scholarly journals Effect of Fiber Surface Modification on the Interfacial Adhesion and Thermo-Mechanical Performance of Unidirectional Epoxy-Based Composites Reinforced with Bamboo Fibers

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2682 ◽  
Author(s):  
Fang Wang ◽  
Min Lu ◽  
Shujue Zhou ◽  
Zhisong Lu ◽  
Siyan Ran
Keyword(s):  
Tensile Strength ◽  
Mechanical Performance ◽  
Interfacial Strength ◽  
Fiber Surface ◽  
Alkali Concentration ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Chemically Modified ◽  
Naoh Solution ◽  
Bamboo Fibers

In this work, bamboo fibers are chemically modified with NaOH solution of 1, 4, and 7 wt% concentrations at room temperature, respectively, and subsequently the untreated and treated fibers are prepared with epoxy resin for unidirectional composites by hot pressing molding technique. Tensile and micro-bond tests are conducted on the composite specimens to obtain mechanical properties, such as tensile strength and modulus, elongation at break, and interfacial strength. Besides, scanning electron microscopy (SEM) is employed to perform morphological observations for constituent damages. In addition, the influence of alkali concentration on the thermal performance of epoxy-based composites is examined by using differential scanning calorimetry (DSC) and thermogravimetric (TG) analysis. It is found that composite tensile strength reaches the maximum when the alkali concentration is 4%, increased by 45.24% compared with untreated composites. The composite elongation at break increases on increasing the concentration. Inversely, the composite modulus decreases as the concentration increases. Besides, the results demonstrate that the chemical treatment on the fiber surface could improve interface adhesion, as observed from its topography by SEM. Micro-bond test reveals that there is maximum interfacial shear strength when the alkali concentration is 4%, which increases by 100.30% in comparison with the untreated samples. In case of thermal properties, the DSC analysis indicates that the glass transition temperature is maximized at 4% alkali concentration, which is increased by 12.95%, compared to those from unmodified fibers. In addition, TG results show that the 4% concentration also facilitates thermal stability improvement, indicative of superior interfacial bonding.

scholarly journals THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES

2021 ◽  
Vol 23 (1) ◽  
pp. 16
Author(s):  
Vienna Saraswaty ◽  
Rossy Choerun Nissa ◽  
Bonita Firdiana ◽  
Akbar Hanif Dawam Abdullah
Keyword(s):  
Tensile Strength ◽  
Physicochemical Characterization ◽  
Face Mask ◽  
Physicochemical Characteristics ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Ft Ir ◽  
The Government ◽  
Plastic Pellets

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.

scholarly journals Fabrication and Characterization of Biodegradable Composites from Poly (Butylene Succinate-Co-Butylene Adipate) and Taihu Lake Blue Algae

2017 ◽  
Vol 26 (5) ◽  
pp. 096369351702600 ◽  
Author(s):  
Wenjing Xia ◽  
Nianqing Zhu ◽  
Zhongbin Ni ◽  
Mingqing Chen
Keyword(s):  
Tensile Strength ◽  
Taihu Lake ◽  
Mechanical Performance ◽  
Value Added ◽  
Melt Blending ◽  
Butylene Succinate ◽  
Elongation At Break ◽  
Biodegradable Composites ◽  
Thermal Stability Of

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.

Effect of Gamma Radiation on Properties of Cellulose Nanocrystal/Natural Rubber Nanocomposites

2018 ◽  
Vol 772 ◽  
pp. 13-17 ◽  
Author(s):  
Wapoon Tappanawatch ◽  
Paweena Prapainainar ◽  
Pongdhorn Sae-Oui ◽  
Surapich Loykulnant ◽  
Peerapan Dittanet
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Gamma Ray ◽  
Mechanical Performance ◽  
Reaction Times ◽  
Tensile Modulus ◽  
Alkaline Treatment ◽  
Corn Cob ◽  
Elongation At Break ◽  
Reinforcing Agent

