scholarly journals Characterization of foams obtained from cassava starch, cellulose fibres and dolomitic limestone by a thermopressing process

2010 ◽  
Vol 53 (1) ◽  
pp. 185-192 ◽  
Author(s):  
Vivian Consuelo Reolon Schmidt ◽  
João Borges Laurindo

Cassava starch, dolomitic limestone and eucalypt cellulose fibres were used to prepare foam trays that could be used to pack foodstuffs. The influence of the cellulose fibre concentration in the composite formulation was investigated using 5, 10, 15, 20, 30 and 40% of fibres. The results indicated that an increase in cellulose fibre concentration promoted a decrease in density and tensile strength of the foam samples. The tensile strength at break for foam trays containing 5% of cellulose fibres was 3.03MPa, whilst the commercial trays of expanded polystyrene used to pack foods in supermarkets presented a tensile strength of 1.49 MPa. The elongation at break of the foam trays obtained in this work varied slightly with increase in cellulose fibre concentration, the values being about 20% lower than the elongation at break observed for commercial foam trays of expanded polystyrene. Thus, the materials developed in this work represented a possible alternative to the use of EPS foam trays for packing dry foods. The trays' properties need to be improved for their use with moist foods.

2011 ◽  
Vol 194-196 ◽  
pp. 484-487 ◽  
Author(s):  
Xian Zhong Mo ◽  
Chen Mo ◽  
Xiang Qi ◽  
Ren Huan Li

Biopolymer cassava starch(ST)-chitosan(CS)/montmorillonite(MMT) nanocomposites were prepared in which MMT was used as nanofiller and diluted acetic acid was used as solvent for dissolving and dispersing cassava starch, chitosan and MMT. XRD and TEM results indicated the formation of an exfoliated nanostructure of ST-CS/MMT nanocomposites. Mechanical properties testing revealed that at the range of the MMT content from 1wt% to 5wt%, tensile strength of the composites increased from 30MPa to 37.5MPa. But the elongation at break fall from 28% to 22% with the increasing of MMT. Obviously, MMT had an enforced effect to the composites. TGA results showed that the nano-dispersed MMT improved the thermal stability of the matrix systematically with the increasing of MMT.


2020 ◽  
Vol 21 (8) ◽  
pp. 741-747
Author(s):  
Liguang Zhang ◽  
Yanan Shen ◽  
Wenjing Lu ◽  
Lengqiu Guo ◽  
Min Xiang ◽  
...  

Background: Although the stability of proteins is of significance to maintain protein function for therapeutical applications, this remains a challenge. Herein, a general method of preserving protein stability and function was developed using gelatin films. Method: Enzymes immobilized onto films composed of gelatin and Ethylene Glycol (EG) were developed to study their ability to stabilize proteins. As a model functional protein, β-glucosidase was selected. The tensile properties, microstructure, and crystallization behavior of the gelatin films were assessed. Result: Our results indicated that film configurations can preserve the activity of β-glucosidase under rigorous conditions (75% relative humidity and 37°C for 47 days). In both control films and films containing 1.8 % β-glucosidase, tensile strength increased with increased EG content, whilst the elongation at break increased initially, then decreased over time. The presence of β-glucosidase had a negligible influence on tensile strength and elongation at break. Scanning electron-microscopy (SEM) revealed that with increasing EG content or decreasing enzyme concentrations, a denser microstructure was observed. Conclusion: In conclusion, the dry film is a promising candidate to maintain protein stabilization and handling. The configuration is convenient and cheap, and thus applicable to protein storage and transportation processes in the future.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yongfang Qian ◽  
Zhen Zhang ◽  
Laijiu Zheng ◽  
Ruoyuan Song ◽  
Yuping Zhao

