<303520C0CCB5BFC8A32E687770>

Size: px

Start display at page:

Download "<303520C0CCB5BFC8A32E687770>"

상길 증
5 years ago
Views:

1 Journal of the Korean Society of Safety, Vol. 32, No. 3, pp , June 2017 by The Korean Society of Safety (pissn , eissn ) All right reserved. 전관옥 이동호 * 인천대학교대학원안전공학과 * 인천대학교소방방재연구센터 ( 접수 / 수정 / 채택 ) A Study for the Fire Retardant-Characteristics of Expandable Graphite Composite Materials Kwan-Ok Chun Dong-Ho Rie * Graduate School of Safety Engineering, Incheon National University * Fire Disaster Protection Research Center, Incheon National University (Received April 11, 2017 / Revised April 24, 2017 / Accepted May 23, 2017) Abstract : In this study, the composite material of expandable graphite was made to the material development for improving such as a composite material of the sandwich panels or material properties of a fire door and was tested by the ISO 1182, ISO (Cone calorimeter Method). For the test, the composite material of expandable graphite, what the expandable graphite ratio was increased by respectively 0g 30g, was classified A1,A2, A3, A4, and made to the test specimens. Through cone calorimeter test, peak heat release rate(hrr) and total heat release(thr), expanded thickness and expansion rate of each composite material of expandable graphite, and fire prone crack and mass loss rate after burning was measured. Thus, the effect of the addition of the expandable graphite and whether is suitable for reference as a fire retardant, was analyzed. Consequently the correlation of THR and fire retardant performance rate was confirmed. Key Words : expandable graphite, total heat release, mass loss rate, fire retardant performance rate 1. 서론 현대사회구조는점차복잡다단해지고건축구조물의지하화및고층화가지속되어감에따라화재발생으로부터인명과재산피해의최소화를확보하기위해보다안전한건축내장재개발을요구하고있다. 국내의경우, 건축자재는건축법시행령제 2 조에의거하여불연재료, 준불연재료, 난연재료로구분하고있다. 이러한재료개발은 ISO 1182 와 ISO ) 및 ISO 2271 에의하여국제표준재료별시험기준을만족하도록규정하고있다. 따라서본연구에서는가연성목재에팽창흑연과난연첨가재를혼합시킴으로서방화성능이개선된건축내장재개발을목표로한다. 본연구에서선정된팽창흑연은흑연의층상구조특성에기인하여흑연층간조직사이에황또는질소화합물을결합후열을가하면입자가수백배팽창함에따라아코디언처럼층의분리현상이발생하는구조적특징을 갖는다. 팽창흑연은이러한물리적특성에기인하여난연플라스틱 17, 난연 EPS, PU- foams, resins, textiles, rubber, roof- coverings 등에매우광범위하게사용되고있다. 팽창흑연관련연구에서 M. Modesti 는 polyiso cyanurate - polyurethane foams 에서팽창흑연을 5% 에서 25 wt% 까지함량을증대시킨결과 Peak HRR 이감소하고 CO/CO2 average value, Oxygen Index 가증가하는것으로나타나팽창흑연이난연성능에기여할수있는재료임을규명하였다 2). A. Laachachi 는팽창흑연이 Epoxy resin 재료에서팽창흑연을 5% 에서 50 wt% 까지함량을증대시킨결과 Peak HRR, THR 이감소하고 Residual weight(%) 가증가하는것으로나타나팽창흑연의난연성능향상을입증하였다 3). 문성철은팽창흑연을포함한 NBR/GTR 발포체의난연및발포특성을실험한결과팽창흑연의함량이증가함에따라 HRR, THR 등이감소하는것으로나타나발포체의난연성 Corresponding Author : Dong Ho Rie, Tel : , riedh@inu.ac.kr Fire Disaster Protection Research Center, Incheon National University, 119 Academiro, Yeonsugu, Incheon 22012, Korea 28

