• Fire Science and Engineering
• /
• v.14 no.2
• /
• pp.7-13
• /
• 2000

We had investigated thermal stability, Ignition temperature and fire gas for polyurethane foams used for manikin, cushion and interior finishing material. Decomposition of polyurethane foams with temperature was investigated using a DSC and the weight loss with temperature increase using a TGA in order to find the thermal hazard of polyurethane foams, and the ignition temperature of polyurethane foams according to species. We studied constant temperature among ignition temperature measuring methods. In addition, noxious gases for polyurethane foams according to combustion condition were analyzed using gas analyzer and GASTEC. As results, initial decomposition temperature of polyurethane foam used for interior finishing material was lower than those for manikin and cushion, and exothermic energy was higher. Ignition temperature of polyurethane foam of interior finishing material was $420^{\circ}$. All of combustion forms at $427^{\circ}$ and under were smoldering combustion, and it was combustion at $500^{\circ}$. As furnace temperature was increased, concentration of noxious gases such as carbon oxide, carbon dioxide, and hydrogen cyanide was increased. And nitrogen oxide at combustion condition($500^{\circ}$) was over 10 ppm.

• Elastomers and Composites
• /
• v.34 no.4
• /
• pp.285-291
• /
• 1999

Effects of catalysts on network structure, hard segment length and distribution of polyurethane foams in the absence of catalysts were investigated. CFC free all MDI-based poly urethane foams were prepared from poly(ethylene adipate)glycol, 4,4'-diphenylmethane diisocyanate, and water. Amino catalysts used were 1,4-diazabicyclo[2,2,2]octane(DABCO), N, N,N',N'-tetramethyl--hexane-1,6-diamine(MR), bis(2-methylamino ethyl)ether(ET), 1,8-diazabicyclo-[5,4,0]-undecene-7(DBU). Dibutyltindilaurate(DBTL) as control was also used. Hard segment components of polyurethane foams were obtained by a selective degradation of polyester chains with 0.01N KOH-methanol solution. The PUFs with DBU catalyst contained more amount of isocyanurate components than other PUFs. On the other hand, the PUFs with ET, MR, DBTL catalysts contained more amount of allophanate and biuret component than the other PUFs.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.23 no.2
• /
• pp.57-64
• /
• 2013

Objectives: Skin exposure to diisocyanates may be an important risk factor for respiratory sensitization to leading asthma. However little is known about the extent of worker's diisocyanates skin exposure and the effectiveness of personal protective equipments in polyurethane foam manufacturing companies. This study provides data on diisocyanates skin exposure, surface diisiocyantes contamination of foams and the effectiveness of personal protective gloves in five polyurethane foam manufacturing companies. Materials and methods Colorimetric SWYPE pads are used for the determination of diisocyanates on surfaces of workers skin and polyurethanes foams. Results: The forearms, necks and faces of workers in polyurethane foam manufacturing companies were found to be contaminated with diisocyanates. Heavy contamination with uncured diisocyanates at large block foams surfaces were found. Personal gloves of workers for skin protection showed significant penetrations by diisocyanates. Conclusions: We found that all workers in polyurethane foam manufacturing companies could be exposed to diisocyanates by skin exposure. Also further researches which would better quantify skin exposure are needed.

• Applied Chemistry for Engineering
• /
• v.31 no.1
• /
• pp.30-35
• /
• 2020

In this study, polyurethane-silica composite foams were synthesized to analyze thermal insulation characteristics and mechanical properties. In order to synthesize polyurethane-silica composite foams, polyester-silica composite polyols were first synthesized via a polymerization reaction with silica sol, dicarboxylic acid and glycol in monomer state. Physical properties of polyurethane-silica composite foams synthesized using the composite polyols were analyzed. From the thermal conductivity analysis, no significant differences among HPUF0, HPUF1, HPUF3 and HPUF5 were found. The compressive strength of polyurethane-silica composite foams increased as the silica content increased. The mechanical property of HPUF5 was also about 25% higher than that of HPUF0.

