scholarly journals Development of Thermoplastic Starch (TPS) Including Leather Waste Fragments

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1811 ◽  
Author(s):  
Silvio Pompei ◽  
Jacopo Tirillò ◽  
Fabrizio Sarasini ◽  
Carlo Santulli
Keyword(s):  
Electron Microscopy ◽  
Dry Matter ◽  
Corn Starch ◽  
Tensile Tests ◽  
Thermoplastic Starch ◽  
Maximum Temperature ◽  
Material Degradation ◽  
Brittle Behavior ◽  
Leather Waste ◽  
Scanning Electron

A thermoplastic starch (TPS) material is developed, based on corn starch plasticized with glycerol and citric acid in a 9:3:1 ratio and further bonded with isinglass and mono- and diglycerides of fatty acids (E471). In TPS, leather fragments, in the amount of 7.5 15 or 22.5 g/100 g of dry matter, were also introduced. The mixture was heated at a maximum temperature of 80 °C, then cast in an open mold to obtain films with thickness in the range 300 ± 50 microns. The leather fragments used were based on collagen obtained from production waste from shoemaking and tanned with tannins obtained from smoketree (Rhus cotinus), therefore free from chromium. Thermogravimetric (TGA) tests suggested that material degradation started at a temperature around 285 °C, revealing that the presence of leather fragments did not influence the occurrence of this process in TPS. Tensile tests indicated an increase in tensile properties (strength and Young’s modulus) with increasing leather content, albeit coupled, especially at 22.5 wt%, with a more pronounced brittle behavior. Leather waste provided a sound interface with the bulk of the composite, as observed under scanning electron microscopy. The production process indicated a very limited degradation of the material after exposure to UV radiation for eight days, as demonstrated by the slight attenuation of amide I (collagen) and polysaccharide FTIR peaks. Reheating at 80 °C resulted in a weight loss not exceeding 3%.

scholarly journals Biocomposites Based on Thermoplastic Starch Reinforced with Recycled Paper Cellulose Fibers

2016 ◽  
Vol 855 ◽  
pp. 126-130 ◽  
Author(s):  
Amnuay Wattanakornsiri ◽  
Sampan Tongnunui ◽  
Tongsai Jamnongkan ◽  
Claudio Migliaresi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Water Absorption ◽  
Corn Starch ◽  
Cellulose Fibers ◽  
Thermoplastic Starch ◽  
Scanning Calorimetry ◽  
Recycled Paper ◽  
Mechanical Tensile ◽  
Scanning Electron

Biocomposites sheets were prepared by compression molding from mixtures of corn starch plasticized by glycerol as matrix and cellulose fibers, extracted from used office paper, as reinforcement filler with contents ranging from 0 to 8% wt/wt of fibers to matrix. Properties of composites were determined by mechanical tensile test, differential scanning calorimetry, thermogravimetric analysis, water absorption measurement, and scanning electron microscopy. The results showed that higher fibers content raised the tensile strength and elastic modulus up to 109% and 112%, respectively, when compared to the non-reinforced thermoplastic starch (TPS). The addition of the fibers improved the thermal resistance and decreased the water absorption up to 63.6%. Scanning electron microscopy illustrated a good adhesion between matrix and fibers.

Effect of Different Processing on Corn Starch and Protein

2012 ◽  
Vol 554-556 ◽  
pp. 990-993
Author(s):  
Jian Zou ◽  
Hai Yan Gao ◽  
Jie Zeng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corn Starch ◽  
Ultra Violet ◽  
Absorption Spectrometry ◽  
Dry Milling ◽  
Wet Milling ◽  
Corn Flour ◽  
Sds Page ◽  
Scanning Electron

Scanning electron microscopy of samples showed that corn flour granules by fermented and wet-milling were angular, pentagonal or elliptical similar to native starches while samples with extruding and cooking were irregularly fibrous and large granules. Protein of samples with wet-milling exhibited an obvious DSC endotherm, To 85.81°C, Tp 92.95°C, Tc 101.73°C and ΔH 1.614J/g.While the fermented and extruded samples had no endotherm. Ultra-violet absorption spectrometry showed that absorbance of fermented and extruded samples increased and the λmax were slightly red shift. The λmax were 294nm, 297nm and 310nm for wet-milling , fermented and extruded flour, respectively. SDS-PAGE patterns of wet-milling flour contained four bands, fermented samples only three bands while extruded samples had same bands with dry-milling.

scholarly journals Polymeric Composites Based on Polyurea Matrix Reinforced with Carbon Nanotubes

2017 ◽  
Vol 54 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Maria Adina Vulcan ◽  
Celina Damian ◽  
Paul Octavian Stanescu ◽  
Eugeniu Vasile ◽  
Razvan Petre ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