Cellulose nanocrystals (CNC) were extracted from corn cob and synthesized by alkaline treatment using 3 wt% sodium hydroxide (NaOH). Acid hydrolysis with 64 wt% sulfuric acid (H2SO4) at different reaction times (30, 45, 60 min) was performed to obtain CNC solutions. CNC was evaluated as a reinforcing agent in natural rubber (NR) at CNC loadings from 1-5 wt%. Gamma-ray radiation was used as vulcanization method and varied at 10 and 20 kGy. The tensile modulus and tensile strength of NR vulcanizates increased with addition of CNC and contents. In addition, radiation by gamma ray impacts the mechanical performance, where CNC/NR composites vulcanized with higher dose of radiation of 20 KGy were found to have the higher values in tensile strength, elongation at break, and modulus than with 10 KGy. Moreover, the tensile strength and elongation at break of the composites after aging were found to slightly increase due to post-curing during the aging process.

Utilization of Maleic Anhydride Modified Ground EVA Waste in NBR Vulcanizates

2005 ◽  
Vol 78 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Bluma G. Soares ◽  
Ana C. O. Gomes ◽  
Viviane X. Moreira ◽  
Marcia G. Oliveira
Keyword(s):  
Tensile Strength ◽  
Maleic Anhydride ◽  
Mechanical Performance ◽  
Dynamic Testing ◽  
Good Resistance ◽  
Adhesion Promoter ◽  
Elongation At Break ◽  
Compression Set ◽  
Lower Elongation ◽  
Poly Ethylene

Abstract The influence of poly(ethylene-co-vinyl acetate) (EVA) waste (EVAW) on the rheological and mechanical properties of NBR vulcanizates compounds was studied. The optimum concentration of EVAW, which has presented higher ultimate tensile strength, was found to be 70 phr. In addition, the influence of EVAW modified with maleic anhydride as adhesion promoter was studied. Two distinct routes of modification with maleic anhydride were selected, originating a carboxylated EVA waste (EVAWCOOH) and an anhydride EVA waste (EVAWMA). An improvement of tensile strength and aging resistance was observed with the substitution of EVAW by EVAWCOOH or EVAWMA. A very good resistance to compression set has been achieved with the addition of EVAWCOOH. The improvement of mechanical performance was attributed to a better dispersion of EVAW along NBR matrix, promoted by the enhanced modified-waste polarity, which allowed a good interaction with polar NBR. The presence of anhydride group in functionalized EVAW resulted in the highest values of tensile strength but lower elongation at break and also lower values of tan delta obtained from dynamic testing. These behaviors have been attributed to an increase of crosslink density due to the reaction between zinc oxide and succinic pendant groups of EVAWMA.

Surface Characteristics of Single Sisal Fiber and Interfacial Adhesion of Composites

2011 ◽  
Vol 391-392 ◽  
pp. 51-55
Author(s):  
Lin Xin Zhong ◽  
Xin Wen Peng ◽  
Jun Li Ren ◽  
Run Cang Sun
Keyword(s):  
Tensile Strength ◽  
Chemical Composition ◽  
Chlorine Dioxide ◽  
Interfacial Adhesion ◽  
Phenolic Resin ◽  
Interfacial Strength ◽  
Fiber Surface ◽  
Surface Characteristics ◽  
Sisal Fiber ◽  
Resin Composites

Surface characteristics including surface morphology and chemical composition of single sisal fiber and their influences on the interfacial adhesion of sisal fiber/phenolic resin composites were investigated by SEM, AFM, and XPS. The results showed that the surface of the untreated single sisal fiber contained a large amount of lignin (up to 51%). Chlorine dioxide treatment could reduce the surface lignin to a low content (20%). Removal of lignin from fiber surface could enhance the interfacial strength of sisal fiber/phenolic resin composites, giving rise to an increase by 36% in tensile strength. These results indicate that the surface properties of single sisal fiber can be tailored to improve the fiber/resin interfacial adhesion.

