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Chemical Research in Toxicology Mar 2021The mainstream smoke yields of five volatile organic compounds (VOCs) were determined from 60 commercial U.S. little cigar products under ISO 3308 and Canadian Intense...
The mainstream smoke yields of five volatile organic compounds (VOCs) were determined from 60 commercial U.S. little cigar products under ISO 3308 and Canadian Intense (CI) smoking regimens on linear smoking machines using a gas sampling bag collection. The five VOCs, 1,3-butadiene, acrylonitrile, benzene, isoprene, and toluene were analyzed using an automated GC/MS analytical method validated for measuring various VOCs in mainstream smoke. The VOCs range in amounts from micrograms to milligrams per little cigar. VOC deliveries vary considerably among the little cigar products under the ISO smoking regimen primarily due to varying filter ventilation. Under the CI smoking regimen where filter ventilation is blocked, the delivery range narrows, although individual and total VOC yields are approximately 2 fold higher than those under the ISO smoking regimen. Correlation analysis reveals strong associations between acrylonitrile and 1,3-butadiene or toluene under the ISO smoking regimen. Compared to cigarettes, little cigars delivered substantially higher VOC mainstream smoke yields under both ISO and CI smoking regimens. Moreover, little cigar smoke also contains higher VOCs than cigarette smoke when adjusted for mass of tobacco.
Topics: Smoke; Tobacco Products; Volatile Organic Compounds
PubMed: 33512154
DOI: 10.1021/acs.chemrestox.0c00215 -
Polymers Sep 2021In this study, acrylonitrile butadiene styrene (ABS)/talc/graphene oxide/SEBS-g-MAH (ABS/Talc/GO/SEBS-g-MAH) and acrylonitrile butadiene styrene/graphene...
In this study, acrylonitrile butadiene styrene (ABS)/talc/graphene oxide/SEBS-g-MAH (ABS/Talc/GO/SEBS-g-MAH) and acrylonitrile butadiene styrene/graphene oxide/SEBS-g-MAH (ABS/GO/SEBS-g-MAH) composites were isolated with varying graphene oxide (0.5 to 2.0 phr) as a filler and SEBS-g-MAH as a compatibilizer (4 to 8 phr), with an ABS:talc ratio of 90:10 by percentage. The influences of graphene oxide and SEBS-g-MAH loading in ABS/talc composites were determined on the mechanical and thermal properties of the composites. It was found that the incorporation of talc reduces the stiffness of composites. The analyses of mechanical and thermal properties of composites revealed that the inclusion of graphene oxide as a filler and SEBS-g-MAH as a compatibilizer in the ABS polymer matrix significantly improved the mechanical and thermal properties. ABS/talc was prepared through melt mixing to study the fusion characteristic. The mechanical properties showed an increase of 30%, 15%, and 90% in tensile strength (TS), flexural strength (FS), and flexural modulus (FM), respectively. The impact strength (IS) resulted in comparable properties to ABS, and it was better than the ABS/talc composite due to the influence of talc in the composite that stiffens and reduces the extensibility of plastic. The incorporation of GO and SEBS-g-MA also shows a relatively higher thermal stability in both composites with and without talc. The finding of the present study reveals that the graphene oxide and SEBS-g-MAH could be utilized as a filler and a compatibilizer in ABS/talc composites to enhance the thermo-mechanical stability because of the superior interfacial adhesion between the matrix and filler.
PubMed: 34578081
DOI: 10.3390/polym13183180 -
Polymers May 2024Prior studies into fatigue crack growth (FCG) in fibre-reinforced polymer composites have shown that the two methodologies of Simple-Scaling and the Hartman-Schijve...
Prior studies into fatigue crack growth (FCG) in fibre-reinforced polymer composites have shown that the two methodologies of Simple-Scaling and the Hartman-Schijve crack growth equation, which is based on relating the FCG rate to the Schwalbe crack driving force, Δ, were able to account for differences observed in the measured delamination growth curves. The present paper reveals that these two approaches are also able to account for differences seen in plots of the rate of crack growth, , versus the range of the imposed stress intensity factor, Δ, associated with fatigue tests on different grades of high-density polyethylene (HDPE) polymers, before and after electron-beam irradiation, and for tests conducted at different ratios. Also, these studies are successfully extended to consider FCG in an acrylonitrile butadiene styrene (ABS) polymer that is processed using both conventional injection moulding and additive-manufactured (AM) 3D printing.
PubMed: 38732768
DOI: 10.3390/polym16091299 -
Molecules (Basel, Switzerland) Mar 2021The compounds ()-2-(phenyl)-3-(2,4,5-trimethoxyphenyl)acrylonitrile with one side (2,4,5-MeO-), one symmetrical...
