Metam-sodium has been generally applied to control Pinus koraiensis, P. densiflora and P. thunbergii infected by pine wilt disease in the forest field of Korea. We determined the atmospheric concentration of nematocidal and insecticidal gaseous methyl isothiocyanate (MITC) and more volatile and toxic gaseous methyl isocyanate (MIC) in the metam-sodium fumigated fields depending on the distance from metam-sodium treated site, time and season by OSHA No. 52 method. Determined atmospheric MIC was below acute exposure limit (50 ㎍/㎥) and chronic exposure limit (1.0 ㎍/㎥) of EPA regulation in all detection point. In summer, the maximum of MITC and MIC was observed to 105.2 ㎍/㎥ in the 1st day and 0.41 ㎍/㎥ in the 4th day after metam-sodium treatment, respectively. On the other hand, in winter, the maximum of MITC and MIC was observed to 4.6 ㎍/㎥ in the 4th day and 0.52 ㎍/㎥ in the 5th day after metam-sodium treatment, respectively. Atmospheric concentrations of MITC and MIC were higher the closer to the metam-sodium treated site, but decreased below LOQ with distance (~ 50 m). This result showed that the reaction rate of metam-sodium to MITC is more affected by temperature and the translation rate of MITC to MIC is generally very low, regardless of season.

To investigate the adhesion effect of sodium bisulfite content in making blocked isocyanate, wood adhesive PB-1, PB-2, PB-3 and PB-4 containing sodium bisulfite content of 15%, 22.5%, 30% and 37.5% were synthesized respectively. As a result, when the amount of sodium bisulfite increased in adhesives, the tensile strength was found to be proportionally increased. The final adhesive mixtures were manufactured using a two-components system which are prepared by mixing two separate protein and BI solutions due to the precipitate in the adhesives. As PVA was added to adhesives to increase tenacity, the plywood dehiscence phenomenon after cold pressing process was declined. By addition of PVA, the tensile strength was improved up to 6.5~7kgf/cm2 with BI/protein ratio from 1:6 up to 1:8. Phase separation between milk fat and aqueous layer was disappeared after addition of emulsifier, Tween 20. Additon of Tween 20 showed tensile strength up to 5 ~ 6.5 kgf/cm2 at NCO/protein ratio of 1:12 ~ 1:14 without phase separation.

목적: 본 연구는 furfuryl isocyanate를 은 나노 물질(Ag nanoparticler)과 기존의 하이드로젤 곤택트렌즈 재료와 공증합 하였으며, 제조된 콘택트렌즈의 물리적 특성을 비교하고, 내구성이 높은 콘택트렌즈 고분자로서의 활용성을 알아보았다. 방법: 교차결합제인 EGDMA(ethylene glycol dimethacrylate)와 HEMA(2-hydroxyethyl methacry-Late), MMA(methyl methacrylate), MA(merhacrylic acid) 그리고 개시제인 AIBN(azobisisobutyronitrile)과 함께 공증합 하였다. 결과: 생성된 고분자의 물리적 특성을 측정한 결과, 함수율 28.98~34.31%, 굴절률 1.441~1.453,UV-B투고율 33.2~72.0%, 접촉각 57.65~79.00° 그리고 인장강도의 경우 0.340~0.71kgf 범위의 분포를 나타내었다. 또한 은 나노 물질 1%에 furfuryl isocyanate를 첨가할수록 UV-B 투과율 저하와 인장강도가 증가한 결과를 보였다. 결론: 본 실험결과로 볼 때 생성된 공중합체는 내구성이 좋고 자외선 차단 효과가 있는 렌즈 재료로 유용하게 활용될 것으로 기대된다.