2 능이향상됨을보고하였다 4). 또한팽창흑연과관련된난연성연구 5-10) 와열적물리적거동연구 11-21) 가많이이루어져왔다. 본연구에서는목재파우더에팽창흑연을첨가시켜열방출율 (HRR), 총열방출률 ( THR), 질량감소율 (Mass loss rate), 팽창비 (Expansion rate) 등난연재료의특성을 Cone calorimeter 를사용하여실험적으로규명하고난연성능지수를산정하여난연성능과의관계를규명하고자한다. 2.1 실험순서 2. 실험방법 복합재료계량, 혼합, 균질화, 샘플제작, 건조, 실험, 데이터분석및평가의전체적인실험순서를 Fig. 1 에나타내었다. Preparation (Composite materials) Measurement (WP, EG, NB) Mixing/Homogenization Sample production ( mm) Artificial Dry (80 6days) Cone-calorimeter setting Analysis (Evaluation) Cause review Result reflection Report making Fig. 1. Flow chart of experimental sequence. 2.2 난연재성능기준건축자재의방화성능에대하여난연재 (Flame retarding material) 기준은 ISO 1182, ISO 에의하여 Table 1 과같이나타냈으며실험시간 5분기준으로총열방출률 (THR) 8 MJ/m 2 이하, 열방출률이 200 kw/m 2 을연속하여초과한시간이 10초이하, 심재의전부용융, 관통하는균열및구멍등의변화가없어야하며가독성은실험용쥐가 9분이상활동하고있어야하는조건을만족시켜야한다. Table 1. The ISO 1182, ISO standard of fire retarding material Item THR (Total heat release) (MJ/m 2 ) Time that heat release rate is exceeded 200 kw/m 2 continuously All core melt, penetrating cracks, slot change, etc., Toxicity Test time Semi -noncombustible material Flame retarding material Below 8 MJ/m 2 Below 8 MJ/m 2 Below 10 sec No core melt, penetrating cracks, slot change Experimental mouse Activity over 9 min 10 min (600 sec) 3. 복합재료구성및시편 Below 10 sec No core melt, penetrating cracks, slot change Experimental mouse Activity over 9 min 5 min (300 sec) 3.1 복합재료의구성본팽창흑연복합재료의난연성연구에사용된구성재료는목재분 (Wood particle), 팽창흑연 (Expandable graphite) 이며시편제작에필요한결합재로서실생활전반에범용적으로사용되고있는천연풀 (Natural binder) 을공통으로사용하였다. 목재분은일반목재의가공과정에서발생되는부산물로서입도 mesh size를선별하여 1개월이상충분히건조한것을기본재료로사용하였으며팽창흑연은 Table 2와같이 Carbon content 93.8%, 80 mesh 수준의재료를선정, 배합하였다. Table 2. Composition of expandable graphite(eg) Carbon content (%) Size (mesh) Expansion ratio (ml/g) Ash (%) Moisture (%) 시편제작본연구실험에필요한시편은 Table 3과같이 4종류의시편으로분류하여제작하였다. 시편은목재분 100 g을기본 Base로하여팽창흑연의첨가량을 10 g, 20 g, 30 g으로순차적으로증가시켰고, 결합재로천연풀을시편별로동일하게 300 g을투입하여 Mixer 에서균일하게혼합하였다. 시편은시편몰드를사용하여크기를 100 mm 100 mm 10 mm size로각각 3개씩제작한다음인공건조기에서 80 로 6일간건조를시켜시편제작을완성하였으며시편중량과형상은 Table 3 하단에나타내었다. PH 한국안전학회지, 제 32 권제 3 호, 2017 년 29

