물유리코팅에 따른 폴리우레탄 폼의 난연성능 개선에 대한 연구

김형준(Hyeong-Jun Kim),박제원(Jewon Park),나혜인(Hyein Na),임형미(Hyung Mi Lim),장가빈(Gabin Chang) 한국화재소방학회 2020 한국화재소방학회논문지 Vol.34 No.2

경질 폴리우레탄(Polyurethane) 폼(Foam)의 난연 성능을 개선하기 위하여 외부에 물유리를 코팅하였다. 무기질인물유리 코팅층이 적용된 우레탄폼의 콘칼로리메터의 열방출율(Heat release rate)은 급격히 감소하였다. 폴리우레탄표면에 코팅된 물유리는 화염에 노출되었거나 가열되었을 때 유리화 반응과 미 탈출 수분에 의한 발포현상으로 인해 유리질 폼을 형성하게 된다. 폴리우레탄 폼 위에 형성된 유리질 폼은 단열층이 되어 10 min 이상 폴리우레탄 폼의연소를 억제하였다. 이러한 결과에 따라서 물유리는 경질 폴리우레탄 폼의 난연 특성을 개선할 수 있음을 확인하였다. In this study, water glass was applied as a coating material to a rigid polyurethane foam to improve the flame-retardantproperties of the foam. The heat release rate of the cone calorimeter of the urethane foam, in which the inorganicwater-glass coating layer was applied, decreased rapidly. The water glass coated on the polyurethane surface formed aglassy foam by foaming with water, which did not escape during the vitrification reaction when the foam or glass washeated. The glassy foam formed on the polyurethane foam became a fire-resistant insulation layer that inhibited thecombustion of the polyurethane foam for more than 10 min. Water glass was found to improve the flame-retardantproperties of the rigid polyurethane foam.

현무암 섬유 보강 폴리우레탄폼의 열적 성능 및 극저온 환경에서의 기계적 특성 평가

전성규,김정대,김희태,김정현,김슬기,이제명 대한조선학회 2022 大韓造船學會 論文集 Vol.59 No.4

LNG CCS which is a special type of cargo hold operated at –163℃ for transporting liquefied LNG is composed of a primary barrier, plywood, insulation panel, secondary barrier, and mastic. Currently, glass fiber is used to reinforce polyurethane foam. In this paper, we evaluated the possibility of replacing glass fiber-reinforced polyurethane foam with basalt fiber-reinforced polyurethane foam. We conducted a thermal conductivity test to confirm thermal performance at room temperature. To evaluate the mechanical properties between basalt and glass-fiber-reinforced polyurethane foam which is fiber content of 5 wt% and 10 wt%, tensile and an impact test was performed repeatedly. All of the tests were performed at room temperature and cryogenic temperature(-163℃) in consideration of the temperature gradient in the LNG CCS. As a result of the thermal conductivity test, the insulating performance of glass fiber reinforced polyurethane foam and basalt fiber reinforced polyurethane foam presented similar results. The tensile test results represent that the strength of basalt fiber-reinforced polyurethane foam is superior to glass fiber at room temperature, and there is a clear difference. However, the strength is similar to each other at cryogenic temperatures. In the impact test, the strength of PUR-B5 is the highest, but in common, the strength decreases as the weight ratio of the two fibers increases. In conclusion, basalt fiber-reinforced polyurethane foam has sufficient potential to replace glass fiber-reinforced polyurethane foam.

Effects of Isocyanate Index and Environmentally-Friendly Blowing Agents on the Morphological, Mechanical, and Thermal Insulating Properties of Polyisocyanurate-Polyurethane Foams

박동협,박건표,김성현,김우년 한국고분자학회 2013 Macromolecular Research Vol.21 No.8

The effects of the isocyanate (NCO) index and blowing agent on the morphology, mechanical strength,thermal conductivity and thermal stability of the polyisocyanurate-polyurethane (PIR-PUR) foams were investigated. When the NCO index was increased, the isocyanurate ring content in the PIR-PUR foams was found to be increased regardless the type of blowing agents. As a results, the thermal stability of the PIR-PUR foams was improved. When the isocyanurate ring content in the PIR-PUR foams was increased, the cell size was slightly decreased. The decreased cell size of the foams affected the decrease in the thermal conductivity of the PIR-PUR foams regardless the type of the blowing agents. From the results of thermogravimetric analysis (TGA), the thermal stability of the PIR-PUR foams was found to increase with an increase in the NCO index. When the NCO index was 200, the compressive strength was maximal for the PIR-PUR foams regardless the type of the blowing agents. The compressive strength of the foams blown by cyclopentane was higher than that of the water blown foams. From the above results, it is suggested that the thermal insulation property and thermal stability of the PIR-PUR foams increased with an increase in the NCO index. However, the compressive strength of the PIR-PUR foams showed maximum value at a specific NCO index.

