scholarly journals Characteristics and Properties of Biofilms Made from Pure Carrageenan Powder and Whole Seaweed (Kappaphycus sp.)

Author(s):  
Eunice Lua Hanry ◽  
Noumie Surugau

Petroleum-based plastics are mass produced to meet customers’ demand due to their low cost and versatility. However, plastic waste has become a serious environmental problem. Hence, degradable plastics from renewable sources (e.g. biomass) are now trending for their “green” properties. In this paper, properties of biofilms made from whole seaweed (WS), Kappaphycus sp. and pure kappa-carrageenan powder (PC) were compared. Glycerol, as plasticizer, was added at differing amounts (1%, 2%, 3%, 4% and 5%, v/v) and their appearance, physical and mechanical properties, solubility, and biodegradability were studied. As results, for colour difference and transparency, WS-1% showed higher ?E at 17.09 ± 0.85 with highest opacity at 13.73 mm-1 and least ?E was at 2.73 ± 0.13 for PC-5% with opacity at 0.49 mm-1. For mechanical properties, PC-1% has the highest tensile strength and elastic modulus at 26.63 ± 2.18 MPa and 253.53 ± 19.43 MPa, respectively, whereas WS-5% has the lowest at 0.71 ± 0.15 MPa and 2.47 ± 0.44 MPa, respectively. As for biodegradability, by the first week, WS-5% lost 80% of its weight and PC-1% only lost 3%. Overall, PC biofilms showed better quality in terms of mechanical and physical properties but WS biofilms were faster to degrade and dissolve in water. Glycerol concentration affects most of the properties except for mechanical properties for WS and solubility of both. This study suggests that PC may be a better base material for stronger biofilms but WS are a better choice from environmental and cost aspects.

2017 ◽  
Author(s):  
Arham Rusli

Appropriate concentration of base material and plasticizer is required to obtain good physical and mechanical properties of edible film for food packaging and preservation functions. The aim of this study was to obtain the best combination of the base material and plasticizer in the manufacture of agar films based on physical and mechanical properties. Results showed that the physical and mechanical properties of the agar edible film were affected by the agar and glycerol concentrations. Increasing agar concentrations resulted in the increase in the film thickness, tensile strength (TS), and elongation at break (EAB), but decreased the filmsolubility. While increasing glycerol concentration tended to increase the film thickness and solubility, but decrease the TS of the film. The best concentration combination of agar and glycerol in this study was 3 and 10%, respectively.


2020 ◽  
Vol 27 (3) ◽  
pp. 67-72
Author(s):  
Farouk Mahdi ◽  
Omar Mahmood

Iron-based composites have found a lot of industrial applications such as bearings, camshafts, connecting rods, pulleys, various valves, oil pump gears and many other applications in the automotive and other industries due to their low cost, availability, and high strength. The present study aims to prepare Fe-10 vol.% Cu - (0 – 5) wt.% nano Y2O3 composites by powder metallurgy technique and studying their physical and mechanical properties. The powders were mixed into ball mill for 30 minutes, followed by room temperature uniaxial compaction at 700 MPa for 3 minutes. The green specimens were sintered at 1000 oC for 1 hour. The results of the present study showed that nano yttrium oxide has significant effects on both physical and mechanical properties of Fe-10%Cu composite. The bulk density was increased by 0.92% and the true porosity was decreased by 6.4% on increasing the nano oxide content from 0% to 3% respectively. Vickers microhardness was increased by 5.9% on increasing Y2O3 up to 1% followed by gradual decrease on further increase above 1%. Wear rate was decreased by 21% on increasing the nano oxide content from 0% to 3%. On the other hand, the compressive strength was decreased by 47% on increasing Y2O3 up to 5%


