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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.

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Surface quality by human inspection

Dekomien K., Huxol A., Riegel A., Ravichandran S., Wagenführ A.

Farby i Lakiery

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2018

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nr 3

42--52

EN

Quality plays a vital role for satisfying the customers and for measuring the reliability of the product. Looking at high gloss surfaces gives an idea of the difficulties in quality inspection. While common measurement techniques like gloss or color measurement are widely used in industry for quality assessment of furniture high gloss surfaces, they indicate only a weak correlation to the quality perceived by the customer. Thus different methods for measurement and sensory evaluation need to be qualified for the application on high gloss surfaces. This report shows how the surface quality of high gloss coated wooden products can be evaluated by means of visual inspection. The evaluation quality is controlled by a developed topography based measuring system. It is possible to find out the reproducibility and repeatability of the operators by implementing six sigma tools such as Analysis of Variance (ANOVA) and Measurement System Analysis (MSA). This method will be highly helpful in the wooden industries since the quality cannot be totally measured, is assessed based on required parameters and it also uses a Hedonic scale for calculating the results, which is quite easier and faster than other methods.

PL

Jakość odgrywa istotną rolę w zaspokajaniu potrzeb klientów i oceny niezawodności produktu. Patrząc na powierzchnie o wysokim połysku mamy wyobrażenie o trudnościach w ich kontroli jakości. Powszechne techniki pomiarowe, takie jak pomiar połysku lub barwy, są szeroko stosowane w przemyśle do oceny jakości powierzchni o wysokim połysku. Wykazują one jednak jedynie słabą korelację z jakością postrzeganą przez klienta. Dlatego też do oceny powierzchni o wysokim połysku muszą być stosowane różne metody pomiaru i oceny sensorycznej. W artykule przedstawiono, w jaki sposób jakość powierzchni drewnianych, powlekanych produktów o wysokim połysku można zbadać za pomocą oceny wizualnej. Jakość oceny jest kontrolowana przez opracowany system pomiaru oparty na topografii. Możliwe jest ustalenie odtwarzalności i powtarzalności operatorów za pomocą narzędzi Six Sigma, takich jak analiza wariancji (ANOVA) i analiza systemu pomiarowego (MSA). Metoda ta będzie bardzo pomocna w przemyśle drzewnym, ponieważ jakość nie może być w pełni zmierzona. Jest ona oceniana na podstawie wymaganych parametrów, a do obliczenia wyników stosuje się skalę hedoniczną, która jest znacznie łatwiejsza i szybsza niż w przypadku innych metod.

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Studies on Schiff Base Complexes of Salicylaldehyde with Sulphamethoxazole and Their Antimicrobial Activities

Sheela C., Gomathi A., Ravichandran S., Tharmaraj P.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 11

1781-1787

EN

New neutral Schiff base complexes of Cu(II), Co(II), Ni(II) and Zn(II) derived from salicylaldehyde and sulphamethoxazole have been synthesized. The structural features of the complexes have been confirmed by microanalytical data, IR, UV-Vis and EPR techniques. The electronic absorption spectra and magnetic susceptibility measurement values of the complexes indicate square-planar geometry for copper and nickel and tetrahedral for cobalt and zinc complexes. The neutral nature of the complexes follows from their low molar conductance values. The EPR spectrum of copper complex in DMSO at 300 K and 77 K was recorded and its salient features are reported. The antimicrobial activity of the complexes has been extensively studied on microorganisms such as Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa by well-diffusion technique using DMSO as a solvent. The values of zone of inhibition were found out at 37 graduateC for a period of 24 h. It has been found that all the studied complexes have higher activity than the free ligand and the standard.

4

New Neutral Schiff Base and Its Metal Complexes Derived from Mannich Base, N-(1-Morpholinobenzyl)acetamideRaman, N.

Raman N., Ravichandran S.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 7

1107-1114

EN

New neutral Schiff base complexes of Cu(II), Co(II), Ni(II) and Zn(II) derived from 4-aminoantipyrine and N-(1-morpholinobenzyl)acetamide (Mannich base) have been synthesized. The structural features of the complexes have been confirmed by microanalytical data, IR, UV-Vis., NMR, EPR, and CV techniques. Electronic absorption spectra of the complexes indicate an octahedral geometry around the metal ion. Their magnetic susceptibility measurements and low conductance data provide evidence for the monomeric and neutral natures of the complexes respectively. The electrochemical behaviour, the anodic and cathodic potential and the number of electrons transferred were calculated using cyclic voltammogram. The X-band EPR spectrum of copper complex in DMSO at 300 K and 77 K was recorded and its salient features are reported. The antimicrobial activity of the ligand and its complexes has been extensively studied on microorganisms such as Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa and the fungi Aspergillus niger and Rhizoctonia bataicola by well-diffusion technique using DMF as solvent. It has been found that all the complexes have higher activity than the free ligand and the standard.

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Studies on Schiff Base Complexes of beta-Diketones/Beta-Ketoesters with 2,4-Dinitrophenylhydrazone and Their Antimicrobial Activities

Raman N., Ravichandran S.

Polish Journal of Chemistry

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2004

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Vol.78 /nr 11-12

2005-2012

EN

2,4-Dinitrophenylhydrazone derivatives of Cu(II), Co(II) and Ni(II) complexes have been synthesized. The structural features of the complexes have been confirmed by microanalytical data, IR,UV-Vis, EPR, CV, TGAand powderXRDtechniques. The electronic absorption spectra and magnetic susceptibility indicate a square-planar geometry for copper and tetrahedral for cobalt and nickel complexes. The neutral nature of the complexes is characterized by their low molar conductance. The cyclic voltammogram of copper complex in DMSO solution shows a quasi-reversible peak. The EPR spectrum of copper complex in DMSO at 300 K and 77 K was recorded and its salient features are reported. The antimicrobial activity of the complexes has been extensively studied on microorganisms such as Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa and the fungi Aspergillus niger and Rhizoctonia bataicola by well-diffusion technique using pyridine as solvent. The values of zone of inhibition were found out at 37°C for a period of 24 h. It has been found that all the product complexes have a higher activity than the parent complexes and the standard.