• Elastomers and Composites
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• v.48 no.1
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• pp.24-29
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• 2013

We have developed the synthetic processes for the monomers of polyamide-type TPEs (thermoplastic elastomers, TPAEs) obtained from vegetable oil. TPAEs have several superior physical properties to those of thermoplastic elastomers (TPEs). From the common starting material, oleic acid, which is commonly found in various vegetable oils, we have synthesized three ${\omega}$-amino acid monomers ($C_9$, $C_{10}$ and $C_{11}$ ${\omega}$-amino acid) and three ${\alpha}$, ${\omega}$-dicarboxylic acids($C_9$, $C_{10}$ and $C_{11}$ ${\alpha}$, ${\omega}$-dicarboxylic acid) for TPAEs in good yields.

• Clean Technology
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• v.18 no.4
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• pp.360-365
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• 2012

With rapid increase in municipal solid waste (MSW) due to the rising economy, solid waste gasification emerges as one of the promising technologies. Separation of the carbon monoxide (CO) and hydrogen ($H_2$) from syngas obtained by gasification of MSW was studied using the polyamide composite membrane. The separation characteristics of the CO and $H_2$ were studied at different gas flow rates and stage cuts. The permeability of CO and $H_2$ along with the selectivity of $H_2$ with respect to CO was obtained. Furthermore, the Arrhenius plots were obtained to estimate the activation energies of CO and $H_2$ permeabilites.

• Membrane and Water Treatment
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• v.7 no.1
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• pp.55-70
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• 2016

Microfiltration/ultrafiltration (MF/UF) Adsorptive polyamide-6 (PA-6) membranes were prepared using wet phase inversion process. The prepared PA-6 membranes are characterized by scanning electron microscopy (SEM), porosity and swelling degree. In this study, the membranes performance has examined by adsorptive removal of copper ions from aqueous solutions in a batch adsorption mode. The $PA-6/H_2O$ membranes display sponge like and highly porous structures, with porosities of 41-73%. Under the conditions examined, the adsorption experiments have showed that the $PA-6/H_2O$ membranes had a good adsorption capacity (up to 120-280 mg/g at the initial copper ion concentration ($C_0$) = 680 mg/L, pH7), fast adsorption rates and short adsorption equilibrium times (less than 1.5-2 hrs) for copper ions. The fast adsorption in this study may be attributed to the high porosities and large pore sizes of the $PA-6/H_2O$ membranes, which have facilitated the transport of copper ions to the adsorption. The results obtained from the study illustrated that the copper ions which have adsorbed on the polyamide membranes can be effectively desorbed in an Ethylene dinitrilotetra acetic acid Di sodium salt ($Na_2$ EDTA) solution from initial concentration (up to 92% desorption efficiency) and the PA-6 membranes can be reused almost without loss of the adsorption capacity for copper ions. The results obtained from the study suggested that the $PA-6/H_2O$ membranes can be effectively applied for the adsorptive removal of copper ions from aqueous solutions.

• Polymer(Korea)
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• v.36 no.4
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• pp.513-518
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• 2012

Polyamide 12 (PA12) oligomers (oPA1) were prepared by dispersion polymerization of ${\omega}$-amino carboxylic acid and dibasic acid in a dispersion medium, thermally stable hydrocarbon liquid paraffin, YK-D130 (a step polymerization). The molecular weight and various properties of other oligomeric PAs (oPA2) obtained by bulk polymerization without the medium were compared with those of oPA1s. The oPA1s showed lighter white color and narrower molecular weight distribution than oPA2s at the same molecular weight. Moreover elastomeric poly(ether-block-amide) (PEBA)s were synthesized with oPA1 and oPA2 as hard segments and poly(tetramethylene glycol) (PTMG) as a soft segment. The molecular weight distribution, and mechanical property of the PEBA originated from the both oligomeric PAs were characterized.

• Polymer(Korea)
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• v.37 no.1
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• pp.34-40
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• 2013

Commercially available polyamide thermoplastic elastomer (PA-TPE) was blended with hybrid filler which was prepared by means of the reaction between polyhedral oligomeric silsesquioxane (POSS) containing amine group and toluene diisocyanate (TDI)-caprolactam (CL) to explore the effect of blending the hybrid filler with the TPE. The chemical structure of the filler was identified by using FTIR and $^1H$ NMR. The composites, PA-TPE/POSS-(TDI+CL), which were the blends of TDI+CL modified POSS filler and PA-TPE up to 7 wt%, showed better elastic recovery delivered from lower tension setting compared to the PA-TPE and the PA-TPE/octaphenyl POSS blend. In addition the tensile strength and the initial modulus increased with increasing the hybrid filled content. Consequently it was assumed that the POSS-(TDI+CL) filler was a suitable material for enhancing strength and modulus without loss of elastic properties for the original PA-TPE.

