磷氮阻燃腈纶结构性能及阻燃机理研究

研究了含磷酸二氢铵和脲复合阻燃剂的共混阻燃腈纶的结构和性能。研究表明，在纤维成形加工过程中，部分阻燃剂聚合生成聚磷酸铵和聚脲，阻燃剂以微粒状均匀分散并包埋在纤维内部；阻燃剂的加入使纤维高序区大分子间等距离排列的规整性和片状结构单元等距离平行排列的程度降低，热稳定性亦略有下降；但纤维的宏形态结构及物理机械性能没有明显变化；磷氮阻燃腈纶具有良好的阻燃性和阻燃耐久性，经碱洗２０次、水洗３０次后，阻燃剂的磷和氮的保留率分别高达８２．９％和８９．５％，纤维的ＬＯＩ值仍在２６％以上。     

Unsteady extinction mechanism of nonpremixed flame interacting with a vortex

The extinction mechanism of a CH₄/N₂-air counterflow nonpremixed flame interacting with a single vortex was numerically studied. An augmented reduced mechanism was used to treat the CH₄ oxidation reactions. The contribution of each term in the energy and the OH species equations were evaluated to investigate the unsteady extinction mechanism of nonpremixed flame. The flame temperature began to decrease due to the convection heat loss when the flame interacted with a vortex. The investigation of the radical behavior during the flame-vortex interaction process also provided useful information on the unsteady extinction mechanism. The OH radical concentration could be used as a good tracer of the state of the unsteady extinction of nonpremixed flame. The reduction mechanism of OH concentration was confirmed by analyzing the contribution of each term in the OH species equation. At initial stage of flame-vortex interaction, the OH production and consumption rates increased gradually, while the OH concentration was kept nearly constant. Near the extinction limit, the OH production rate decreased rapidly due to the low flame temperature, and the balance between the OH production and OH consumption by diffusion could not be maintained. The unsteady nonpremixed flame interacting with a vortex under the conditions of regime (V) shown in the spectral combustion diagram [Thévenin, D., Renard, P.H., Fiechtner, G.J., Gord, J.R., Rolon, J.C., 2000. Regimes of non-premixed flame-vortex interactions. Proceedings of the Combustion Institute 28, 2101-2108.] was finally extinguished due to low reactivity, which was induced by the low flame temperature.     

塑料阻燃剂的合成研究进展

通过对常用塑料的燃烧特性和阻燃剂的阻燃机理的分析,论述了卤系、聚合型有机磷系、磷—氮系和无机系等不同类型阻燃剂的阻燃特性、发展动向及几种具有发展前途的新型阻燃技术,指出无卤、高效、低烟、低毒、多功能的新型阻燃剂合成及其新型阻燃技术的研究是阻燃剂的发展方向。     

二甲醚火焰传播速度的实验测定

二甲醚被誉为21世纪的绿色燃料，是目前理想的内燃机与民用替代燃料．为了获得二甲醚应用的重要基础参数——火焰传播速度，在定容球弹法、本生火焰法和平面火焰法作出比较分析后，采用本生火焰法实验测定了二甲醚火焰的传播速度．得出了二甲醚火焰传播速度与一次空气系数的关系曲线，并且在一次空气系数约为0．85处，二甲醚火焰传播速度的峰值为0．48m／s．     

IFR-2000阻燃聚丙烯热性能研究

研究了用无卤膨胀型阻燃剂IFR-2000作阻燃剂的阻燃聚丙烯的热性能和阻燃性能。     

阻燃抗紫外聚酯及纤维的研究

在聚酯的合成过程中加入磷系阻燃剂和抗紫外添加剂及其它助剂,使聚酯切片及纤维具有阻燃及抗紫外线性能。生产实践证明:阻燃抗紫外聚酯的可纺性良好,制得的纤维强度、伸长较纯聚酯纤维稍低,但仍可满足后加工要求;纤维的阻燃性、抗紫外性良好。     

火焰原子吸收光谱法测定苋菜中8种矿物元素

用空气-乙炔火焰原子吸收光谱法对苋菜中钾、钙、镁、铁、锌、铜、锰、铅8种矿物元素进行了测定,对样品前处理方法、酸度、共存元素干扰及元素线性范围进行了实验。在选定的实验条件下,可以用火焰原子吸收光谱法对苋菜中8种元素进行分别测定,互不干扰。方法的相对标准偏差为0.08%~3.17%(n=5),加标回收率为91.5%~102%。     

Different effects of tri(acryloyloxyethyl) phosphate on the thermal degradation of photopolymerized epoxy acrylate and polyurethane acrylate films

Tri(acryloyloxyethyl) phosphate (TAEP) was blended in different ratios with epoxy acrylate EB600 and polyurethane acrylate EB270 to obtain a series of UV curable flame retardant resins. The thermal degradation mechanisms of their cured films in air were studied by thermogravimetric analysis, in situ Fourier‐transform infrared spectroscopy, and direct pyrolysis/mass spectrometry measurements. The results showed that the phosphate group in TAEP first degraded to form poly(phosphoric acid) before the degradation of EB600. Then, the formed poly(phosphoric acid) effectively promoted the conversion of EB600 to form char, which prevented the sample from further burning. However, urethane group in EB270 degraded simultaneously with phosphate group in TAEP, leading to not effectively increase the conversion of EB270 to char during the thermal degradation. It was thus found that the addition of TAEP more effectively improved the thermal stability, flame retardance, and the char yield during combustion of EB600 than those of EB270. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3130–3137, 2006     

卤化石蜡系列阻燃剂研究进展

综述了卤化石蜡系列阻燃剂的品种、性能和用途。并讨论了溴化石蜡的几种溴化反应方法,即烯烃法、N-溴代丁二酰亚胺法和氧化汞催化法,指出溴素法生产溴化及溴氯化石蜡是卤化石蜡合成工艺的突破。最后对卤化石蜡的生产方法进行了简要介绍。     

Thermal degradation behaviors of polypropylene with novel silicon‐containing intumescent flame retardant

The N‐[3‐(dimethoxy‐methyl‐silanyl)‐propyl]‐N′‐ (9‐methyl‐3,9‐dioxo‐2,4,8,10‐tetraoxa‐3,9‐diphospha‐spiro[5.5]undec‐3‐yl)‐ethane‐1,2‐diamine/dimethoxy dimethyl silane copolymer (PSiN II), which simultaneously contains silicon, phosphorus, and nitrogen, is synthesized and incorporated into polypropylene (PP). The flame retardancy is evaluated by the limiting oxygen index value, which is enhanced to 29.5 from 17.4 with 20% total loading of PSiN II. The thermal degradation behavior of PP/PSiN II is investigated by thermogravimetric analysis under N₂ and air. The PP/PSiN II sample degrades at 400°C for different amounts of time, and the process of degradation is studied by Fourier transform IR. The morphology of the char formed at 400°C for 10 min is investigated by scanning electron microscopy. The swollen inner structure, close, and smooth outer surface provide a much better barrier for the transfer of heat and mass during fire and good flame retardancy. The thermal stability of PP is improved by incorporation of PSiN II. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2487–2492, 2005