• Elastomers and Composites
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• v.48 no.4
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• pp.256-262
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• 2013

We synthesized thermoplastic polyurethane elastomer (TPU) with different contents of sulfuric acid group, and characterized their physical properties such as mechanical, thermal and grip properties. And the results were compared with carboxylic acid-introduced TPU. Wet slip, tensile strength and abrasion properties were increased by the introduction of acid group. Mechanical properties increased with increasing the acid content up to 0.3 wt%. However, wet slip was continually increased as the acid content increased due to increase of hydrophilicity of TPU.

• Applied Chemistry for Engineering
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• v.30 no.1
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• pp.81-87
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• 2019

In this study, synthetic methods and physical properties for a new class of glycidyl azide polymer (GAP) were investigated for energetic thermoplastic elastomers (ETPE). Four kinds of GAP copolymer polyols were synthesized by introducing nucleophiles such as azide, alkoxide and alkyl amine into poly(epichlorohydrin) (PECH). The GAP copolymer synthetic reaction can be evaluated as an environmental benign and efficient synthetic method due to the simultaneous one-step reaction using two kinds of nucleophiles and the complete consumption of sodium azide. The relative stoichiometric substitution ratio analysis and the progress of reaction were checked and monitored by inverse gated decoupled $^{13}C$ NMR and Fourier transform infrared (FT-IR) spectroscopy. The glass transition temperature and molecular weight were measured by differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) analysis. The synthesized poly($GA_{0.8}-butoxide_{0.2}$), poly($GA_{0.7}-n-butylamine_{0.3}$), poly($GA_{0.7}-dipropylamine_{0.3}$) and poly($GA_{0.7}-morpholine_{0.3}$) had a glass transition temperature ranged from -39 to $-26^{\circ}C$.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.305-313
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• 2013

In this study, we investigated effects of thermal annealing on the thermal properties and microphase separation behaviors of glycidyl azide-based thermoplastic polyurethane elastomers (ETPE). The GAP-based ETPEs were characterized by attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimeter (DSC), dynamic mechanical analysis (DMA), and gel permeation chromatography (GPC). The effects of annealing temperature conditions ($80{\sim}130^{\circ}C$, 1 h or 24 h) on the properties of the ETPEs were investigated. The intensity of azide group absorption peak of ATR-FTIR spectra and the solubility of ETPE for methylene chloride and dimethylformamide solvent decreased after the annealing at $130^{\circ}C$ for 1 h and at $105^{\circ}C$ for 24 h. With increasing the annealing temperature from $80^{\circ}C$ to $110^{\circ}C$, the high temperature rubbery plateau region of storage modulus curves from DMA thermogram for GAP-based ETPEs was extended to the higher temperature.

• Polymer(Korea)
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• v.36 no.6
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• pp.721-726
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• 2012

Thermoplastic polyurethane (TPU) elastomer is used as an encapsulant in undersea sonar devices. A new material for sonar encapsulant exhibiting better mechanical strength than TPU along with a lower swelling ratio for seawater and oil is required to prolong its application. TPU grafted silica nanoparticles (TPU-g-silica) were prepared and then they were melt mixed with TPU to fabricate desirable composites for underwater applications. The composite containing silica nanoparticles exhibited better tensile strength and lower swelling ratios in the seawater and oil than TPU regardless of the surface treatment of the silica particles. At fixed silica content in the composite, the TPU/TPU-g-silica composite exhibited better tensile strength and lower swelling ratio than the TPU composite with the pristine silica particles. Furthermore, the TPU/TPU-g-silica composite exhibited enhanced tensile strength as compared to TPU after being impregnated with oil.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.18-18
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• 2012

전 세계적으로 이산화탄소 배출량 저잠을 위해 모든 산업분야에서 연구개발의 중점을 두고 있다. 그의 일환으로 자동차 산업에서는 EU규제에 따라 리사이클이 가능한 소재 개발이 요구되고 있으며, 그중 많은 양이 사용되고 있는 PU Foam의 대체 재료 개발이 시급한 실정이다. 기존 자동차의 흡음재로 주로 사용되고 있는 PU Foam 소재는 통기성이 부족할 뿐만 아니라 연소 시 인체에 유해한 HCN Gas를 발생시키고, 한번 성형된 부품은 Recycle 및 Re-Use가 불가능하다는 단점이 있다. 또한 장시간 사용시 황변 발생과 악취가 발생하는 등으로 최근 대두되고 있는 자동차 내장재 감성품질 향상 측면에 한계를 나타내고 있다. 이러한 Low Melting 성능을 가지는 PET 부직포 소재의 한계를 극복하기 위하여 저융점 성능의 Elastic Fiber의 개발과 함께 고탄성 복합부직포 소재의 개발을 통해 높은 변형률과 우수한 복원력을 나타내는 환경친화형 열가소성 탄성체(Thermoplastic Elastomer) 개발을 추진하고 있다. 고탄성 복합부직포는 자동차 내장재 성형 시 열을 가하더라도 Elastomer 자체의 탄성 발현을 통해 초기의 Bulky성을 유지할 수 있으며, Recycle 및 Re-use가 가능하여 환경 친화적인 측면에서도 큰 장점을 갖고 있다. 자동차용 흡음 내장재뿐만 아니라 각종 수송용 차량의 경량화 및 쾌적성 향상을 위한 용도로써 자동차 내장용 PU Foam의 57% 이상을 차지하고 있는 Seat Cushion재 등의 대체가 가능하며, 다양한 산업분야에서 사용되고 있는 PU Foam의 대체로 다양한 용도 전개가 가능할 것으로 예상된다. 본 연구에서는 PU Foam의 대체 재료로 각광받고 있는 Elastic PET를 개발하여 자동차 내장재로의 적용 가능성을 검토하였다.

