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The crystallization properties of polypropylene (PP), a widely used polymer in industry, can be modified to overcome its mechanical limitations. In the current work, we investigated the effect of ethylene octene copolymer (EOC), blend morphology, nanoclay loading, nano‐localization, and component ratios on PP/EOC crystallization behavior in various aspects, including crystallization rate, degree of crystallinity, nucleation state, and crystalline phases. The results revealed that adding EOC with varying ratios can decrease PP crystallinity both in degree and rate due to the partial miscibility of components through grafting. Furthermore, it was found that the effect of the nanoclay on the crystallization behavior of PP is dependent on the nanoclay loading and its localization in the blend. The nanoclay, therefore, served as a nucleation agent at low nanoparticle contents, accelerating the crystallization rate regardless of the blend's microstructure. However, the crystallization rate of the blend samples at high nanoclay contents (above the rheological percolation threshold) was strongly influenced by the type of morphology. Accordingly, high nanoclay concentrations in blends with matrix‐dispersed morphologies reduced crystallization rates (increasing half‐time from 164 to 216 and 186 s), primarily because PP chains slowed down due to their interactions with nanoparticles and nanoclay hindrance. In contrast, in a blend with a co‐continues‐type morphology, the crystallization rates increased (decreasing half‐time from 624 to 270 and 236 s) due to nano‐localization at the interface and morphology transformation to the matrix‐dispersed one. The blends and nanocomposites based on PP/EOC were also investigated to determine the relationship between the crystallization behavior and mechanical properties. [ABSTRACT FROM AUTHOR]

Polyurethane, as a rubber material, can relieve the load on the ground and provide seismic design for the venue, which is of great significance for sports venues. In order to improve the seismic resistance and abrasion resistance of materials for sports fields and reduce accidents in sports, this article has carried out research on the polyurethane elastomer layered nanocomposites for sports fields and their preparation. Today's world is a challenging era of science and technology. The fields of biotechnology, information, medicine, energy, environment, and national defense and security are closely related to the development of high tech, and the requirements for materials are becoming increasingly diversified. Polymer nanocomposite coating has the dual characteristics of organic and inorganic components. It not only retains the advantages of a polymer but also endows it with versatility. It meets the current application needs. It is a hot spot in today's research. Among them, there are two major problems in the composite process of nanomaterials and polymers: dispersion and compatibility. How to improve the dispersion of nanoparticles and enhance the compatibility between nanoparticles and polymers is an urgent problem to be solved. In the method part, this article introduces a small amount of polyurethane and polyurethane elastomers formed after polyurethane modification and introduces layered compounds and nanocomposites and introduces several models involved in nanomaterials in terms of algorithms. In the analysis part, this paper conducts a comprehensive analysis of the hard segment mass fraction, mechanical properties, thermal decomposition behavior, degradation mechanism, and dynamic mechanical properties. With the increase of GO content, the tensile strength increases significantly and the elongation at break becomes smaller and smaller. When the GO content increases from 0% to 2%, the tensile properties of the WPU film increase from 2.6 MPa to 7.9 MPa and the fracture of the elongation decreased from 201.7% to 62.8%. This shows that the increase in GO content will make the composite material harder and brittle. It can be seen from the experimental results that the preparation of the polyurethane elastomer layered nanocomposite material designed in this paper has a good application effect on sports venues. [ABSTRACT FROM AUTHOR]

DOPO‐based dicarboxylic acid (DODA) was synthesized and used to prepare DOPO‐based polyamide (DOPA) using a direct polycondensation reaction. Also, DODA was used for the surface modification of Mg(OH)2 nanoparticles. Polyamide/Mg(OH)2 nanocomposites (DPANC) were prepared based on DOPA and the organically modified Mg(OH)2 nanoparticles through the solvent casting method. Further, to investigate the effect of the DOPO structure on the thermal and combustion properties, a poly(amide‐imine) (PAIm) without the DOPO structure was synthesized. The structure and morphology of the prepared nanocomposites were studied using various techniques. The results indicated that nanoparticles were uniformly dispersed in the polymer matrix. According to thermogravimetric analysis results, the temperature at 10% mass loss was increased from 309 to 337 °C in the DPANC sample containing 8 mass% of nanoparticles as compared to DOPA in inert atmosphere. Further, according to microscale combustion calorimetry results, the peak heat release rate (pHRR) was decreased from 33 to 19 W g−1 in the DPANC 5 sample, as compared to DOPA. Also, the pHRR value of PAIm was obtained as 138 W g−1, which was about 105 W g−1 higher than that of polyamide. © 2020 Society of Industrial Chemistry [ABSTRACT FROM AUTHOR]

