Meta-aramid 나노섬유의 전기방사 공정인자들이 물성과 투습성에 미치는 영향

박영신,남영식,이민성,박원호,Park, Young Shin,Nam, Young Sik,Lee, Min Sung,Park, Won Ho 한국섬유공학회 2012 한국섬유공학회지 Vol.49 No.4

Meta-aramid nanofibers were prepared by the electrospinning process. In this study, electrospun meta-aramid nanofiber webs were prepared with various velocity ratios of a collector drum, the fiber diameter and thickness of electrospun nanofiber webs, and then compared with values of tensile properties and breathable water-resistance. The meta-aramid nanofiber webs were analyzed by field-emission scanning electron microscopy, a tensile tester, water vapor permeability, an X-ray diffractometer and thermogravimetric analysis. The diameter of meta-aramid nanofibers ranging from 165 to 252 nm was obtained by electospinning. The tenacity, young's modulus and crystallinity of meta-aramid webs were decreased by increasing the diameter of meta-aramid nanofibers, however, water vapor permeability increased. It was confirmed that the breathable water-resistance of meta-aramid nanofiber webs were similar to that of chemical treated PTFE film.

Effects of Aluminum Deposition on the Functional Properties of the Meta-aramid Fabrics

이선영,박종현,이승구 한국섬유공학회 2018 Fibers and polymers Vol.19 No.1

Meta-aramid fabrics were deposited with aluminum to examine the effects of aluminum deposition on the functional properties of meta-aramid fabrics. Various functional properties of the aluminum deposited meta-aramid fabrics were assessed with sputtering processing parameters such as chamber pressure and sputtering power. SEM-EDX was utilized to investigate surface morphology and compositions of the deposited meta-aramid fabrics. The optical, thermal, electric, and abrasive properties of the deposited meta-aramid fabrics were measured by color reader, KES-F7 thermo-Lab 2 system, milliohm meter, and abrasion testing machine. The obtained results indicated the optical, thermal, electric, and abrasive properties of the deposited meta-aramid fabrics were influenced clearly by deposition processing parameters. The light reflectance, thermalconductivity, electric resistance, and abrasion strength of the aluminum deposited meta-aramid fabrics were shown to be a maximum at a chamber pressure and a sputtering pressure, and the optimum deposit condition could be established.

A novel and effective approach to enhance the interfacial interactions of meta-aramid fibers

Hui Zhang,Xiaoyun Du,Jiawei Liu,YunHong Bai,Jingyi Nie,Jiaojun Tan,Zhibin He,Meiyun Zhang,Jinbao Li,Yonghao Ni 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.120 No.-

Meta-aramid paper exhibits some unique properties, including high temperature resistance, electricalinsulation. However, due to the inherent chemical inertness of aramid fibers, the interfacial bondingbetween fibers is weak, which negatively affect the properties of aramid paper. Herein, we report a simple,effective and scalable process for substantially improving the interfacial bonding between aramidfibers, thus, mechanical and insulating properties of the meta-aramid composite paper, and it wasachieved by surface coating of aramid paper with meta-aramid stock solution that contains N, N dimethylacetamide(DMAc)-CaCl2 and high molecular weight poly (m-phenylene isophthalamide) polymers. Results show that the tensile strength, modulus, internal bond strength and tearing index of the resultantall-PMIA paper increased by 83 %, 58 %, 173 % and 89 %, respectively, in comparison with those of the control. The breakdown strength of the improved aramid paper is 190 % higher than that of the control paper,attaining 26.46 KV/mm. This work provides a simple, economical, efficient, and scalable method toimprove the overall performance of meta-aramid paper, which has great potential to be implementedat the industrial scale.

