Aqueous urethane dispersion resin begins to assume commercial importance due to increasing environmental awareness of VOC in coating industry. Moreover there have been strong industrial needs for the development of reactive-type polyurethane flame retardant coatings. In this study, chlorinated polyester polyols were synthesized by two step polycondensation reaction using mono chloroacetic acid, adipic acid, trimethylol propane, and 1,4-butanediol. In the next step polyurethane dispersion was prepared using these chlorinated polyester polyols and isophorone diisocyanate with dimethylol propionic acid(DMPA) and trimethylamine. The structure of chlorinated polyol was characterized by GPC, FT-IR and NMR. Particle size and its distribution were examined in terms of various dispersion parameters including molecular weight and composition of polyol, amount of DMPA, and NCO/OH ratio, etc. The effect of chlorinated polyols on flammability was also evaluated.

ZMR공정에서 발생하기 쉬운 폴리실리콘의 엉김현상(agglomeration), 슬림, 그리고 실리콘기판이 국부적으로 녹는 현상 등을 방지하기 위한 방법과 재결정화된 박막의 질을 향상시키기 위하여 폴리실리콘과 보호 산화막(capping oxide)두계를 변화시킨 실험 결과를 서술한다. 폴리실리콘의 엉김현상은 폴리실리콘과 보호 산화막 그리고 폴리실리콘과 매몰 산화막(buried oxide)의 계면에서의 wetting각과 관계되는데, 엉김현상을 방지하기 위해서는 암모니아 가스 분위기에서 1100˚C, 3시간 동안 열처리하여 폴리실리콘과 보호 산화막 그리고 폴리실리콘과 매몰 산화막의 계면에 질소를 주입시키면 된다. 실리콘 기판의 뒷면이 국부적으로 녹아 SOI구조가 파괴되는 현상과 슬립은 실리콘 기판의 뒷면을 모래타격(sandblast)하여 약 20μm의 거칠기를 가지도록 했을때 방지할 수 있었다. 재결정화된 폴리실리콘의 두께가 두꺼워짐에 따라 재결정화된 박막에서 subboundary의 간격은 넓어지고, 재결정화된 실리콘 두께의 균일성은 보호 산화막이 두꺼울수록 향상된다. 폴리실리콘의 두께를 1μm로 하였을때 subboundary의 간격은 약 70-120μm정도였고 폴리실리콘의 두께가 1μm이고 보호산화막의 두께가 2.5μm일때, 재결정화 후 실리콘의 두게 균일도는 약 ±200Å정도였다.

Industrial waste water which was highly loaded by halogenide phenols was photooxidized by laboratory-scale photooxidation of these organic impurities in the presence of aerotropic and titaniumdioxide as photocatalyst. The disappearance of organic compounds was determined as a function of the irradiation time. Some contaminants such as 2-chlorophenol, 2-bromophenol, 3-bromophenol, 4-bromophenol, 2,4-dibromophenol and 2,6-dibromophenol were photodegraded separately to obtain information on the reaction rates, reactivities, and reaction mechanisms of the photooxidation, and on the stoichiometric correlation between organic reactant and inorganic products concentration in the course of the photocatalytic photoreaction.

The rates of photodegradation, reactivities, and mechanisms of photooxidation for the aqueous solution containing with halogen derivatives of aliphatic hydrocarbons have been discussed with respect to the kinds of photocatalysts, concentration of photocatalytic suspensions, strength of radiant power , time of illumination, changes of pH of substrate solution, wavelength of radiation, and pressure of oxygen gas saturated in the solution. These aqueous solutions suspended with 0.5 gL^-1 TiO_2 powder have been photodecomposed in the range of 100 and 93.8% per 1 hour if it is illuminated with wavelength (λ≥ 300nm) produced from Xe-lamp(450W). The photocatalytic abilities have been increased in the order of Fe_2O_3 < CdS < CeO_2 < Y_O2_3 < TiO_2, and rates of photodegradation for the solution have maximum values in the condition of pH 6∼8 and 3 psi-O_2 gL^-1. These rates for the photooxidation per 1 hour were dependent on the size of molecular weight and chemical bonding for organic halogen compounds and the rates of photodegradation were increased in the order of C_2H_5Br < CH_2Br_2 < C_5H_11Cl C_2H_4Cl_2 < trans-C_2H_2Cl_2 < cis-C_2H_2Cl_2 The t_1/2 and t_99% for these solutions were 5∼21 and 40∼90 minutes, respectively, and these values were coincided with initial reaction kinetics(r_0). It was found that reaction of photodegradation has the pseudo first-order kinetics controlled by the amount of h^+_VB diffused from a surface of photocatalysts.