3 전관옥 이동호 Table 3. Test specimen of EG composite material Material Composite Materials Specimen Sample A1 A2 A3 A4 EG 0g 10 g 20 g 30 g Wood particle 100 g 100 g 100 g 100 g Natural binder 300 g 300 g 300 g 300 g Sum 310 g 320 g 330 g 340 g Mass 47.6 g 51.8 g 53.8 g 55.4 g Shape 으로난연재료기준이하로나타났고연소후크랙, 홀등이존재하지않아시편중난연성능이가장우수한것으로나타났다. 또한시험편에대한팽창비 (Expansion rate) 를 Table 5 에나타내었다. 실험전시험편의초기두께는 10 mm 로동일하나실험후시험편의연소반응두께를측정해본결과 A1 은 10 mm 전체가연소되어팽창 layer 두께가 0 mm 로팽창비 0.0, A2 는 5 mm 가연소반응하여팽창 layer 두께가 25 mm 로팽창비가 5.0, A3 는 4 mm 4. 실험 4.1 실험환경조건팽창흑연복합재료의난연성능기준에대한적합여부에대한측정은 ISO : 2008 기준에따라 Cone Calorimeter를사용하여실험을시행하였고시험방법역시 ISO 에근거하여건축물마감재료의난연성능기준에따랐다. 시험은콘칼로리미터시험실온도 28+1, 상대습도 60+5% R.H. 환경에서이루어졌으며실험시간은시험편별로 5분으로설정하였고콘칼로리미터의히터와시료간의거리는 60 mm, Heat flux 는 50 kw/m 2 로설정하였다. Fig. 2. Peak heat release rate variations of specimen. 4.2 실험결과 Cone Calorimeter 실험은 A1, A2, A3, A4 각시편별로각각 3 회실시하고측정된 Data 평균값을 Table 4 와같이정리하여나타내었다. 팽창흑연첨가량을 0 g 에서 30 g 까지증가시킬수록 Peak heat release rate(hrr) 는 Fig. 2 에나타낸바와같이 197.6, 96.0, 61.0, 41.0 kw/m 2 으로점차감소하였고 Total heat release(thr) 는 Fig. 3 과 4 에서 300 sec 를기준으로 27.0, 14.8, 9.9, 7.0 MJ/m 2 까지감소하였다. 그리고 Mass loss rate(%) 도 Fig. 5 에서 90.3%, 65.2%, 53.5%, 32.5% 로점차감소되었다. 결과적으로 A4 시편의총열방출률 (THR) 이 7.0 MJ/m 2 Fig. 3. Total heat release variations of specimen. Table 4. Experimental data of composite materials Item Cone calori-meter Sample A1 A2 A3 A4 Indication THR (MJ/m²) Partially Suitable Time that heat release rate is exceeded 200 kw/m 2 continuously Suitable All core melt, penetrating cracks, slot change, etc., N/A N/A N/A N/A N/A Ignition time(sec) PHRR(kW/m 2 ) Mass change Pre-test Post-test Mass loss rate(%) J. Korean Soc. Saf., Vol. 32, No. 3, 2017

Fig. 4. Total heat release variations of specimen. 4.4 고찰 A1, A2, A3, A4 복합재료시편에대한실험결과를고찰하여보면 Fig.

값이점차적으로감소하는것으로나타나팽창흑연첨가량이증가될수록난연성능이향상되는것을확인할수있었다.

을형성시키고높아지게하는것으로판단하였다. 또한이러한팽창성과열적저항으로연소반응진행이지연되어결과적으로열방출률이감소되고질량감소율 (Mass loss rate) 도낮아지는것으로확인이되었다. Fig. 5.

0 으로나타났다. Fig. 6. Total heat release(thr) according to expandable graphite addition. Table 5.

4 Fig. 4. Total heat release variations of specimen. 4.4 고찰 A1, A2, A3, A4 복합재료시편에대한실험결과를고찰하여보면 Fig. 6 에서팽창흑연첨가량이 0 g 에서 30 g 으로순차적으로증가시킴에따라 Peak heat release rate(hrr), Total heat release(thr) 값이점차적으로감소하는것으로나타나팽창흑연첨가량이증가될수록난연성능이향상되는것을확인할수있었다. 이러한현상은팽창흑연의재료특성상연소반응에따른팽창성 (Expansibility) 이뛰어나팽창비가크게증가함으로서 Heat flow 관점에서팽창층 (Expansion layer) 확대가열적저항 (Thermal resistance) 을형성시키고높아지게하는것으로판단하였다. 또한이러한팽창성과열적저항으로연소반응진행이지연되어결과적으로열방출률이감소되고질량감소율 (Mass loss rate) 도낮아지는것으로확인이되었다. Fig. 5. Mass loss rate of experimental specimens. 가연소반응하여팽창 layer 두께가 40 mm 로팽창비 10.0, A4 는 3 mm 가연소반응하여팽창 layer 두께가 42 mm 로팽창비가 14.0 으로나타났다. Fig. 6. Total heat release(thr) according to expandable graphite addition. Table 5. Expansion rate data of specimens Distribution Specimen initial thickness (mm) Expansion reaction layer (mm) shape layer (mm) rate A1 (EG 0 g, WP 100 g) A2 (EG 10 g, WP 100 g) A3 (EG 20 g, WP 100 g) A4 (EG 30 g, WP 100 g) 한국안전학회지, 제 32 권제 3 호, 2017 년 31