2012 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Djoko Purwanto

Timber Acacia mangium (Acacia mangium, Willd) for Furniture. The study aims to determine the mechanical and physical properties and the decorative value (color and fiber) wood of acacia mangium with using finishing materials. This type of finishing material used is ultran lasur natural dof ,ultran lasur classic teak, aqua politur clear dof, aqua politur akasia dan aqua politur cherry. After finishing the wood is stored for 3 months. Test parameters were observed, namely, physical and mechanical properties of wood, adhesion of finishing materials, color and appearance of the fiber, and timber dimensions expansion. The results showed that the mechanical physical properties of acacia wood qualified SNI. 01-0608-89 about the physical and mechanical properties of wood for furniture, air dry the moisture content from 13.78 to 14.89%, flexural strength from 509.25 to 680.50 kg/cm2, and compressive strength parallel to fiber 342.1 - 412.9 kg/cm2. Finishing the treatment process using five types of finishing materials can increase the decorative value (color and fiber) wood. Before finishing the process of acacia mangium wood has the appearance of colors and fibers and less attractive (scale scores 2-3), after finishing acacia wood fibers have the appearance of colors and interesting and very interesting (scale 4-5).Keywords: mangium wood, mechanical properties, decorative value, finishing, furniture.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1369
Author(s):  
Sanjeev Kumar ◽  
Lalta Prasad ◽  
Vinay Kumar Patel ◽  
Virendra Kumar ◽  
Anil Kumar ◽  
...  

In recent times, demand for light weight and high strength materials fabricated from natural fibres has increased tremendously. The use of natural fibres has rapidly increased due to their high availability, low density, and renewable capability over synthetic fibre. Natural leaf fibres are easy to extract from the plant (retting process is easy), which offers high stiffness, less energy consumption, less health risk, environment friendly, and better insulation property than the synthetic fibre-based composite. Natural leaf fibre composites have low machining wear with low cost and excellent performance in engineering applications, and hence established as superior reinforcing materials compared to other plant fibres. In this review, the physical and mechanical properties of different natural leaf fibre-based composites are addressed. The influences of fibre loading and fibre length on mechanical properties are discussed for different matrices-based composite materials. The surface modifications of natural fibre also play a crucial role in improving physical and mechanical properties regarding composite materials due to improved fibre/matrix adhesion. Additionally, the present review also deals with the effect of silane-treated leaf fibre-reinforced thermoset composite, which play an important role in enhancing the mechanical and physical properties of the composites.


2018 ◽  
Vol 3 (1) ◽  
pp. 80-85
Author(s):  
Ernawati Kawa ◽  
Minsyahril Bukit ◽  
Albert Zicko Johannes

Abstrak Telah dilakukan penelitian tentang penentuan sifat mekanis dan fisis batu bata dengan penambahan tempurung kelapa asal alor. Penenlitian ini bertujuan mengetahui kualitas batu bata yang memenuhi standar kelayakan sebagai bahan konstruksi dengan penambahan arang tempurung kelapa aal alor dengan presentasi 0%, 5%, 10%, 15% terhadap tanah liat (lempung). Batu bata dicetak dengan prosedur pemadatan, pengringn dan pembakaran. Setelah prosedur pencetakkan selesai kemudian di lanjutkan dengan pengujian sefat mekanis dan sifat fisis, yaitu uji kuat tekan (compression strength), densitas (density), porositas (porosity) hasil  kuat tekan batu bata didapatkan berdasarkan pengujian: a) uji kuat tekan, batu bata tanpa penambahan (0%) : 4,94 meemenuhi standar kuat tekan kelas 50 (SNI 15-2094-2000), b) uji porositas, batu bata 0% dan 5% : 3,82% dan 17,93% memenuhi standar porositas dengan batas maksimum 20% (SNI 15-2094-2000) dan uji densitas, batu bata tidak ada yang memenuhi standar (SII 0021-1978) Kata kunci: sifat mekanis, sifat fisis, tempurung kelapa, densitas, porositas, kuat tekan Abstract A research had been conducted to determine physical and mechanical properties of the bricks with the addition coconut shell charcoal from alor. This research aims at the quality of the bricks to meet the standars of eligibility as a contruction material. The addition of coconut shell charcoal is variate with the presentage 0%, 5%, 10%, 15% to the clay mass. The brick being printed with procedure compaction, drying, and baking. After the printing procedure is done then next is testing the mechanical and physical properties, that is compression strength test, density test, and porosity test. The brick quality result is obtained based on the test: a) compression strength test, the brick without addition (0%) : 4,94  (SNI 15-2094-2000) is comply with the standard compression strength the class 50 , b) porosity test, the brick 0% and 5% (3,82% and 17,93%) meet the standard with the maximum limit 20% ( SNI 15-2094-2000)  , and c) density test, every bricks does not meet the standard (SII 0021- 1978). Keywords: mechanical properties, physical properties, coconut shell, density, porosity, compression strength


