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New Series of Semi-Fluorinated Polysilazanes and Their Omniphobic Coating Applications
( Lo Nu Hoang Tien ),박인 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1
A series of semi-fluorinated polysilazane were prepared by ammonolysis of dichloro(1H,1H, 2H,2H-perfluorodecyl)methylsilane and dichloromethylsilane. The control experiments, where the ratio of fluorosilane/ dichloromethylsilane was varied, also support our finding that fluoroalkyl chains play a key role for omniphobic properties. The obtained products were characterized by nuclear magnetic resonance (NMR) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), and thermal gravimetric analysis (TGA). These semi-fluorinated polysilazanes outperform traditional alkylpolysilazane by having the fluorinated functional groups which provide a super repellent surface and chemical resistance due to their extremely low surface energy. Simultaneously the fluoroalkyl chains preserve superior solubility and adhesion characteristics.
술폰산으로 표면개질된 메조기공 실리카 촉매의 제조 및 Octamethylcyclotetrasiloxane 개환중합에서의 촉매 활성
이연송 ( Yeonsong Lee ),황하수 ( Ha Soo Hwang ),이지영 ( Jiyoung Lee ),로누호앙티엔 ( Lo Nu Hoang Tien ),느윙티엔지앙 ( Nguyen Tien Giang ),이동현 ( Donghyun Lee ),박인 ( In Park ) 한국공업화학회 2020 공업화학 Vol.31 No.4
프로필 술폰산으로 개질된 메조기공 실리카 고체 산 촉매를 octamethylcyclotetrasiloxane (D4)의 양이온 개환중합을 위해 합성하였다. 서로 다른 기공 크기를 갖는 두 세트의 MCM-41 (1.7 및 2.8 nm) 및 SBA-15 (8.1 및 15.9 nm)을 촉매의 지지체로 사용하였고, 이를 (3-mercaptopropyl)trimethoxysilane으로 표면개질하고 산화시켜 술폰산으로 개질된 고체 산촉매를 제조하였다. 제조된 촉매는 기공 크기와 비표면적, 기공 부피가 약간씩 감소하였음을 X선 회절, 질소흡탈착을 통하여 확인하였다. 또한 적외선분광법과 핵자기공명법의 분광학적 방법을 이용하여 술폰산이 개질되었음을 확인하였다. 입도의 촉매 활성에 대한 효과를 관찰하기 위하여 주사전자현미경으로 관찰하였다. D4의 개환중합을 통한 PDMS 합성을 위하여 촉매를 사용하였으며, 중합 반응의 전환율과 중합 속도는 촉매의 기공 크기, 비표면적, 입자크기 및 입자의 응집도에 의존하였다. 중합 속도의 순서는 8.1 nm의 SBA-15으로 제조한 촉매가 가장 반응속도가 빨랐으며, 가장 좋은 촉매 활성을 보였다. Mesoporous silica solid catalysts modified with sulfonic acid were prepared for cationic ring-opening polymerization of octamethylcyclotetrasiloxane (D4). Two sets of MCM-41 (1.7 and 2.8 nm) and SBA-15 (8.1 and 15.9 nm) with different pore sizes were used as catalyst supports. The surface of silica materials was modified with (3-mercaptopropyl)trimethoxysilane by silylation reaction and oxidized to sulfonic acid. The structures of the prepared catalysts were examined by X-ray diffraction and nitrogen adsorption-desorption. The pore size, specific surface area, and pore volume of the modified solid catalysts decreased slightly. In addition, the modification of the sulfonic acid on the silica surface was confirmed by using infrared spectroscopy and nuclear magnetic resonance spectroscopy. To observe the effect of the particle size on the catalytic activity, it was observed with a scanning electron microscope. The catalysts were used to synthesize PDMS through a ring-opening polymerization of D4, and the conversion and polymerization rate of the polymerization reaction depended on the pore size, specific surface area, particle size, and particle agglomeration of the catalysts. In order for the polymerization rate, th