氮-磷协同阻燃聚氨酯保温材料性能研究

为了提高硬质聚氨酯的阻燃性能,采用磷改性聚醚,并添加三聚氰胺(Melamine)和聚磷酸胺(APP),并对试件的燃烧行为和热性能进行了研究。结果表明:在含磷硬质聚氨酯保温隔热材料中等比例添加Melamine和APP,能形成氮-磷协同阻燃体系,材料的阻燃性能得到显著提高,其中氧指数达34.43%,水平燃烧等级达到FH-1,垂直燃烧等达FV-0。     

水乳型丙烯酸酯类阻燃涂料的合成与性能

采用乳液聚合的方法合成了一种以TBPMI为阻燃剂的水乳型丙烯酸酯阻燃涂料,并对该涂料的硬度、附着力、耐热性和阻燃性进行了测试分析。研究结果表明,该涂料的耐热阻燃性能优异,热分解温度达到340～375℃,有着可观的经济价值和应用前景。     

关于用ISO 9705评价材料的火焰传播

虽然性能化规范尚未达到通用的程度 ,但中国香港建筑业消防安全条款已用于“工程方法”设计中 ,在回顾了四个标准试验 ,即 ASTM E1 32 1 - 97a、BS4 76 :Part:1 997、ASTM E84 -99/ NFPA2 5 5和 ISO970 5 :1 993(E)之后 ,介绍了 ISO970 5 ,供地方政府评估各种材料的火焰传播。为妥善处理新的建筑材料 ,应将材料和构件的火焰传播试验列入说明中     

钢结构超薄膨胀型防火涂料的研究(Ⅲ)--颜料对涂料性能的影响

在以HHCPE和丙烯酸酯树脂为基料，三聚氰胺磷酸盐和季戊四醇为防火助剂的钢结构超薄膨胀型防火涂料中，分别加入有机颜料和无机颜料，制备了色彩鲜艳的彩色钢结构防火涂料．讨论了颜料品种和加入量对涂料耐火性能和其他综合性能的影响．     

Flame Retardance and Smoke Suppression of Poly(vinyl chloride) Using Multicomponent Systems

Metal-based organic complexes (MBO) are a class of FRSS additives that comprise a transition metal and an organic ligand that cleaves at an elevated temperature thereby releasing the metal in a reactive state. They help in the formation of char and thus act as an effective smoke suppressant. Use of MBO complexes as flame retardant smoke suppressants, phosphate ester as a flame retardant and active filler as endothermic material is reported here as multicomponent FRSS systems. MBOs used in the present study are the chelates of pentanediono. They were used alone as well as in combination with aluminum trihydrate (ATH) as filler were used to impart flame retardancy and smoke suppression to poly vinylchloride. Their performance was measured in terms of flammability, smoke generation, char formation and evolution of combustion gases. MBOs of molybdenum and chromium were found to be very efficient flame retardant smoke suppressants.     

Exposure and effects assessment of persistent organohalogen contaminants in arctic wildlife and fish

Persistent organic pollutants (POPs) encompass an array of anthropogenic organic and elemental substances and their degradation and metabolic byproducts that have been found in the tissues of exposed animals, especially POPs categorized as organohalogen contaminants (OHCs). OHCs have been of concern in the circumpolar arctic for decades. For example, as a consequence of bioaccumulation and in some cases biomagnification of legacy (e.g., chlorinated PCBs, DDTs and CHLs) and emerging (e.g., brominated flame retardants (BFRs) and in particular polybrominated diphenyl ethers (PBDEs) and perfluorinated compounds (PFCs) including perfluorooctane sulfonate (PFOS) and perfluorooctanic acid (PFOA) found in Arctic biota and humans. Of high concern are the potential biological effects of these contaminants in exposed Arctic wildlife and fish. As concluded in the last review in 2004 for the Arctic Monitoring and Assessment Program (AMAP) on the effects of POPs in Arctic wildlife, prior to 1997, biological effects data were minimal and insufficient at any level of biological organization. The present review summarizes recent studies on biological effects in relation to OHC exposure, and attempts to assess known tissue/body compartment concentration data in the context of possible threshold levels of effects to evaluate the risks. This review concentrates mainly on post-2002, new OHC effects data in Arctic wildlife and fish, and is largely based on recently available effects data for populations of several top trophic level species, including seabirds (e.g., glaucous gull (Larus hyperboreus)), polar bears (Ursus maritimus), polar (Arctic) fox (Vulpes lagopus), and Arctic charr (Salvelinus alpinus), as well as semi-captive studies on sled dogs (Canis familiaris). Regardless, there remains a dearth of data on true contaminant exposure, cause-effect relationships with respect to these contaminant exposures in Arctic wildlife and fish. Indications of exposure effects are largely based on correlations between biomarker endpoints (e.g., biochemical processes related to the immune and endocrine system, pathological changes in tissues and reproduction and development) and tissue residue levels of OHCs (e.g., PCBs, DDTs, CHLs, PBDEs and in a few cases perfluorinated carboxylic acids (PFCAs) and perfluorinated sulfonates (PFSAs)). Some exceptions include semi-field studies on comparative contaminant effects of control and exposed cohorts of captive Greenland sled dogs, and performance studies mimicking environmentally relevant PCB concentrations in Arctic charr. Recent tissue concentrations in several arctic marine mammal species and populations exceed a general threshold level of concern of 1 part-per-million (ppm), but a clear evidence of a POP/OHC-related stress in these populations remains to be confirmed. There remains minimal evidence that OHCs are having widespread effects on the health of Arctic organisms, with the possible exception of East Greenland and Svalbard polar bears and Svalbard glaucous gulls. However, the true (if any real) effects of POPs in Arctic wildlife have to be put into the context of other environmental, ecological and physiological stressors (both anthropogenic and natural) that render an overall complex picture. For instance, seasonal changes in food intake and corresponding cycles of fattening and emaciation seen in Arctic animals can modify contaminant tissue distribution and toxicokinetics (contaminant deposition, metabolism and depuration). Also, other factors, including impact of climate change (seasonal ice and temperature changes, and connection to food web changes, nutrition, etc. in exposed biota), disease, species invasion and the connection to disease resistance will impact toxicant exposure. Overall, further research and better understanding of POP/OHC impact on animal performance in Arctic biota are recommended. Regardless, it could be argued that Arctic wildlife and fish at the highest potential risk of POP/OHC exposure and mediated effects are East Greenland, Svalbard and (West and South) Hudson Bay polar bears, Alaskan and Northern Norway killer whales, several species of gulls and other seabirds from the Svalbard area, Northern Norway, East Greenland, the Kara Sea and/or the Canadian central high Arctic, East Greenland ringed seal and a few populations of Arctic charr and Greenland shark.     