The global concern over the environmental protection and bio‐sustainability of plastic waste materials has prompted a vibrant search for renewable and biodegradable polymers in the academia and industrial sectors. Amidst other biopolymers, poly(lactic acid) (PLA) is identified as the most promising thermoplastic aliphatic polyester. PLA is derived from agricultural products with unique physical and mechanical properties that are comparable with the conventional petroleum‐derived polymers. Yet, some of the properties are insufficient for advanced materials applications. Rigid nanoparticles are incorporated in the PLA matrix to alleviate its properties for specific high‐performance applications. Here, we report various approaches of preparing functional PLA nanocomposites with emphasis on the strengths and weaknesses of each of the methods, as well as the achieved properties enhancement for a targeted application. Designing high‐performance PLA nanocomposite involves careful selection of the most appropriate nanofillers or combinations of nanofillers, preparation technique and processing parameters. Besides multi‐walled carbon nanotubes (CNT) and montmorillonite (MMT) that are prominent as nucleating agents to achieve high thermal and mechanical properties, other nanofillers like silver nanoparticles (AgNP) play critical roles in improving antibacterial and high‐performance properties of PLA. [ABSTRACT FROM AUTHOR]

Summary: In this work, an efficient approach to improving the fire retardancy and smoke suppression for intumescent flame‐retardant polypropylene (PP) composites is developed via incorporating functionalized sepiolite (organo‐modified sepiolite [ONSep]). The PP composites with different amounts of intumescent flame retardants and ONSep were prepared by melt compounding. The morphology, thermal behavior, fire retardancy, smoke suppression, and mechanical property of flame‐retardant PP composites were studied. The results indicate an appropriate amount of ONSep in the flame‐retardant PP composites can increase thermal degradation temperature and char formation as well as a reduction of the peak heat release rate and total heat release; moreover, the addition of ONSep significantly decreases the CO production, total smoke production, smoke production rate, and smoke temperature. Simultaneously, the impact strength of intumescent flame‐retardant PP composite is also maintained by introducing an appropriate amount of ONSep as compared with that without ONSep. [ABSTRACT FROM AUTHOR]

ABSTRACT: Photodegradable poly(lactic acid) (PLA)/titanium dioxide (TiO2) nanocomposites could be utilized as an eco‐friendly material. The photocatalytic degradation was investigated under accelerating artificial ultraviolet irradiation conditions for the period up to 100 days according to GB/T16422.3/ISO 4892.4. The change of surface color, gloss loss, morphology, weight loss, intrinsic viscosity, chemical structure, mechanical properties at different irradiation times were verified via solid reflection spectrophotometer, scanning electron microscopy, Ubbelohde viscometer, Fourier transform infrared spectrometer, and tensile test. The structural change accompanied by the degradation of the irradiated samples clearly showed that the photodegradation of PLA/TiO2 nanocomposites process was via a bulk erosion mechanism. The photodegradability of PLA/TiO2 samples was higher than that of pure PLA and benefitted a lot from a good dispersion of TiO2 nanoparticles. The present study suggests that the photodegradation of PLA could be controlled by loading dispersed g‐TiO2 nanoparticles. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46509. [ABSTRACT FROM AUTHOR]

