scholarly journals Structural and Thermal Properties of Ethiopian Eri and Mulberry Silk Fibres

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Getnet Melesse ◽  
Desalegn Atalie ◽  
Ayano Koyrita
Keyword(s):  
Tensile Strength ◽  
Thermal Properties ◽  
Linear Density ◽  
Addis Ababa ◽  
Morphological Structure ◽  
Water Removal ◽  
Silk Fibre ◽  
Filament Length ◽  
Degradation Temperature ◽  
Eri Silk

Silk fibre has received attention in the biomedical sector rather than textile production because of its excellent biocompatibility properties in the past century. Although silk fibre properties are different from area to area, it has created an opportunity in the biomedical sector to develop new silk-based medical textile products. This research work aimed to study the structural, physical, mechanical, and thermal properties of Ethiopian silkworm cocoon’s filament. Eri and mulberry silk fibre properties such as morphological structure, chemical properties, linear density, filament length, tensile strength, elongation, thermal property, and luster were measured using ES ISO and ASTM standard methods. Statistical analysis result showed that eri silk fibre from Arba Minch had water removal temperature between 100°C and 125°C with a degradation temperature of around 400°C and eri silk fibre from both Addis Ababa and Awassa had an almost similar water removal temperature around 100°C and degradation temperature around 420°C. Tensile strength and elongation of both eri and mulberry silk fibres had significant differences among each region. The highest tensile strength of 4.47 cN was observed from Addis Ababa, and the highest elongation of 20.01% was found from the Arba Minch eri silk fibre. The coarser linear density of 2.496 dtex from Arba Minch and finer count of 2.392 dtex were exhibited from Awassa. Arba Minch eri silk fibre had the highest filament length of 403.04 m and the least fibre length of 399.2 m recorded at Addis Ababa, and a better whiteness (Rd) value of 58.21 was observed at Arba Minch eri silk fibre. Bivoltine and multivoltine mulberry silk fibres had an average tensile strength of 8.01 and 11.83 cN, elongation of 10.3 and 12.1%, fineness of 3.2 and 3.16 dtex, and filament length of 1208.6 and 1028.26 m, respectively, in the same place of Arba Minch. The morphological structure of eri silk fibre from each region had an almost smooth and clean surface, but bivoltine and multivoltine mulberry silk fibres were somehow rough and had spots. According to the comparison results, Ethiopian silk fibres can be utilised more in the biomedical application and competitive in the global market.

Synthesis and Characterization of Microcellular Injection Molded Polyolefin/Polycaprolactone Composites

2021 ◽  
Vol 1041 ◽  
pp. 11-15
Author(s):  
Shyh Shin Hwang ◽  
Shia Chung Chen ◽  
Chiu Lan Yang
Keyword(s):  
Tensile Strength ◽  
Thermal Properties ◽  
Cell Size ◽  
Cell Density ◽  
Synthesis And Characterization ◽  
Degradation Temperature ◽  
The Matrix ◽  
Filler Dispersion ◽  
Injection Molded

This study investigated the effect of polycaprolactone (PCL) loading (0.5, 1, and 3 wt%) on the morphology, tensile strength, and thermal properties of microcellular injection molded PP/PCL and PPgMA/PCL composites. We used the filler, PCL, that is micro-material in size. Results showed that 0.5 wt% loading of PCL on foamed PP has the largest tensile strength. However, tensile strength was almost similar to that of PPgMA composites. Tensile strength depends on the filler dispersion in the matrix and cell size present on the foamed composites. Good dispersion resulted in good tensile strength. The elongation decreased on PP but increased on PPgMA composites. The highest degradation temperature for PP/PCL and PPgMA/PCL was noted for 3.0 wt% PCL loading and neat PPgMA respectively. Cell size decreased and cell density increased with the addition of PCL into the PP and PPgMA matrix.

Thermal and mechanical properties of copper/photopolymer composite

2016 ◽  
Vol 22 (4) ◽  
pp. 684-690
Author(s):  
Shih-Hsuan Chiu ◽  
Cheng-Lung Wu ◽  
Shun-Ying Gan ◽  
Kun-Ting Chen ◽  
Yi-Ming Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Rapid Prototyping ◽  
Copper Powder ◽  
Thermal And Mechanical Properties ◽  
Electron Microscopic ◽  
Content Type ◽  
Degradation Temperature