scholarly journals Development of technology for producing biodegradable hybrid composites based on polyethylene, starch, and monoglycerides

2021 ◽  
Vol 15 (6) ◽  
pp. 44-55
Author(s):  
I. Yu. Vasilyev ◽  
V. V. Ananyev ◽  
V. V. Kolpakova ◽  
A. S. Sardzhveladze
Keyword(s):  
Tensile Strength ◽  
Mechanical Performance ◽  
Hybrid Composites ◽  
Composite Films ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Elongation At Break ◽  
Biodegradable Composite ◽  
Develop Technology ◽  
Distilled Monoglycerides

Objectives. This work aimed to develop technology to produce biodegradable hybrid composite (BHC) films based on low-density polyethylene (LDPE) 115030-070 and thermoplastic starches (TPS) of various origins (corn, pea, and rice), with distilled monoglycerides as the plasticizer. The properties of the produced BHC films were studied and the optimal native starch : glycerol : monoglycerides ratio is proposed.Methods. TPS and BHC films based on this material were produced from different types of native starches in laboratory extruders (Brabender and MashPlast, Russia), and the extruded melts were subjected to ultrasonic vibrations. The structure and appearance of the BHC films were studied using scanning electron microscopy and rheology. Their biodegradability was assessed by immersing them in biocompost for three months. To evaluate the mechanical performance of the BHC films produced with and without ultrasound, the changes in tensile stress and elongation at break were determined during the biodegradation process.Results. The BHC films had a homogeneous structure, except small agglomerates (non-melted starch grains), which did not reduce their quality. The films with monoglycerides had high tensile strength, which was comparable with low-density polyethylene. After removing samples of the BHC films from the biocompost, their tensile strength decreased by 20%, which shows their biodegradability.Conclusions. The produced biodegradable composite films and the technology used to produce them will be applicable for the packaging industry to reduce environmental impact.

The Photo-Oxidation of Polypropylene Monofilaments

1976 ◽  
Vol 46 (8) ◽  
pp. 590-599 ◽  
Author(s):  
D. J. Carlsson ◽  
F. R. S. Clark ◽  
D. M. Wiles
Keyword(s):  
Tensile Strength ◽  
Chemical Analysis ◽  
Radical Scavenging ◽  
Fiber Surface ◽  
Oxidation Products ◽  
Polypropylene Film ◽  
Elongation At Break ◽  
Photo Oxidation ◽  
Polypropylene Monofilament ◽  
Oxidized Polypropylene

The photo-oxidation of commercial, isotactic polypropylene monofilament, initiated by xenon-arc irradiation in air, leads to the initial accumulation in the fiber surface of both carbonyl species and hydroperoxide groups. These chemical changes are accompanied by a severe drop in the elongation at break. Extended irradiation leads to a substantial accumulation of these oxidation products throughout the fiber and to a loss of tensile strength. Oxidation products were identified and estimated from transmission and internal reflection in spectroscopy [∼C(O)∼ and —OH] and by chemical analysis (—OOH). Marked increases in fiber wettability were also found to accompany photo-oxidation. Distinct differences in product ratios from photo-oxidized polypropylene film and fiber samples were observed. These differences are consistent with the morphological control of the efficiency of initiation after hydroperoxide photocleavage, but are more likely to result from some radical scavenging by the unextractable phenolic additive in the commercial fiber.

scholarly journals PREPARATION AND CHARACTERIZATIONS OF LATEX/FILLER NANOCOMPOSITES

2020 ◽  
Vol 21 (2) ◽  
pp. 230-238
Author(s):  
Mohamad Firdaus Omar ◽  
NURIAH MOHAMAD ◽  
Fathilah Ali
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Coupling Agent ◽  
Morphological Properties ◽  
Rubber Matrix ◽  
Silane Coupling Agents ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Silane Coupling ◽  
Latex Compounding

