• 청정기술
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• 제20권3호
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• pp.226-231
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• 2014

본 연구는 미세 몰드 기술을 이용하여 산세기 자극에 따라 모양이 변화하는 야누스 입자를 제조하는 방법에 관한 것이다. 야누스 입자는 산세기(pH) 응답형 단량체인 acrylic acid (AA)를 사용하여 친수성 부분을 제조하고, trimethylolpropane triacylate (TMPTA)를 사용하여 소수성 부분을 제조하였다. 제조된 야누스 입자는 산세기 변화에 따라서 친수성 부분의 팽윤이 유도되며 결과적으로 자극 응답성을 가짐을 증명 하였다. 자극 응답성 정도는 산세기의 범위 또는 AA의 조성을 다양화 함으로써 제어가 가능하다. 더 나아가 야누스 입자의 양쪽 부분이 반대 전하를 띄는 특성을 부여하기 위해 AA와 2-(dimethylamino)ethyl methacrylate (DAEMA)를 사용하여 양극성 야누스 입자를 제조하였다. 양극성 야누스 입자는 동일한 산세기 조건에서 서로 다른 팽윤율을 갖게 되며 비대칭적 형상을 띄게 된다. 결론적으로, 본 연구에서는 야누스 입자의 친수성 부분에 산세기 응답형 단량체를 사용함으로써, 산세기 자극에 의해 가역적으로 모양 변형이 가능한 야누스 입자를 제조하였다. 본 연구를 통해 제조된 자극 응답형 야누스 입자는 향후 바이오 센서나 검출 기구 등에 활용 될 것으로 기대한다.

• 폴리머
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• 제35권2호
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• pp.106-112
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• 2011

열적 안정성과 기계적 강도에서 우수한 장점을 지니고 있는 파라계 aramid 세그먼트와 제막 특성이 우수하고 내 가수분해성이 우수한 sulfone 세그먼트로 이루어진 공중합체를 이용하여 연료 전지용 막으로써의 응용가능성을 연구하였다. 아라미드 고분자의 용해도를 향상시키기 위해 아민기를 갖는 sulfonated ether sulfone 단량체와 p-phenylene diamine 그리고 terephthaloyl chloride를 일정한 순서로 반응시켜 아민으로 말단화된 공중합체를 합성하고 이것을 epoxy group을 함유하고 있는 trimethylolpropane triglycidyl ether(TMPTGE)와 열 가교를 통해 고분자 전해절막으로 제조되었으며, 전구체의 합성을 비롯한 각 단계의 반응은 $^lH$ NMR, FTIR, 및 적정에 의하여 확인되었다. 얻어진 전해질막은 이온교환용량과 함수율, 수소이온전도도 등이 측정되었으며 sulfonated ether sulfone 단량체의 함유량이 증가할수록 이온교환용량, 함수율, 수소이온전도도가 증가하는 것이 관찰되었다. Sulfonic acid sulfone 세그먼트를 60 몰%로 갖는 고분자 전해질막의 경우 이온교환용량이 1.88 meq/g, 함수율은 110wt% 이하의 수치를 보였으며, 가장 높은 수소이온전도도의 값은 상대습도 100%, $25^{\circ}C$에서 $7.4{\times}10^{-2}$ S/cm이었다.

• 폴리머
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• 제36권5호
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• pp.668-676
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• 2012