Generalization of the memory integer model for the analysis of the quasi-static behaviour of polyurethane foams

Hamdi Jmal,Ming Lei Ju,Raphael Dupuis,Evelyne Aubry 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.11

Polyurethane foam is a cellular material characterized by an interesting mechanical spectrum of properties: low density, capacity to absorbthe deformation energy and low stiffness. This spectrum of properties makes polyurethane foam commonly used in many thermal,acoustic and comfort applications. Several models, such as memory, hyper-elastic and pseudo-elastic models have been developed in theliterature to describe the mechanical response of polyurethane foam under quasi-static and dynamic test conditions. The main disadvantageof these models is the dependence of their parameters against the test conditions (strain rate, maximum compression level, etc). Thisaffects the general character of their representativeness to the quasi-static and dynamic behaviours of polyurethane foam. The main goalof this article is to implement reliable mechanical model which is able to provide the quasi-static response of the polyurethane foam underdifferent strain rates and large compressive deformation. The dimensional parameters of our model can be expressed by the productof two independent parts; the first contain only the test conditions and the second define the dimensionless and invariant parameters thatcharacterize the foam material. The developed model has been proposed after several experimental studies allowing the apprehension ofthe quasi-static behaviour (through unidirectional compression tests). The polyurethane foam, under large deformations, exhibits anonlinear elastic behaviour and viscoelastic behaviour. To assess the ability of our model to be a general representation, three industrialpolyurethane foams have been considered.

Prepolymer와 Resin Premix로 부터 제조된 Polyurethane Foam의 기계적 성질

김태성 ( Tae Sung Kim ),박찬영 ( Chan Young Park ) 한국고무학회 2013 엘라스토머 및 콤포지트 Vol.48 No.3

polyester형 polyurethane foam은 낮은 내가수분해성을 가지므로 quasi prepolymer법에 의한 acrylic polyol을 사용함으로써 극복될 수 있다. acrylic polyol을 함유한 polyurethane foam은 acrylic polyol 함량이 증가함에 따라 인장강도와 경도가 증가하였다. 하지만 split 인열강도와 인열강도는 약간씩 변화되었다. polyurethane foam의 내가수분해성은 인장강도의 손실 백분율로 측정하였으며 acrylic polyol 함량이 25.5g에서 102g으로 증가함에 따라 향상되었다. Polyester type polyurethane foam has low hydrolysis resistance. It was overcome with addition of acrylic polyol by quasi prepolymer method. Tensile strength and hardness of polyurethane foam contained acrylic polyol was increased with increasing of acrylic polyol contents. But split tear strength and tear strength was slightly changed. Hydrolysis resistance of polyurethane foam was measured by loss % of tensile strength. It was improved with increasing of acrylic polyol contents from 25.5g to 102g.

Processing of Polyurethane/polystyrene Hybrid Foam and Numerical Simulation

Lee, Won Ho,Lee, Seok Won,Kang, Tae Jin,Chung, Kwansoo,Youn, Jae Ryoun The Korean Fiber Society 2002 Fibers and polymers Vol.3 No.4

Polyurethane foams were produced by using a homogenizer as a mixing equipment. Effects of stirring speed on the foam structure were investigated with SEM observations. Variation of the bubble size, density of the foam, compressive strength, and thermal conductivity were studied. A hybrid foam consisting of polyurethane foam and commercial polystyrene foam is produced. Mechanical and thermal properties of the hybrid foam were compared with those of pure polyurethane foam. Advancement of flow front during mold filling was observed by using a digital camcorder. Four types of mold geometry were used for mold filling experiments. Flow during mold filling was analyzed by using a two-dimensional control volume finite element method. Variation of foam density with respect to time was experimentally measured. Creeping flow, uniform density, uniform conversion, and uniform temperature were assumed for the numerical simulation. It was assumed for the numerical analysis that the cavity has thin planar geometry and the viscosity is constant. The theoretical predictions were compared with the experimental results and showed good agreement.

