T. Aghalya, R. Tamizharasi^*

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 431-460, 2024, DOI:10.32604/cmes.2024.046635

Abstract In this study, the characteristics of heat transfer on an unsteady magnetohydrodynamic (MHD) Casson nanofluid over an exponentially accelerated vertical porous plate with rotating effects were investigated. The flow was driven by the combined effects of the magnetic field, heat radiation, heat source/sink and chemical reaction. Copper oxide () and titanium oxide () are acknowledged as nanoparticle materials. The nondimensional governing equations were subjected to the Laplace transformation technique to derive closed-form solutions. Graphical representations are provided to analyze how changes in physical parameters, such as the magnetic field, heat radiation, heat source/sink and chemical reaction, affect the velocity, temperature… More >

KM. MEENU, DIBYENDU S. BAG^*, REKHA LAGARKHA^a

Journal of Polymer Materials, Vol.36, No.3, pp. 275-292, 2019, DOI:10.32381/JPM.2019.36.03.7

Abstract Functional photoactive polysilane copolymers of poly(methylphenylsilane) (PMPS) and disperse yellow 7 methacrylate (DY7MA) were synthesized using UV-technique. In the same manner functional polysilane copolymers of poly(methylphenylsilane-co-dimethylsilane) (CPS) and disperse yellow 7 methacrylate (DY7MA) were also synthesized. By the UV irradiation polysilanes (PMPS and CPS) give rise to silyl macroradicals which initiate the polymerization of photoactive monomer (DY7MA). The synthesized samples were characterized by FTIR, NMR, and UV-Vis spectroscopy. The molar mass of synthesized photoactive functional polysilane copolymers is of order of 103 gm/mol. They exhibited multimodal optical and photoluminescence functional properties. Optical absorbance was observed at 336 nm due to… More >

MERYEM KORUYUCU^a, FEHMi SALTAN^a,b, GÖKHAN KÖK^a, HAKAN AKAT^a, YEŞIM SALMAN^a,*

Journal of Polymer Materials, Vol.36, No.3, pp. 207-216, 2019, DOI:10.32381/JPM.2019.36.03.1

Abstract The present study has demonstrated that novel acrylic glycopolymers are successfully prepared by using monosaccharides containing an acrylate group (9-12). For this purpose, sugar based acrylate monomers were synthesized via ring opening method (Method B) and homopolymerization of this sugar oxypropylacrylates was performed using free radical polymerization. The characterization of all the monomers and polymers were verified by ¹HNMR, ¹³CNMR, FTIR and GPC techniques. The Glass transition temperatures and thermal characteristics of the polymers were also analyzed by using DSC and TG techniques. The thermal stability of prepared polymers have changed with the stereochemistry of the carbohydrate moiety. Also, the… More >

FEHMI SALTAN^1,2, AYLIN PALAMUTLU², HAKAN AKAT^2,*

Journal of Polymer Materials, Vol.36, No.2, pp. 133-147, 2019, DOI:10.32381/JPM.2019.36.02.3

Abstract In this work, tetraphenylporphyrin (TPP) compound was first synthesized by the condensation reaction of pyrrole and benzaldehyde using Adler method. Then, the synthesized tetraphenylporphyrin was nitrated with sodium nitrite. Nitro-functionalized porphyrin (TPP-NO₂ ) compound was reduced to amine-functional using ammonia and this amine- functionalized porphyrin was reacted with methacryloyl chloride to obtain porphyrin-derived radical monomer (TPP-MAO). Copolymer was synthesized with obtained porphyrin functional monomer and styrene by free radical polymerization method. Structural characterization and spectroscopic studies of the synthesized compounds were carried out by FTIR, H¹ -NMR, UV spectroscopy. The molecular weight and thermal properties of the copolymer were determined… More >

XIAOYAN LIU^a,*, XU CHEN^a, HONGXING ZHANG^b, CHANGJUN ZHANG^a, SHIYUAN YANG^a, GUANGQUAN LI^a

Journal of Polymer Materials, Vol.36, No.2, pp. 121-132, 2019, DOI:10.32381/JPM.2019.36.02.2

Abstract In this work, three in situ impact polypropylene copolymer(IPC) samples were prepared through Ziegler-Natta catalyst only changing the feed composition (ethylene to ethylene and propylene molar ratio, C2/C2+C3) in gas-phase polymerization reactor. Polymer (IPC) were characterical by solvent classification, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), successive self-nucleation and annealing (SSA), nuclear magnetic resonance(13C-NMR) and scanning electron microscopy(SEM). The mechanical properties of IPC samples were tested.The results indicate that with similar ethylene content, the feed composition which determines the content and structure of EPR and EbP component in IPC, further impacts the rubber phase size and distribution in IPC,… More >