This paper deals with the synthesis of polyurea and its use as polymer matrix for nanocomposites reinforced with multi-walled carbon nanotubes (MWCNT). Two types of materials were obtained during this research, the first cathegory uses the polyurea as matrix and the second one uses a mixture between epoxy resin and polyurea. The nanocomposites were characterized by Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM) and Tensile Tests .The elastomeric features of nanocomposites were highlighted by the results which showed low value of Tg. Also higher thermal stability with ~40oC compared with commercial products (M20) were observed, but lower mechanical properties compared to neat polyurea.

scholarly journals What Is Considered a Variation of Biomechanical Parameters in Tensile Tests of Collagen-Rich Human Soft Tissues?—Critical Considerations Using the Human Cranial Dura Mater as a Representative Morpho-Mechanic Model

Medicina ◽  
2020 ◽  
Vol 56 (10) ◽  
pp. 520
Author(s):  
Johann Zwirner ◽  
Mario Scholze ◽  
Benjamin Ondruschka ◽  
Niels Hammer
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Soft Tissue ◽  
Dura Mater ◽  
Soft Tissues ◽  
Tensile Tests ◽  
Interquartile Range ◽  
Tissue Structure ◽  
Mechanical Parameters ◽  
Scanning Electron

Background and Objectives: Profound knowledge on the load-dependent behavior of human soft tissues is required for the development of suitable replacements as well as for realistic computer simulations. Regarding the former, e.g., the anisotropy of a particular biological tissue has to be represented with site- and direction-dependent particular mechanical values. Contrary to this concept of consistent mechanical properties of a defined soft tissue, mechanical parameters of soft tissues scatter considerably when being determined in tensile tests. In spite of numerous measures taken to standardize the mechanical testing of soft tissues, several setup- and tissue-related factors remain to influence the mechanical parameters of human soft tissues to a yet unknown extent. It is to date unclear if measurement extremes should be considered a variation or whether these data have to be deemed incorrect measurement outliers. This given study aimed to determine mechanical parameters of the human cranial dura mater as a model for human soft tissues using a highly standardized protocol and based on this, critically evaluate the definition for the term mechanical “variation” of human soft tissue. Materials and Methods: A total of 124 human dura mater samples with an age range of 3 weeks to 94 years were uniformly retrieved, osmotically adapted and mechanically tested using customized 3D-printed equipment in a quasi-static tensile testing setup. Scanning electron microscopy of 14 samples was conducted to relate the mechanical parameters to morphological features of the dura mater. Results: The here obtained mechanical parameters were scattered (elastic modulus = 46.06 MPa, interquartile range = 33.78 MPa; ultimate tensile strength = 5.56 MPa, interquartile range = 4.09 MPa; strain at maximum force = 16.58%, interquartile range = 4.81%). Scanning electron microscopy revealed a multi-layered nature of the dura mater with varying fiber directions between its outer and inner surface. Conclusions: It is concluded that mechanical parameters of soft tissues such as human dura mater are highly variable even if a highly standardized testing setup is involved. The tissue structure and composition appeared to be the main contributor to the scatter of the mechanical parameters. In consequence, mechanical variation of soft tissues can be defined as the extremes of a biomechanical parameter due to an uncontrollable change in tissue structure and/or the respective testing setup.

Structure and mechanical properties of Ni/Ti multilayered composites produced by accumulative roll-bonding process

2019 ◽  
Vol 54 (8) ◽  
pp. 1119-1126
Author(s):  
Mohammad Mokhles ◽  
Morteza Hosseini ◽  
Habib Danesh-Manesh ◽  
Seyed Mojtaba Zebarjad
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Accumulative Roll Bonding ◽  
Tensile Tests ◽  
Total Elongation ◽  
Uniaxial Tensile ◽  
Roll Bonding ◽  
Multilayered Composites ◽  
Scanning Electron

This research studies the structure and mechanical properties of Ni/Ti multilayered composites produced from commercial pure Ni and Ti foils by accumulative roll-bonding technique. To investigate these properties, scanning electron microscopy, Vickers microhardness, and uniaxial tensile tests were conducted at different processing cycles. Studies showed that in terms of structure, Ni and Ti layers maintain their continuity even up to 10 cycles of accumulative roll-bonding. Moreover, the energy-dispersive spectroscopy in scanning electron microscopy detected no deformation induced diffusion or reactive interfacial zones. It was found that by increasing the accumulative roll-bonding cycles, tensile and yield strengths as well as the hardness of the composite enhance and the total elongation reduces continuously.

Analysis of Applicability of the Hollow Carbon Fibres for Self-Repairing Composites

2012 ◽  
Vol 729 ◽  
pp. 246-251 ◽  
Author(s):  
Sándor Kling ◽  
Tibor Czigány
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Tensile Tests ◽  
Single Fibre ◽  
Internal Diameter ◽  
Carbon Fibres ◽  
Hollow Carbon ◽  
Scanning Electron

The geometry and mechanical properties of solid and hollow carbon fibres were investigated by light-and scanning electron microscopy, and by single fibre tensile tests. The hollowness factor of fibres was determined by their external and internal diameter. The tensile strength was determined by single fibre tensile break tests. It was shown that the bigger the diameter of the fibres the lower the mechanical properties is. It was found that the hollow carbon fibres are suitable for preparation of a self-repairing composite with the advantage over other solutions because of their geometrical and mechanical properties.