ABSTRACT: Fe‐ and P‐based compounds have demonstrated promising performance in enhancing flame retardancy of epoxy resins. In this context, this work focuses on the preparation of new Fe/P hybridized nanomaterials and their effect on flame retardancy of epoxy resins. The Fe/P hybrids were facilely prepared via forming ferric phosphinates and phosphonates using hydrothermal reaction. Attractively, ferric phosphinates and phosphonates exhibit the morphology of 1D nanorod and 2D nanosheet, respectively. When incorporating these two fillers in epoxy resin, the limiting oxygen index values of composites were enhanced to above 28 and the composites exhibited self‐extinguishing behavior, thus indicating greatly improved fire resistance. Further investigation revealed that the flame retarding behavior, in particular for ferric phosphonate nanosheets, took place mainly in gas phases via delaying the release of flammable gas. Attractively, it was found that the Fe/P hybrids took part into the pyrolysis reaction of epoxy resins through forming FeO and PO bonds. This finding may provide a new insight to design a series of high performance flame retardants for epoxy resins. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46206. [ABSTRACT FROM AUTHOR]

ABSTRACT To improve the crystallization rate and melt strength of polylactide (PLLA), nano-size amino silica grafted by four-arm PLLA (4A-PLLA) with different molecular weight was synthesized. 1H nuclear magnetic resonance proved that 4A-PLLA had been grafted onto the surface of SiO2 successfully, and the grafting ratios and the degradation behaviors of the grafted SiO2 nanoparticles ( g-SiO2) were studied. When the grafted silica was introduced into PLLA matrix, the crystallization rate and melt strength of composites were found to be improved and the length of grafted chain played an important role. The extension rheology indicated that long grafted 4A-PLLA on the surface of SiO2 was more efficient in enhancing the elongational viscosity of PLLA, owing to the stronger interactions between the grafted chains and the matrix. The crystallization behavior of ungrafted silica filled composite was similar to that of neat PLA, while g-SiO2 played a role of nucleating agent. The crystallinities and the crystallization rates of the composites depended on the content of g-SiO2 and the grafted chain length of 4A-PLLA, especially the latter. Longer grafted chain acted as nucleation site in the matrix and significantly improved the crystallization behaviors of PLLA. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45675. [ABSTRACT FROM AUTHOR]

ABSTRACT The action of metals on the flame retardancy of thermoplastic has aroused much interest in recent years. However, their action on thermosets is still not clear. In this work, metal-phosphorus hybridized nanomaterials with different metal centers were prepared via hydrothermal reaction between metal hydroxide/salts with phosphinic/phosphonic acids. The loading of these hybrids in epoxy (EP) resins resulted in great change on fire resistance. Thermogravimetric analysis, solid and gas phase analysis results indicated that the flame retardant action of the hybrids perhaps didn't take place following the conventional models in condensed and gas phase. It was found that the flame retardancy was greatly correlated with the action of metal centers with EP resin, which resulted in the formation of metal-oxygen bonds and the delayed release of flammable compounds from EP resin. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45445. [ABSTRACT FROM AUTHOR]

ABSTRACT In this work nanocomposites based on poly ( l-lactide) (PLLA) and zinc oxide (ZnO) nanoparticles with a concentration up to 5 wt % have been prepared by solvent-precipitation followed by compression moulding at 200 °C. Structural evolution of nanocomposites as a function of time and nanoparticle concentration has been monitored by differential scanning calorimetry (DSC). Results reveal a marked reduction of the enthalpy relaxation rate βH from 3.273 J/g for neat polymer to 0.912 J/g for its 0.25 wt % reinforced counterpart, revealing slower aging dynamics induced by zinc oxide. It is shown by field emission scanning electron microscopy (FE-SEM) that concentrations larger than 1 wt % yield nanoparticle agglomeration. These large aggregates decrease the amount of nanoparticle surfaces exposed to PLLA chains, notably reducing the efficiency of ZnO nanoparticles to delay the physical aging of its hosting matrix. Mechanical tests show an increased stiffness upon ZnO loading as denoted by the increase in modulus from 2310 MPa to 2780 MPa for the 1 wt % nanocomposite. Obtained findings through this work lead the way for the development of nanocomposites based on renewable polymers and natural fillers to be used in packaging applications, where the use of nonbiodegradable materials for short-term applications is extended. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43619. [ABSTRACT FROM AUTHOR]