JALPA V. CHOPDA, DHARMESH B. SANKHAVARA, JIGNESH P. PATEL, P. H. PARSANIA^*

Journal of Polymer Materials, Vol.36, No.1, pp. 101-109, 2019, DOI:10.32381/JPM.2019.36.01.8

Abstract The epoxy resin (EMBHBC) of (2E,6E)-bis (4-hydroxybenzylidene)-4-methyl cyclohexanone (MBHBC) was synthesized by condensing 0.5 mol MBHBC and 2.5 mol epichlorohydrin in 500 mL isopropyl alcohol as a solvent and 1.0 mol NaOH in 50 mL water as a catalyst at 80°C for 3 h. The structure of EMBHBC was supported by UV-Vis, FTIR, ¹ HNMR and ¹³CNMR spectroscopic techniques. Molecular weights and molecular weight distribution of EMBHBC were determined by gel permeation chromatography. DSC thermogram of EMBHC showed one endothermic transition (95.9°C) and two exothermic transitions (317.7°C and 382.2°C) due to melting and decomposition transitions, respectively. EMBHBC is thermally stable… More >

RAJEEV KUMAR

Journal of Polymer Materials, Vol.37, No.3-4, pp. 131-142, 2020, DOI:10.32381/JPM.2020.37.3-4.2

Abstract The optical, electrical and acoustical properties of a polymer solution based on polyvinyl pyrrolidone (PVP) doped with different concentration of cupric sulphate (CuSO₄ ) were studied.UVVIS spectroscopy results reflected that absorption increases in asymmetric manner and the absorption peak showed red shift with increasing Cu ions concentration. The optical band gap (direct and indirect) was found to decrease with increase in Cu ions concentration in the polymer due to increase in the density of localized states in the band-gap.The value of Urbach energy is also evaluated from the transmission spectra and the activation energies are also evaluated from the conductivity… More >

JITENDRA. S. TATE^1,2,*, HARISH KALLAGUNTA^1,2, ANDREW ALVAREZ¹

Journal of Polymer Materials, Vol.38, No.1-2, pp. 101-120, 2021, DOI:10.32381/JPM.2021.38.1-2.9

Abstract The exponential growth in composites and their increased use in military, aerospace, energy, and automotive industry is driven by their high performance and light weight. High performance thermosetting polymers such as cyanate ester have received considerable attention due to its ability of volatile-free curing. It also offers advantages such as excellent radiation shielding, high thermal stability, and hydrophobicity with lots of potential for enhanced mechanical strength. This research article discusses the results of effects of multiwalled carbon nanotubes (MWCNT) at predetermined loading levels of 0.5wt%, 1wt% and 1.5wt% on mechanical, thermal and flammability properties of cyanate ester modified carbon fiber… More >

ZHIHUI HUANG¹, JIAMIAO CHEN¹, YANPING HUO¹, JINGWEI ZHAO²

Journal of Polymer Materials, Vol.38, No.3-4, pp. 257-269, 2021, DOI:10.32381/JPM.2021.38.3-4.7

Abstract The effect of the ether/keto ratios on the thermal properties, mechanical performances and crystallization behavior of the Poly(aryl ether ketone)s (PAEK) were investigated. A formula was proposed the estimate the melting temperatures of the PAEKs with high accuracy. Glass transition temperatures were affected by the ether/keto ratios and molecular weights, and were related with the brittle-tough transition of the PAEKs. Mechanical performances of tensile, impact, flexural and compressive strength decreased with the increase of ether/keto ratios, while elongation had a trend of increase. The non-isothermal crystallization curves exhibited well linearity when treated with Jeziorny’s model, and two crystallization processes were… More >

Haoxue Wu^#, Xiaohan Zhang^§,#, Xiaoyu Chen, Kang Li, Aixia Xu, Zhen Huang, Jungang Dong, Chengyu Yu^*

Phyton-International Journal of Experimental Botany, Vol.93, No.3, pp. 627-640, 2024, DOI:10.32604/phyton.2024.050321

Abstract Genetic manipulation (either restraint or enhancement) of the biosynthesis pathway of α-linolenic acid (ALA) in seed oil is an important goal in Brassica napus breeding. B. napus is a tetraploid plant whose genome often harbors four and six homologous copies, respectively, of the two fatty acid desaturases FAD2 and FAD3, which control the last two steps of ALA biosynthesis during seed oil accumulation. In this study, we compared their promoters, coding sequences, and expression levels in three high-ALA inbred lines 2006L, R8Q10, and YH25005, a low-ALA line A28, a low-ALA/high-oleic-acid accession SW, and the wildtype ZS11. The expression levels of… More >