Latex compounding which incorporates various types of clays as filler to the rubber can significantly give reinforcement in the rubber matrix when rubber/clay nanocomposites are formed, but the filler agglomerates. Thus, study was conducted by using Kaolin clay as the filler in the rubber nanocomposites with silane coupling agent to functionalize the surface of the filler. This study was done in order to investigate the mechanical properties of various functionalized Kaolin in latex nanocomposites, to prepare various ratios of Kaolin to rubber, and to characterize mechanical, thermal and morphological properties of the Kaolin in latex nanocomposites. To achieve these, six types of silane coupling agents was used for Kaolin filler surface functionalization purpose during the filler’s incorporation in latex compounding. The optimized coupling agent, USi-7301 (?-chloropropyltrimetoxysilane) – with tensile strength value of 32.77 MPa, elongation at break value of 632.589 % and force at break value of 6.737 N – was used to further functionalize Kaolin filler in different ratios so as to achieve the optimum mechanical, thermal and morphological properties of the filler in the polymer matrix. Universal tensile machine was used to analyze the mechanical properties of the nanocomposites, while the Scanning Electron Microscopy (SEM) and Differential Scanning Calorimetry (DSC) were used to observe the morphological and thermal properties of the nanocomposites, respectively. The results showed that reducing the Total Solids Content (TSC) of Kaolin filler to 26 % somehow showed the optimized properties of the nanocomposites, giving 34.00 MPa tensile strength, 576.494 % elongation at break and 6.564 N force at break. Rough surface morphology was observed under SEM suggesting the occurrence of phase separation between the hydrophilic filler and the hydrophobic rubber matrix. In the DSC plot, sample with USi-7301 and with functionalized Kaolin filler 26 % TSC showed glass transition temperature shifted to lower region compared to normal nitrile rubber. The reinforcement of nanocomposites formed will not only enhance the properties of the nanocomposites, but is also economically feasible thus brings advantages to the industry. ABSTRAK: Penyebatian lateks yang menggabungkan pelbagai jenis tanah liat sebagai pengisi dalam getah dapat memberi pengukuhan dalam matriks getah dengan ketara apabila nanokomposit getah / tanah liat terbentuk, tetapi pengisi mengagregat. Oleh itu, kajian dijalankan dengan menggunakan tanah liat Kaolin sebagai pengisi dalam nanokomposit getah dengan ejen gandingan silan untuk menambah-fungsi permukaan pengisi tersebut. Kajian ini dilakukan untuk mengenalpasti sifat mekanik pelbagai Kaolin (yang berfungsi) dalam nanokomposit lateks, untuk menyediakan pelbagai nisbah Kaolin terhadap getah, dan untuk mencirikan sifat mekanik, haba dan morfologi Kaolin dalam nanokomposit lateks. Untuk mencapainya, enam jenis ejen gandingan silan digunakan untuk tujuan menambah-fungsi permukaan pengisi Kaolin semasa penggabungan pengisi dalam penyebatian lateks. Ejen gandingan silan yang paling optimum, USi-7301 (?-silan kloropropiltrimetoksi) - dengan nilai kekuatan tegangan 32.77 MPa, nilai pemanjangan ketika pemutusan 632.589% dan kekuatan daya ketika pemutusan 6.737 N - digunakan dengan lebih lanjut untuk menambah-fungsi pengisi Kaolin dalam nisbah yang berbeza untuk lebih mencapai sifat mekanikal, haba dan morfologi optimum pengisi dalam matriks polimer lateks. Mesin tegangan universal digunakan untuk menganalisis sifat mekanik nanokomposit, sementara Mikroskopi Elektron Pengimbasan (SEM) dan Kalorimetri Pengimbasan Berbeza (DSC) digunakan untuk menganalisa sifat morfologi dan haba nanokomposit tersebut. Hasil kajian menunjukkan bahawa pengurangan Jumlah Kandungan Pepejal (TSC) pengisi Kaolin kepada 26% menunjukkan sifat optimum nanokomposit, dengan kekuatan tegangan 34.00 MPa, pemanjangan ketika pemutusan sebanyak 576.494% dan daya ketika pemutusan sebanyak 6.564 N. Morfologi permukaan kasar diperhatikan di bawah SEM dan ia menunjukkan berlakunya pemisahan fasa antara pengisi hidrofilik dan matriks getah hidrofobik. Dalam plot DSC, sampel dengan USi-7301 dan dengan pengisi Kaolin yang difungsikan dengan 26% TSC menunjukkan suhu peralihan kaca beralih ke kawasan yang lebih rendah berbanding getah nitril biasa. Pengukuhan nanokomposit yang terbentuk bukan sahaja akan meningkatkan sifat nanokomposit, tetapi juga dapat dilaksanakan secara ekonomi sehingga memberi banyak kelebihan kepada industri.

