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TDI계 수분산성 폴리우레탄 접착제의 특성에 Diisocyanate의 구조가 미치는 영향
강승구,송봉근,이재흥,박찬조,류해일 한국공업화학회 2003 공업화학 Vol.14 No.3
수년 전부터 많은 연구자들에 의해 폴리우레탄의 수용화, 수분산화의 연구가 수행되어 왔다. 그럼에도 불구하고 폴리우레탄의 특성에 디이소시아네이트가 구조에 미치는 영향에 대한 연구는 많이 진행되지 않았고 또한 미흡한 상태이다. 따라서 번 연구에서는 디이소시아네이트의 형태와 함량 변화에 따른 폴리우레탄의 특성을 연구하였다. 폴리우레1탄 수분산체(PUD)는 poly(tetramethylent ether) glycol (PTMG), isophorone diisocyanate (IPDI), toluene 2,4-diisocyanate (TDI), dimethylol propionic acid (DMPA), trethylamine (TEA) 등을 사용하여 제조하였다. 제조한 폴리우레탄 수분산체(PUD)의 구조를 FT-IR을 이용하여 확인하였다. 폴리우레탄 수분산체의 특성은 DSC, gel permeation chromatography (GPC), particle analyzer, universal testing machine (UTM) 등을 사용하여 측정하였다. 폴리우레탄 수분산체(PHD)에서 입자크기는 IPDI 함량이 증가할수록 작아지는 경향을 나타내었으며, 유리전이온도(Tg)는 IPDI 함량이 증가할수록 조금씩 낮아지는 경향을 나타내었다. 또한, 폴리우레탄 수분산체(PUD)의 접착세기 변화에서는 [NCO]/[OH] 몰비를 1.2로 유지되도록 하면서 합성에 관여하는 [NCO] 양에 해당하는 [TDI]/[IPDI] 몰비를 변화시켜 얻은 폴리우레탄 수분산체의 접착세기는 [TDI][IPDI] 몰비가 50/50일때 좋은 집착세기를 나타내었다. 또한 [NCO]/[OH] 몰비를 1.6으로 일정하게 유지되도록 하고 [TDI]/[IPDI] 몰비를 변화시켜 얻은 폴리우레탄 수분산체의 접착세기는 [TDI]/[IPDI] 몰비가 75/25일 때 좋은 접착세기를 나타내었다. Aqueous polyurethane dispersions (PUD) has been investigated by many researchers for a long time. However, relatively little systematic work has been reported, in detail, on the effect of structure of the diisocyanate on the properties of polyurethane. This work describes the properties of polyurethane in relation to the variation of diisocyanate type and contents. Aqueous polyurethane dispersions (PUD) were prepared from the poly(tetramethylene ether) glycol (PTMG), toluene 2,4-diisocyanate (TDI), isophorone diisocyanate (IPDI), dimethyol propionic acid (DMPA), and triethylamine (TEA). Differential scanning calorimetry (DSC), FT-IR, GPC, universal testing machine (UTM), and particle analyzer were utilized to characterize the physical and mechanical properties of PUD according to diisocyanate type and contents. As the content of IPDI in PUD increased, the particle size decreased. The glass transition temperatures (Tg) of PUT were shifted to a lower temperature as IPDI conent increased. When [NCO]/[OH] mole ratio was 1.2, the adhesion force of PUD shown the best result at [TDI]/[IPDI] mole ratio of 50/50. And, at [NCO]/[OH] mole ratio of 1.2, the adhesion force of PUD was the best when [TDIl/[IPDI] mole ratio was 75/25.
Correlation Between Levels of N-terminal Pro-B-Type Natriuretic Peptide and Degrees of Heart Failure
( Bong Geun Song ),( Eun Seok Jeon ),( Yong Hoon Kim ),( Min Kyung Kang ),( Joon Hyung Doh ),( Phil Ho Kim ),( Seok Jin Ahn ),( Hye Lim Oh ),( Hyun-Joong Kim ),( Ji Dong Sung ),( Sang Chol Lee ),( Hye 대한내과학회 2005 The Korean Journal of Internal Medicine Vol.20 No.1
Song, Bong-Geun,Jung, Jae Hee,Bae, Gwi-Nam,Park, Hyung-Ho,Park, Jong-Ku,Cho, So-Hye American Scientific Publishers 2013 Journal of Nanoscience and Nanotechnology Vol.13 No.9
<P>Cu(In,Ga)Se2 (CIGS) is a compound semiconductor and is one of the most attractive light-absorbing materials for use in thin film solar cells. Among the various approaches to prepare CIGS thin films, the powder process offers an extremely simple and materials-efficient method. Here, we report the mechano-chemical preparation of CIGS compound powders suitable for fabrication of CIGS films by a powder process. We found that the CIGS phase was formed from the elemental powders of Cu, In, and Se and liquid Ga using high energy milling process with a milling time as short as 40 min at 200 rpm due to a self-accelerating exothermic reaction. The morphology and size of the CIGS powders changed with a function of the milling speed (100-300 rpm), leading to an optimal condition of milling at 200 rpm for 120 min. We also found that it was difficult to obtain a monolithic phase of the CIGS powders without severe particle aggregation by mechano-chemical milling alone. Therefore, in combination with the milling, subsequent heat-treatment at 300 degrees C was performed, which successfully provided monolithic CIGS nanopowders suitable for powder process. When a thin film was fabricated from the monolithic CIGS nanopowders, a highly dense film with large crystalline grains was obtained. The CIGS film preserved its chemical composition of CuIn0.7Ga0.3Se2 after sintering as evidenced by Raman spectroscopy, EDS and SAED pattern of transmission electron microscopy. The film was also found suitable for a light absorbing layer of CIGS solar cells with its band gap energy of 1.14 eV evaluated by transmittance spectroscopy.</P>