5 전관옥 이동호 Table 6. Fire retardant performance rate(8 MJ/m 2 rate 1.0 standard) Items A1 (EG 0 g, WP 100 g) A2 (EG 10 g, WP 100 g) A3 (EG 20 g, WP 100 g) A4 (EG 30 g, WP 100 g) THR (MJ/m 2 ) Standard of fire retardant performance (MJ/m 2 ) Fire retardant performance rate under 나팽창흑연을활용한복합재료가난연성능을구현할수있음을규명하였다. 2) 본실험조건내팽창흑연복합재료의연소반응후팽창비가팽창흑연 30 g 첨가수준에서 14.0 까지높게나타나이러한팽창층 (Expansion layer) 이열적저항을높이고연소를지연시켜총열방출량 (THR) 감소와중량감소율 (Mass loss rate) 에영향을미치는것으로판단하였다. 3) 팽창흑연첨가량을 0 g 에서 30 g 수준까지증대시킬수록총열방출률 (THR) 이점차감소하고상대적으로복합재료의난연성능지수는향상되는것으로나타나총열방출률 (THR) 과난연성능간에는서로음의상관관계를가지고있는것으로나타났다. References Fig. 7. Relationship THR and fire retardant performance rate. 그리고팽창흑연첨가량을 0 g 에서 30 g 으로순차적으로증가시킴에따라시편별로총열방출률 (THR) 값이 27.0, 14.8, 9.9, 7.0 MJ/m 2 으로나타났으며 A4 시험편이난연성능기준 (8.0 MJ/m 2 미만 ) 을만족하여난연성능을구현할수있는것으로판단이되었다. 또한난연성능 8.0 MJ/m 2 을난연성능지수 (Fire retardant performance rate) 1.0 기준으로설정하여각시편의총열방출률 (THR) 값을난연성능지수로산정한결과 Table 6 과같이 0.30, 0.54, 0.81, 1.14 로나타나 Fig. 7 과같이팽창흑연첨가량을증대시킴에따라총열방출률량 (THR) 이감소되는것으로나타났고난연성능지수는반대로향상되는것으로확인되었다. 5. 결론 가연성목분 (Wood Particle) 을기반으로한팽창흑연첨가복합재료의 Cone Calorimeter 실험결과다음과같은결론을도출하였다. 1) 목분 (Wood Particle) 을 100g 을기반으로팽창흑연첨가량을 0 g 에서 30 g 수준까지증대시킬수록총열방출률 (THR) 이점차감소하였고팽창흑연첨가량 30 g 수준에서난연성능기준을만족시키는것으로나타 1) ISO , Reaction-to-fire Tests-Heat Release, Smoke Production and Mass Loss Rate-Part 1 : Heat Release Rate(Cone Calorimeter Method), Korean Agency for Technology and Standards, KSA, ) M. Modesti, A. Lorenzetti, F. Simioni and G. Camino, Expandable Graphite As An Intumescent Flame Retardant in Polyisocyanurate-polyurethane Foams, Polymer Degradation and Stability, vol. 77, pp , ) A. Laachachi, N. Burger, K. Apaydin, R. Sonnier and M. Ferriol, Is expanded graphite acting as flame retardant in epoxy resin, Polymer Degradation and Stability, vol. 117, pp , ) S. C. Moon, J. K. Choi and B. W. Jo, Flame Retardancy and Foaming Properties of the NBR/Ground Tire Rubber Foams Containing Expandable Graphite, Polymer (Korea), vol. 28, No. 5, pp , ) B. Dittrich, K. A. Wartig, D. Hofmann, R. Mulhaupt and B. Schartel, Flame Retardancy Through Carbon Nanomaterials : Carbon Black, Multiwall Nanotubes, Expanded Graphite, Multi-layer Graphene and Graphene in Polypropylene, Polymer Degradation and Stability, vol. 98, pp , ) Youming Yu, Junfeng Hou, Zhiziang Dong, Cong Wang, Fengzhu Lu and Pingan Song, Evaluating the Flammability Performance of Portland Cement-bonded Particleboards with Different Cement-wood Ratios using a Cone Calorimeter, Journal of fire sciences, vol. 34, No. 3, pp , ) A. M. Pereyra and C. A. Giudice, Flame -retardant Impregnants for Woods based on Alkaline Silicates, Fire 32 J. Korean Soc. Saf., Vol. 32, No. 3, 2017

