addition, the proper integration of GO into the PAN nanofibers improves the protein rejection rate and water flux during the filtration process, which indicates the possibility of utilizing these types of composite membranes in water treatment systems. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45858.
TL;DR: In this paper, the authors present a panoramic sketch of various sustainable rubbers and functional rubber additives in this field and intend to provide a direction to their plausible future developments, which can be seen as a kind of future roadmap.
Abstract: Rubber is one of the most versatile materials having myriad of applications—from niche rubber band and eraser to highly engineered spacecraft seal. Of late, the glittering concept of “sustainability” has been able to infiltrate within the domain of elastomer science and technology to a significant extent - in both academia and industry. This fervent context thus necessitates a systematic documentation of brief history, present research scenario and future perspective of sustainable developments in this field. The present review aims to portray a panoramic sketch of various sustainable rubbers and functional rubber additives in this field and intends to provide a direction to their plausible future developments. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45701.
TL;DR: A comprehensive overview of polymer/BA nanocomposites in the open literature can be found in this article, where polymer matrices are grouped into thermoplastics, thermosets, and rubbers.
Abstract: Boehmite is an aluminum oxyhydroxide [AlO(OH)] which is preferentially used as precursor for the production of (transition) aluminum oxides. Boehmite alumina (BA) nanoparticles are available in various morphologies due to versatile synthesis routes, which are briefly introduced. The peripheral hydroxyl groups of BA offer manifold functionalization possibilities for tailoring the dispersion and filler/matrix adhesion properties. The incorporation of BA nanofillers, with and without surface treatments, may yield improved mechanical and novel functional properties in polymers. BA can be introduced in polymers and polymer composites through different methods. This comprehensive overview covers the basic results reported on polymer/BA nanocomposites in the open literature. In this review, polymer matrices are grouped into thermoplastics, thermosets, and rubbers. Using literature results and our own findings, we have identified promising R&D trends with polymer/BA nanocomposites. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45573.
TL;DR: In this paper, the effect of individual addition of two different nanofillers (Gr and CNT) in epoxy matrix, for a range of nanofiller content (0.1 − 1 wt %), has been investigated.
Abstract: Graphene-nanoplateles (Gr) and multiwalled carbon nanotubes (CNTs) reinforced epoxy based composites were fabricated using ultrasonication, a strong tool for effective dispersion of Gr/CNTs in epoxy. The effect of individual addition of two different nanofillers (Gr and CNT) in epoxy matrix, for a range of nanofiller content (0.1–1 wt %), has been investigated in this study. This study compares mechanical and thermomechanical behavior of Gr and CNT reinforced epoxy. Gr reinforcement offers higher improvement in strength, Young's modulus, and hardness than CNT, at ≤0.2 wt %. However, mode-I fracture toughness shows different trend. The maximum improvement in fracture toughness observed for epoxy-Gr composite was 102% (with 0.3 wt % loading of Gr) and the same for epoxy-CNT composite was 152% (with 0.5 wt % loading of CNT). Thorough microstructural studies are performed to evaluate dispersion, strengthening, and toughening mechanisms, active with different nanofillers. The results obtained from all the studies are thoroughly analyzed to comprehend the effect of nanofillers, individually, on the performance of the composites in structural applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46101.
TL;DR: In this article, a multifunctional and antimicrobial nanofibrous membranes were prepared by electrospinning the soy protein isolate (SPI)/polymide-6 (PA6)-silver nitrate system followed by ultraviolet reduction.
Abstract: Soy proteins are gaining more and more attention because of its multifunction and biodegradability. Silver nanoparticles (AgNPs) are introduced into the nanofibers to prevent growth of microorganisms over the filter media. In the present study, the multifunctional and antimicrobial nanofibrous membranes were prepared by electrospinning the soy protein isolate (SPI)/polymide-6 (PA6)-silver nitrate system followed by ultraviolet reduction. The morphology of SPI/PA6 nanofibrous membranes was characterized by scanning electron microscopy. Antibacterial property of nanofibrous membranes were investigated against Escherichia coli and Bacillus subtilis. The optimized fiber membrane exhibited over 95% filtration efficiency of PM0.3 (particulate matter size less than 0.3 μm). The successful synthesis of SPI/PA6-AgNPs nanofibrous membranes would make it to be the potential candidate for novel antibacterial and high-performance air filter. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45766.