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1

X-ray diffraction and thermo gravimetric analysis of surface modified areca sheath fibre epoxy composites

Chandrappa Ravi Kumar, Kamath Sakshi Shantharam

Journal of Mechanical and Energy Engineering

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2022

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Vol. 6, No 2

1--6

EN

Focus of the current study is to shed more light on thermal behaviour of composites made up of areca sheath fibres. The XRD analysis revealed that crystallinity index and crystallinity percentage increased with different treatments, as it leads to better interaction of fibre and resin. The crystallinity percentage of alkali treated fibre and benzoyl peroxide treated fibre increased by 5.87 and 8.44% respectively compared to untreated fibre. This was further evident in thermal studies which proved better thermal stability in benzoyl peroxide treated fibre composite.

2

Influence of fiber reinforcement towards the physical characteristics of low density polyethylene laminated composites

Ravichandran S., Raj A. Daniel, Visvanath P. Balaji, Mohammad Faruq, Al-Lohedan Hamad A., Sagadevan Suresh

Polimery

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2020

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T. 65, nr 6

449--457

EN

In recent years, the increased interest in the design and fabrication of lightweight polymer composites with various combinations and stoichiometry is due to their enhancement of electrical, mechanical, thermal, and biological properties compared to the properties of conventional materials. With that view, the present study deals with the effects of low density polyethylene composites (LDPE) reinforced with epoxy resin, glass fiber, carbon fiber, and Kevlar towards the mechanical, thermal, and water absorption properties. The mechanical studies showed that the LDPE composite reinforced carbon fiber has the best tensile properties compared to other composites and this can be mostly due to the proper bonding and associated interaction between the polymeric matrix and the bidirectional layer of the fibers. Also, the carbon fiber reinforced composite has superior properties of impart energy compared to the other composites and the non-reinforced ones and this is attributed to the crystalline nature of carbon fiber. Further studies of the thermal properties indicated that the retention of thermal stability for all the fiber-reinforced polymer composites, while the water absorption revealed a considerable increase in the weight of Kevlar fiber-reinforced composite. From the overall analysis, the enhanced properties of LDPE matrix reinforced fibers are linked to the morphological changes that occurred and are directly affected by the nature of the fiber.

PL

Zwiększone w ostatnich latach zainteresowanie projektowaniem i wytwarzaniem lekkich kompozytów polimerowych wynika z ich lepszych właściwości elektrycznych, mechanicznych, termicznych i biologicznych w porównaniu z cechami materiałów konwencjonalnych. Zbadano wpływ rodzaju wzmocnienia (włókno szklane, włókno węglowe i włókno Kevlar) na właściwości mechaniczne, termiczne i absorpcję wody laminatowych kompozytów polietylenu małej gęstości (LDPE) z żywicą epoksydową. Stwierdzono, że kompozyt LDPE z włóknem węglowym, w porównaniu z innymi kompozytami, wykazuje najlepszą wytrzymałość na rozciąganie, co może wynikać głównie z interakcji polimerowej osnowy z dwukierunkową warstwą włókien. Ponadto kompozyt ten ma większą zdolność przenoszenia energii niż pozostałe badane kompozyty, co można przypisać krystalicznej budowie włókna węglowego. Badania właściwości termicznych wykazały stabilność termiczną wszystkich kompozytów polimerowych wzmocnionych włóknami oraz znaczną absorpcję wody kompozytu wzmocnionego włóknem Kevlar.

3

Synthesis, growth, structural, thermal and third order nonlinear optical properties of novel organic single crystal: 4-methylpyridinium 3-nitrophthalate

Reena Devi S., Suresh S., Kalaiyarasi S., NizamMohideen M., Mohan Kumar R.

Materials Science Poland

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2018

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Vol. 36, No. 4

597--608

EN

A novel 4-methylpyridinium 3-nitrophthalate (4MP3NP) was synthesized and the crystals were grown by using slow evaporation method. The structural data of the grown crystal was collected by single crystal X-ray diffraction. It revealed that the 4MP3NP crystal belongs to triclinic crystal system with a space group P1. Structure of the synthesized compound was established using SHELXL 97 program package. The crystalline nature and composition of the grown crystal was established using high resolution X-ray diffraction and FT-IR analyses. UV-Vis transmittance and photoluminescence studies revealed the optical transmission window and electronic transition mechanism of ions, respectively. The laser damage threshold of the grown crystal was estimated by Nd:YAG laser and these results were mutually related to specific heat capacity of the grown crystal. The third-order nonlinear optical susceptibility of the grown crystal was studied by Z-scan technique.

4

Growth and characterization of NLO crystal: L-leucine phthalic acid potassium iodide

Jagadeesh M. R., Kumar H. M. S., Kumari R. A.