The compounds ()-2-(phenyl)-3-(2,4,5-trimethoxyphenyl)acrylonitrile with one side (2,4,5-MeO-), one symmetrical (2,2')-2,2'-(1,4-phenylene)bis(3-(2,4,5-trimethoxyphenyl)acrylonitrile), (both sides with (2,4,5-MeO-), and three positional isomers with pyridine ()-2-(pyridin-2- 3, or 4-yl)-3-(2,4,5-trimethoxyphenyl)acrylonitrile, - were synthetized and characterized by UV-Vis, fluorescence, IR, H-NMR, and EI mass spectrometry as well as single crystal X-ray diffraction (SCXRD). The optical properties were strongly influenced by the solvent (hyperchromic and hypochromic shift), which were compared with the solid state. According to the solvatochromism theory, the excited-state () and ground-state () dipole moments were calculated based on the variation of Stokes shift with the solvent's relative permittivity, refractive index, and polarity parameters. SCXRD analyses revealed that the compounds and crystallized in the monoclinic system with the space group, 2/ and 2/, respectively, and with = 4 and 2. , , and crystallized in space groups: orthorhombic, ; triclinic, -1; and monoclinic, 2 with = 1, 2, and 2, respectively. The intermolecular interactions for compounds - were investigated using the CCDC Mercury software and their energies were quantified using PIXEL. The density of states (DOS), molecular electrostatic potential surfaces (MEPS), and natural bond orbitals (NBO) of the compounds were determined to evaluate the photophysical properties.
PubMed: 33801942
DOI: 10.3390/molecules26061500 -
Polymers Oct 2020To produce flame retardant poly(acrylonitrile-co-vinylidene chloride) (PANVDC) fibers with limiting oxygen index (LOI) values above 28%, flame retardants are added to...
To produce flame retardant poly(acrylonitrile-co-vinylidene chloride) (PANVDC) fibers with limiting oxygen index (LOI) values above 28%, flame retardants are added to fibers. Because antimony trioxide (ATO) used widely for PANVDC is suspected as a carcinogen, non-toxic zinc hydroxystannate (ZHS) could be the alternative for reduction of ATO usage. Moreover, a flame retardant efficiency of the combination of ATO with ZHS could be expected because it was reported that ATO resists flame in the gas phase, whereas ZHS reacts in the condensed phase. Therefore, this study discussed the flame retardant mechanisms of ATO and ZHS in PANVDC, and evaluated the efficiency of the combination. PANVDC fibers with ATO and ZHS in 15 phr were produced by wet spinning. When ZHS was added, a more cyclized structure was detected (e.g., 1-methylnaphthalene) through pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS). As a result of SEM-EDX analysis, Sb and Cl hardly remained in char layers of PANVDC-ATO; meanwhile, Zn, Sn, and Cl remained in that of PANVDC-ZHS. This implied that SbCl from reaction of ATO and HCl reacts in the gas phase, whereas ZnCl and SnCl from ZHS and HCl promotes the cyclization reaction of PANVDC in the condensed phase. The LOI values of PANVDC, PANVDC-ATO, and PANVDC-ZHS were 26.4%, 29.0%, and 33.5%, respectively. This suggests that ZHS is a highly effective for PANVDC. Meanwhile, the LOI of PANVDC containing ATO-ZHS mixture is 31.0%. The combination of ATO and ZHS exhibited no efficiency. The addition of ATO and ZHS slightly reduced the tenacities of the fibers, respectively, 3.11 and 3.75 from 4.42 g/den.
PubMed: 33105755
DOI: 10.3390/polym12112442 -
Membranes Jan 2021In this study, a magnetic/polyetherimide-acrylonitrile composite nanofiber membrane with effective adsorption of nickel ions in an aqueous solution was created using a...
In this study, a magnetic/polyetherimide-acrylonitrile composite nanofiber membrane with effective adsorption of nickel ions in an aqueous solution was created using a simple electrospinning method. Iron oxide nanoparticles (NPs) were stirred and ultrasonically dispersed into a polyetherimide-acrylonitrile solution to create a homogenous NPs suspension, which was placed in an electrospinning machine to produce a uniform and smooth nanofiber composite membrane. Nanoparticle incorporation into this membrane was confirmed using scanning electron microscope, energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and NPs aqueous stability from a leaching test. The high adsorption capability of the membrane on nickel ions was attributed to the combination of magnetic NPs, polyetherimide-acrylonitrile matrix, and the nanostructure of the membrane. A membrane containing magnetic NPs demonstrated the maximum adsorption capabilities (102 mg/g) of nickel ions in an aqueous solution. Various kinetic and isotherm models were applied to understand the adsorption behavior, such as pseudo-second-order kinetic and Langmuir isotherm models. A polyetherimide-acrylonitrile composite nanofiber membrane containing magnetic NPs could be used as an environmentally friendly and nontoxic adsorbent for the removal of nickel ions in an aqueous medium due to its ease of preparation and use and stability in aqueous mediums.
PubMed: 33445745
DOI: 10.3390/membranes11010050 -
Journal of Neuroendovascular Therapy 2021Although Onyx has made effective embolization possible in the endovascular treatment of arteriovenous malformation (AVM), its infusion requires a high level of skill and...
OBJECTIVE
Although Onyx has made effective embolization possible in the endovascular treatment of arteriovenous malformation (AVM), its infusion requires a high level of skill and experience. The purpose of this study is to create a simulation model that will help to solve this technical issue.