Fire Spread and Flame Length in Large-Scale Tunnel Fires

An analysis of fire spread during four large-scale fire tests that were performed in the Runehamar tunnel in Norway is presented. The fire loads consisted of mock-ups simulating a Heavy Goods Vehicle (HGV) trailer. The fire spread downstream of the HGV trailer mock-ups was studied, both to large targets with the same type of commodities as used in the trailer mock-up for each tests, and to small pieces of wood and plastic poles placed at different distances from the fire. The purpose was to determine a critical distance for fire spread between HGV trailers for different heat release rate histories. The time to ignition of a second object and fire spreading distances were estimated from post-visual observations and temperature measurements. Correlations for flame length were developed from the experimental results. Since the average temperature of the cross-section often is used to estimate fire spread, results from a model for the average temperature were compared with the measured temperatures.     

浅谈阻燃电缆的应用和发展

文章论述了阻燃电缆的重要性和阻燃机理，介绍了阻燃电缆最新技术和发展趋势，提出了相关规范的修改建议。     

Corrosion of concrete sewers--the kinetics of hydrogen sulfide oxidation

The widespread occurrence of polybrominated diphenyl ethers (PBDEs) in the environment has attracted considerable attention, leading to concerns about the extent and magnitude of wildlife and human exposure. In this work, we focus on the occurrence and fate of PBDEs in a Norwegian air-plant-herbivore-carnivore system. Specifically, we have analysed for PBDEs in moss, livers from various terrestrial herbivores (moose, grouse, and European roe deer) and, for the first time, livers from the top predator lynx. The samples were collected from different sites and time periods (1990-2004) to identify possible spatial and temporal trends in contaminant levels and patterns. The general finding was that PBDEs were found in all (biotic) samples, although at lower concentrations than previously observed in mammals from the marine environment. The PBDE levels in the herbivores ranged from less than 0.5 ng/g lipid weight to 9.4 ng/g lipid weight as the highest. The median PBDE concentration in lynx was approximately one order of magnitude higher than in the herbivores. In the lynx samples there was a predominance of BDE-153 whereas BDE-47 and 99 dominated in the herbivores. This probably reflects different bioaccumulation properties or metabolic transformation processes of the BDE-congeners, and food choice. Levels of PBDEs in both moss and herbivores showed a general decline towards the northern parts of Norway. No clear temporal trends were observed. The PBDE levels observed in this study were low and are probably of limited toxicological significance.     

Extinction condition of counterflow spray diffusion flame with polydisperse water spray

The effect of polydisperse water droplet size distribution on the burning behavior and extinction condition of counterflow spray diffusion flame was investigated experimentally in this study. N-heptane as liquid fuel spray and nitrogen as a carrier gas were introduced from the lower duct while water spray and oxidizer consisting of oxygen and nitrogen was issued from the upper duct. The burning behavior of spray flame for different fuel droplet size with and without water spray was observed and the extinction condition of counterflow spray diffusion flame was characterized by oxygen concentration at extinction. The results show that the minimum value of oxygen concentration at extinction for counterflow spray diffusion flame with water spray is similar to the extinction condition without water spray for higher mean droplet diameter of water. The minimum value of oxygen concentration at extinction shifts to the smaller fuel droplet size when decreasing the water droplet size. For fuel droplet size higher than 48 μm, the optimum of water droplet size for suppressing counterflow spray diffusion flame was smaller than gaseous flame. The explanation of optimum water droplet size based on the coupled effect of Stokes number and vaporization Damköhler number can be used for prediction of the effectiveness of water droplet on the suppression of counterflow spray diffusion flame.