scholarly journals Preparation of sago starch-based biocomposite reinforced microfibrillated cellulose of bamboo assisted by mechanical treatment

Author(s):  
S. Silviana ◽  
H. Hadiyanto
REAKTOR ◽  
2017 ◽  
Vol 17 (3) ◽  
pp. 151 ◽  
Author(s):  
Silviana Silviana ◽  
Puji Rahayu

Sago starch based bioplastics as food packaging have drawbacks such as soft, and easily broken. This paper explains improvement of sago starch-based bioplastics reinforced with bamboo microfibrillated cellulose (MFC). Furthermore, this paper investigates effect of dispersing agent on mechanical property by using of potassium chloride (KCl) assisted by ultrasonic homogenizer. Variable used experiments were bamboo MFC concentration of 1%; 3% and 5% w/w and KCl concentration of 1%; 2% dan 3% w/v. Sago starch-based solution was prepared from 4% w/v of commercial sago starch. The mixed solution was gelatinized at temperature of 90 oC. The result showed that the 5% of bamboo MFC increased tensile strength of sago starch-based bioplastics due to purpose of bamboo MFC as reinforcement of sago starch. Further, additional of KCl reduced the dispersing time for 1 hour. Optimum result in this preliminary experiment was obtained at bamboo MFC of 5% w/w and KCl concentration of 1% w/v resulting tensile strength of 17.99 MPa.


2020 ◽  
Vol 18 (2) ◽  
pp. 37
Author(s):  
Yuli Darni ◽  
Lia Lismeri ◽  
Muhammad Hanif ◽  
Sarkowi Sarkowi ◽  
Dita Synthauli Evaniya

Abstrak. Penelitian ini membahas tentang pengaruh rasio pati terhadap kitosan (dalam basis berat) dan konsentrasi microfibrillated cellulose sebagai filler dalam pembuatan bioplastik menggunakan pati sorgum, kitosan dan gliserol. Dalam penelitian ini, rasio pati terhadap kitosan yang divariasikan adalah 10:0, 9,5:0,5, 8,5:1,5, 7,5:2,5, 6,5:3,5, 5,5:4,5 (gr/gr). Microfibrillated cellulose sebagai filler disintesis dari batang sorgum dengan metode semimekanis. Perlakuan kimia diawali dengan delignifikasi batang sorgum dengan KOH 4% pada temperatur 80oC selama 1 jam untuk menghilangkan lignin. Setelah itu dicuci dan dipucatkan (bleaching) sebanyak dua kali menggunakan H2O2 6% pada suhu 70oC. Serbuk batang sorgum yang sudah kering dilanjutkan dengan perlakuan mekanis yaitu dimasukkan ke dalam disk mill  selama 90 menit dan dilanjutkan dengan high energy milling (HEM) untuk mengecilkan ukurannya sampai dengan rata-rata 4-8 µm. Filler ditambahkan, dan konsentrasinya (dalam basis berat) divariasikan dari 0, 1, 2, dan 3 %. Pati dan kitosan berukuran 63 mikron (lolos ayakan), waktu  pengadukan selama 35 menit pada kecepatan 375 rpm, dan penambahan 10% berat gliserol sebagai plasticizer dijaga konstan. Hasil terbaik pada penelitian ini diperoleh pada formulasi 8,5:1,5 (gr/gr). dan konsentrasi filler 3%. Produk bioplastik ini memiliki kuat tarik 11,64 MPa, persen perpanjangan 10,98%, modulus Young 105,96 MPa, densitas 0,915 gr/ml, dan penyerapan air  38,3%. Kata kunci: bioplastik, gliserol, kitosan, microfibrillated cellulose, sorgum. Abstract. The Improving of Bioplastic Tensile Strength with Microfibrillated Cellulose Filler from Sorghum Stem. This study discusses the effect of starch on chitosan ratio (in weight basis) and also the concentration of microfibrillated cellulose as a filler in the preparation of bioplastics using sorghum starch, chitosan, and glycerol. In this study, the ratio of starch to chitosan varied was 10:0, 9.5:0.5, 8.5:1.5, 7.5:2.5, 6.5:3.5, 5.5:4,5 (gr/gr). Microfibrillated cellulose as filler was encouraged from the sorghum stem by the semi-mechanical method. The delignification of sorghum stem initiated chemical treatment with a 4% KOH solution on 80oC for 1 hour to remove lignin. Bleaching is done after delignification using 6% H2O2 at 70oC. The dried sorghum powder is further followed by mechanical treatment that is put into disk mill for 90 minutes and continued with high energy milling (HEM) to reduce its size to an average of 4-8 µm. The filler is added, and the concentration (on a weight basis) varies from 0, 1, 2, and 3%. Starch and chitosan measuring 63 microns (sieve pass), stirring time for 35 minutes at a speed of 375 rpm, and the addition of 10% by weight of glycerol as a plasticizer is kept constant. The best results in this study were obtained in formulations 8.5:1.5 (gr/gr) and 3% filler concentration. This bioplastic product has 11.64 MPa tensile strength, 10.98% elongation, 105.96 MPa Young moduli, 0.915 gr/ml density, and 38.3% water uptake. Keywords: bioplastic, chitosan, glycerol, microfibrillated cellulose, sorghum.Graphical Abstract 