에탄올 비용매를 이용한 메타아라미드 피브리드 제조 및 형태학적 특성

백병운,김완진,정용식,Baek, Byungwoon,Kim, Wan Jin,Chung, Yong Sik 한국섬유공학회 2014 한국섬유공학회지 Vol.51 No.3

Fibrids are materials of a complex fibrous, film-like, or intermediate form. The diameter of the particles varies between $20-50{\mu}m$, and $100-10,000{\mu}m$. The optimal form and size of the particles depends in each case on the area of application. The fibrid form is the result of two processes, viz. a wave process and diffusion. The life span and break-up pattern of the polymer depend on the interphase surface tension, the viscosity of the polymer, and the diffusion speed ratio of the polymer and medium. In this study, m-aramid was polymerized at low temperature and in solution with an equal molar ratio of MPD and IPC in DMAc. The meta-aramid solution was prepared by dissolution in DMAc, and ethanol was used as a coagulation bath. The rotation speed was the main factor affecting the formation and morphology of the fibrid. Meta-aramid paper was produced from m-aramid fiber with meta-aramid fibrid by wet laying. The results showed that fibrid particle sizes decreased with increasing rotation speeds and decreasing concentrations of m-aramid in the solution. The properties of the m-aramid fibrid as a function of the processing conditions were investigated using an image analyzer, optical microscopy, and SEM. The resulting meta-aramid paper was analyzed in terms of its morphology, thickness, air permeability, and mechanical properties.

Dyeing and Fastness Properties of Oxidation Dyes on Meta-Aramid Knitted Fabric

김영도,이종민,이정진 한국섬유공학회 2023 Fibers and polymers Vol.24 No.10

Oxidation dyes are typically used as permanent hair dyes. When dye intermediates are applied, they produce oxidation dyes through oxidation and addition reactions during dyeing process. Owing to the small size of the dye intermediates, they can penetrate into hairs or fibers easily. In this study, three oxidation dye intermediates (p-phenylenediamine, o-phenylenediamine, and N-phenyl-p-phenylenediamine) were applied for dyeing of meta-aramid knitted fabric. Color yields (K/S values) of meta-aramid fabric dyed with oxidation dyes were highly dependent upon dyeing temperature, dyebath pH, and concentration of hydrogen peroxide. The oxidation dyes exhibited good build-up property when dyed at high temperature (110–130 °C), but showed poor build-up in the low temperature dyeing method (40 °C, 12 h). The dyed meta-aramid fabric exhibited brown, gray, pink, purple, and black hues. Wash fastness of meta-aramid fabric from high temperature dyeing was moderate to very good and that from low temperature dyeing was poor to moderate. Lightfastness was moderate with 4 rating for high temperature dyed meta-aramid fabric but it was very poor in the low temperature dyeing.

The study of efficiency of Al₂O₃ drop coated electrospun meta-aramid nanofibers as separating membrane in lithium-ion secondary batteries

Jeon, K.S.,Nirmala, R.,Navamathavan, R.,Kim, K.J.,Chae, S.H.,Kim, T.W.,Kim, H.Y.,Park, S.J. North-Holland 2014 Materials Letters Vol.132 No.-

This paper presents a relatively simple and low-cost approach to prepare Al<SUB>2</SUB>O<SUB>3</SUB> coated with electrospun meta-aramid nanofibers. These Al<SUB>2</SUB>O<SUB>3</SUB>/meta-aramid composite nanofiber mats can be directly used as separating membrane in rechargeable lithium-ion batteries. The manufacture, characteristics, performance and modifications of these Al<SUB>2</SUB>O<SUB>3</SUB>/meta-aramid composite nanofiber separators are introduced and discussed. In cell test, the capacity efficiency of Al<SUB>2</SUB>O<SUB>3</SUB> coated M-aramid nanofibers separator was much better than that of M-aramid nanofibers. The LiCoO<SUB>2</SUB>/graphite cells assembled with the Al<SUB>2</SUB>O<SUB>3</SUB> ceramic coated M-aramid nanofibers separator exhibited reversibility up to 4.2V with a 232mAh/g discharge capacity. Among numerous battery separators, the thermal shutdown and ceramic based separators are of special importance in enhancing the safety of lithium-ion batteries.

배트 염료를 이용한 메타아라미드 직물의 염색성 및 견뢰도

김미리,이정진,Kim, Mi Ri,Lee, Jung Jin 한국섬유공학회 2013 한국섬유공학회지 Vol.50 No.6

Herein, 100% meta-aramid woven fabric was dyed with three vat dyes and their dyeing and fastness properties were investigated. Color yields of the vat dyes on the meta-aramid fabric were dependent on dyeing temperature, amount of reducing agent, and amount of salt. Dyeing behavior of the vat dye on the meta-aramid fiber was very similar to that on cellulose fibers. It was found that the meta-aramid fabric dyed with 1% owf of Indanthren Black 5589 satisfied the tolerance of the NIR reflectance spectrum of charcoal color in the Korean military standard. Wash and perspiration fastness was generally good, while rubbing fastness was moderate and light fastness was unsatisfactory.