ABSTRACT Morphology and crystallization behavior of poly(ɛ-caprolactone) (PCL) in its 80/20 blends with poly(styrene-co-acrylonitrile) (SAN) containing hydrophobic or hydrophilic nanosilica was investigated. It was found that hydrophilic nanosilica displayed a more significant refinement effect on co-continuous morphology of PCL/SAN blends than hydrophobic nanosilica for its selective distribution within the PCL matrix but closer to the two-phase interface. Ring-banded spherulites were observed in both kinds of nanosilica-filled blends, the periodic distance of which decreased with increasing nanosilica content. Hydrophilic nanosilica reduced the dependence of the periodic distance of ring-banded spherulites on the crystallization temperature more efficiently than hydrophobic nanosilica. Furthermore, crystallization process of PCL/SAN blends filled with hydrophobic nanosilica was suppressed as the restriction effect of nanosilica on the crystal growth always outweighed their heterogeneous nucleation effect. In contrast, low content of hydrophilic nanosilica (≤1 wt %) were more likely to exhibit growth restriction effect rather than nucleation effect, whereas heterogeneous nucleation effect of higher content of hydrophilic nanosilica (>1 wt %) dominated over growth restriction effect on facilitating the crystallization behavior. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44157. [ABSTRACT FROM AUTHOR]

ABSTRACT We extended our work to a fast and facile nanocomposites (NCs) manufacturing by incorporation of ZnO nanoparticles (NPs) on to a recycled poly(ethylene terephthalate) PET as a polymer matrix prepared by a dissolution/reprecipitation method. The surface of ZnO NPs was functionalized with synthesized optically active diacid containing alanine amino acid. Organo-modified NPs which provided using solution blending technique through ultrasonic irradiation, were embedded into recycled PET. PET@ZnO/DA NCs containing different loadings of functionalized NPs (1, 3, 5 wt %) were investigated by thermal gravimetric analysis, field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and UV-visible spectroscopy. Morphological studies revealed uniformly dispersed ZnO/DA NPs in the polymer matrix. The crystalline nature of PET slightly improved as a function of the NPs concentration. Char yield in TGA and LOI values indicated that the obtained NCs were capable of exhibiting flame retardant properties. The NCs were found to exhibit more absorbance in the UV and visible region in compare to the neat PET. The effect of ultrasonication in different solvent on the morphology of the recycled polymer particle was also studied. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43433. [ABSTRACT FROM AUTHOR]

ABSTRACT Poly( l-lactide) (PLLA)/ZnO nanocomposites have been developed as efficient UV-shielding coatings for packaging applications. ZnO have been selected as the most suitable UV-shielding material over 10 different metallic nanoparticles. Results reveal a nucleating effect of ZnO in which PLLA crystallization half time is reduced from 7.4 to 4.7 min with only 0.05 wt % ZnO. UV-vis spectroscopy confirms the UV-shielding effect in PLLA/ZnO nanocomposites, where the ultraviolet spectrum is blocked by 61.2% for a concentration as low as 0.45 vol %, while the 95.9% of the visible radiation passes through the material. A schematic representation explaining obtained UV-shielding effect is constructed based on the photon mean free path reduction as ZnO concentration increases. Water contact angle increased from 81° up to 91° for the 5 wt % nanocomposite, which would result beneficial in view to develop materials for packaging applications. Dynamic mechanical analysis exhibits a Tg increase with nanoparticle loading arising from the chain confinement caused by the presence of ZnO interacting surfaces. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42426. [ABSTRACT FROM AUTHOR]

ABSTRACT Poly(lactic acid) (PLA) nanocomposites characterized by multifunctional end-use properties are of high interest as new biosourced materials for the production of smart films, fibers, and injection-molded components. In this work, PLA-ZnO nanocomposites designed for the extrusion of films were obtained by melt-compounding PLA with up to 5 wt % ZnO rod-like nanoparticles, nanofiller previously surface-treated with a specific silane (triethoxycaprylylsilane). To improve the processing and performances of nanocomposites such as their stability at high temperature, the addition of a selected chain-extender (CE) was considered. It was revealed that the co-addition of nanofiller (ZnO) and epoxy functional styrene-acrylate oligomeric CE (Joncryl® ADR 4300F) leads to a very significant enhancement of the properties (molecular, rheological, thermal, etc.) of PLA-ZnO nanocomposites. After addition of 1% CE into nanocomposites, the PLA molecular weights were found to be nearly twofold higher, while the isothermal tests (at 220 and 240°C) confirmed a significant increase in thermal stability. Because the CE plays a key role in limiting the degrading effects of ZnO, due to a gain in melt viscosity and increased molecular mass, a better ability to process nanocomposites by extrusion was found. The good nanofiller dispersion and specific end-use characteristics owing to the presence of ZnO nanoparticles (such as UV shielding) were again confirmed on extruded films. These developments are being viewed as a promising approach that can open new perspectives in the application of PLA-ZnO nanocomposites with specific end-use properties (UV protection, antibacterial, gas-barrier, and self-cleaning) at larger scale. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42480. [ABSTRACT FROM AUTHOR]