• Polymer(Korea)
• /
• v.30 no.5
• /
• pp.402-406
• /
• 2006

New antibacterial Polyurethane foams for car seat with Urushiol extracted from a natural lacquer were prepared. Influences of antibacterial agent's concentration on the reactivity with isocyanate and the mechanical properties of foams were investigated. It was observed that the urethane formation reaction was delayed a little when the amount of Urushiol was increased. However, the foams made using Urushiol showed similar property to the neat polyurethane foam. In terms of antibacterial property, the foams prepared with Urushiol showed better performance than the neat polyurethane foam.

• Journal of Adhesion and Interface
• /
• v.11 no.1
• /
• pp.3-8
• /
• 2010

Thermal properties, flame retardant property, and sound-damping properties of polyurethane (PU) nanocomposite foams prepared with oligomeric 1,2-propanediol isobutyl polyhedral silsesquioxane (POSS) were investigated. It was found that the PU nanocomposite foams showed good sound-damping performances comparing to the PU foams without POSS.

• Carbon letters
• /
• v.18
• /
• pp.11-17
• /
• 2016

Monolithic carbon foams with hierarchical porosity were prepared from polyurethane templates and resol precursors. Mesoporosity was achieved through the use of soft templating with surfactant Pluronic F127, and macroporosity from the polyurethane foams was retained. Conditions to obtain high porosity materials were optimized. The best materials have high specific surface areas (380 and 582 m² g^-1, respectively) and high electrical conductivity, which make them good candidates for supports in sensors. These materials showed an almost linear dependence between the potential and the pH of aqueous solutions.

• Polymer(Korea)
• /
• v.34 no.1
• /
• pp.8-13
• /
• 2010

The physical properties of polymeric foams depend on the density of foams, physical properties of base polymers, the content of open cells, and cell structures including the size and its distribution, the shape of cell, and the thickness of skin layer. The foam density is affected by the chemistry of raw materials, the concentration of crosslinking agent and the blowing agent as well as the operating parameters during production process. In this study, the basic formulations of foams are composed of polyester polyol, MDI, amine catalyst, tin catalyst, silicone surfactant, and water. Cross-linking density of polyurethane was increased by using chain extenders. Also, the mechanical properties of polyurethane foam were improved by using the inorganic fillers (silica 1,2 and talc 1,2) having different $SiO_2$ contents and particle sizes. We investigated the properties of modulus, tensile strength, compressive strength and hardness of foams obtained by changing kind of inorganic filler and chain extender, and observed the distribution of inorganic filler as well as variation of cell size within the foams by electron microscopy.

• Textile Coloration and Finishing
• /
• v.17 no.6 s.85
• /
• pp.36-41
• /
• 2005

The effects of low temperature plasma treatment on the properties of three types of foams, polyurethane(PU), injection phylon(IP), and phylon(PH) that used for footwear mid-sole were examined. The change of surface properties of foams were characterized by electron scanning microscope, contact angle measurement, and universal testing machine. Adhesion was tested by T-peel tests of plasma treated foams/polyurethane adhesive joints. The contact angle of three types of foams were decreased dramatically with the plasma treatment time, specifically noticeable in the case of phylon(Ph). It has shown the relationship with the contact angle of phylon(PH) and the distance between electrode and samples. The peel strength of foams were increased with the increase of plasma treatment time.

• Transactions of Materials Processing
• /
• v.11 no.1
• /
• pp.69-74
• /
• 2002

In addition to lightweight and moldable characteristics, polymeric foams possess an excellent energy absorbing capability that can be utilize for a wide range of commercial applications, especially in the crashworthiness of the automobiles. The purpose of the present study is to develop experimental methodology to characterize the pressure dependent yield behavior of the energy absorbing polymeric foams. For the compression test in a triaxial stress sate, a specially designed device was placed in a hydraulic press to produce and control oil pressure. For the test material, the polyurethane foams of two different densities were used. The displacement of the specimen, the load subjected to the specimen, and oil pressure applied to the specimen were measured and controlled. Stress strain curves and yield stresses for the four different oil pressure were obtained. It was found from the present experiments that the polyurethane foams exhibited significant increases in yield stress with applied pressure or mean normal stress. Based on this observation, a yield criteria which included the effect of the stress invariant were established for the polymeric foams. The obtained experimental constants which constituted the pressure-dependent yield criterion were verified.