• Journal of the Korean Society of Safety
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• v.31 no.1
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• pp.61-65
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• 2016

In this study, we considered the ignition possibility for the shredded thermoplastic elastomer at the fire ground loaded the waste TPE. The average moisture content of the TPE sample was almost 0.33 wt.% at $110^{\circ}C$ and the range of ignition point was $461.9{\sim}491.9^{\circ}C$ approximately. In addition, we analyzed the change of weight and calorie the TPE sample according to temperature variations using the TG-DTA analyzer. As a result, the weight loss occurred twice in $250{\sim}420^{\circ}C$ and $420{\sim}473^{\circ}C$, and we found the second weight loss temperature range was the ignition point of TPE. Also, we conducted the spontaneous ignition tests of TPE for the wet and dry samples and we confirmed that the possibility of spontaneous ignition of TPE was very low. The elapsed time and humidity had little influence on the spontaneous ignition of TPE in this experimental conditions. In conclusion, the spontaneous of the shredded waste TPE in this study.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.3 s.18
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• pp.129-139
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• 2004

DXD-19 is a flexible sheet explosive, which is a new polymer-bonded explosives(PBX's). DXD-19 is relatively insensitive and can be extruded into various configurations to be applied to munitions. A typical application includes multi-point initiation for the warhead, cutting/severance devices and transfer lines. The DXD-19 composition employs a binder system derived from the thermoplastic elastomer(HyTemp 4454) containing $5\%$ OH terminated with isocyanate curable for increasing mechanical properties. The use of an elastomer CAB increases its mechanical properties and the use of an energetic plasticizer BDNPF/BDNPA(F/A) improves the process ability as well as energy contents. The composition of the extruded DXD-19 formulation is formed $\%$ weight of $PETN/HyTemp/ATEC/(F/A)/CAB=72\~73/12\~13/6\~7/6\~7/1\~2$. Our safety tests of DXD-19 shows Insensitivity to an impact test and friction test, good thermal stability and excellent mechanical properties.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.1
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• pp.119-124
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• 2001

Dimethyl terephthalate (DMT). 1.4-butanediol (1.4-BD) and poly (tetramethylene ether) glycol (PTMG) in the molecular weight of 2000 (g/mol) were used to synthesize poly(ether-b-ester) thermoplastic elastomers (TPEEs). The final copolymers were annealed to improve thermal stability at elevated temperatures and mechanical properties. This study showed that as the proportion of soft segment increases melting temperature and degree of crystallinity of TPEEs decrease constantly. In case of mechanical properties like flexural strength and flexural elastic modulus. $35-PTMG^{2000}$ indicates the highest values due to more efficient physical interlock.

• Elastomers and Composites
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• v.45 no.4
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• pp.245-249
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• 2010

Much interest on the thermoplastic elastomers (TPEs) has recently been attracted in commercial fields as well as scientific and applied research. The TPEs have their own characteristic area especially in relation with block copolymers as well as many other polymeric materials, since they show interesting features displayed by the conventional vulcanized rubber, and at the same time, by the thermoplastics. In addition, they are characterized by a set of interesting properties inherent to block and graft copolymers, variety of blends and vulcanized materials. The importance of TPE as organic materials can be evaluated by the number of published reports (papers, patents, technical reports, etc). For the suitable introduction of the TPE, historic, scientific, technical and commercial considerations should be taken into account. This review article starts with a brief discussion on historical considerations, followed by a introduction of the main preparations and analytical techniques utilized in chemical, structural, and morphological studies. The properties, processing tools, the position among organic materials, and applications of TPEs are also briefly reviewed. Finally, the most probable trends of their future development are discussed in a short final remarks.

• Composites Research
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• v.34 no.3
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• pp.192-198
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• 2021

Due to enormous market growing of electric vehicles without combustion engine, reducing unwanted BSR (buzz, squeak, and rattle) noise is highly demanded for vehicle quality and performance. Particularly, innerbelt weatherstrips which not only block wind noise, rain, and dust from outside, but also reduce noise and vibration of door glass and vehicle are required to exhibit high damping properties for improved BSR performance of the vehicle. Thermoplastic elastomers (TPEs), which can be recycled and have lighter weight than thermoset elastomers, are receiving much attention for weatherstrip material, but TPEs exhibit low material damping and compression set causing frictional noise and vibration between the door glass and the weatherstrip. In this study, high damping EPDM (ethylene-propylene-diene monomer)/PP (polypropylene) thermoplastic vulcanizates (TPV) were investigated by varying EPDM/PP ratio and ENB (ethylidene norbornene) fraction in EPDM. Viscoelastic properties of TPV materials were characterized by assuming that the material damping is directly related to the viscoelasticity. The optimum material damping factor (tanδ peak 0.611) was achieved with low PP ratio (14 wt%) and high ENB fraction (8.9 wt%), which was increased by 140% compared to the reference (tanδ 0.254). The improved damping is believed due to high fraction of flexible EPDM chains and higher interfacial slippage area of EPDM particles generated by increasing ENB fraction in EPDM. The stick-slip test was conducted to characterize frictional noise and vibration of the TPV weatherstrip. With improved TPV material damping, the acceleration peak of frictional vibration decreased by about 57.9%. This finding can not only improve BSR performance of electric vehicles by designing material damping of weatherstrips but also contribute to various structural applications such as urban air mobility or aircrafts, which require lightweight and high damping properties.