• Membrane Journal
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• v.27 no.6
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• pp.506-510
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• 2017

The interfacial polymerization method has been applied to various fields as a reaction in which reactive monomers dissolved in two immiscible solutions cause polymerization at the interface. In the case of water treatment membranes, m-phenylene diamine and trimesoyl chloride are used as reactants. The performance of the membrane is affected by various polymerization factors. In this study, we investigated how the spreading rate of the organic solution influences the surface and structure of the membrane. Spreading rate of organic solutions was adjusted to 7.6 and 25 mm/sec. The solution volume of the organic phase was adjusted to 1~3 drops. The observed results showed that cracks were not found in the polyamide membrane when dropping at a drop of 7.6 mm/sec and dropping two drops at 25 mm/sec. On the other hand, cracks occurred in all cases. Therefore, the spreading rate of the initial organic solvent is expected to greatly affect the performance of the polyamide membrane.

• Journal of the Society of Disaster Information
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• v.7 no.1
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• pp.43-50
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• 2011

The Application of Steel Fiber Shotcrete in tunneling construction has become part of tunneling practice at least since the 1970s because of its high bending and tensile properties. Over the past 3 decades, researcher from all over the world have been significantly developing the associated technologies for improved performance of SFRS. But still it has some major drawbacks in terms of durability, damage of pumping hose, wastage due to rebound concrete, corrosion and it costs high. To overcome this situation researcher has to look for some alternative material. Therefore, this part study deals with the three types of fiber in order to find good alternative for steel fiber. Polyamide and Polypropylene fiber were used in this study with 0.6, 0.5% mixing ratio. To evaluate its fresh and harden properties air content, slump, compressive, split tensile and bending strength were measured. After comparing the results of all three types of fiber reinforced concrete with its different mixing proportion this study propose that polyamide fiber with addition ratio of 0.6 % for field use.

• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.827-833
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• 2005

This study focused on the establishment of optimum formulation of polyamide based hot melt adhesive through adhesive synthesis, study of physical property, and adhesion study. In the previous study, the optimum formulation of base resins (CM831, 843P) and tackifying resin (terpene resin) was determined. The weight ratio of CM831, 843P, and terpene resin was 75, 25, and 10, respectively. Based on the optimum formulation, the effect of wax and filler addition was examined in this study. According to the results, the maximum adhesion strength with the steel could be obtained by the addition of 5 wt% of polyethylene wax although the melt viscosity of adhesive decreased continuously with the addition of wax. In the case of filler, the optimum adhesion property could be achieved by the addition of 10 wt% of talc. However, the addition of filler caused little increase of melt viscosity of adhesive.

• Composites Research
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• v.33 no.6
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• pp.415-420
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• 2020

The interfacial properties in carbon fiber composites, which control the overall mechanical properties of the composites, are very important. Effective interface enhancement work is conducted on the modification of the carbon fiber surface with carbon nanotubes (CNTs). Nonetheless, most surface modifications methods do have their own drawbacks such as high temperatures with a range of 600~1000℃, which should be implemented for CNT growth on carbon fibers that can cause carbon fiber damages affecting deterioration of composites properties. This study includes the use of in-situ interfacial polymerization of polyamide 610/CNT to fabricate the carbon fiber composites. The process is very fast and continuous and can disperse CNTs with random orientation in the interface resulting in enhanced interfacial properties. Scanning electron microscopy was conducted to investigate the CNT dispersion and composites morphology, and the thermal stability of the composites was analyzed via thermogravimetric analysis. In addition, fiber pull-out tests were used to assess interfacial strength between fiber and matrix.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_3
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• pp.1297-1303
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• 2023

Research on enhancing the mechanical strength, lightweight properties, electrical conductivity, and thermal conductivity of composite materials by incorporating nano-materials is actively underway. Thermoplastic resins can change their form under heat, making them highly processable and recyclable. In this study, Polyamide-Nylon 6 (PA6), a thermoplastic resin, was utilized, and as reinforcing agents, fused carbon nano-materials (FCN) formed by structurally combining Carbon Nanotube(CNT) and Graphene were employed. Nano-materials often face challenges related to cohesion and dispersion. To address this issue, Silane functional groups were introduced to enhance the dispersion of FCN in PA6. The manufacturing conditions for the composite materials involved determining the use of a dispersant and varying FCN content at 0.05 wt%, 0.1 wt%, and 0.2 wt%. Tensile strength measurements were conducted, and FE-SEM analysis was performed on fracture surfaces. As a result of the tensile strength test, it was confirmed that compared to pure PA6, the strength of the polymer composite with a content of 0.05 wt% was improved by about 60%, for 0.1 wt%, about 65%, and for 0.2 wt%, the strength was improved by 50%. Also, when compared according to the content of FCN, the best strength value was shown when 0.1 wt% was added. The elastic modulus also showed an improvement of about 15% in the case of surface treatment compared to the case without surface treatment, and an improvement of about 70% compared to pure PA6. Through FE-SEM, it was confirmed that the matrix material and silane-modified nanomaterial improved the dispersibility and bonding strength of the interface, helping to support the load evenly and enabling effective stress transfer.