Purpose The purpose of this study is to increase the thermal and mechanical properties of the photopolymer by filling with the copper powder for the application of rapid tooling. Design/methodology/approach In this study, the photopolymer is filled with the different loading of copper powder for investigating the thermal and mechanical properties of the copper/photopolymer composite. The thermal properties of the copper/photopolymer composite are characterized with the degradation temperature and with the thermal conductivity. The mechanical properties of copper/photopolymer composite are performed with the tensile strength and hardness testing. Moreover, the copper/photopolymer composite is imaged by using a scanning electron microscopic with energy dispersive spectroscopy. Findings The tensile strength of the copper/photopolymer composite is increased over 45 per cent at 20 phr copper loading. The hardness of the photopolymer has a negative correlation with the increasing copper loading and is decreased about 28.5 per cent at 100 phr copper loading. The degradation temperature of the copper/photopolymer composite is increased about 7.2 per cent at 70 phr copper loading. The thermal conductivity of the copper/photopolymer composite is increased over 65 per cent at 100 phr copper loading. Originality/value The photopolymer used in rapid prototyping system is generally fragile and has poor thermal properties. This study improves the thermal and mechanical properties of the photopolymer with the copper filling which has been never investigated in the field of rapid prototyping applications.

scholarly journals Effect of Organo-Modified Montmorillonite Nanoclay on Mechanical, Thermo-Mechanical, and Thermal Properties of Carbon Fiber-Reinforced Phenolic Composites

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 754
Author(s):  
Jantrawan Pumchusak ◽  
Nonthawat Thajina ◽  
Watcharakorn Keawsujai ◽  
Pattarakamon Chaiwan
Keyword(s):  
Thermal Properties ◽  
Carbon Fiber ◽  
Bending Strength ◽  
Mechanical And Thermal Properties ◽  
Fiber Reinforced ◽  
Heat Resistant ◽  
Degradation Temperature ◽  
Modified Montmorillonite ◽  
Carbon Fiber Reinforced ◽  
Montmorillonite Nanoclay

This work aims to explore the effect of organo-modified montmorillonite nanoclay (O-MMT) on the mechanical, thermo-mechanical, and thermal properties of carbon fiber-reinforced phenolic composites (CFRP). CFRP at variable O-MMT contents (from 0 to 2.5 wt%) were prepared. The addition of 1.5 wt% O-MMT was found to give the heat resistant polymer composite optimum properties. Compared to the CFRP, the CFRP with 1.5 wt% O-MMT provided a higher tensile strength of 64 MPa (+20%), higher impact strength of 49 kJ/m2 (+51%), but a little lower bending strength of 162 MPa (−1%). The composite showed a 64% higher storage modulus at 30 °C of 6.4 GPa. It also could reserve its high modulus up to 145 °C. Moreover, it had a higher heat deflection temperature of 152 °C (+1%) and a higher thermal degradation temperature of 630 °C. This composite could maintain its mechanical properties at high temperature and was a good candidate for heat resistant material.

The Effect of Yarn Linear Density on Mechanical Properties of Plain Woven Kenaf Reinforced Unsaturated Polyester Composite

2013 ◽  
Vol 465-466 ◽  
pp. 962-966 ◽  
Author(s):  
Mohd Pahmi bin Saiman ◽  
Mohd Saidin Bin Wahab ◽  
Mat Uzir Wahit
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Linear Density ◽  
Unsaturated Polyester ◽  
Composite Panel ◽  
Composite Yarn ◽  
Polyester Composite ◽  
The Impact ◽  
Woven Kenaf

To produce a good quality of dry fabric for reinforced material in a natural-based polymer composite, yarn linear density should be in consideration. A woven kenaf dry fabric with three different linear densities of 276tex, 413.4tex and 759tex were produced. The fabrics with different linear densities were been optimize with the assistance of WiseTex software. The optimized dry fabrics were infused with unsaturated polyester to produce composite panel using vacuum infusion process. The composites properties were tested on the tensile strength, flexural strength and the impact strength. The result shows that the mechanical properties of the composite increased when the yarn linear densities increased.

scholarly journals Comparison of Thermal Properties of PCB Photoresist Films Cured by Different Techniques

2016 ◽  
Vol 15 (2) ◽  
pp. 20
Author(s):  
Piyachat Wattanachai ◽  
Christian Antonio ◽  
Susan Roces
Keyword(s):  
Thermal Properties ◽  
Printed Circuit Boards ◽  
Molecular Structures ◽  
Limiting Factor ◽  
Circuit Boards ◽  
Microwave Technology ◽  
Hot Plate ◽  
Degradation Temperature ◽  
Strong Material ◽  
Curing Method

