Synthesis, Characterization and Properties of Poly (ε-Caprolactone) Glycol Based Casting Polyurethane Elastomers Containing Nano-Size Sio2 Particles

2010 ◽  
Vol 148-149 ◽  
pp. 1394-1399
Author(s):  
Xiao Dong Chen ◽  
Tie Jun Ma ◽  
Hai Zhang ◽  
Rong Sheng Chen

Poly(ε-caprolactone) (PCL) glycol based casting polyurethane elastomers (CPUE) filled with nano-SiO2 particles within different surface properties were synthesized by mean of in-situ polymerization. The macro-static/dynamic mechanical properties and micro-dispersed state were characterized by an electronmechanical universal testing machine, a durometer, a rubber resilience experimental machine, a dynamic-mechanical analyzer (DMA) and a scanning electron microscope (SEM). The tensile modulus at 100% and 300%, elongation at break, tensile strength and tear strength of PCL urethane nanocomposites increased substantially in the presence of a certain amount of nano-SiO2 compared with their pristine state. Furthermore, the tensile strength and tear strength at 100 of the PCL CPUE with 5% nano-SiO2 pretreated by γ-glycidochloropropyl methyl trimethoxy silane (SI-CA) were 1.50 and 1.94 times than those of the pure PCL CPUE, respectively. The addition of the nano-SiO2 had little effect on the hardness, but the impact resilience decreased slightly. DMA analyses showed that the loss factor peaks of two nano-SiO2 polyurethane composites were higher obviously than the pure PCL CPUE and the glass transition temperature (Tg)of the two nano-SiO2 polyurethane composites increased to higher temperature region. SEM fractographs showed that the surface treatment by the optimum silane coupling agent influenced the dispersibility of nano-SiO2 in the PCL CPUE distinctly. The agglomerating phenomenon, and even some nano-agglomerates with more than 1 μm diameter can be observed in the PCL CPUE with 5% untreated nano-SiO2, but the nano-SiO2 pretreated by SI-CA was dispersed in the PCL CPUE in nano-scale.

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1406
Author(s):  
Daoyuan Chen ◽  
Mingjin Ding ◽  
Zhixiong Huang ◽  
Yanbing Wang

In order to study the dynamic mechanical properties of styrene–acrylic latex with a core/shell structure, a variety of latexes were synthesized by semi-continuous seeded emulsion polymerization based on “particle design” with the same material. The latexes were characterized by rotary viscosimeter, dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), dynamic mechanical analysis (DMA), and universal testing machine. The effects of difference at the glass transition temperature (Tg) of core and shell and the introduction of the “transition layer” on the damping and mechanical properties of latex film were studied. The results indicate that as the Tg of core and shell gets closer, the better the compatibility of core and shell, from phase separation to phase continuity. Furthermore, the introduction of the “transition layer” can effectively improve the tensile strength and tan δ (max) of the latex film. The tensile strength and maximum loss factor (f = 1 Hz) of latex with the “transition layer” increased by 36.73% and 29.11% respectively compared with the latex without the “transition layer”. This work provides a reference for the design of emulsion for damping coating.


2012 ◽  
Vol 191 ◽  
pp. 23-28 ◽  
Author(s):  
Jaroslaw Piątkowski

The object of the studies was A390.0 alloy (AlSi17Cu5Mg), similar to A3XX.X series, gravity cast into sand and metal moulds. This alloy is mainly used for cast pistons operating in I.C. engines, for cylinder blocks and housings of compressors, and for pumps and brakes. The A390.0 alloy was poured at temperatures 880 and 980°C, holding the melt for 30 minutes and casting from the temperature of 780°C. The assessment of the impact of the degree of overheating was to analysis the tensile strength. Studies were carried out on a normal-running fatigue testing machine, which was the mechanically driven resonant pulsator. For the needs of quantitative reliability evaluation and the time-to-failure evaluation, the procedures used in survival analysis, adapted to the analysis of failure-free operation with two-parametric Weibull distributions, were applied. Having determined the boundary value σ0 for Weibull distribution, the value of „m” modulus was computed along with other coefficients of material reliability, proposed formerly by the authors. Basing on the obtained results, a model of Weibull distribution function was developed for the tensile strength with respective graphic interpretation.