Author(s):  
L.E. Murr

Ledges in grain boundaries can be identified by their characteristic contrast features (straight, black-white lines) distinct from those of lattice dislocations, for example1,2 [see Fig. 1(a) and (b)]. Simple contrast rules as pointed out by Murr and Venkatesh2, can be established so that ledges may be recognized with come confidence, and the number of ledges per unit length of grain boundary (referred to as the ledge density, m) measured by direct observations in the transmission electron microscope. Such measurements can then give rise to quantitative data which can be used to provide evidence for the influence of ledges on the physical and mechanical properties of materials.It has been shown that ledge density can be systematically altered in some metals by thermo-mechanical treatment3,4.


Author(s):  
O.N. Negreba ◽  
◽  
E.V. Bondarenko ◽  
M.A. Belik ◽  
T.A. Yurina ◽  
...  

The article presents the results of research on modern technologies for weed control in production crops of corn for grain. The best results were obtained in the basic version of technology No. 5 with the following plant protection system: mechanical treatment of crops (cross-row harrowing and three row-to-row cultivation) in combination with chemical treatment with the herbicide Mаister-150 g/ha.


2017 ◽  
Author(s):  
Akwasi Asamoah

<p>One sample of 1D bundle of cellulose microfibrils in the form of lignified flax fibre (0.10526 mm x 10 mm), and one 2D networks of cellulose microfibrils in the form of tunicate cellulose (0.07 mm x 5 mm x 10 mm), bacterial cellulose (0.135 mm x 5 mm x 10 mm) and microfibrillated cellulose (0.08 mm x 5 mm x 10 mm) were put on a glass slide parallel to the principal spectrometer axis. Raman spectra were measured all round in-plane under both half (in 5° steps) polarisation from 0° to 360° in extended mode between 100 cm<sup>-1</sup> and 1150 cm<sup>-1</sup> in 3 accumulations at 10s exposure and 100% laser power. The cursor was placed at the peak of the 1095 cm<sup>-1</sup> band, and intensity read.</p>


Author(s):  
A. S. Oryshchenko ◽  
V. A. Malyshevsky ◽  
E. A. Shumilov

The article deals with modeling of thermomechanical processing of high-strength steels at the Gleeble 3800 research complex, simulating thermomechanical processing with various temperature and deformation parameters of rolling and with accelerated cooling to a predetermined temperature. The identity of steel hardening processes at the Gleeble 3800 complex and specialized rolling mills, as well as the possibility of obtaining steels of unified chemical composition, are shown.


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