The possibility of implementing microwave technology to photoresist film curing which is a major process in the production of electronic printed circuit boards (PCB) was investigated and compared with a conventional curing method, e.g. UV lithography. Since both techniques involved irradiation, hot plate curing which relies on thermal conduction was undertaken to study the effect of a heat transfer approach. Two film thicknesses were studied, i.e. 0.0012 and 0.002 inch, and the effects of curing power and time were investigated. Thermal properties, i.e. percent cure, glass transition temperature (Tg), composition and degradation temperature (Td), were evaluated using a Differential Scanning Calorimeter (DSC) and Thermogravimetric Analysis (TGA) and it was found that the commercial UV irradiation was sufficient to completely cure the thin film but only reached 76% cure for the thicker film, resulting in a lower Tg. The results show that the required processing conditions using a conventional household microwave to obtain almost complete curing were 1,000 Watts and 10 minutes curing time. In addition, improved curing was achieved in the thicker film because microwave can transmit into polar materials whereas UV cannot penetrate very far into the material. The hot plate curing was observed to produce a higher degree of curing and Tg, however, the uniformity of heating was found to be a major limiting factor of this technique. Slight differences in decomposition profiles of the films cured by different techniques implied slight differences in molecular structures. Compared to UV and hot plate curing, microwave technology was demonstrated as a potential curing technique in the production of PCBs due to its ability to efficiently cure thick films resulting in a strong material with high Tg. To apply the technique to other processes, optimal conditions, i.e. power and time, should be further investigated as well as the prevention of hot spots.

Effect of Beating and Fibre Furnish on the Properties of Silk Paper

2011 ◽  
Vol 55-57 ◽  
pp. 1753-1758
Author(s):  
Li Zheng Sha ◽  
Hui Fang Zhao
Keyword(s):  
Tensile Strength ◽  
Pore Size ◽  
Average Pore Size ◽  
Silk Fibre ◽  
Upward Trend ◽  
Average Pore ◽  
Tensile Index ◽  
Plant Fibre

The aim of this work is to study the influence of beating and refining as well as the fibre furnish on the properties of silk paper, such as air permeance, softness, pore size, tensile index and burst index. The results showed that the beating characteristic of silk fibre was similar to that of plant fibre, they all had the characteristic of fibrillation. Silk paper had excellent softness and air permeance when the beating degree of silk pulp was 20 °SR, 181.3 μm/Pa·s and 2.5 mN·m2/g respectively, which was superior to paper made from plant fibres of the same beating degree. The minimum average pore size of silk paper was 5.11 μm at the beating degree of 20 °SR, and it decreased with the increase of beating degree, reached 0.79 μm at the beating degree of 67 °SR. With the increase of beating degree, the tensile index of silk paper increased at first, and then decreased. The burst index of silk paper showed a upward trend, but the softness and air permeance of it constantly decreased. The tensile strength of paper made from mixed-furnish pulp consisting of silk and softwood reached the maximum when the amount of silk fibre was 4%, and its air permeance increased with the increase of silk fibre.

Synthesis and Thermal Properties of a Boron-Containing Bisphenol-S Formaldehyde Resin

2011 ◽  
Vol 239-242 ◽  
pp. 2905-2908 ◽  
Author(s):  
Jun Gang Gao ◽  
Wei Hong Wu ◽  
Xing Li
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Thermal Properties ◽  
Degradation Rate ◽  
Formaldehyde Resin ◽  
Curing Process ◽  
Bisphenol S ◽  
Coordinate Structure ◽  
H Nmr ◽  
Degradation Temperature

Boron-containing bisphenol-S formaldehyde resin (BBPSFR) was synthesized by formalin method. The structure and thermal properties of BBPSFR were characterized by 1H NMR, FTIR, torsional braid analysis (TBA) and thermogravimetric analysis (TGA), respectively. The results showed that the borate had formed, and the six-member ring containing boron-oxygen coordinate structure also formed during the curing process. The glass transition temperature (Tg) of BBPSFR is higher 104°C than that of bisphenol-S formaldehyde resins (BPSFR); the initial degradation temperature (Ti ) increases about 43°C; thermal degradation rate decrease and thermal stability increase significantly.

Morphological Structure and Thermal Property of PLA/PCL Nanofiber by Electrospinning

2014 ◽  
Vol 1048 ◽  
pp. 418-422 ◽  
Author(s):  
Rui Tian Zhu ◽  
Ming Hao Tan ◽  
Peng Zhang ◽  
Liang Zhang ◽  
Xiao Ming Chen ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Medical Equipment ◽  
Morphological Structure ◽  
Diameter Distribution ◽  
Poly Lactic Acid ◽  
Adhesive Film ◽  
Mean Diameter ◽  
Blend Fiber ◽  
Biomedical Field ◽  
Poly Caprolactone

Poly (lactic) acid (PLA)/poly (caprolactone) (PCL) blends nanofibers, with mean diameter about 600nm, were prepared by electrospinning. This research focused on the morphological and thermal properties of nanofibers made from PLA/PCL bends with different PCL content. The results showed that the addition of PCL could improve the morphology of the nanofibers. The film with blend fiber at PLA/PCL ratio of 80:20 is characterized with the smoothest surface and the highest orientation. The diameter distribution of blend fibers is wider than that of pure PLA. The glass-transition temperature of PLA for blend fiber is higher than that of pure PLA, and their melting temperature is lower than that of pure PLA. It can be used in biomedical field for degradable membrane, anti-adhesive film and medical equipment.