Design and fabrication of nanofibrous scaffolds should mimic the native extracellular matrix. This study is aimed at investigating electrospinning of polycaprolactone (PCL) blended with chitosan-gelatin complex. The morphologies were observed from scanning electron microscope. As-spun blended mats had thinner fibers than pure PCL. X-ray diffraction was used to analyze the degree of crystallinity. The intensity at two peaks at 2θof 21° and 23.5° gradually decreased with the percentage of chitosan-gelatin complex increasing. Moreover, incorporation of the complex could obviously improve the hydrophilicity of as-spun blended mats. Mechanical properties of as-spun nanofibrous mats were also tested. The elongation at break of fibrous mats increased with the PCL content increasing and the ultimate tensile strength varied with different weight ratios. The as-spun mats had higher tensile strength when the weight ratio of PCL to CS-Gel was 75/25 compared to pure PCL. Both as-spun PCL scaffolds and PCL/CS-Gel scaffolds supported the proliferation of porcine iliac endothelial cells, and PCL/CS-Gel had better cell viability than pure PCL. Therefore, electrospun PCL/Chitosan-gelatin nanofibrous mats with weight ratio of 75/25 have better hydrophilicity mechanical properties, and cell proliferation and thus would be a promising candidate for tissue engineering scaffolds.


2021 ◽  
Vol 23 (1) ◽  
pp. 16
Author(s):  
Vienna Saraswaty ◽  
Rossy Choerun Nissa ◽  
Bonita Firdiana ◽  
Akbar Hanif Dawam Abdullah

THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES. The government policy to wear a face mask during the COVID-19 pandemic has increased disposable face mask wastes. Thus, to reduce such wastes, it is necessary to evaluate the physicochemical characteristics of disposable face masks wastes before the recycling process and the recycled products. In this study, physicochemical characterization of the 3-ply disposable face masks and the recycled plastic pellets after disinfection using 0.5% v/v sodium hypochlorite were evaluated. A set of parameters including the characterization of surface morphology by a scanning electron microscope (SEM), functional groups properties by a fourier transform infra-red spectroscopy (FT-IR), thermal behavior by a differential scanning calorimetry (DSC), tensile strength and elongation at break were evaluated. The surface morphological of each layer 3-ply disposable face mask showed that the layers were composed of non-woven fibers. The FT-IR evaluation revealed that 3-ply disposable face mask was made from a polypropylene. At the same time, the DSC analysis found that the polypropylene was in the form of homopolymer. The SEM analysis showed that the recycled plastic pellets showed a rough and uneven surface. The FT-IR, tensile strength and elongation at break of the recycled plastic pellets showed similarity with a virgin PP type CP442XP and a recycled PP from secondary recycling PP (COPLAST COMPANY). In summary, recycling 3-ply disposable face mask wastes to become plastic pellets is recommended for handling disposable face mask wastes problem.


2019 ◽  
Vol 35 (1) ◽  
pp. 221-227
Author(s):  
Maulida Lubis ◽  
Mara Bangun Harahap ◽  
Iriany Iriany ◽  
Muhammad Hendra S. Ginting ◽  
Iqbal Navissyah Lazuardi ◽  
...  

Cooking oil waste that has been disposed could contamine the environment. However, if it is processed well, it can potentially become a raw material of polyurethane. The aim of this study was to determine the best polyurethane on the tensile strength, impact strength, elongation at break, water absorption, characterization of Fourier Transform Infra-Red (FTIR) and the characterization of Scanning Electron Microscopy (SEM). The variables used in this study were ambient process temperature with 440 rpm stirring speed, 1-minute stirring time, the ratio of polyoland WCO was 7:3 (% w/w), and the ratio of Toluene Diisocyanate (TDI) and WCO was 1:1; 1:2; 1:3; 1:4 (% w/w). The results obtained from the analysis of the best tensile strength against the polyurethane synthetic was in the 1:1 ratio of mixed variations between oil and TDI with a value of 0.403 MPa. The best impact strength was in the ratio of mixed variations between oil and TDI with 1:4 (% w/w) with a value of 600.975 J/m2. The best elongation at break against polyurethane foam synthetic was in the 1:3 ratio of mixture variations of oil and TDI with a value of 4.506%.


