• 한국동물위생학회지
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• 제38권4호
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• pp.241-248
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• 2015

This study was aimed to investigate factors that affected the status of wearing personal protective equipment (PPE) for handling poultry carcasses with potential exposure to virulent avian infectious agents. A large outbreak of high pathogenic avian influenza (HPAI) occurred in South Korea in 2014. Many public officers participated for euthanizing and handling livestock carcass. However, several safety issues with using PPE were revealed. Therefore, a questionnaire survey was conducted for 340 people who participated euthanasia and carcass disposal in the place where HPAI mainly occurred in 2014. It was found that 31.8% of the respondents had ever taken off their protective equipment during operations because of its inconvenience. The most inconvenient PPE was goggles (54.6%), followed by mask (20.2%), latex gloves (11.6%), shoe covers (5.9%) and protective clothing (5.3%). The main complaints about this individual PPE was unclear sight, damp emitted toward eye, sweating, tearing easily and sweating, respectively. Considering such problems of PPE, new possible directions for improvement of gloves and goggles were suggested. With newly developed rubber coating fabric gloves and conventionally using latex and fabric gloves, H3N2 influenza virus transmission experiment was conducted. Rubber coating fabric gloves showed similar efficiency for blocking virus transmission with latex laboratory gloves and were not easily torn by sharp claws of chicken. In addition, air flow control safety eyewear was suggested to minimize moisture formation. The air flow control system efficiently suppressed moisture formation inside the goggles. Therefore our study will provide more specific directions about new PPE development for safety protection of actual wearers.

• Elastomers and Composites
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• 제41권4호
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• pp.260-267
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• 2006

유기화 클레이(organically modified layered silicates)가 보강된 SBR 나노 복합체를 라텍스법(latex method)에 의해서 제조하였다. 유기화 MMT는 dodecylamine으로 유기화한 DA-MMT와 dimethyldodecylamine으로 유기화한 DDA-MMT의 두 가지를 제조하였다. 유기화 클레이의 층간거리와 분산도를 확인하기 위하여 XRD와 TEM촬영을 하였다 Na-MMT, DA-MMT, DDA-MMT의 XRD 회절 패턴을 분석한 결과 Na-MMT는 $2{\theta}=7.2^{\circ}$로써 층간거리가 $12.3{\AA}$, DA-MMT는 $2{\theta}=5.1^{\circ}$로 층간거리가 $17{\AA}$를 나타내었으며, DDA-MMT의 경우, 회절 피크는 $2{\theta}=4.8^{\circ}$로써. 층간거리는 $18.4{\AA}$으로 나타났다. 이는 DDA-MMT와 DA-MMT가 각각 5 phr 첨가된 SBR 나노 복합체의 TEM 결과에서도 확인할 수 있었다. SBR 나노 복합체에 filler system (carbon black/silica/OLS)을 적용 후 시편을 제조하였다. 제조된 시편의 동적 점탄성 평가 (DMTA)는 $-20^{\circ}C{\sim}80^{\circ}C$ 사이에서 이루어졌으며, loss factor (tan $\delta$)의 거동을 확인하였다. 그 결과, 타이어 트래드용 컴파운드를 대상으로 할 경우, 카본블랙과 실리카의 혼용비가 35:25일 때, 빗길 제동특성과 연비특성을 대변하는 $0^{\circ}C$와 $50{\sim}60^{\circ}C$에서의 tan $\delta$가 가장 우수함을 알 수 있었다. 또한 이 시스템에 실리카의 일정 부분을 DDA-MMT($0{\sim}10phr$)로 대체할 경우, $0^{\circ}C$의 tan $\delta$값은 높아지는 반면, $50{\sim}60^{\circ}C$의 tan $\delta$값은 감소하였다.

• 공업화학
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• 제5권5호
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• pp.786-794
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• 1994

폴리머-시멘트 모르타르의 강도와 내구성에 대하여 검토하였다. 폴리머-혼화제로서 styrene-butadiene rubber(SBR) 라텍스, ethylene-vinyl acetate(EVA) 에멀젼 및 polyacrylic ester(PAE) 에멀젼을 사용하고, 폴린머-시멘트 비를 다양하게 변화시켜(5, 10, 15, 20 wt%) 공시체를 제작하였다. 내구성의 평가시험으로는 동결융해시험, 내산성시험 및 내열성 시험을 수행하였다. 폴리머-시멘트 모르타르의 내동해성은 폴리머-시멘트비가 증가될수록 현저히 향상되었으나 내산성과 내열성은 저하되었다. SBR 폴리머-시멘트 모르타르의 강도(압축 및 휨강도)는 폴리머-시멘트비가 증가될수록 향상되었으나 EVA 및 PAE 폴리머-시멘트 모르타르는 폴리머-시멘트비 10wt%에서 최대치를 나타내었다.

• 공업화학
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• 제8권6호
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• pp.979-984
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• 1997

폴리머 혼화제로서 styrene-butadiene rubber(SBR)라텍스, ethylene-vinyl acetate(EVA)에멀젼 및 polyacrylic ester(PAE)에멀젼을 사용하여 동일한 스럼프에서 폴리머-시멘트비를 변화시켜 공시체를 제조하여, 압축과 휨강도시험, 흡수시험, 세공분포측정 및 미세구조 관찰 등을 실시하였다. 그 결과 폴리머-시멘트비의 증가와 더불어 압축과 휨강도 모두 향상되었고, 동해에 큰 영향을 주는 모세관 공극범위의 세공량은 감소되었으며, 폴리머 시멘트비 15wt% 이상에서 연속적인 폴리머필름이 형성되었다.

