Revisiting flexible polyurethane foam flammability in furniture and bedding in the United States

The flammability of flexible polyurethane foam has been well studied to date, via smoldering and flaming ignition. Its contribution to fire loss in the United States has also been well documented, as the flammability of this material will contribute to large fire events when not protected from ignition and heat sources. Despite this known fire risk, fire protection approaches for polyurethane foam are being questioned in regards to fire protection performance, as well as proven and hypothesized concerns over health impacts before and after fire events. The flammability of flexible polyurethane foam in furniture and bedding is a clear and present danger that must be addressed, and this article discusses the current available technologies for fire protection, with pros and cons of these approaches. Known physical and chemical behavior of these foams in fires is discussed, as well as how this behavior contributes to large fire events. Finally, issues that still need further research and information to definitively address the polyurethane foam flammability in the United States is discussed.     

Pulverized polyurethane foam particles reinforced rigid polyurethane foam and phenolic foam

Polyurethane consumption has been increasing in recent years, raising concerns about how to deal with the polymer waste. Post‐consumer rigid polyurethane foams or polyurethane foam scraps (PPU) ground into particles were utilized to strengthen mechanical properties of rigid polyurethane foam (PUF) and phenolic foam (PF). Viscosity of prepolymer with PUF was measured and PPU was well dispersed in prepolymer, as observed by optical microscope. Microstructures and morphologies of the reinforced foam were examined with scanning electron microscope (SEM) while cell diameter and density were measured by Scion Image software. Universal testing machine was employed to optimize compressive properties at various weight ratios of PPU. Both PUF and PF with 5 wt % PPU, respectively, exhibited considerable improvement in mechanical properties especially compressive property. The compressive modulus of PUF with 5 wt % PPU was 12.07 MPa, almost 20% higher than pure PUF while compressive strength of PF with 5 wt % PPU reached 0.48 MPa. The thermal stability of the reinforced foam was tested by thermal gravity analysis (TGA) and the result shows no obvious impact with PPU. The decomposition temperatures of PUF with PPU and PF with PPU were 280°C, because PPU has relatively weak thermal stability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39734.     

The relationship between polyurethane foam microstructure and foam aging

Correlations between polyurethane foam formulation and foam aging are shown to simplify when sufficient data are available to eliminate casual relationships. The numerous factors that are purported to result in faster or slower foam aging are shown to primarily reflect how those factors influence polyurethane hard segment structure. Specifically, changes in formulation that results in better phase separated (but co-continuous) structures exhibit less humid and heat aging than foams with poorer phase separation (broader interfacial phase mixing). This is demonstrated for aging tests that probe the polymer phase structure at higher stress or strain levels than that sometimes used. Tests that do not adequately stress the foam do not truly probe differences in foam structure that result in property decrements. Humid aged compression set and heat aged load loss data for a large number of foams are related to their formulation, catalysis, foaming rheology, and their hard segment structure determined by AFM and X-ray analyses.     

增强型泡沫新工艺

随着塑料加工技术的不断发展,涌现出利用共注射玻璃纤维或惰性填料加工聚氨酯泡沫制品等多种工艺技术。其中,意大利Cannon公司除研发出已被实践证明处于领先地位的InterWet工艺技术之外,最近又开发出了OuterWet工艺。OuterWet主要     

Recycling of polyurethane and polyisocyanurate foam

Heating of isocyanate derived foams with glycol mixtures is a simple and economically attractive recycling process. The process is emission free, not sensitive to varying product mixes and the obtained polyols can be completely reused in the manufacture of rigid polyurethane or polyisocyanurate foam.     

聚酰亚胺的合成方法

聚酰亚胺以其优异的热性能而引起人们广泛关注,40多年后的今天它仍然是在高耐热塑料中保持领先地位的-种优异的高分子材料.本文从二酐与二胺两步法及-步法合成聚酰亚胺展开论述.     

导电聚氨酯泡沫的制备

以聚氨酯软泡为基体制备了炭黑/聚氨酯泡沫复合材料,实验以热塑性聚氨酯(TPU)粉末为黏结剂,采用浸渍法制备导电聚氨酯泡沫材料,研究了溶剂、导电炭黑用量及聚氨酯泡沫泡孔对所制备复合材料电学及力学性能的影响。实验表明,丙酮为溶剂、m(炭黑):m(TPU)为0.36时使用低密度泡沫制备出的复合材料具有更优异的电学和物理性能。     

A comparative study of polyurethane foam by substituting LBA using green polyurethane foam CFA-1

Polyurethane foams are well-known optimal thermal-insulating materials, which have good thermal insulation performance, high strength, and lightweight properties. Here, we describe a chlorine-free and fluorine-free polyurethane chemical foaming agent (CFA-1) that can react with isocyanate to release CO₂ gas and foam polyurethane. We systematically studied its application performance in the field of polyurethane spraying by substituting the current most advanced and environment-friendly physical foaming agent 1-chloro-3,3,3-trifluoroprop-1-ene in different proportions. The results show that highly competitive mechanical properties lead to economical, environment-friendly, and efficient features. The lower thermal conductivity, more compact and smaller bubble structure, and excellent compression strength were achieved by tuning the proportion of CFA-1 from 20% to 60%. Thus, a promising material system was established for the development of the rigid polyurethane foam industry.     