Study on rigid polyurethane foam composited with silica aerogel

고혜인,홍창국 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

Silica aerogels are known as the mesoporous material with the high porosity and the low thermal conductivity. Rigid polyurethane foam is insulation material widely used due to its good mechanical strength and workability. In this study, the rigid polyurethane foam (PU foam) composited with silica aerogels were prepared by compositing method using homogenizer. The change of polyurethane foam with the content of silica aerogels was observed. Silica aerogels were prepared with IPA, HCl, TMCS and water glass via the sol-gel method. Silica aerogels dispersed polyol solution and MDI were used to prepare the polyurethane foams. The particle size and structure were analyzed by HR-TEM and FE-SEM, and the dispersivity of silica aerogels in PU foam were characterized with FE-SEM and EDS.

공사장 폴리우레탄폼의 화재 위험성 연구

장창훈,이윤칠,문광식 한국화재감식학회 2021 한국화재감식학회 학회지 Vol.12 No.3

Polyurethane foam is often used as an insulation material in modern society due to its excellent insulation function, light weight and low density. As a result, fires are occurring frequently at construction sites using polyurethane foam. Due to the characteristics of polyurethane foam, the spread of fire is fast and toxic gases erupt in large quantities, causing property damage and human damage Most of the causes of the fire are caused by carelessness of workers during heat of work around the area, such as welding spark and torch use, with polyurethane foam applied. In response, this study experimented with the possibility of direct ignition on polyurethane foam applied using welding spark, grinder, and torch, which are the heat of works mainly used in construction sites. Experiments show that the applied polyurethane foam was easily ignited by welding spark, torches, and oil vapor except grinder spark. The purpose of the project is to prevent fires by prohibiting heat work such as welding at polyurethane foam work places and thoroughly observing and supervising prescribed fire safety rules.

Effects of Nucleating Agent on the Thermal Conductivity and Creep Strain Behavior of Rigid Polyurethane Foams Blown by an Environment- Friendly Foaming Agent

장로빈,이영범,송광호,김우년 한국고분자학회 2021 Macromolecular Research Vol.29 No.1

The effects of liquid-type additive, methoxynonafluorobutane, on the morphology, thermal conductivity, creep strain, and mechanical strength of polyurethane (PU) foams with an environment-friendly foaming agent, hyrdofluoroolefin, were investigated. The methoxynonafluorobutane under the trade name of NOVEC likely acted as a nucleating agent during the formation of PU foams. When NOVEC was added in the amount of 3 parts per hundred polyol by weight (php), the cell size of the foam was minimal, and the cell size distribution was relatively uniform. At the NOVEC content of 3.0 php, the thermal conductivity of the PU foams was also minimal. This decrease in thermal conductivity was due to the smaller cell size of the foams lowering their thermal conductivity. At 3.0 php NOVEC content, the creep strain of the PU foams was minimal being 0.29% at 1,000 h. At 3.0 php NOVEC, the estimated creep strain of the PU foam exhibited the lowest creep strain of 3.47% at 50 years. As a result, at 3.0 php NOVEC content, the cell wall was relatively less fractured, resulting in a small deformation of the PU foam. These results suggest that the main factors in improving the thermal insulation properties and stability of the PU foams are smaller cell size and narrow cell size distribution.

실리카 에어로겔을 첨가한 폴리머 폼의 기계적 특성

안재혁(Jae-Hyeok Ahn),김정현(Jeong-Hyeon Kim),김정대(Jeong-Dae Kim),박성균(Sungkyun Park),박강현(Kang Hyun Park),이제명(Jae-Myung Lee) 한국해양공학회 2017 韓國海洋工學會誌 Vol.31 No.6

In the present study, silica-aerogel-polyurethane foams were synthesized to improve the mechanical characteristics and insulation performance of the polyurethane foam applied to a liquefied natural gas carrier at a cryogenic temperature of -163℃. A silica-aerogel-polyurethane foam bulk was prepared using a homogenizer by varying the weight ratio of the silica aerogel (0, 1, 3, and 5 wt%), while maintaining the contents of the polyol, isocyanate, and blowing agent constant. Compression tests were performed at room and cryogenic temperatures to compare the mechanical properties of the silica-aerogel polyurethane foams. The internal temperature of the universal testing machine was maintained through the cryogenic chamber. The thermal conductivity of the silica-aerogel-polyurethane foam was measured using a heat flow meter to confirm the insulation performance. In addition, the effect of the silica aerogels on the cells of the polyurethane foam was investigated using FE-SEM and FTIR. From the experimental results, the 1 wt% silica aerogel polyurethane foam showed outstanding mechanical and thermal performances.