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증점성분을 포함하는 Propylene Glycol(PG) 기반 고속철도차량용 제·방빙액의 특성
박진명,강부윤,이준구,윤차중,이홍기 한국철도학회 2022 한국철도학회논문집 Vol.25 No.4
동절기 고속철도차량 하부 및 대차부에 착설로 인한 결빙된 설빙이 차량 운행 시 도상자갈구간에서 낙하하여 도상 자갈의 연쇄적인 비산을 일으켜 철도 차량 구조물 및 시설물의 피해가 지속적으로 보고되고 있으며, 이로 인해 고속철도 운행의 지연 및 불편을 초래하고 있다. 이와 같은 문제를 해결하기 위해 감속 운행, 인력 제빙, 이동식 열풍기 등의 단기 대책들을 마련하여 적용하고 있으나 효율성이 떨어진다. 기존보다 효율적인 제·방빙에 대한 연구가 진행되고 있으며, 본 연구에서는 효율적인 제·방빙을 위해 증점 성분을 포함하는 Propylene glycol 기반의 화학적 제·방빙액에 대해 연구 및 성능 비교 평가를 실시하였다. 증점제 4종 중 Polyacrylic acid(PA) 증점제가 가장 우수한 점도 특성을 보였고, PA 증점제 함량에 따른 제·방빙액의 특성을 연구하였다.
랜덤상태의 E-유리 단섬유 강화 불포화 폴리에스터 기반 수지 복합재료의 물성 - E-유리 단섬유의 길이와 함량 및 적층수의 영향 -
박진명,박영광,이영희,서대경,이장훈,김한도,Park, Jin-Myung,Park, Young-Gwang,Lee, Young-Hee,Seo, Dae-Kyung,Lee, Jang-Hun,Kim, Han-Do 한국염색가공학회 2015 韓國染色加工學會誌 Vol.27 No.3
To develop automobile parts, the unsaturated polyester based matrix resin(PR)/reinforcement(randomly oriented chopped E-glass fiber, GF) composites were prepared using sheet molding compound(SMC) compression molding. The effects of GF length(0.5, 1.0 1.5 and 2.0inch)/content (15, 20, 25, 30wt%) and number of ply(3, 4 and 5) on the specific gravity and mechanical properties of PR/GF composites were investigated in this study. The optimum length of GF was found to be about 1.0inch for achieving improved mechanical properties(tensile strength and initial modulus). The tensile strength and initial modulus of composites increased with increasing GF content up to 30wt%, which is favorable content range for SMC. The specific gravity, tensile strength/initial modulus, compressive strength/modulus, flexural strength/modulus and shear strength increased with increasing the number of ply up to 5, which is the maximum number of ply range for SMC. The effectiveness of ply number increased in the flexural strength > shear strength > compressive strength > tensile strength.
UV-Curable Fluorinated Crosslinkable Polyurethane-Acrylates for Marine Antifouling Coatings
박진명,김성열,안승국,이영희,김한도 한국청정기술학회 2017 청정기술 Vol.23 No.2
To prepare UV-curable polyurethane-acrylate oligomer, NCO-terminated urethane prepolymers with trimethylolpropane, [TMP; 0 (0), 0.1 (0.021) and 0.2 (0.043) mole (mole fraction)] as crosslinkable tri-functional chain extender were end-capped with pentaerythritol triacrylate [PETA; 2.0 (0.400), 1.7 (0.354) and 1.4 (0.304) mole (mole fraction)] with one hydroxyl group/three vinyl functionalities. The stable as-formulated UV-curable polyurethane-acrylates [stable mixtures of PETA-capped oligomer/ reactive acrylic monomer diluents without/with heptadecafluorodecyl methacrylate (PFA; 0, 6 and 9 wt%)] were formed up to 0.2 (0.043) mole (mole fraction) of TMP content in the prepolymer, while homogeneous-mixing failed at 0.3 (0.068) mole (mole fraction), in which the crosslink density in NCO-terminated urethane prepolymer was too high to enable the formation of stable mixture. This study examined the effect of TMP/PETA molar ratio and heptadecafluorodecyl methacrylate (PFA) content (wt%) on the properties of UV-cured polyurethane-acrylates as marine antifouling coating materials. The properties of UV-cured polyurethane-acrylate were found to be significantly dependent on the crosslinkable TMP/PETA ratio and PFA content. With the increasing of the TMP and PFA contents, the contact angles increased, and consequently the surface tension decreased. The adhesion of algae/barnacles to PFA contained film samples were found to be sufficiently weak to allow their easy removal. These results suggest that the UV-cured samples containing PFA have strong potential as coating materials for antifouling applications.