2019 ◽  
Vol 33 (10) ◽  
pp. 1336-1357 ◽  
Author(s):  
Nazlı Arman ◽  
Emre Tekay ◽  
Sinan Şen

Poly(styrene -b-ethylene- co-butylene -b-styrene) (SEBS)/organophilic halloysite nanotube (Org-HNT) nanocomposites were prepared by solution mixing and then compression molded. Maleic anhydride grafted SEBS (SEBS- g-MA) was also used as a compatibilizer in preparation of SEBS/SEBS- g-MA/Org-HNT ternary nanocomposites. Surface morphologies and both static and dynamic mechanical analyses as well as thermal stabilities of the nanocomposites were carried out. Both the binary and ternary nanocomposites exhibited higher tensile moduli, tensile strength, and toughness values compared to neat SEBS. The elastic modulus was found to increase about 385% and 320% with addition of 3 and 5 phr Org-HNT into the SEBS matrix, respectively, while the maximum toughness was achieved via SEBS-5H composite with an increase of 45%. The ternary nanocomposite having 3 phr Org-HNT and 10 phr SEBS- g-MA (3H10SMA) gave about a 325% and 103% increase in the elastic modulus and toughness, respectively, together with a 75% increase in the tensile strength as the maximum value. This result was ascribed to interactions of the surface of the nanotubes with the maleic anhydride (MA) group of the compatibilizer. The same nanocomposite was also found to have two times higher dynamic storage modulus at 25°C than neat SEBS and almost the same damping value, which is an indication of improvement in the elastic character of SEBS without impairing its damping ability. Although a much higher damping value was obtained via use of 20 phr SEBS- g-MA with the same amount of nanotubes, the corresponding storage modulus decreased too much, close to that of neat SEBS. The enhanced tensile modulus, strength, and toughness of the 3H10SMA nanocomposite, which is consistent with its dynamic mechanical properties, indicate a good balance between the toughness/damping and stiffness. Moreover, all the nanocomposites exhibited better thermal stabilities than neat SEBS, showing higher midpoint degradation temperatures and peak maximum temperatures at which the maximum degradation occurs.


2012 ◽  
Vol 535-537 ◽  
pp. 154-160 ◽  
Author(s):  
Anizah Kalam ◽  
M.N. Berhan ◽  
Hanafi Ismail

Hybrid composites were prepared by incorporating oil palm fruit bunch (OPFB) fibre in the mixture of clay and polypropylene as secondary filler. OPFB and MAPP loadings were varied to investigate it effects on the performance. Tensile and impact tests were performed on the hybrid composites to evaluate their mechanical performances. Water absorption and thermal degradation tests were also conducted on the hybrid composites. Results indicated that the incorporation of OPFB in PP/PPnanoclay has decreased the thermal stability of hybrid composites. Tensile modulus of hybrid composites increased as the OPFB loading increases and further increased with the increasing of MAPP loading. Generally the tensile strength has decreased with the addition of OPFB, however slight increased was observed when the MAPP loading was increased. The impact strength has also increased with the increasing of OPFB for higher MAPP loading.


2021 ◽  
Vol 10 (1) ◽  
pp. 1-7
Author(s):  
Rohit Kumar ◽  
Ramratan . ◽  
Anupam Kumar ◽  
Rajinder Singh Smagh

Elephant dung is an excellent source of cellulosic fiber that is a basic requirement for paper making. But they contributed to very small percentage production of elephant dung. So, researchers are trying to find a new area of utilization of elephant dung fiber pulp as in reinforcement’s polymer composite. In this experiment element dung fiber pulp in the natural fiber component chemically treated with alkaline and soda AQ solution in this study, it has been aimed to use elephant dung fiber pulp in composite material and to study mechanical properties of the produced material. The produced composite samples were then characterized using tensile test, Izod impact test, thickness test. The fracture surface of the polymer composite sample was also inspected with the help of SEM. The content of elephant dung fiber pulp is varied (35%, 45%, 55%) weight percentage whereas the epoxy resin is varied (50%, 40%, 30%) percentage is kept constant 15% in hardener. The entire sample has been tested in a universal testing machine as per ASTM standard for tensile strength and impact strength. It is observed that composite with 35% fiber pulp is having the highest tensile strength of 4mm 6.445 Mpa and 8mm 11.80 Mpa. The impact strength of composite with 35% fiber pulp washes highest than 45% to 55% dung fiber pulp. This produces composite sheet will be used for the surfboards, sporting goods, building panel this not only reduces the cost but also save from environmental pollution.


2020 ◽  
pp. 002199832092314
Author(s):  
Adefemi Adeodu ◽  
Lateef Mudashiru ◽  
Ilesanmi Daniyan ◽  
Abdulmalik Awodoyin

Mechanical properties (impact, hardness and tensile strength) characterization of samples containing homogenous mixtures of Al 6063 matrix and varying amount of silver nanoparticles mixed with calcium carbonate at 2, 4, 6% weight fractions, respectively, produced by method of stir casting were carried out. Measurement of impact energy, hardness and tensile strength of the produced samples at 24℃ (ambient) temperature was done by Charpy impact, Brinell hardness and universal tensile testing machine in accordance to ASTM E23, E384 and E8/E8M-13M, respectively. The magnitude of impact and hardness increased evidently with increase in percentage weight fraction of the AgNPs. The refined samples were examined under an optical microscope. The fracture surfaces of the impact test samples were further examined by scanning electron microscopy. There is an increase in tensile strength, elongation and modulus of elasticity of Al-AgNP composites compared to as-cast aluminium alloy. The use of stir-casting technique influences the homogeneity and microstructure of the composites positively. It is concluded that Al-silver nanocomposites possess better qualities in hardness and strength and can replace conventional aluminium alloy in terms of performance and longer life in industrial application.