Fabrication and Characterization of Meta-Aramid-Based Nanocomposite Films Reinforced with Graphene

전길우,정영규 한국섬유공학회 2019 한국섬유공학회지 Vol.56 No.5

Herein, we report the microstructures and thermal and electrical properties of meta-aramid-based nanocomposite films containing different graphene contents of 0− 10.0 wt%, which are fabricated by solution-casting of meta-aramid and graphene mixtures in N,N-dimethylacetamide and lithium chloride. The microstructure, thermal stability, and dynamic mechanical thermal and electrical properties of the nanocomposite films were investigated by considering the dispersion and loading content of the graphene sheets. The electron microscopic images and X-ray diffraction patterns revealed that the graphene sheets were well dispersed in the nanocomposite films with relatively low graphene loadings of 0.1−1.0 wt%. However, partially ordered graphene aggregates were formed in the nanocomposite films with high graphene contents of 3.0−10.0 wt%. The thermal stability and dynamic mechanical thermal properties were observed to increase with the graphene content in the nanocomposite films. The electrical percolation threshold of the nanocomposite films was attained at a critical graphene content between 1.0 wt% and 3.0wt%. Consequently, the electrical resistivity decreased substantially from ~1016 Ω cm of the neat meta-aramid film to ~102 Ω cm of the nanocomposite film with 10.0 wt% graphene loading.

Improved Dyeing of Meta-aramid Based on Particle Flow Dyeing Mechanism Using Hot-pressing Dyeing Method

Xin Chen,Dan Sheng,Honghui Xia,Weilin Xu,Bo Deng,Genyang Cao 한국섬유공학회 2020 Fibers and polymers Vol.21 No.12

In this study, a combined dyeing method by integrating the advantages of both carrier dyeing and hot-pressingdyeing was utilized for the dyeing of meta-aramid. A rapid dyeing with increased mechanical properties of the fibers wasachieved for the meta-aramid fiber. A so-called particle flow mechanism involving both N,N-dimethylacetamide (DMAc)and dye molecules was proposed to explain the accelerating effect of this unique dyeing method. The mechanical propertiesand thermodynamic stability of the fiber after hot-pressing were both increased. XRD results showed increasedcorresponding fiber crystallinity. TEM showed that the disperse dyes were well dispersed in DMAc. Cross-sectional opticalphotographs of dyed fibers revealed that the dyes were successfully carried into the interior of the fiber under the synergiceffect of temperature and pressure. Combined with hot-pressing dyeing, the dyeing cycle for the meta-aramid could begreatly shortened and the amounts of dyes and carriers could be significantly reduced.

PTFE/아라미드 복합 백필터 여재 제조 및 특성

배영환,공다정,이소희,여상영 한국섬유공학회 2020 한국섬유공학회지 Vol.57 No.5

Nonwoven fabrics are widely used as filter bags in dust collection facilities, which are industrial air pollution prevention facilities with high dust collection efficiency. The filter bag media is the most important factor that determines the performance of the pulse-jettype dust collection facility. In general, the materials used for filter bag media are polyester, nylon, and polypropylene fibers. Because of the effects of the operating temperature, meta-aramids and polyphenylene sulfide are used at a high temperature of around 200 °C, while glass fiber, polyimide, and polytetrafluoroethylene (PTFE) are used at an ultra-high temperature of approximately 260 °C. Among these, PTFE membranes show/exhibit excellent heat resistance, chemical resistance, non-adhesiveness, and filtration efficiency. Despite the advantages of these fibers, there are no studies on the preparation and properties of filter bag media mixed with meta-aramid staple and PTFE fibers. Therefore, in this study, expanded PTFE filaments were processed into staple fibers to enable carding; mixed with meta-aramid staple fibers by ratio to form the upper and lower webs; and then applied with a PTFE and aramid scrim. The filter bag media was manufactured through a needle punching process and finishing. The air permeability, pore size, tensile strength, filtration performance, and durability of the prepared mixed filter bag media were evaluated. The results show that the prepared low differential pressure filter bag media had improved heat resistance and durability, while maintaining the 100% dust collection efficiency of the existing aramid medium.