Yunfa Zhang¹, Xiaozhou Xia^{1, *}, Zhenjie Wu¹, Qing Zhang¹

CMC-Computers, Materials & Continua, Vol.62, No.1, pp. 413-442, 2020, DOI:10.32604/cmc.2020.04660

Abstract Considering the fact that the initial defects, like the imperfect interfacial transition zones (ITZ) and the micro voids in mortar matrix, weaken the mechanical properties of concrete, this study develops corresponding constitutive models for ITZ and matrix, and simulates the concrete failure with finite element methods. Specifically, an elastic-damage traction-separation model for ITZ is constructed, and an anisotropic plastic-damage model distinguishing the strength-difference under tension and compression for mortar matrix is proposed as well. In this anisotropic plastic-damage model, the weakening effect of micro voids is reflected by introducing initial isotropic damage, the distinct characteristic More >

Zhiqiang Huang^{1, 2}, Yufeng Nie^{1, *}, Yiqiang Li¹

CMC-Computers, Materials & Continua, Vol.62, No.1, pp. 245-265, 2020, DOI:10.32604/cmc.2020.06284

Abstract This paper is devoted to the microstructure geometric modeling and mechanical properties computation of cancellous bone. The microstructure of the cancellous bone determines its mechanical properties and a precise geometric modeling of this structure is important to predict the material properties. Based on the microscopic observation, a new microstructural unit cell model is established by introducing the Schwarz surface in this paper. And this model is very close to the real microstructure and satisfies the main biological characteristics of cancellous bone. By using the unit cell model, the multiscale analysis method is newly applied to 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… More >

R. VENKATESAN^*, S. R. DARSON IMMANUEL JOHN, N. RAJESWARI

Journal of Polymer Materials, Vol.36, No.3, pp. 261-273, 2019, DOI:10.32381/JPM.2019.36.03.6

Abstract Nanocomposite films of chitosan (CH) incorporated with different wt. % of the polyoligomericsilsesquioxane (POSS) were prepared by solution casting. The thermal, mechanical, morphological and antimicrobial properties of the nanocomposites were examined. TGA analyses of the nanocomposites indicate that the filler enables the enhancement of thermal stability of chitosan. The tensile strength of the nanocomposite films is enhanced (10.9 MPa for neat chitosan to 24.0MPa for 5wt. % filled chitosan) by the addition of POSS while the elongation at break is reduced. The nanocomposite films exhibited excellent antimicrobial activity against both gram positive and gram negative 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 More >

KAVITA^*, R.K. TIWARI

Journal of Polymer Materials, Vol.36, No.2, pp. 195-205, 2019, DOI:10.32381/JPM.2019.36.02.7

Abstract The effect of poly (vinyl butyral) and acid functionalized multiwalled carbon nanotubes (f-MWCNT) on the thermal and mechanical performance of Kevlar fiber reinforced novolac epoxy nanocomposites was investigated and presented in this paper. Nanocomposite containing 1.5 wt. % poly (vinyl butyral) and 0.5 wt. % f-MWCNT exhibited best thermal and mechanical properties (except flexural strength) among all the nanocomposites reported here. It showed ~5%, 27% and 126 % improvement in tensile strength, young’s modulus and impact strength respectively as compared to the neat novolac epoxy Kevlar composite.Nanocomposite containing 0.5 wt. % f- MWCNT and 2 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 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 More >

KRISHAN KUMAR PATEL, RAJESH PUROHIT

Journal of Polymer Materials, Vol.36, No.1, pp. 23-37, 2019, DOI:10.32381/JPM.2019.36.01.3

Abstract Microwave (MV)-induced thermo-responsive shape memory thermoplastic polyurethane (SMTPU)/ MWCNT composites were prepared in micro-compounder. Composites containing different amount of multiwall Carbon nanotube (MWCNT) varying from 0 to 1.5 phr in SMTPU matrix were prepared. Maximum stretching strength, recovery force and tensile strength for 1.5 CNTPU (1.5 phr MWCNT in SMTPU matrix) was increased by 120%, 100% and 24% respectively as compared to SMTPU. MV-induced shape memory is a novel approach for fast, clean and remote heating during operation. MWCNT is strong absorber of microwave irradiation so that SMTPU/ MWCNTs nanocomposites successfully triggered by microwave. More >

B.B. Divya^a , G. Manjunatha^a,† , C. Rajashekhar^a, Hanumesh Vaidya^b, K.V. Prasad^c

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-9, 2019, DOI:10.5098/hmt.12.15

Abstract The present paper examines the peristaltic mechanism of a Jeffrey fluid through an elastic tube. The influence of velocity slip, convective boundary conditions, and variable liquid properties are taken into account. Closed form solutions are obtained for velocity, flux and temperature fields. In order to linearize the temperature equation, perturbation technique is employed. Also, the flux is determined theoretically via Rubinow and Keller and Mazumdar approach and the results are compared graphically. The effects of various vital parameters on the fluid flow are sketched and analyzed graphically. The findings emphasize the importance of elastic parameters More >