ABSTRACT The effects of the chemical nature and size of the hybrid nanoparticle external layer on the structures and properties of polylactide composites are investigated. Polylactide is used as the matrix polymer, and molecular silicasol particles with γ-hydroxypropylic, (methoxyacetyl)oxy, and acetoxy surface groups serve as fillers. A preliminary assessment of the thermodynamic compatibility of polylactide with the surface groups of molecular silicasols is performed. The hydrophilic shells of the silicasols prevent their aggregation in the bulk of the nanocomposite. It shows variations in the chemical structure of the surface layer of the nanoparticles as well as their sizes and concentration make it possible to conduct a controlled change of the characteristics of the composites, particularly to eliminate one of the drawbacks of PLA, the low speed of its crystallization. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41894. [ABSTRACT FROM AUTHOR]

ABSTRACT Poly(lactic acid) (PLA)/nano zinc oxide/copper chlorophyll acid (CCA) antibacterial nanocomposites with excellent mechanical properties were prepared in the presence of a chain extender named tolylene diisocyanate (TDI). The effect of the chain extender on the PLA long chain was confirmed by the increased molecular weight shown in the mass flow rate and gel permeation chromatography. Escherichia coli were adopted to examine the antibacterial ability of the blends. The effect of CCA is also discussed with regard to the enhancement of the antibacterial effect of zinc oxide (ZnO) over E. coli. Scanning electron microscopy and transmission electron microscopy were used to view the agglomeration and dispersion of ZnO in the PLA matrix. Differential scanning calorimetry and thermogravimetric analysis revealed a relatively stable thermal performance of the nanocomposites with and without TDI. A sharp increase in the mechanical properties was also observed after the addition of the chain extender under different processing conditions. Additionally, we found that the nanocomposites with the incorporation of TDI and the masterbatches in batches effectively improved the mechanical properties of PLA/ZnO/CCA without a sacrifice of the antibacterial effect. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41561. [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, nanofillers composed of alumina, titania, and organoclay were separately embedded in 50% polypropylene (PP) and 50% ethylene propylene diene monomer (EPDM) blends. Several formulations of PP/EPDM nanocomposites were prepared using an internal mixer and were molded using a compression mold to produce test samples. The effects of filler loading (2, 4, 6, and 8 vol %) on the dielectric breakdown strength, dielectric properties, hydrophobicity, and flammability were determined. The addition of nanofillers improved the breakdown strength (up to 2 vol %) and increased the dielectric constant and dielectric loss of the PP/EPDM nanocomposites. The hydrophobicity of PP/EPDM/Al2O3 increased, whereas the hydrophilicity of PP/EPDM/TiO2 and PP/EPDM/organoclay increased. Flammability test results showed that PP/EPDM/TiO2 had a lower burning rate than PP/EPDM/Al2O3 and PP/EPDM/organoclay. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41184. [ABSTRACT FROM AUTHOR]