Materials Science Poland

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2015

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Vol. 33, No. 3

529--536

EN

A new semi-organic non linear optical crystal, L-leucine phthalic acid potassium iodide (LLPPI) has been grown from an aqueous solution by slow evaporation method. The grown crystals were subjected to different characterizations, such as single crystal XRD, FT-IR, UV-Vis, TGA, SEM, EDAX, micro hardness, dielectric and powder SHG. Single crystal structure was determined from X-ray diffraction data and it revealed that the crystal belongs to triclinic system with the space group P1. The vibrational frequencies of various functional groups were derived from FT-IR spectrum. Thermal stability of the grown crystal was investigated by TG-DTA studies and it was observed that the crystal was thermally stable up to 192 °C. Optical absorption study was carried out and a good transparency in the entire visible region was observed at the lower cutoff wavelength of 227 nm. Dielectric study was performed as a function of frequency and normal dielectric behavior was observed. The micro hardness test was carried out and the load dependent hardness was measured. Kurtz powder method was employed to explore the NLO characteristics of the grown crystal.

5

Zastosowanie termowizji w badaniach procesu wytłaczania

Sasimowski E.

Postępy Nauki i Techniki

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2011

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nr 8

68-75

PL

Celem badań było określenie wpływu, na temperaturę otrzymywanej wytłoczyny, współdziałania w układzie uplastyczniającym wytłaczarki ślimaka przetwórczego klasycznego lub specjalnego z tuleją obrotową cylindra. Badania przeprowadzono z zastosowaniem specjalnego stanowiska badawczego wyposażonego w wytłaczarkę jednoślimakową z cylindrem o budowie segmentowej, w którego jednym z segmentów umieszczona została tuleja obrotowa cylindra. Za pomocą kamery termowizyjnej podczas wytłaczania PE-LD przeprowadzono pomiary temperatury otrzymywanej wytłoczyny przy zmiennej szybkości obrotowej dwóch badanych ślimaków przetwórczych oraz zmiennej szybkości tulei obrotowej cylindra. Stwierdzono, że zarówno rozwiązanie konstrukcyjne zastosowanego ślimaka oraz jego szybkość, jak również szybkość tulei obrotowej cylindra ma znaczący wpływ na wartości oraz rozkład temperatury otrzymywanej wytłoczyny.

EN

The aim of this study was to determine the effect, the temperature obtained extrudate, interaction in the plasticizing system of extruder the classical screw as well as special screw with rotating sleeve of the barrel. Research was conducted on a special test stand equipped with an extruder with a cylinder on the construction segment, in which one of the segments was placed in the rotating sleeve of the barrel. Using the infrared camera during extrusion of LDPE were obtained extrudate temperature measurements at variable speed the processing of two sample screws and variable rotational speed of the barrel sleeve. It was found that both the design solution used screw and its speed as well as the rotational speed of the barrel sleeve has a significant impact on the value and the temperature distribution obtained extrudate.

6

Synthesis, Characterization and Reactivity of Bis(4-tert-butylphenolato)dichlorotin(IV)

Chaudhry S. C., Bandna K., Bhatt S. S., Sharma N.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 9

1537-1545

EN

The bis(4-tert-butylphenolato)dichlorotin(IV) complex of composition SnCl2(OC6H4But-4)2 (1) has been synthesized by the reaction of tin tetrachloride with bimolar amount of 4-t-butylphenol in benzene under reflux and characterized by elemental analyses, molar conductance measurements, molecular weight determination, IR, 1H, 13C NMR and FAB mass spectral techniques. Thermal behaviour of the complex has been investigated using TG-DTA technique. Lewis acid character of (1) has been explored by isolating its addition compounds with some nitrogeneous bases viz. diethylamine, triethylamine, imidazole, benzimidazole (L); 2,2'-bipyridyl, and 1,10-phenanthroline (B) of composition, SnCl2(OC6H4But-4)2×2L and SnCl2(OC6H4But-4)2×B, characterized by physicochemical and IR spectral studies.

7

Physico-Chemical Studies of Polyurethanes with Dipolar Chromophore

Arora S., Kumar S.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 2

225-235

EN

Polyurethanes with varying concentrations of dipolar chromophore, namely 4-{4-[bis(2- hydroxyethyl) amino] phenylazo} benzonitrile were synthesized and characterized by thermal and spectral techniques. The effect of varying concentrations of dipolar chromophore on physicochemical properties of the polymers was studied. The polymers were obtained with very high yield possessing solubility in polar aprotic solvents like N,N-dimethylformamide, tetrahydrofuran, etc. Molecular weights of the resulting polymers determined by GPC were found to be in the range Mw = 5050–5730 (Mw/Mn =1.89–1.98). DSC curves of the polymers showed absence of melting process, indicating the polyurethanes to be noncrystalline. The synthesized polymers were found to possess high glass transition temperatures (Tg) and high thermal stabilities. Optical band gaps of these polyurethanes were in the range 2.30–2.51 eV. Vacuum-deposited thin films of these polyurethanes were corona-poled to study relaxation behaviour of aligned dipoles. The results indicate that polymeric films possess good temporal stability of aligned dipoles.