2012 ◽  
Vol 06 (04) ◽  
pp. 402-407
Author(s):  
Boniek Castillo Dutra Borges ◽  
Eduardo José Souza-Júnior ◽  
Anderson Catelan ◽  
Luís Alexandre Maffei Sartini Paulillo ◽  
Flávio Henrique Baggio Aguiar

ABSTRACTObjective: This study aimed to evaluate the impact of extended photoactivation time on ultimate tensile strength (UTS), water sorption (WS) and solubility (WSB) of resin-based materials used as fissure-sealantsMethods: A fissure-sealant (Fluroshield) and a flowable composite (Permaflo) polymerized for 20 and 60 seconds were tested. For UTS, 20 hourglass shaped samples were prepared representing two materials and two photoactivation time (n=5). After 24-h dry-storage, samples were tested in tension using a universal testing machine at a cross-head speed of 0.5 mm/min (UTS was calculated in MPa). For WS and WSB, 20 disks with 5 mm diameter and 1 mm height (n=5) were prepared and volumes were calculated (mm3). They were transferred to desiccators until a constant mass was obtained (m1) and were subsequently immersed in distilled water until no alteration in mass was detected (m2). Samples were reconditioned to constant mass in desiccators (m3). WS and WSB were determined using the equations m2-m3/V and m1-m3/V, respectively. Data were subjected to twoway ANOVA and Tukey’s HSD test (P<.05).Results: There was no significant difference between materials or photoactivation times for the UTS and WS. Permaflo presented lower but negative WSB compared to Fluroshield.Conclusions: Extended photoactivation time did not improve the physical properties tested. Fluroshield presented physical properties that were similar to or better than Permaflo. (Eur J Dent 2012;6:402-407)


2021 ◽  
Vol 903 ◽  
pp. 134-139
Author(s):  
Jānis Zicans ◽  
Remo Merijs Meri ◽  
Tatjana Ivanova ◽  
Andrejs Kovalovs ◽  
Piotr Franciszczak

Investigation presents an experimental study of mechanical properties of hybrid bio-composites made from man-made cellulose fibres and soft wood microfiller embedded into polypropylene homopolymer matrix at different weight contents. Mechanical properties such as elastic modulus, tensile strength, and impact resistance of the reinforced composites determined for various total weight contents of both biobased fillers were used as the design parameters. The problem was solved by planning the experiments and response surfaces method. The results demonstrate that using the both filler types enhance the mechanical properties. The tensile modulus increases by ~115%. The bio-composite with the highest weight content of man-made cellulose fibres and the lowest content of soft wood microfibers possesses maximum tensile strength (more 66 MPa). Addition of man-made cellulose fibres demonstrate a significant influence on the impact resistance of the investigated composites.


2014 ◽  
Vol 638-640 ◽  
pp. 1536-1540 ◽  
Author(s):  
Hu Zhu Zhang ◽  
Yuan Fang

In order to evaluate the flexural-tensile property of cement stabilized coal gangue roadbase materials, flexural-tensile strength and flexural-tensile modulus of materials, whose cement dosage range from 4% to 7%, were tested on the automatic servo universal material testing machine with one-third loading method. Based on the test data, correlation equations between cement dosage and flexural-tensile strength and flexural-tensile modulus were established. Results show that: cement dosage is an important influence factor of flexural-tensile property, both flexural-tensile strength and flexural-tensile modulus increase linearly with the increase of the cement dosage. Cement stabilized coal gangue roadbase materials have a good flexural-tensile property and suitable for base in the pavement structure.


2020 ◽  
Vol 9 (2) ◽  
pp. 8-15
Author(s):  
Anupam Kumar ◽  
Ramratan . ◽  
Rohit Kumar

The aim of this study is utilized agricultural waste which may be profitable, pollution free and economically viable for the farmer and industries. In this experiment short flax fiber pulp is the natural fiber component chemically treated with alkaline solutions. Six specimens will be prepared in different volume percentage of flax fiber pulp and epoxy resin in order to get more accurate results. In this study it has been aimed to use flax fibres in composite materials and to study the mechanical properties of the produced samples. The mechanical tests results (thickness test, Tensile strength and impact strength tests) and SEM micrographs indicated flax fibres as an alternative natural fibre source for developing reinforced composites for various industries. The content of short flax fiber pulp is varied (35%, 45%, 55%) weight percentage whereas the epoxy resin is varied (50%, 40%, 30%) percentage is kept constant 15% in hardener. All the sample have been tested in universal testing machine as per ASTM standard for tensile strength and impact strength it is observed that composite with 35% flax fiber pulp is having highest tensile strength of 4 mm (4.57 Mpa) and 8 mm (6.04 Mpa). The impact strength of composite with 35% flax fiber pulp was highest than 45% to 55% flax fiber pulp.


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