본 연구에서는 실리카 나노입자를 bis[3-(trimethoxysilyl)propyl]amine(BTMA) 실란 커플링제로 표면 개질한 후, 실리카에 도입되는 2차 아미노기인 -NH기와 Michael 부가반응이 가능한 acrylate기를 가지는 trimethylolpropane ethoxylate triacrylate(TMPET)와 3-(acryloyloxy)-2-hydroxypropyl methacrylate(AHM)로 표면 처리를 하여 반응성(meth)acrylate기를 가지는 brush를 도입하는 연구를 수행하였다. 1분자에 Michael 부가반응성이 있는 acrylate기를 3개 갖는 TMPET와 1분자에 반응성이 있는 acrylate기와 반응성이 없는 methacrylate기를 각각 1개씩 갖는 AHM을 사용하여, 처리 몰(mol)수의 변화가 실리카 표면에 도입되는 (meth)acrylate기에 미치는 영향을 Fourier transform infrared spectroscopy(FTIR), elemental analysis(EA) 및 고체 상태 cross-polarization magic angle spinning(CP/MAS) nuclear magnetic resonance spectroscopy(NMR)법을 사용하여 분석하였다. BTMA로 개질된 실리카를 TMPET로 처리하면, 액체상태의 순수 TMPET와 순수 BTMA의 반응과는 달리 TMPET 1분자당 3개씩 결합있는 acrylate기 대부분이 BTMA의 -NH기와 Michael 부가반응이 일어나는 것을 확인하였다. 따라서 BTMA로 처리한 실리카에 Michael 부가반응으로 반응성 (meth)acrylate기를 도입하기 위하여서는 AHM과 같이 Michael 부가반응성이 있는 acrylate기와 Michael 부가반응성이 없는 methacrylate기를 각각 1개씩 가지는 AHM을 사용하는 것이 필요함을 확인하였다.

• Elastomers and Composites
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• 제52권3호
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• pp.187-193
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• 2017

In this study, the effect of the cure, mechanical properties, and oil resistance of NBR (acrylonitrile-butadiene rubber)/peroxide compounds were investigated for various co-agents. NBR compounds were characterized using a swelling test, a rheometer (MDR), and a compression set test. Mechanical properties were tested with original compounds, heated in air and exposed to the ASTM No.1, IRM 903 oil. NBR compounds were prepared using peroxide as the crosslinking agent. Trimethylolpropane trimethacrylate (TMPTMA), triallyl isocyanurate (TAIC), and 1,2-polybutadiene (HVPBD) were used as co-agents. The NBR compounds containing TMPTMA and HVPBD lowered the scorch time, while the addition of TAIC did not significantly change the scorch time. NBR compounds containing TMPTMA increased the crosslinking density, while the addition of TAIC and HVPBD lowered the crosslinking density. Moreover, the addition of TMPTMA improved the oil resistance of the NBR compound.

• 한국응용과학기술학회지
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• 제24권3호
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• pp.287-295
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• 2007

Three phosphorus functional groups were introduced in one structural unit of polymer backbone to enhance the flame retardancy of PU coatings. In the first step, we synthesized tetramethylene bis(orthophosphate) (TBOP) that contained two phosphorus functional groups in one structural unit. In the next step, we synthesized modified polyesters (ATBTP-10C, -20C, -30C) that contained triphosphorus group using TBOP, 1,4-butanediol, trimethylolpropane, adipic acid, and another functional monomer, phenylphosphonic acid (PPA). The amount of PPA in ATBTPs was adjusted from 10 wt% to 30 wt%. The structure and characteristics of ATBTPs were examined using FT-IR, NMR, GPC, and TGA analysis. From the thermo-behavior test of diphosphorus modified polyester (ATBT) and ATBTPs, the afterglow of ATBT, ATBTP-10C, ATBTP-20C, and ATBTP-30C were 24.7, 27.1, 29.0, and 31.7%, respectively. It was found from this result that the afterglow increased with the amount of PPA component.

• 한국응용과학기술학회지
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• 제17권4호
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• pp.240-247
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• 2000

Two-component polyurethane flame-retardant coatings were prepared by blending trichloro aromatic modified polyesters(TCMPs) and polyisocyanate. TCMPs were synthesized by polycondensation of trichlorobenzoic acid(TCBA), a flame-retardant component, with adipic acid, 1,4-butanediol, and trimethylolpropane. The content of TCBA was varied in 10, 20, and 30 wt% for the reaction. These new flame-retardant coatings showed various properties comparable to other non-flame-retardant coatings. Moreover, we carried out the combustion test and the flammability test for our flame-retardant coatings. The results of vertical burning test for the coatings containing more than 20 wt% of TCBA were determined as 'no burn'. The results of flammability test for the coatings with 20 wt% and 30 wt% of TCBA contents indicated the limiting oxygen index(LOI) values of 25% and 28% respectively, which implied relatively good flame retardancy.