2019 ◽  
Vol 131 ◽  
pp. 01052
Author(s):  
Yu Wang

Nanocellulose fibres can be hand-spun from different intermediate states, such as nanocellulose paper and filter cake, which are made from the BC suspension as well as wet pellicle (WP) and dry pellicle (DP) from BC pellicles. In this study, it can be concluded that increasing the hanging weight can increase the Young’s modulus and the tensile strength of fibres. Nanofibres produced from BC pellicles as raw material have better performance than those made from BC suspension. The best properties obtained from the fibres produced from wet pellicles and suspended to a 100g hanging weight upon drying are Young’s modulus (33.8 GPa), tensile strength (610 MPa) and elongation at break (3.6%).


2017 ◽  
Vol 26 (5) ◽  
pp. 096369351702600 ◽  
Author(s):  
Wenjing Xia ◽  
Nianqing Zhu ◽  
Zhongbin Ni ◽  
Mingqing Chen

Biodegradable composites from poly (butylene succinate-co-butylene adipate) (PBSA) and Taihu Lake (Wuxi, China) blue algae were prepared by melt blending. The property and structure of biocomposites were investigated. By adding extra amount of water to blue algae, the formulated blue algae acted as a plastic in the composites during blending, and exhibited a reinforcing effect on the PBSA matrix. With increasing blue algae content, the thermal stability of the composites decreased; the tensile strength at break and elongation at break of the composites reduced, but the Young's modulus of the composites increased. However, the composite with 30% blue algae loading still exhibited good mechanical performance (tensile strength at break of 21.3 MPa, elongation at break of 180%). The fabrication of value-added PBSA/algae composites appeared as an effective approach to reduce the secondary environmental pollution of Taihu blue algae.


2014 ◽  
Vol 931-932 ◽  
pp. 68-72
Author(s):  
Komsun Temna ◽  
Nitinart Saetung ◽  
Anuwat Saetung

In this work, the sponge rubbers based on cassava starch masterbatch in latex phase with the difference technique (non-gelatinized and gelatinized cassava starch) were preformed. The cassava starch contents from 0 to 70 phr were also studied. The cure characteristic, mechanical and morphological properties were investigated. It was found that the scorch time and cure time were increased with an increasing of cassava starch contents in both techniques. The mechanical properties i.e., tensile strength, elongation at break and tear strength were decreased with an increasing of cassava starch contents, except 500% modulus. However, the sponge based on gelatinized technique gave the better mechanical properties than that of non-gelatinized cassava starch. The SEM micrographs of sponge NR from gelatinized technique were also able to confirm a good interfacial interaction between hydrophilic cassava starch and hydrophobic NR.


2020 ◽  
Vol 2 (1) ◽  
pp. 34-41
Author(s):  
Syahrul Humaidi

This study investigated the characteristics of a conductive plastic based on root starch and CuSO4 filler. The mixture variation was (95:5)%; (90:10)%; (85:15)%; (80:20)% and (75:25)%. Glycerol is used to change the material as desired (plasticizer) which is called a plasticizer. The method used in the manufacture of this material is melt intercalation. Mechanical testing includes tensile strength (tensile strength) and elongation at break. Thermal testing was done using DTA (Differential Thermal Analysis) and material conductivity testing. The characterization results showed that the optimum starch composition: CuSO4 (75:25)% had a conductivity value of 7.3 x 10-2S.m-1, a thermal test value of 410ºC. The optimum tensile strength value occurs in the composition (80:20)% with a value of 4.606 MPa


2011 ◽  
Vol 284-286 ◽  
pp. 459-463 ◽  
Author(s):  
Yuan Yuan Qi ◽  
Bin Liu ◽  
Xing Bin Yan

Nanofibrous scaffolds of PVA and HA were prepared by electrospinning. SEM showed the scaffolds had porous nanofibrous morphology, and the diameter of the fibers was in the range of 200-1000 nm. FTIR and XRD showed the presence of HA in the scaffolds. The mechanical properties of the scaffolds changed by the adding content of HA. For the nanoscaffolds with 2wt % HA, the ultimate tensile strength and the elongation at break was 7.5 MPa and 17%. The PVA/HA nanoscaffolds prepared by electrospinning indicated good properties, and had a potential applications in bone tissue engineering and drug delivery systems.


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