Mechanical properties of heat-treated cellulose nanofiber-reinforced polyvinyl alcohol nanocomposite

2016 ◽  
Vol 51 (14) ◽  
pp. 1971-1977 ◽  
Author(s):  
NH Noor Mohamed ◽  
Hitoshi Takagi ◽  
Antonio N Nakagaito
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Polyvinyl Alcohol ◽  
Tensile Tests ◽  
Cellulose Nanofiber ◽  
Heat Treated ◽  
Scanning Electron ◽  
Polyvinyl Alcohol Films

The mechanical properties of cellulose nanofiber-reinforced polyvinyl alcohol composite were studied. Neat polyvinyl alcohol films, cellulose nanofiber sheets, and their nanocomposites containing cellulose nanofiber weight ratios of 5, 15, 30, 40, 45, 50 and 80 wt% were fabricated. Heat treatment by hot pressing at 180℃ was conducted on the specimens to study its effect to the mechanical properties and the results were compared with the non heat-treated specimens. Morphology of the composites was studied by scanning electron microscopy and the mechanical properties were evaluated by means of tensile tests. The results showed that increase of cellulose nanofiber content from 5 wt% to 80 wt% has increased the tensile strength of the composites up to 180 MPa, with cellulose nanofiber content higher than 40 wt% yielding higher tensile strength. The heat-treated specimens exhibited higher tensile strength compared to those of untreated specimens.

Evaluation of Dicamba Persistence among Various Agricultural Hose Types and Cleanout Procedures Using Soybean (Glycine max) as a Bio-Indicator

Weed Science ◽  
2017 ◽  
Vol 65 (2) ◽  
pp. 305-316 ◽  
Author(s):  
Gary T. Cundiff ◽  
Daniel B. Reynolds ◽  
Thomas C. Mueller
Keyword(s):  
Electron Microscopy ◽  
Dry Matter ◽  
Dry Matter Yield ◽  
Polyethylene Blends ◽  
Synthetic Rubber ◽  
Polyethylene Blend ◽  
Sequestration Potential ◽  
Wall Depletion ◽  
Scanning Electron ◽  
Methoxybenzoic Acid

Synthetic rubbers, synthetic plastic polymers (polyvinyl chlorides [PVC]), polyurethane blends, and polyethylene blends make up modern-day agricultural spray hoses. The objective of this study was to determine whether agricultural hose types would differ with respect to 3,6-dichloro-2-methoxybenzoic acid (dicamba) sequestration. Field and greenhouse studies were conducted to evaluate the sequestration potential of dicamba within five agricultural hose types when cleaned with different cleanout procedures. Rinsate solutions were applied to soybean, which was used as a bio-indicator to test for cleanout efficiency. Differences among hose types and cleanout procedures exist with observations including soybean injury, height reduction, dry matter, yield, and part per million by volume (ppmv) analyte retained. The makeup of PVC polyurethane-blend and synthetic rubber–blend hoses increased retention of dicamba analyte when compared with the polyethylene blend hose. No differences were observed after the addition of ammonia to the cleanout solution when compared with water alone. Differences in a hose type’s ability to sequester the dicamba analyte may have more to do with the hose’s internal chemical composition, manufacturing process, and composition breakdown. Scanning electron microscopy revealed imperfections in new PVC polyurethane and synthetic rubber hoses that eventually lead to inner wall depletion of these hose types. This is in contrast to what was found in the polyethylene-blend hose type, in which the inner wall is smooth and free of imperfections.

scholarly journals Stress Corrosion Cracking in an Extruded Cu-Free Al-Zn-Mg Alloy

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1194
Author(s):  
Adrian Lervik ◽  
John C. Walmsley ◽  
Lars Lodgaard ◽  
Calin D. Marioara ◽  
Roy Johnsen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Aluminium Alloys ◽  
Double Cantilever Beam ◽  
Tensile Tests ◽  
Corrosion Cracking ◽  
Comprehensive Understanding ◽  
Beam Method ◽  
Scanning Electron

Stress corrosion cracking (SCC) in Cu-free Al-Zn-Mg (7xxx) aluminium alloys limits its use in many applications. In this work, we study in detail the microstructure of a peak and slightly overaged condition in an AA7003 alloy using transmission- and scanning electron microscopy in order to provide a comprehensive understanding of the microstructural features related to SCC. The SCC properties have been assessed using the double cantilever beam method and slow strain rate tensile tests. Grain boundary particles, precipitate free zones, and matrix precipitates have been studied. A difference in the SCC properties is established between the two ageing conditions. The dominating difference is the size and orientation of the hardening phases. Possible explanations correlating the microstructure and SCC properties are discussed.

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