scholarly journals Preparation and Characterization of K-Carrageenan/Nanosilica Biocomposite Film

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Lokesh R. Rane ◽  
Niranjan R. Savadekar ◽  
Pravin G. Kadam ◽  
Shashank T. Mhaske

The purpose of this study is to improve the performance properties of K-carrageenan (K-CRG) by utilizing nanosilica (NSI) as the reinforcing agent. The composite films were prepared by solution casting method. NSI was added up to 1.5% in the K-CRG matrix. The prepared films were characterized for mechanical (tensile strength, tensile modulus, and elongation at break), thermal (differential scanning calorimetry, thermogravimetric analysis), barrier (water vapour transmission rate), morphological (scanning electron microscopy), contact angle, and crystallinity properties. Tensile strength, tensile modulus, and crystallinity were found to have increased by 13.8, 15, and 48% whereas water vapour transmission rate was found to have decreased by 48% for 0.5% NSI loaded K-CRG composite films. NSI was found to have formed aggregates for concentrations above 0.5% as confirmed by scanning electron microscopy. Melting temperature, enthalpy of melting, and degradation temperature of K-CRG increased with increase in concentration of NSI in K-CRG. Contact angle also increased with increase in concentration of NSI in K-CRG, indicating the decrease in hydrophilicity of the films improving its water resistance properties. This knowledge of the composite film could make beneficial contributions to the food and pharmaceutical packaging applications.

2013 ◽  
Vol 718-720 ◽  
pp. 176-185 ◽  
Author(s):  
Kimmo Hämäläinen ◽  
Timo Kärki

Wood-plastic composites are a group of materials with potential to penetrate markets currently dominated by plastic or wood products. The surface properties of wood-plastic composite materials have been found to be similar to those of polyolefin materials, thereby presenting a challenge to the use of adhesive joining methods. Plasma chemistry can be performed to improve the adhesive properties of polyolefin materials. In this research, the effect of atmospheric plasma treatment on polypropylene and spruce (Picea abies) wood-plastic composite surfaces is investigated by contact angle measurement with sessile drop method and tensile strength tests of glued samples. The plasma treatment is performed on extruded WPC profiles. Confocal Raman microscopy and scanning electron microscopy are used for analysis of the material surface. The results show an increase in the contact angle of plasma treated WPC materials and an improvement in the tensile strength of glued samples following plasma treatment. Observation of the Raman spectrum indicates an increase in polar groups after plasma treatment. Scanning electron microscopy shows changes in the surface of the treated samples, which can be seen as increased porosity, possibly due to etching as a result of the plasma treatment. It is concluded that atmospheric plasma treatment for adhesion improvement of WPC materials can therefore be applied successfully, although it has a mechanical effect on the surface of the material.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2174
Author(s):  
Diana Gregor-Svetec ◽  
Mirjam Leskovšek ◽  
Blaž Leskovar ◽  
Urška Stanković Elesini ◽  
Urška Vrabič-Brodnjak

Polylactic acid (PLA) is one of the most suitable materials for 3D printing. Blending with nanoparticles improves some of its properties, broadening its application possibilities. The article presents a study of composite PLA matrix filaments with added unmodified and lignin/polymerised lignin surface-modified nanofibrillated cellulose (NFC). The influence of untreated and surface-modified NFC on morphological, mechanical, technological, infrared spectroscopic, and dynamic mechanical properties was evaluated for different groups of samples. As determined by the stereo and scanning electron microscopy, the unmodified and surface-modified NFCs with lignin and polymerised lignin were present in the form of plate-shaped agglomerates. The addition of NFC slightly reduced the filaments’ tensile strength, stretchability, and ability to absorb energy, while in contrast, the initial modulus slightly improved. By adding NFC to the PLA matrix, the bending storage modulus (E’) decreased slightly at lower temperatures, especially in the PLA samples with 3 wt% and 5 wt% NFC. When NFC was modified with lignin and polymerised lignin, an increase in E’ was noticed, especially in the glassy state.