Influence of Palm Oil Fibers Length Variation on Mechanical Properties of Reinforced Crude Bricks

2022 ◽  
Author(s):  
Mazhar Hussain ◽  
Daniel Levacher ◽  
Nathalie Leblanc ◽  
Hafida Zmamou ◽  
Irini Djeran Maigre ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Composite Materials ◽  
Physical Properties ◽  
Palm Oil ◽  
Mechanical Characteristics ◽  
Natural Fibers ◽  
Indirect Tensile

Crude bricks are composite materials manufactured with sediments and natural fibers. Natural fibers are waste materials and used in construction materials for reinforcement. Their reuse in manufacturing reinforced crude bricks is eco-friendly and improves mechanical and thermal characteristics of crude bricks. Factors such as type of fibers, percentage of fibers, length of fibers and distribution of fibers inside the bricks have significant effect on mechanical, physical and thermal properties of biobased composite materials. It can be observed by tests such as indirect tensile strength, compressive strength for mechanical characteristics, density, shrinkage, color for physical properties, thermal conductivity and resistivity for thermal properties, and inundation test for durability of crude bricks. In this study, mechanical and physical characteristics of crude bricks reinforced with palm oil fibers are investigated and effect of change in percentage and length of fibers is observed. Crude bricks of size 4*4*16 cm3 are manufactured with dredged sediments from Usumacinta River, Mexico and reinforced with palm oil fibers at laboratory scale. For this purpose, sediments and palm oil fibers characteristics were studied. Length of fibers used is 2cm and 3cm. Bricks manufacturing steps such as sediments fibers mixing, moulding, compaction and drying are elaborated. Dynamic compaction is opted for compaction of crude bricks due to energy control. Indirect tensile strength and compressive strength tests are conducted to identify the mechanical characteristics of crude bricks. Physical properties of bricks are studied through density and shrinkage. Durability of crude bricks is observed with inundation test. Thermal properties are studied with thermal conductivity and resistivity test. Distribution and orientation of fibers and fibers counting are done to observe the homogeneity of fibers inside the crude bricks. Finally, comparison between the mechanical characteristics of crude bricks manufactured with 2cm and 3cm length with control specimen was made.

Effect of conventional degumming methods on Eri silk fibers produced in Kenya

2020 ◽  
Vol 24 (2) ◽  
pp. 163-182
Author(s):  
Edison Omollo Oduor ◽  
Lucy Wanjiru Ciera ◽  
Vijay Adolkar ◽  
Odoch Pido
Keyword(s):  
Thermal Properties ◽  
Rural Areas ◽  
Fiber Strength ◽  
Silk Fiber ◽  
Small Scale ◽  
Content Type ◽  
Silk Fibers ◽  
Fiber Production ◽  
Alkali Medium ◽  
Eri Silk

Purpose This paper aims to determine the best conventional degumming technique for use by rural farmers practicing Eri silk fiber production in Kenya. Design/methodology/approach Three conventional silk degumming methods (water, soap and alkali) were analyzed under the factors, namely, time, pressure and degumming media, following the multilevel factorial design of experiments. The effect of variables on degumming weight loss was determined. The effects of the conventional degumming methods that produced complete sericin removal on chemical structure, surface morphology, thermal properties, crystallinity and fiber strength on Eri silk fibers produced in Kenya were then determined. The optimal degumming condition was then evaluated. Findings Soap and water degumming led to incomplete sericin removal. Alkali degumming media had the most effect, especially when pressure cooked at 103 kPa. Increasing time during alkali degumming beyond 30 min did not to have any major difference on degumming loss (at p 0.05). There were no major changes in chemical and thermal properties after degumming. However, the tensile strength and elongation deteriorated especially on alkali medium. Decreasing degumming time in alkali medium from 120 min to 30 min reduced the strength loss from 45% to 33%. Optimal degumming was found to be in an alkali media at 103 kPa for 30 min. Originality/value There is very little information available on Eri silk fibers produced in Kenya. Results of this study provide an optimized conventional degumming procedure suitable for small scale farmers in rural areas practicing Eri silk fiber production.

Sign in / Sign up

Export Citation Format

Share Document