Pasting, Rheological, and Thermal Properties and Structural Characteristics of Large and Small Arenga pinnata Starch Granules

2020 ◽  
Vol 72 (11-12) ◽  
pp. 1900293
Author(s):  
Jiang‐Yang Mei ◽  
Lu Zhang ◽  
Ying Lin ◽  
Shu‐Bo Li ◽  
Cong‐Hao Bai ◽  
...  
2011 ◽  
Vol 287-290 ◽  
pp. 2648-2651
Author(s):  
Wen Yu Wang ◽  
Xin Jin ◽  
Shuan Qing Hou ◽  
Yu Feng Zhang ◽  
Xiao Xu Sha

The effect of acid modification using 1mol/L HCl on viscosity, thermal properties and mechanical properties of potato starch pastes and starch film were investigated. After acid modification, the surface of starch granules did not show more roughness and viscosity of starch pastes become lower. The results of DSC indicated that acid should act on amorphous region of starch firstly and would act on the crystallization region with the longer treatment time. In the very close viscosity scope, the mechanical properties of starch films were increased obviously after acid modification.


1997 ◽  
Vol 16 (4) ◽  
pp. 303-325 ◽  
Author(s):  
A.A. Hamza ◽  
I.M. Fouda ◽  
M.A. Kabeel ◽  
E.A. Seisa ◽  
F.M. El-sharkawy

2016 ◽  
Vol 96 (3) ◽  
pp. 404-412 ◽  
Author(s):  
Shian Shen ◽  
Hongwei Hou ◽  
Chunbang Ding ◽  
Deng-Jin Bing ◽  
Zhen-Xiang Lu

Protein and starch are two major components in field peas. In this study, we investigated the starch morphologies, compositions, and thermal properties between high protein peas (approximately 30%) and other market types of field peas (yellow, green, maple, and marrowfat peas, with approximately 23% protein contents). For the shape and size, high protein peas had the compound starch granules that could be easily fragmented into small irregular and polygonal granules, whereas other pea types had oval or kidney-like starch granules with high percentage of large granule sizes. High protein peas had significantly lower starch contents (27.2%–34.2%) than other pea types (45.5%–47.4%). However, the amylose content (74.6%–89.2%) in high protein peas were significantly higher that of other pea types (50.1%–54.1%). Our differential scanning calorimeter (DSC) data showed that the onset temperature (To), peak temperature (Tp), and conclusion temperature (Tc) of starch gelatinization in high protein peas were significantly higher than those of other pea types, whereas the enthalpy change (ΔH) of high protein peas was significantly lower than those of other pea types. The unique properties of high protein peas characterized in this study provided useful information to further improve pea quality.


1956 ◽  
Vol 29 (3) ◽  
pp. 789-793
Author(s):  
B. I. Gengrinovich

Abstract The structural characteristics of high polymers and the sharp dependence of their properties on the physical state create a need for a detailed study of these materials in the region where their physical state undergoes a qualitative change. Besides, a study of the phase transitions of high polymers which crystallize is of independent interest. The study of the transition of natural rubber from the oriented crystalline state to the non-oriented amorphous state was the problem of this work. The determination of calorific and thermal properties in the transition region was adopted as the method of investigation. It should be noted that, for rubbers, these properties have been studied to a much lesser extent than have the other thermodynamic properties, particularly the mechanical properties. In order to obtain crystalline rubber, strips of smoked sheet were subjected to repeated rapid stretching at 50°, followed by cooling of the stretched samples to 12–14° C. The stress applied to the rubber during stretching overcomes the deorienting effect of the thermal motion, which impedes the crystallization of non-deformed rubber. At the same time, the heating employed promotes a more complete straightening of the chains since, during heating, intermolecular action diminishes and the chaotically-grouped oriented portions of the macromolecules present in the samples are disrupted. Rapid cooling of the oriented rubber, obtained under such conditions, to temperatures below the melting point of the crystals which formed led to the preservation of the physical state, which was distinguished by an increase of the crystalline phase content, and by a higher degree of orientation, compared with the state of rubber crystallized during the same time by lowering the temperature without stretching. On an average, the extent of stretching amounted to 1400 per cent of the original length.


Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2847 ◽  
Author(s):  
Marta Goliszek ◽  
Beata Podkościelna ◽  
Olena Sevastyanova ◽  
Barbara Gawdzik ◽  
Artur Chabros

This work investigates the impact of lignin origin and structural characteristics, such as molecular weight and functionality, on the properties of corresponding porous biopolymeric microspheres obtained through suspension-emulsion polymerization of lignin with styrene (St) and/or divinylbenzene (DVB). Two types of kraft lignin, which are softwood (Picea abies L.) and hardwood (Eucalyptus grandis), fractionated by common industrial solvents, and related methacrylates, were used in the synthesis. The presence of the appropriate functional groups in the lignins and in the corresponding microspheres were investigated by attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FT-IR), while the thermal properties were studied by differential scanning calorimetry (DSC). The texture of the microspheres was characterized using low-temperature nitrogen adsorption. The swelling studies were performed in typical organic solvents and distilled water. The shapes of the microspheres were confirmed with an optical microscope. The introduction of lignin into a St and/or DVB polymeric system made it possible to obtain highly porous functionalized microspheres that increase their sorption potential. Lignin methacrylates created a polymer network with St and DVB, whereas the unmodified lignin acted mainly as an eco-friendly filler in the pores of St-DVB or DVB microspheres. The incorporation of biopolymer into the microspheres could be a promising alternative to a modification of synthetic materials and a better utilization of lignin.


2019 ◽  
Vol 35 (3) ◽  
pp. 138-148
Author(s):  
Soney C George ◽  
Jiji Abraham ◽  
Thomasukutty Jose ◽  
Riya Thomas ◽  
Teresa Jacob ◽  
...  

In this report, we demonstrate that both mechanical behaviour and thermal stability of polybutadiene rubber (PBR) nanocomposites could be improved by incorporating exfoliated graphite (EG) using melt mixing method. Incorporation of the filler EG in the polybutadiene (PBD) matrix is confirmed by infrared spectra and X-ray diffraction analysis. The structural characteristics, mechanical properties and thermal properties of these newly modified PBR nanocomposites were systematically analysed and studied. Thermal properties of the nanocomposites were studied using thermogravimetric analysis under nitrogen atmosphere. Thermogravimetric studies showed that PBR8 is having higher thermal stability than that of the PBR gum sample. Mechanical properties like tensile strength, Young’s modulus, tear strength, hardness and compression set of the nanocomposites were studied. Mechanical properties are also high for the modified PBR nanocomposites with maximum filler content. The permeability of organic vapours such as dichloromethane (CH2Cl2), chloroform (CHCl3) and carbon tetrachloride (CCl4) through PBR/EG nanocomposites was also studied. In vapour permeation studies, PBR4 exhibits the least permeability in CH2Cl2, CHCl3 and CCl4 solvents. Polybutadiene rubber–natural graphite (PBR/NG) nanocomposites were also prepared for comparison.


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