2013 ◽  
Vol 750-752 ◽  
pp. 1919-1923 ◽  
Author(s):  
Guo Xian Zhou ◽  
Ming Wei Yuan ◽  
Lin Jiang ◽  
Ming Long Yuan ◽  
Hong Li Li

The laponite-poly (L-lactide) composite films are prepared by the method of solution blending with polylactide (PLA) and laponite. The result shows that the homogeneous and smooth composite film is prepared with 1, 4-dioxane. Thermogravimetry analysis (TG) and tensile strength studies demonstrate that the thermal stability and tensile strength are improved with the laponite added. The scanning electron microscopy (SEM) measurement indicates that the pores of composite films get uniform and network structure is more and more compact with compared to pure PLA film. The present study reveals that the laponite as a complexing agent can improve the mechanical properties and thermal stability of PLA.


2018 ◽  
Vol 186 ◽  
pp. 02001
Author(s):  
Teng-wei Zhu ◽  
Cheng-liang Miao ◽  
Zheng Cheng ◽  
Zhipeng Wang ◽  
Yang Cui ◽  
...  

The influence of the mechanical properties of X70 pipeline steel under different annealing temperature was studied. The corresponding microstructure was investigated by the Field Emission Scanning Electron Microscopy. The results showed that the yield strength and the tensile strength both experienced from rise to decline with the increase of annealing temperature. The grain sizes were coarse and a large amount of cementite precipitated due to preserving temperature above 550 °, which induced matrix fragmentation and deteriorate the -10 ° DWTT Toughness. There were little changes on the microstructure and mechanical properties when the annealing temperature was under 500 °.


2010 ◽  
Vol 8 (1) ◽  
pp. 1-10
Author(s):  
ARINDA KARINA RACHMAWATI ◽  
R. BASKORO KATRI ANANDITO ◽  
GODRAS JATI MANUHARA

Rachmawati AK, Anandito RBK, Manuhara GJ. 2010. Extraction and characterization of pectin on green cincau (Premna oblongifolia) in edible film production. Biofarmasi 8: 1-10. The use of green cincau pectin was presumed to influence the result of edible film characteristics, i.e. thickness, solvability, elongation, tensile strength, and water vapour transmission (WVTR). The aims in this research were: (i) to find out the chemical characteristics of green cincau pectin on the physical (thickness and solvability) and mechanical properties (elongation and tensile strength), (ii) to determine the edible film inhibition of green cincau pectin against the water vapour transmission rate, and (iii) to find out the edible film capability in inhibiting the weight loss on green grape by wrapping and coating method. The five major steps in this research were material preparation (making green cincau powder and pectin extraction), the characterization of extraction result pectin, making edible film, edible film characterization, and edible film application. This research used a completely randomized design with twice replications in edible film making for each treatment concentration and twice replication for edible film characteristic testing in each edible film making replication. Variance analysis was used to analyze data, if there was a significant difference, it will be continued with a Duncan Multiple Range Test at a significance level of 0.05. The yield of green cincau powder and pectin were 27.5% and 15.2%, respectively. The extraction result pectin consisted of 5.09% water, 11.06% protein, 0.35% fat, 28.5% ash, 55.00% carbohydrate (by different), and 12.15% crude fiber. The increasing of pectin concentration tends to increase the thickness and tensile strength, but reduced the water vapour transmission rate. The lowest water vapour transmission rate occurred at the edible film with 30% pectin concentration. Its water vapour transmission rate was 0.317 g.mm/m2.hour. The green grape weight loss with a wrapping method was 0.0212 g/hour, and the green grape weight loss with a coating method was 0.0634 g/hour.


2011 ◽  
Vol 194-196 ◽  
pp. 1740-1744 ◽  
Author(s):  
Qiu Hong Wang ◽  
Gu Huang

Flax fabric was woven and composites were produced by using the VARI technique with flax fabric as the reinforcement and unsaturated polyester as the matrix. Laminates with two, three and four layers were fabricated respectively. After saturated in the water for different durations of time (7, 14, 21 and 30 days), the tensile strength of the composites was tested. After being soaked in the water for 7, 14 and 21 days, the tensile strength of the two-layer composites was decreased. For the three and four layers specimens, the tensile strength was increased initially with water treatment for 7 and 14 days,and decreased for 21 and 30 days. Scanning electron microscopy (SEM) confirmed that it might be contributed to the thickness of the two-layer composites. The thinner specimen is easier to be damaged by the penetrated moisture owing to the delamination between the fiber and the matrix after water immersion. For the three and four layers specimens, their contradictory tensile strength suggests that the thicker specimen can delay the moisture permeation and is of better water durability.