6 Safety Journal, vol. 44, pp , ) H. J. Seo, S. M. Kim and D. W. Son, The Evalution of Flame Retardant Performance of the Wood-based Building Materials Applied to Carbon Materials, Journal of Korean Soc.Living Environ. Sys, vol. 21, No. 5, pp , ) O. D. Kwon, J. C. Lee, K. S. Seo, C. S. Seo and S. B. Kim, Effect of Flame Retardants on Flame Retardancy of Flexible Polyurethane Foam, Applied Chemistry for Engineering, vol. 24, No. 2, pp , ) J. M. Cha, S. H. Hyun, J. B. Kim and M. O. Yoon, A Study on the Flame Retardant Performance of MDF Wood According to Flame Retardant Treatment Method, Journal of Korean Institute of Fire Science, vol. 25, No. 6, pp , ) B. K. Choi, W. K. Choi, Y. S. Kuk, H. G. Kim and M. K. Seo, A Study on Thermal Behaviors of Expanded Graphite/Erythritol Composite, Appl. Chem. Eng., vol. 25, No. 5, pp , ) S. J. Park, K. S. Kim and J. R. Lee, Thermal and Mechanical Interfacial Properties of Expanded Graphite/ Epoxy Composites, Journal of Korean Ind. Eng. Chem., vol. 15, No. 5, pp , ) S. Y. Park, D. H. Kim and H. S. Im, The Experimental Study for the Combustion- Property of Sandwich Panels using ISO 5660 Cone Calorimeter, Korean Institute of Fire Science & Engineering, vol. 1208, No. 4, ) J. W. Lee, B. W. Lee, S. P. Kwon, B. H. Lee, H. S. Kim and H. J. Kim, Burning Behavior of Flooring Materials in the Cone Calorimeter and Evaluation of Toxic Smoke, Journal of Mokchae Konghak, vol. 36, No. 1, pp , ) S. B. Kwak, C. H. Jung, J. D. Nam, J. H. Kim. M. A. Choi and J. H. Kong, Fire Resistance and Thermal Stability Study of Fire-Retarded Polypropylene Systems by Using Cone Calorimeter and Thermogravimetry, Polymer Korea, vol. 24, No. 6, pp , ) S. H. Min, J. S. Sun, S. C. Kim, Y. M. Choi and S. K. Lee, A Study on Fire Performance Evaluation of EIFS on Anti-Flaming Finish by Cone Calorimeter Test, Journal of Korean Institute of Fire Science, vol. 26, No. 3, pp , ) K. W. Lee, K. E. Kim and D. H. Lee, Combustion Characteristics of Fiber Reinforced Plastic by Cone Calorimeter, Korean Institute of Fire Science & Engineering, vol. 18, No. 2, ) J. S. Jeon, J. K. Seo and S. M. Kim, Suggestion of Thermal Environment Miniature for Evaluation of Heating Efficiency Based on Thermal Conductivity Measurement Method of Building Materials, Journal of Mokchae Konghak, vol. 39, No. 3, pp , ) W. S. Ahn, Effects of GTR and Unexpanded Expancel Powders on Thermal Conducting Characteristics of Rigid Polyurethane Foams, Journal of the Korea Academia- Industrial cooperation Society, vol. 13, No. 6, pp , ) J. H. Han, S. U. Kim and K. H. Lee, Transfer Characteristics of Porous Metallic Salt-Expanded Graphite Reactive Media The Korean Society for Energy, pp , ) S. J. Park, K. S. Kim and S. K. Hong, Preparation and Characterization of Expanded Graphites by Wet Process, HWAHAK KONG HAK, vol. 41, No. 6, pp , 한국안전학회지, 제 32 권제 3 호, 2017 년 33

14.531~539(08-037).fm

14.531~539(08-037).fm G Journal of the Korea Concrete Institute Vol. 20, No. 4, pp. 531~539, August, 2008 š x y w m š gj p { sƒ z 1) * 1) w w Evaluation of Flexural Strength for Normal and High Strength Concrete with Hooked