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Hexamethoxymethylmelamine 이 고무 - 황동피복코드간의 접착에 미치는 영향
김완영,김윤섭,육경창,김형순,이정용,최상원 ( Wan Young Kim,Youn Sop Kim,Gyeong Chang Yug,Hyung Soon Kim,Jeong Yong Lee,Sang Won Choi ) 한국공업화학회 1992 공업화학 Vol.3 No.3
본 연구는 고무와 황동피복 코드간의 접착력 향상을 위하여 사용되는 resorcinol formaldehyde(RF) resin과 hexamethoxymethylmelamine(HMMM)이 고무 컴파운드내에서 나타내는 morphology와 접착특성에 대하여 고찰하였다. 가황후 resin은 구형의 형태로 시편 전체에 고르게 분포되어 있었고 그의 입경은 약 2000Å정도였다. 코드와 함께 가황시킨 시편에서 코드 주위에 존재하는 resin함락이 감소한 것으로 보아 resin이 코드쪽으로 이동이 있었던 것으로 생각된다. 또한 모듈러스는 methylene donor인 HMMM의 양이 많을수록 증가하였으며, 접착층이 더 두껍게 형성되었다. 접착력은 열노화에 의하여 상실되며 이는 대부분 초기에 발생함을 알 수 있었다. 접착컴파운드에서 가장 유리한 RF resin과 HMMM의 비는 물성, 접착층의 안정성, 열노화특성 등을 고려할 때 1 : 0.9이었다. The morphology and adhesion properties of rubber compounds containing resorcinol formaldehyde(RF) resin and hexamethoxymethylmelamine (HMMM) used in adhesion of rubber to brass-plated steel cord was investigated. The resins were spherical particles about 2000Å diameter and distributed in rubber compounds homogeneously, and the cured compound with steel cord showed migration of resin to steel cord. Also, modulus was increased with increasing HMMM contents. The loss of adhesion between rubber and steel cord was likely to be at initial stages by thermal aging. Considering the physical properties, stability of adhesion layer and thermal aging property, optimum ratio of RF resin and HMMM was 1 : 0.9.
Membranes of Polyurethanes Containing Crystalline Soft Segments: Oxygen Permeability and Morphology
오효진,김완영,정용섭,이윤식,O, Hyo Jin,Kim, Wan Yeong,Jeong, Yong Seop,Lee, Yun Sik Korean Chemical Society 2001 Bulletin of the Korean Chemical Society Vol.22 No.2
In order to look for polymeric materials applicable to the oxygen electrode membranes of biosensors, polyurethanes (PUs) were synthesized from poly(butylene succinate) diol (Mn 1150), poly(ethylene glycol) (Mn 200), and 4,4'-methylenebis(cyclohexyl isocyanate). The PUs (Mn 15000-100000) underwent the crystallization and melting transitions in the temperature range of 20-30 $^{\circ}C$ and 90-110 $^{\circ}C$, respectively. The oxygen permeability for the PU membranes prepared by the solution casting method could not be measured since oxygen simply leaked through the membranes with an audible noise. However, when the PUs were blended with carboxylated poly(vinyl chloride) (CPVC), the permeability could be measured. The oxygen permeability coefficient (Po2) of the PU/CPVC $(96}4)$ membranes (6.4 Barrer) was high enough for the application as the electrode membranes. The Po2 decreased dramatically when the CPVC content increased from 4 to 5 wt%, but decreased very slowly and approached to that of CPVC (~0.26 Barrer) when the CPVC content increased further. The scanning electron micrographs of the membranes revealed that the PU membranes were composed of large crystal grains with many pores, but the size of the PU crystal grains and pores decreased progressively with increasing the CPVC content.
안희종 ( An Hui Jong ),이찬 ( Lee Chan ),김완영 ( Kim Wan Yeong ),김영옥 ( Kim Yeong Og ),양철우 ( Yang Cheol U ),김용수 ( Kim Yong Su ),김진 ( Kim Jin ),방병기 ( Bang Byeong Gi ) 대한신장학회 2004 Kidney Research and Clinical Practice Vol.23 No.3
목적 : 허혈/재관류 신손상(I/R injury)에 있어 mycophenolate mofetil (MMF)의 전처치가 mitogen activated portein (MAP) kinase의 활성과 아포프토시스에 의한 세포사멸에 미치는 영향을 연구하였다. 방법 : Sprague-Dawley 쥐를 이용하였다. 첫 번 실험은 I/R injury 쥐에서 저용량 및 고용량의 MMF (20 ㎎/㎏과 60 ㎎/㎏)를 일주일 동안 전처치하여 I/R 손상에 대한 효과를 판정하였고, 두 번째 실험은 MMF를 I/R injury 전에 투여하여 MAP kinase의 발현에 미치는 영향을 조사하였다. 결과 : 신기능은 sham 군에 비해 I/R injury 군에서 유의하게 저하되었으나 MMF 전처치군에서는 회복하였다. Pro-inflammatory cytokine 및 아포프토시스 관련 mRNA의 발현은 sham 군에 비해 I/R injury 쥐에서 증가한 반면 MMF 전처치군에서는 유의하게 감소하였다. MAP kinase는 MMF 전처치 군에서 I/R injury군에 비하여 유의하게 감소하였다. 결론 : MMF의 전처치는 I/R injury에 의한 염증 관련 cytokine과 아포프토시스 관련 유전자들의 발현을 억제하며 MAPK의 발현을 감소시킨다. 이러한 소견은 MMF의 I/R injury에 대한 예방효과를 반영한다. Background : This study was performed to investigate the effects of pretreatment of mycopheno-late mofetil (MMF) on mitogen activated protein(MAP) kinase expression and apoptotic cell death in rat kidneys with ischemidreperfusion (I/R) injury. Methods : Three experiments were done separately, In the first experiment, the effect of MMF (20 or 60 mg/kg) on I/R injury was observed. In the second experiment, MAP kinase expression were observed according to the time interval after I/R injury. Finally, the effect of pretreatment of MMF (20 or 60 mg/kg) on I/R injury in terms of apoptotic cell death and MAP kinases were evaluated. We also studied pro-inflammatory cytokines (IL-1 and TNF-alpha) using PCR. Results : BUN and Serum creatinine level increased in rats with I/R injury but their levels were significantly decreased with MMF Pro-inflammatory cytokines (TNF- a & IL-1) and apoptosis-related gene (caspase-1 and caspase-3 activities) were also significantly decreased as compared with rats with I/R injury. Expressions of MAP kinase were significantly increased in kidneys with I/R injury compared with sham-operated control, but significantly decreased with MMF pretreatment. Conclusion : Pretreatment of MMF showed a significant decreases of apoptotic cell death, apoptosis-related genes, and MAP kinase expression. This may explain beneficial effect of MMF on subsequent I/R injury. (Korean J Nephrol 2004;23(3):368-376)