2018 ◽  
Vol 38 (7) ◽  
pp. 641-647
Author(s):  
Jean Aimé Mbey ◽  
Fabien Thomas ◽  
Sandrine Hoppe

Abstract In the present study, a combined use of photonic microscopy, scanning electron microscopy and 3D X-ray tomography is carried out in order to analyze the dispersion and the distribution of raw and dimethyl sulfoxide (DMSO)-intercalated kaolinite used as filler in cassava starch-based films. It is shown that the association of these techniques allows a valuable analysis of clay dispersion in polymer-clay composite films. In the case of kaolinite-starch composite films on which this study is focused, it is obvious that previous intercalation of kaolinite with DMSO is an efficient way to improve dispersion and distribution of kaolinite in a starch polymer matrix.


2019 ◽  
Vol 33 (11) ◽  
pp. 1466-1477
Author(s):  
Qingfa Zhang ◽  
Wenyu Lu ◽  
Liang Zhou ◽  
Donghong Zhang ◽  
Hongzhen Cai ◽  
...  

Biocomposites were prepared with corn straw slagging (CSS) and high-density polyethylene (HDPE) at four loading levels (10, 20, 30, and 40 wt%) by extrusion method. CSS/HDPE composites were tested by tension, oxygen index meter, differential scanning calorimetry, X-ray diffraction, and the scanning electron microscopy. The scanning electron microscopy showed that CSS was dispersed uniformly in the HDPE matrix and strong interfacial interaction was achieved, which had an important influence on the tensile strength of the composites. The tensile strength of the composites could be improved with proper increase of CSS and reached maximum value at 30 wt% content. Furthermore, the addition of CSS played an important role in improving the flame-retardant ability of CSS/HDPE composites, and the limited oxygen index was 31.26% at 40 wt% content, good flame-retardant effect achieved.


2019 ◽  
Vol 815 ◽  
pp. 139-144
Author(s):  
Tao Mu

In this paper, acrylic acid was grafted to chitosan in order to change the structure; polymer was obtained from modified chitosan. A series of novel toughened composite NF memebranes were prepared by over-coating the polysulfone ultrafiltration membrane with the polymer of modified chitosan. The chitosan derivatives and the polymer were characterised by infrared spectrophotometer (IR); the structure of the membrane was characrerised by scanning electron microscopy (SEM) and atomic force microscope (AFM). The composite NF membrane’s performances were strictly related to the structure of polymer. The rejection of the membrane was 96.3% with flux as high as 386.46 L m-2 h-1 with the 1000 mg/L of NaCl. Tensile strength of membrane increased 46%. The HCl (5%) resistance increased from 20.3 to 36.8h. The NaOH (5%) resistance increased from 18.3 to 31.6h. These results indicated the prepared toughened composite NF memebrane was excellent NF membrane, which had a wide application prospect.


2020 ◽  
Vol 861 ◽  
pp. 378-382
Author(s):  
Sophoan Phal ◽  
Muhammad Rafiullah Khan ◽  
Pattarin Leelaphiwat ◽  
Vanee Chonhenchob

Sodium alginate based films containing turmeric oil (TEO) at different concentrations (1, 2 and 3%) were developed. The film with no TEO was used as control. Incorporation of TEO had the effects on the film properties. With increasing TEO concentrations, thickness, elongation at break, permeability of oxygen and water vapor of the films significantly (p ≤ 0.05) increased. Whereas moisture content, tensile strength and modulus of elasticity significantly (p ≤ 0.05) decreased. Scanning electron microscopy (SEM) analysis showed more numerous pores and rougher surface of the antifungal films than the control film.


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