Jamal N. Al Abbasi¹, Ahmed Z. Afify^2,*, Badr Alnssyan^3,*, Mustafa S. Shama^4,5

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 513-536, 2024, DOI:10.32604/cmes.2024.046533

Abstract This study proposes a new flexible family of distributions called the Lambert-G family. The Lambert family is very flexible and exhibits desirable properties. Its three-parameter special sub-models provide all significant monotonic and non-monotonic failure rates. A special sub-model of the Lambert family called the Lambert-Lomax (LL) distribution is investigated. General expressions for the LL statistical properties are established. Characterizations of the LL distribution are addressed mathematically based on its hazard function. The estimation of the LL parameters is discussed using six estimation methods. The performance of this estimation method is explored through simulation experiments. The usefulness and flexibility of the… More >

Joseph O. Dirisu^1,*, Imhade P. Okokpujie^2,3,*, Olufunmilayo O. Joseph¹, Sunday O. Oyedepo¹, Oluwasegun Falodun⁴, Lagouge K. Tartibu³, Firdaussi D. Shehu¹

Journal of Renewable Materials, Vol.12, No.3, pp. 485-511, 2024, DOI:10.32604/jrm.2024.045188

Abstract Research into converting waste into viable eco-friendly products has gained global concern. Using natural fibres and pulverized metallic waste becomes necessary to reduce noxious environmental emissions due to indiscriminately occupying the land. This study reviews the literature in the broad area of green composites in search of materials that can be used in automotive brake pads. Materials made by biocomposite, rather than fossil fuels, will be favoured. A database containing the tribo-mechanical performance of numerous potential components for the future green composite was established using the technical details of bio-polymers and natural reinforcements. The development of materials with diverse compositions… More > Graphic Abstract

Mingyue Miao^1,#, Fei Wang^1,#, Qing Li¹, Longchen Tao¹, Chenchen Dai¹, Yu Liu¹, Shujuan Han¹, Wenshuai Chen^1,*, Ping Lu^2,*

Journal of Renewable Materials, Vol.12, No.3, pp. 443-455, 2024, DOI:10.32604/jrm.2023.030412

Abstract The rheological properties of nanocellulose aqueous suspensions play a critical role in the development of nanocellulose-based bulk materials. High-crystalline, high-aspect ratio, and slender nanofibrillated cellulose (NFC) were extracted from four biomass resources. The cellulose nanofibrils and nanofibril bundles formed inter-connected networks in the NFC aqueous suspensions. The storage moduli of the suspensions with different concentrations were higher than their corresponding loss moduli. As the concentration increased, the storage and loss modulus of NFC dispersion increased. When the shear rate increased to a certain value, there were differences in the changing trend of the rheological behavior of NFC aqueous suspensions derived… More > Graphic Abstract

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 >

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 bacteria. This activity increases with… 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 >

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 wt. % poly (vinyl butyral)… 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 >

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 >