ABSTRACT Poly(lactic acid) (PLA), a biobased, degradable polymer has been used recently in the field of oil and gas. These applications require rapid hydrolytic degradation of PLA especially at low temperatures. This work reports a simple and ready-to-scale up chemistry of using zinc oxide nanoparticles (ZnO NPs) to catalyze the hydrolytic degradation of PLA at the temperatures well below its glass transition temperature. Furthermore, for the first time, we have applied the nondestructive analytical method of 1H T2 NMR relaxometry to measure the apparent rate constants of PLA hydrolysis in solid, heterogeneous/composite systems that have multiple and complex reaction kinetics. We demonstrate that the activation energy for ZnO catalyzed PLA hydrolysis is about 38% lower than that of pure PLA hydrolysis. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40287. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA) chains are directly grafted onto a silicon surface by in situ amidation and PLA/PLA-grafted SiO2 nanocomposites are compounded using a Haake torque rheometer. To have a better understanding of the interaction between grafted polymer chains and PLA matrix, thermal, and rheological properties of PLA/PLA-grafted SiO2 nanocomposites are explored. DSC analysis shows that PLA-grafted-SiO2 can accelerate the cold crystallization rate and increase the degree of crystallinity of PLA. Shear rheology testing indicates that PLA/PLA-grafted-SiO2 nanocomposites still exhibits the typical homopolymer-like terminal behavior at low frequency range even at a content of PLA-grafted-SiO2 of 5 wt %, compared to PLA/SiO2, it is also found that the nanocomposites show stronger shear-thinning behaviors in the high frequency region after grafting. In addition, elongation viscosity testing shows the entanglement between grafted chains and matrix that is needed to improve the melt strength of PLA. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

This work aims at preparing and characterizing poly(butyl acrylate) (PBA)-laponite (LRD) nanocomposite nanoparticles and nanocomposite core (PBA-LRD)-shell poly(methyl methacrylate) (PMMA) nanoparticles, on the one hand, and the morphology and properties of poly(lactic acid) (PLA)-based blends containing PBA-LRD nanocomposite nanoparticles or (PBA-LRD)/PMMA core-shell nanoparticles as the dispersed phase, on the other hand. The PBA and (PBA-LRD)/PMMA nanoparticles were synthesized by miniemulsion or emulsion polymerization using LRD platelets modified by 3-methacryloxypropyltrimethoxysilane (MPTMS). The grafting of MPTMS onto the LRD surfaces was characterized qualitatively using FTIR and quantitatively using thermogravimetric analysis (TGA). The amounts of LRD in the PBA-LRD nanocomposites were characterized by TGA. The PBA/PMMA core-shell particles were analyzed by 1H-NMR. Their morphology was confirmed by SEM and TEM. Mechanical properties of (PBA-LRD)/PLA blends and (PBA-LRD)/PMMA/PLA ones were tested and compared with those of the pure PLA, showing that core-shell particles allowed increasing impact strength of the PLA while minimizing loss in Young modulus and tensile strength. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA)-based nanocomposites comprising two different types of nanofillers, i.e. sepiolite (SEP) and nano calcium carbonate (NCC), were prepared by internal mixing and injection molding. Because of the different aspect ratio, surface area, and surface property of the nanofillers, their effects on the morphological, mechanical, dynamic mechanical, rheological, and thermal properties of the nanocomposites were shown to be very different. NCC demonstrated more uniform particle dispersion and matrix compatibility than did SEP because of the former's surface treatment, thus leading to higher strength and strain-at-failure of PLA/NCC composites. On the other hand, larger aspect ratio and surface area of SEP caused higher melt viscosity, stronger shear thinning, and better thermal resistance of PLA/SEP composites. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

SUMMARY Hybrid buckypapers (HBP) were developed and showed potential as efficient fire-retardant materials by implementing multiple fire retardance mechanisms. The fabrication of HBP was performed using multi-walled carbon nanotubes (MWCNTs) and magnesium hydroxide (Mg(OH)2) nanoparticles. The Mg(OH)2 nanoparticles were well dispersed throughout the CNTs network, as revealed by scanning electron microscopy and Energy Dispersive X-ray spectroscopy. Thermogravimetric analysis and differential scanning calorimetry both confirmed the decomposition of magnesium hydroxide in the HBPs and heat absorption under elevated temperatures. Our initial results indicated that when used as a skin layer, the HBP has the potential to significantly improve the fire-retardant properties of epoxy carbon fiber composites. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Uniform monodisperse FeOOH and hematite (Fe2O3) nanoparticles were synthesized at room temperature via a facile sonochemical reaction between FeCl3 and NaOH. Fe2O3 nanoparticles were then added to acrylonitrile-butadiene-styrene (ABS) polymer. Nanoparticles and nanocomposites were characterized using X-ray diffraction, scanning electron microscopy, Fourier transform infrared, and photoluminescence (PL) spectroscopy techniques. The effect of the presence of FeOOH and Fe2O3 nanoparticles in the polymer matrix on the thermal properties was studied using thermogravimetric analysis and derivative thermogravimetric analysis, in both air and nitrogen atmospheres. The magnetic properties of the samples were also investigated using an alternating gradient force magnetometer. We found that the Fe2O3 nanoparticles exhibit a ferromagnetic behavior with a saturation magnetization of 0.869 emu/g and a coercivity of 191 Oe at room temperature. The coercivity of ABS/ Fe2O3 (5%) nanocomposites is found to be 252 Oe, higher than 226 Oe which is obtained for ABS/Fe2O3 (20%). © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