MODEL PRESENTATION
Using data of 3D DSA images of a clinical case, an acrylonitrile-butadiene-styrene (ABS) resin model of the AVM was created with a 3D printer. Then, a hollow elastic model was created by applying silicone and eluting the ABS resin, which was finally connected to the human vascular model. Simulation of angiography and Onyx embolization using the model showed similar angiographic features and flow dynamics of contrast media and Onyx. During Onyx embolization, the plug and push technique could be performed as in a clinical case.
CONCLUSION
3D AVM model created with 3D printer enabled us to stimulate Onyx embolization of AVM.
PubMed: 37502265
DOI: 10.5797/jnet.tn.2020-0141 -
Applied Ergonomics Nov 2021Additive Manufacturing (AM) facilitates product personalization and iterative design, which makes it an ideal technology for ergonomic product development. In this... (Review)
Review
Additive Manufacturing (AM) facilitates product personalization and iterative design, which makes it an ideal technology for ergonomic product development. In this study, a systematic review was conducted of the literature regarding the use of AM in ergonomic-product design, and methodological aspects of the studies were analyzed. A literature search was performed using the keywords "3D print*," "additive manufacturing," "ergonomic*" and "human factors". Included were studies reporting the use of AM specifically in ergonomic design of products/prototypes including the detailing of an ergonomic testing methodology used for evaluation. Forty studies were identified pertaining to the fields of medicine, assistive technology, wearable technology, hand tools, testing devices and others. The most commonly used technology was fused deposition modeling with polylactic acid, but the overall preferred material was acrylonitrile butadiene styrene. Various combinations of objective/subjective and qualitative/quantitative product evaluation methods were used. Based on the findings, recommendations were developed to facilitate the choice of most suitable AM technologies and materials for specific applications in ergonomics.
Topics: Ergonomics; Humans; Printing, Three-Dimensional; Technology
PubMed: 34256321
DOI: 10.1016/j.apergo.2021.103528 -
Polymers Apr 2022As a result of the search for alternatives to the known methods for the synthesis of PLA/vinyl polymer block copolymers, a new approach based on the "iniferter" concept...
As a result of the search for alternatives to the known methods for the synthesis of PLA/vinyl polymer block copolymers, a new approach based on the "iniferter" concept was demonstrated in this article. In this approach, the introduction of a group that was capable of forming radicals and initiating radical polymerization into the polylactide (PLA) chain was conducted. Then, the obtained functional PLA was heated in the presence of a radically polymerizable monomer. The tetraphenylethane (TPE) group was chosen as a group that could dissociate to radicals. PLA with a TPE group in the middle of the chain was prepared in several steps as follows: (1) the synthesis of 4-(2-hydroxyethoxy)benzophenone (HBP-ET); (2) the polymerization of lactide, which was initiated with HBP-ET; and (3) the coupling of HBP-ET chains under UV radiation to form TPE-diET_PLA. A "macroiniferter", i.e., TPE-diET_PLA, was used to initiate the polymerization of acrylonitrile (AN) by heating substrates at 85 °C. H and C NMR and SEC analyses of the products indicated that the triblock copolymer PLA-PAN-PLA formed and thus confirmed the assumed mechanism of the initiation of AN polymerization, which relied on the addition of the radical that formed from TPE (linked with the PLA chain) to the monomer molecule. Copolymerizations were performed with the application of prepared TPE-diET_PLA with three different M's (1400, 2200, and 3300) and with different AN/PLA ratios, producing copolymers with varied compositions, i.e., with AN/LA ratios in the range of 2.3-11.1 and M's in the range of 5100-9400. It was shown that the AN/LA ratio in the copolymer was increasable by the applied excess of AN with respect to the PLA macroiniferter in the feed and that more AN monomer was able to be introduced to PLA with shorter chains.
PubMed: 35458278
DOI: 10.3390/polym14081529 -
Nanomaterials (Basel, Switzerland) Aug 2022Carbon Nanotube (CNTs)-based masterbatches have been mixed with thermoplastic polymers currently used to manufacture automotive components. These mixtures have been...
Carbon Nanotube (CNTs)-based masterbatches have been mixed with thermoplastic polymers currently used to manufacture automotive components. These mixtures have been tailored to integrate an effective heating function in the materials. The manufacturing method for composite compounding and processing conditions significantly affects the electrical resistivity of the developed materials. The resistivity of the material can be controlled within tight tolerances sufficient to meet automotive requirements. The optimal compounding parameters of the melt process technologies were defined to obtain uniform filler dispersion and distribution. Heating and de-icing tests were performed on sheet specimens with optimized CNT content and electrical conductivity suitable for effective electro-thermal behaviour with low input voltages (≤24 V DC), making them safe for users. Finally, a simplified analytical model of the Joule effect arising from an energy balance of the system under study (heat equation) was developed and validated by comparison with experimental data for use in future development for the purpose of the preliminary design of components in the automotive sector.
PubMed: 36080016
DOI: 10.3390/nano12172979