목적: 본 연구는 이소시아네이트 그룹을 기존의 하이드로젤 콘택트렌즈 재료와 공중합 하였으며, 제조된 콘택트렌즈의 물리적 특성을 비교하고, 내구성이 높은 콘택트렌즈 고분자로서의 활용성을 알아보았다. 방법: 2-Fluorophenethyl isocyanate, 4-fluorophenethyl isocyanate, furfuryl isocyanate를 가교제인 ethylene glycol dimethacrylate를 사용하여 2-hydroxyethyl methacrylate, methyl methacrylate, methacrylic acid와 공중합 하였으며, 개시제로는 azobisiobutyonitrile를 사용하였다. 또한 제조된 렌즈의 물리적 특성을 평가하기 위해 함수율, 굴절률, 접촉각, 분광투과율, 인장강도 등을 측정하였다. 결과: 생성된 고분자 재료의 물리적 특성을 측정한 결과 함수율 13.29~31.34%, 굴절률 1.454~1.499, 가시광선 투과율 78.0~91.5%를 나타내었다. 또한, 이소시아네이트 그룹의 첨가 비율이 증가할수록 굴절률 은 증가하였으며, 함수율은 감소하였다. Furfuryl isocyanate를 첨가한 공중합체의 경우, UV-B 3.0~84.0%, UV-A 13.0~68.0%의 투과율을 나타내어 자외선 차단 효과를 갖는 것으로 나타났다. 결론: 본 실험결과로 볼 때 생성된 공중합체는 내구성이 높은 하이드로젤 콘택트렌즈 재료로 사용될 수 있을 것으로 판단된다.

In order to obtain the maximum flame retardancy with the minimal deterioration of physical properties of PU flame-retardant coatings, chlorine and phosphorous functional groups were introduced into the pre-polymer of modified polyesters. In the first step, the tetramethylene bis(orthophosphate) (TBOP) and neohexanediol dichloroacetate (DCA-adduct) intermediates were synthesized. In the second step, 1,4-butanediol and adipic acid monomers were polymerized with the two kind of intermediates to obtain copolymer. The modified polyesters containing chlorine and phosphorous (ATBA-10C, -20C, and -30C) were synthesized by adjusting the contents of chlorine compound (dichloroacetic acid, 10, 20, 30 wt%) with fixed the content of phosphorous compound (2 wt%). The PU flame-retardant coatings (TTBAH -10C, -20C, and -30C) were prepared using the synthesized ATBAs and HDI-trimer as curing agent at room temperature. The physical properties of PU flame-retardant coatings with chlorine and phosphorous were inferior to those with phosphorous only and the properties were getting worse with increasing chlorine content. Flame retardancy was tested with three methods. With the vertical method, Complete combustion time of ATBAHs were 259~347 seconds, which means that the prepared coatings are good flame-retardant. With the 45˚ Meckel burner method, char lengths of the three prepared coatings were less than 2.9 cm, which indicates that the prepared coatings are 1st grade flame retardancy. With the limiting oxygen index (LOI) method, the LOI values of the three prepared coatings were in the range of 30~35%, which proves good flame retardancy of the prepared coatings. From the results of flame retardancy tests of the specimens that contain the same amounts of flame retarding compounds, it was found that the coatings containing both phosphorous and chlorine show higher flame retardancy than the coatings containing phosphorous alone. This indicates that some synergy effect of flame retardancy exists between phosphorous and chlorine.

PU type flame-retardant coatings (TBAO/L-75, TBAOL ; TBAO/N-100, TBAON) were prepared by blending bromine-containing modified polyester (TBAO) which was synthesized in our earlier work. with two kinds of isocyanate curing agents, Desmodur L-75 and Desmodur N-100. Physical properties of the prepared flame-retardant coatings were tested. TBAOL shows better hardness than TBAON, while TBAON shows better viscosity, accelerated weathering resistance, yellowness index and lightness index difference than TBAOL. There were no remarkable differences in fineness of grind, 60˚ specular gloss, cross-hatch adhesion, and abrasion resistance of TBAOL and TBAON. There was no discernable difference in flame-retardancy between the two flame-retardant coatings, TBAOL and TBAON. When the content of tribromo acetic acid, which is flame-retarding component, was 30wt% the LOI value was in a range of 29~30%, which indicates that the two coatings are good flame-retardant coatings.

In the previous study, three kinds of monomers and the functional monomer, acetoacetoxyethyl methacrylate (AAEM), which could improve the film property and cross-linkage, were polymerzied into acrylic resin copolymers (HSA-98-20, HSA-98-0, HSA-98+20) containing 80% solid content. In this study, the high-solid coatings(HSA-98-20C, HSA-98-0C, HSA-98+20C) were prepared by the curing reaction between acrylic resins containing 80% solid content and isocyanate at room temperature. Various properties were examined for the film coated with the prepared high-solid coatings. The introduction of AAEM in the coatings enhanced the abrasion resistance and solvent resistance of coatings, which indicated the possible use of high-solid coatings for top-coating materials of automobile. The curing times measured by viscoelastic measurement were 350, 264, and 212 min for HSA-98-20C, HSA-98-0C, and HSA-98+20C, respectively. This shows that the curing times become shorter with increasing Tg values.