A finishing process with polyhedral oligomeric silsesquioxane (POSS) and bohemite nanoparticles has been exploited for enhancing the thermal stability and flame retardancy of cotton fabrics. The thermal behavior of flame retardant treated cellulosic fabric has been studied by thermogravimetric analyses (TGAs). It has been found that such nanoparticles favor the carbonization of the cellulose and slow down the kinetics of thermo-oxidation in air. At the same time, the finished fabrics have turned out to be more efficient with respect to neat cotton as far as the flame retardancy is concerned, pointing out an increase of the time to ignition (TTI) and a decrease of the heat release rate (HRR). Furthermore, a comparison between the fire performances of the nanoparticles under study and a commercial phosphorus-based flame retardant has been investigated. The morphology and elemental composition present in the treated fabrics have been also investigated using scanning electron microscopy (SEM) coupled to the energy dispersive spectroscopy (EDS), and the results have been compared with the untreated fabric. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

Aluminum nitride nanoparticle (nano-AlN) organically modified with the silane-containing epoxide groups (3-glycidoxypropyltrimethoxy silane, GPTMS) was incorporated into a mixture of poly(ether imide) (PEI), and methyl hexahydrophthalic anhydride-cured bisphenol A diglycidyl ether grafted by GPTMS was prepared for nanocomposite. Scanning electron microscopy, transmission electron microscopy, and atomic force microscopy were used to investigate the microscopic structures of nanocomposites. According to experimental results, it was shown that addition of nano-AlN and PEI into the modified epoxy could lead to the improvement of the impact and bend strengths. When the concentrations of nano-AlN and PEI were 20 and 10 pbw, respectively, the toughness/stiffness balance could be achieved. Dynamic mechanical analysis (DMA) results displayed that two glass transition temperatures (Tg) found in the nanocomposites were assigned to the modified epoxy phase and PEI phase, respectively. As nano-AlN concentration increased, Tg value of epoxy phase had gradually increased, and the storage modulus of the nanocomposite at the ambient temperature displayed an increasing tendency. Additionally, thermal stability of the nanocomposite was apparently improved. The macroscopic properties of nanocomposites were found to be strongly dependent on their components, concentrations, dispersion, and resulted morphological structures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [ABSTRACT FROM AUTHOR]

In this study, an N‐alkoxy‐hindered amine‐based UV stabilizing agent (NOR‐116) and nanosized silica particles (Aerosil R‐972) were combined with a cyclic phosphonate based‐flame retardant (FR; PCO‐900) and incorporated into polypropylene via melt extrusion in a microcompounder. In order to stimulate the conditions in the favor of further processing such as fiber spinning, the content of additives in polypropylene was kept low (up to 6.5 wt %). The effects of the PCO‐900, alone and in combination with NOR‐116 and Aerosil‐R972, on the flammability and thermal stability of polypropylene were evaluated by limit oxygen index (LOI) tests, cone calorimetry, and thermogravimetric analysis. The proposed system with 3.5 wt % PCO‐900/1.5 wt % NOR‐116/1 wt % Aerosil‐R972 decreased the heat release, increased the LOI and thermo‐oxidative stability, and, thus, improved the fire resistance of polypropylene. The possible mode of FR activity was also discussed based on the analysis. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48308. [ABSTRACT FROM AUTHOR]