2021 ◽  
Vol 1043 ◽  
pp. 133-139
Author(s):  
Tolya Khezhev ◽  
Artur Zhurtov ◽  
Alim Kazharov ◽  
Tamerlan Zrumov ◽  
Asharbek Samgurov

The research results on the development of fire-retardant composite cement mortar mixtures on exfoliated vermiculite and volcanic ash with the use of a multifunctional additive are presented D-5. Compositions of fire-retardant composite mortars, which make it possible to significantly improve the physical and mechanical properties of mortar mixtures and mortars, are proposed. Introduction of a multifunctional supplement D-5 in mortar mixtures makes it possible to improve the composite mortar mixtures properties and improve the solution characteristics. Replacement of finely dispersed fraction of exfoliated vermiculite d<0,63 mm volcanic ash by volume in mortar mixtures does not cause a noticeable increase in the solution density, while their strength characteristics increase. The developed composite mortar mixtures meet the requirements of GOST 28013–98 and have a low-cost price due to volcanic ash use.


2017 ◽  
Vol 52 (1) ◽  
pp. 49-52
Author(s):  
Elias ◽  
AK Das ◽  
MM Rahman ◽  
MA Islam

This research intends to explore the mechanical and physical properties of waterlogged rain tree (Samanea saman). The variation of mechanical and physical wood properties grown in waterlogged and non-waterlogged area were studied. Four trees of the species were selected from two areas. Important mechanical and physical properties were examined for the wood of two types of trees Oven dry density for the wood of waterlogged tree was 420 kg/m3 whether it was 550 kg/m3 for the wood of non-waterlogged tree. The MOR of wood of waterlogged tree was 58.2 N/mm2 and wood of non-waterlogged tree produced 78.1 N/mm2. The MOE of the wood of waterlogged tree and non-waterlogged tree were 1478 and 4876 N/mm2. The physical and mechanical properties were lower for the wood of waterlogged tree. Such findings may in proper uses of the species.Bangladesh J. Sci. Ind. Res. 52(1), 49-52, 2017


2019 ◽  
Vol 91 ◽  
pp. 02041
Author(s):  
Sergey Udodov ◽  
Yuriy Galkin ◽  
Philip Belov

Additive manufacturing (3D printing) is becoming more and more common in the field of modern construction. However, for wider implementation of this technology, it is necessary to solve a number of material-oriented scientific problems related to development of concrete composition with targeted rheological, stress-strain, physical and mechanical properties. It has been established that time periods between successful applications of layers play the crucial role in ensuring monolithic features of the “printed” structures. Application of mathematics planning of the experiment allowed establishing the main principles of formation of basic physical and mechanical properties of fine-grained concrete depending on material composition.


Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1145 ◽  
Author(s):  
Jiajia Xu ◽  
Yu Zhang ◽  
Yunfang Shen ◽  
Cong Li ◽  
Yanwei Wang ◽  
...  

Thermal modification (TM) is an ecological and low-cost pretreated method to improve the dimensional stability and decay resistance of wood. This study systematically investigates the relevance between the evolution of chemical structure and the physical and mechanical properties during wood thermal modification processes. Moreover, the volatility of compounds (VOCs) was analyzed using a thermogravimetric analyzer coupled with Fourier transform infrared spectrometry (TGA-FTIR) and a pyrolizer coupled with gas chromatography/mass spectrometer (Py-GC/MS). With an increase of TM temperature, the anti-shrink efficiency and contact angle increased, while the equilibrium moisture content decreased. This result indicates that the dimensional stability improved markedly due to the reduction of hydrophilic hydroxyl (–OH). However, a slight decrease of the moduli of elasticity and of rupture was observed after TM due to the thermal degradation of hemicellulose and cellulose. Based on a TGA-FTIR analysis, the small molecular gaseous components were composed of H2O, CH4, CO2, and CO, where H2O was the dominant component with the highest absorbance intensity, i.e., 0.008 at 200 °C. Based on the Py-GC/MS analysis, the VOCs were shown to be mainly composed of acids, aldehydes, ketones, phenols, furans, alcohols, sugars, and esters, where acids were the dominant compounds, with a relative content of 37.05−42.77%.


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