Effect of Bamboo Fiber Modification on Tribological Performance of Brake Composites

2010 ◽  
Vol 150-151 ◽  
pp. 1801-1805 ◽  
Author(s):  
Fu Shan He ◽  
Cheng Hui Gao ◽  
Shao Yan Ye
Keyword(s):  
Heat Treatment ◽  
Alkali Treatment ◽  
Fiber Surface ◽  
Tribological Performance ◽  
Fiber Modification ◽  
Wear Rates ◽  
Microstructure Observation ◽  
Naoh Solution ◽  
Bamboo Fibers ◽  
Coupling Treatment

In this paper, a novel no-asbestos brake composite reinforced by natural bamboo fibers is studied. The bamboo fibers are modified by heat treatment, alkali treatment and coupling treatment respectively. Tribological performance of different fibers reinforced composites are developed by means of friction test and microstructure observation. The results show that heat treatment of bamboo fibers at 140 for 4 hours makes the friction and wear characteristics of brake composites more stable than the untreated ones, but poor wear resistance at low temperature and heat fade still exist. There is no significant change on fiber surface. The alkali treatment of 17% NaOH solution for 12 hours contributes to desirable combination of higher friction coefficients and lower wear rates, and the surface morphology shows a number of deep grooves that avail the interface bonding. The effect of coupling treatment with KH550 on tribological performance of composites have the similar rule to that of the alkali treated ones except of heat fade, and the fiber surface is evenly coated with the coupling agent, which enhances the bonding of fibers and resin but fails at elevated temperature.

A clean and efficient processing system to improve the fluffiness of down fibers based on multi-enzymes

2021 ◽  
pp. 004051752199747
Author(s):  
Taotao Qiang ◽  
Yadong Pu ◽  
Qi Zhang
Keyword(s):  
Thermal Stability ◽  
Tensile Strength ◽  
Large Scale ◽  
Moisture Absorption ◽  
Processing System ◽  
Insulation Material ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Main Index ◽  
Efficient Processing

Down fiber – a natural and environmentally recyclable insulation material – is applied mainly in the area of natural-filled products. However, owing to its natural deficiencies of low fluffiness and thermal stability, large-scale application is limited. In our work, an enzyme preparation (transglutaminase (TGase)) was used as a fluffy agent to improve the fluffy degree of down. With fluffy as the main index, the single factor condition of only using TGase enzyme was optimized, and fluffiness was increased by 22%. On the basis of this optimum condition, the compound dosage of papain and TGase was further optimized. The fluffy degree of down was improved by hydrolysis of papain and crosslinking of TGase. Amino group content, thermogravimetry (TG), differential scanning calorimetry (DSC), moisture absorption, tensile strength, and elongation at break of down treated with different enzyme reagents were tested. The results showed that the thermal stability of down fiber treated with the multi enzyme increased significantly, the denaturation temperature was increased from 53.7°C to 77.4°C, and the moisture absorption was also improved. The elastic property also exhibited a great enhancement; elongation at break increased from 12.4% to 37.7%, nearly three times higher than the original property, and the tensile strength increased from 180 MPa to 370 MPa, almost 2.1 times as much as before, increased by 105.6%.

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