• 한국응용과학기술학회지
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• 제25권3호
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• pp.332-340
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• 2008

Two component polyurethane (PU) flame retardant coatings were prepared by blending trichloro modified polyesters (TCMPs) and isophorone diisocyanate isocyanurate. TCMPs were synthesized by polycondensation of trichlorobenzoic acid (TCBA), a flame retardant component, with adipic acid, 1,4 butanediol, and trimethylolpropane. The content of TCBA was varied in 10, 20, and 30 wt% for the reaction. Theses new flame retardant coatings showed various properties comparable to other non flame retardant coatings. Moreover, we carried out the combustion test and the flammability test for our flame retardant coatings. The results of vertical burning test for the coatings containing more than 20 wt% of TCBA were determined as no burn. The results of flammability test for the coatings with 20 wt% and 30 wt% of TCBA contents indicated the limiting oxygen index (LOI) values of 26% and 29% respectively, which implied relatively good flame retardancy.

• 한국염색가공학회지
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• 제11권4호
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• pp.1-7
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• 1999

Urethane-acrylate propelymers for secondary coating of optical fiber and high - performance material were prepared from the 4,4'-diphenylmethane diisocyanate(MDI), poly(tetramethylene oxide)glycol(PTMG, Mw 650 or 1000), 1,6-hexanediol(HD), 2-hydroxyethyl acrylate(HEA), and dibutyltin dilaurate as a catalyst. UV-Curable polyurethane acrylates were formulated from the urethane-acrylate prepolymers, three types of reactive diluents(DTs) having mono-, di-, and trifunctional-phenoxyethyl acrylate(PEA), hexanediol diacrylate(HDDA), and trimethylolpropane triacrylate(TMPTA), and 1-hydtoxycyclohexyl phenyl ketone(Irgacure 184) as a photoinitiator. The UV-cured films of polyurethane acrylates were obtained by curing using a medium-pressure mercury lamp(U W/cm, $\lambda_{max}=365\;nm)$. In this work, the effects of molecular weights of polyol and diol with low molecular weight into polymer chain on mechanical and dynamic mechanical properties of UV-cured polyurethane acrylates were studied. The structure and properties of the films obtained from the UV photopolymerization of urethane-acrylate prepolymer were investigated by FT-IR spectroscopy, dynamic mechanical measurement, tensile testing, and X-ray diffractometry.

• 폴리머
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• 제37권2호
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• pp.232-239
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• 2013

A series of novel imidazole-blocked diisocyanate bioadhesives (IBAs) were synthesized from reaction of toluene 2, 4-diisocyanate (TDI), isophorone diisocyanate (IPDI), hydroxyl-terminated polylactide (HO-PLA-OH), 1,1,1-trimethylolpropane (TMP), and imidazole. Synthesis of IBAs was confirmed by Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). Differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) revealed that the TDI-based IBA had lower thermal dissociation temperature and a faster deblocking rate than IBA based on IPDI. Hydroxyl-terminated polyurethane (HPU) was introduced to study the adhesive effect of the synthesized IBAs. Improvement on elastic modulus, tensile strength and water resistance of IBA-modified HPU in comparison with neat HPU suggested the good adhesive effect of IBA due to the strong chemical reaction between released NCO groups from IBA and hydroxyl groups from HPU.

• Elastomers and Composites
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• 제55권2호
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• pp.95-102
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• 2020

Currently, peroxide cure is a widely used cure system for rubber materials. To improve its effectivity, co-agents are used to enhance the peroxide efficiency and mechanical properties of rubber materials. Co-agents are multifunctional organic compounds that are highly reactive towards free radicals. These co-agents provide higher cross-link densities for a given peroxide concentration and improve the mechanical properties of peroxide-cured rubber composites. In this study, trimethylolpropane trimethacrylate (TMPTMA) and high vinyl 1,2-polybutadiene (HVPBD) were used as co-agents. In order to obtain a concentration that achieves a favorable balance between mechanical properties and co-agent concentration, this research investigated the effects of co-agent content on the curing characteristics, chemical structures, and mechanical properties of HNBR composites. Additionally, the heat aging properties and compression sets of HNBR composites were investigated. Based on the results, we found that the HNBR composites with TMPTMA co-agents exhibited higher Shore A hardness and 10% modulus and better heat aging resistance and compression set than that of the HVPBD co-agent. The heat aging resistance and compression set deteriorated with increasing HVPBD content.