• Elastomers and Composites
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• 제6권1호
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• pp.71-81
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• 1971

The intention of this study is to investigate the properties of polymer blend, NBR/PVC vulcanizates and blending procedures such as roll-mixing temperatures and sequences for polymer blending of NBR and PVC(resin type). The results obtained are as follows: 1. The roll temperature applied for polymer blending is around $150^{\circ}C$. At this temperature region, the degradation of rubber stock, which may be caused by heat, can be minimized and mill processing in practical application in industries can also be facilitated. 2. It is obviously necessary that a small amount of plasticizers should be added to the stock for improving processibility of roll mixing and physical properties. 3. On roll-mixing sequence, it is more effective that PVC compounded with plasticizer is added to NBR milled on hot roll. 4. The vulcanizates of the blends with different degree of polymerization of PVC ale similar to one another in properties. 5. NBR/PVC(70/30) blends shows the better physical characters than eve,-made foreign latex blend except abrasion-resistance. 6. As PVC addition ratio is increased, the physical properties such as resistance to ozone, tear, heat and oil and tensile strength, modulus, hardness have also improved, on the other hand, tension set and rebound character decreased. 7. The curve of ultimate elongation have point of inflection at the ratio of $30\sim40$ part of PVC. 8. While CR is blended, the physical properties such as brittle point, rebound and resistance to oil in high temperature have improved. 9. Polymer blend of NBR and domestic PVC is applied for the industrial utility such as rubber sole and heel, electric wire cover and oil-resistant packing, coating and gasket, printing roll, film for food packing etc.

• Elastomers and Composites
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• 제29권5호
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• pp.419-425
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• 1994

폴리에스테르와 SBR 1502 고무의 접착을 위해 RTFL(resorcinol-tannin-formaldehyde-latex) 접착제를 사용하였다. T-peel geometry를 이용하여 접착력을 평가한 결과 접착제 조성에서 레소시놀과 탄닌이 4대 6의 중량비로 합성된 접착제를 사용한 경우 뛰어난 접착력을 보였다. 폴리에스테르 표면의 소수성과 활성기의 부족에도 불구하고 SBR 고무와 높은 접착력을 보인 이유는 RTFL 접착제 자체의 일정 조성에서 나타나는 toughness 때문이었다. 또한 폴리에스테르와 고무 접착을 위한 single dip 시스템인 N-3형 접착제와 RTFL 접착제를 사용하여 폴리에스테르와 SBR 고무를 접착시킨 후 $-20^{\circ}C{\sim}100^{\circ}C$의 온도 범위와 $0.2cm/min{\sim}50cm/min$의 박리속도 조건아래서 박리 실험하여 얻은 mastercurve들을 비교한 결과 전 범위에서 RTFL 접착제는 기존의 N-3형 접착제와 거의 필적할만한 접착 결과를 나타내었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 봄 학술발표회 논문집
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• pp.93-98
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• 1993

In order to discuss the mechanical properties of fiber reinforced composites with fly ash, lime, gypsum and polymer emulsion-Stylene Butadiene Rubber Latex (SBR) , experimental studies on FRC were carried out. The kinds of fiber used in FRC are PAN-dervied and Pitch-derived carbon fiver, alkali-resistance glass fiber. As a test results, the flexural strength and tougthness of fiber reinforced fly ash. lime.gypsum cement composites are remarkably increased by fiber contents ,but compressive strength of the composites are influenced by kinds of fiber more than by fiber contents. Also, addition of a polymer emulsion (SBR) to the composites decreased the bulk specific gravity, but compressive and flexural strengths, toughness of the composites are not influenced by it, are considerably improved by increasing fiber contents.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.261-262
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• 2012

The field application through the quality control of self adhesive rubberized asphalt waterproofing sheet was regulated by KS F 4934 of Korea Standard in 2003. However, regulations that different material properties of self-Adhesive waterproofing sheets are difficult on the standard. Therefore, this research was performed for of quality control all affiliations of self-adhesive waterproofing sheet through basic properties test and proposed quality standard revised bill in KS F 4934.

• International Journal of Concrete Structures and Materials
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• 제10권2호
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• pp.249-256
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• 2016

This paper deals with the effects of silica fume content and polymer-binder ratio on the properties of ultrarapid-hardening polymer-modified mortar using silica fume and ethylene-vinyl acetate redispersible polymer powder instead of styrene-butadiene rubber latex to shorten the hardening time. The ultrarapid-hardening polymer-modified mortar was prepared with various silica fume contents and polymer-binder ratios, and tested flexural strength, compressive strength, water absorption, carbonation depth and chloride ion penetration depth. As results, the flexural, compressive and adhesion strengths of the ultrarapid-hardening polymer-modified mortar tended to increase as increasing polymer-binder ratio, and reached the maximums at 4 % of silica fume content. The water absorption, carbonation and chloride ion penetration resistance were improved according to silica fume content and polymer-binder ratio.

• 한국세라믹학회지
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• 제31권9호
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• pp.949-956
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• 1994

In order to investigate the relationship between pore size distribution and freezing-thawing resistance of mortars, polymer-cement mortars were prepared by using styrene-butadiene rubber latex, ethylene-vinyl acetate emulsion and polyacrylic ester emulsion with various polymer-cement ratios at constant flow. From the results of the test, polymer-cement mortars had a good pore size distribution for freezing-thawing resistance compared with unmodified mortars because of having a small pore volume in the pore radius range of 103~104 $\AA$ affecting on the frost damage. And the freezing-thawing resistance of polymer-cement mortars was improved with increasing polymer-cement ratio.