Fire testing of upholstered furniture and bedding

Considerable concern has been expressed about the increasing number and changing pattern of fires and the fact that modern upholstered furniture is relatively easy to ignite and, once ignited, burns rapidly to produce large quantities of smoke and toxic gas. This led to a number of major research programmes and to the evolution of a number of test procedures in the UK. The first major test procedure was published in 1976 by the BPF in conjunction with RAPRA, BRMA and FIRA. An important aspect of this approach was the linking of ignition and rate of initial burning data with the application of the product and the environmental hazard. It was evolved within a short period of time to proved furniture designers and specifies with a means of avoiding products of high risk. The DOE/PSA are using a comprehensive series of Fire Retardant Specifications to control and specify their upholstered furniture and bedding. Specifications have been developed which enable individual components and sub-assemblies as well as the final product to be characterized in terms of ignitability and burning characteristics, i.e. temperatures, smoke, and carbon monoxide production. BS DD58 and BS 5852 Part1, ignitability tests for upholstered seating are essentially a combination of BPR and DOE/PSA test procedures. Cigarettes, gas flames and wooden cribs are used for the ignition sources and are positioned on a composite seat/back test rig.     

非异氰酸酯聚氨酯泡沫研究进展

简要介绍了非异氰酸酯聚氨酯的特点及合成机理,详细综述了非异氰酸酯聚氨酯泡沫的合成技术进展,并指出了未来非异氰酸酯聚氨酯泡沫的发展前景。     

Bubble-scale observations of polyurethane foam expansion

We describe experiments designed to inform computational models of the dynamic filling process of chemically blown, polyurethane foams, especially subgrid models to predict bubble size affecting foam properties. Three experimental methods are used to observe the evolution of bubble sizes during blowing. Magnified views of bubbles at a transparent wall of a channel are recorded during the foaming. The bubble sizes in the final frame after the expansion has stopped are compared to scanning electron microscope images of the interior of the cured samples to determine wall effects. In addition, diffusing wave spectroscopy is used to determine the average bubble sizes across the width of a similar channel during foam expansion. We conclude that the bubble size distribution is dependent on the formulation of foam being tested, temperature, the height in the foam bar, the proximity to a wall, and the degree of overpacking.     

辐射接枝型聚氨酯泡沫的研制

采用辐射接枝方法研制成功了辐射接枝型聚氨酯泡沫。扫描电镜的观察结果表明，研制的泡沫具有比较理想的泡孔结构。检测结果表明制得的泡沫具有优良的吸隔声性能。另外，还制备了以聚氨酯泡沫为芯层的复合板材，并对它们的吸隔声性能进行了测试分析。     

Compressive creep of flexible polyurethane foam

The compressive creep rate of polyurethane foams was found to be a complex function of deflection and time. The complexity has been shown to be related to the buckling of the cell struts as the foam is compressed. Of the parameters normally varied in the foam formulation, both the polyol molecular weight and the water content of the foam formulation seemed to have a measureable effect on the creep rate.     

聚氨酯泡沫的阻燃研究

3聚氨酯泡沫的燃烧和阻燃是-个非常复杂的过程.介绍了对聚氨酯泡沫进行阻燃处理的重要性,以及聚氨酯泡沫塑料阻燃研究领域的技术进展.简要介绍了阻燃剂的阻燃机理、聚氨酯泡沫塑料用阻燃剂的研究开发,较全面地综述了提高聚氨醇阻燃性的方法.包括反应型阻燃剂和添加型阻燃剂的特点及效果.对我国聚氨酯用阻燃剂的发展提出建议.     

硬质聚氨酯泡沫塑料研究进展

介绍了合成硬质聚氨酯泡沫塑料的主要原料,包括主体成分和发泡剂、泡沫稳定剂等;对硬质聚氨酯泡沫塑料的物理性能,如力学性能、阻燃性能、老化性能等及其在工程上的应用情况进行了综述。     

聚氨酯预聚体增韧改性酚醛泡沫塑料

采用异氰酸酯封端且不含游离异氰酸酯单体的聚氨酯预聚体作为酚醛泡沫的增韧改性剂,并在后期混合发泡工艺中减少酸性固化剂的用量,制备了不粉化、韧性高的改性酚醛泡沫体,并考察了异氰酸酯基含量对酚醛泡沫体的表观密度、压缩强度、吸水率、阻燃性和导热性能等的影响.结果表明:随着聚氨酯预聚体用量以及异氰酸酯基含量的增加,改性酚醛泡沫体的表观密度、压缩强度增大;当异氰酸酯基含量为8.6%时,抗粉化程度最好;随着聚氨酯预聚体用量的增加,吸水率和热导率变化不大,当聚氨酯用量不超过6%时,临界氧指数仍大于40.     

Density modeling of polyurethane box foam

A model based on about a dozen fundamental differential equations is used to evaluate and simulate the urethane reactions and physical processes of urethane box foaming. This work focuses on quantitative modeling of foam density for foams using water and physical blowing agents. The final densities of foams range from 30 to 90% of the density as projected with full utilization of the blowing agent. The primary sources of inefficient use of blowing agent are loss of the physical blowing during open‐air mixing and degassing—basically, physical blowing agents with boiling points between 25 and 80°C will evaporate and experience cell rupture in box foams. This loss of blowing agent would not apply to in‐line mixers used for commercial production and should be taken into account with scaling up box or cup foams commercial processes. POLYM. ENG. SCI., 54:1503–1511, 2014. © 2013 Society of Plastics Engineers