复合型氢氧化镁阻燃剂的改性研究

采用石灰乳法制备氢氧化镁阻燃剂,对混合碱用量、溶剂总量、水/醇比和反应时间进行考察,并采用三种典型的改性剂———磷酸三苯酯、双咪唑啉、双子磺酸钠对氢氧化镁阻燃剂进行改性。结果表明,Mg（OH）2的最佳制备条件为：氯化镁与混合碱的摩尔比为1∶2.2,溶剂的总量为2 100 mL,水/醇的体积比为4∶1,反应时间为30 min。采用晶须改性剂磷酸三苯酯时,温度在80℃,改性时间4 h,添加量2%（质量百分比）时,活化指数较好;采用双咪唑啉、双子磺酸钠时,温度在40℃,改性时间2 h,添加量4%（质量百分比）时,活化指数较好。     

结晶型氢氧化镁阻燃剂制备工艺研究

以卤片和氨水为原料,采用控制结晶工艺制备阻燃级氢氧化镁,研究了反应温度、反应时间对氢氧化镁合成的影响.并在间歇合成氢氧化镁条件实验的基础上进行了连续合成实验和水热改性实验,结果表明连续控制结晶合成的氢氧化镁产物的结晶形貌及性能明显优于间歇结晶产物.     

氢氧化镁协同阻燃剂的研究进展

综述了氢氧化镁阻燃剂的阻燃机理,介绍了Mg(OH)2高效协同阻燃剂的研究现状;展望了氢氧化镁协同阻燃剂未来的发展趋势和研究方向。     

氢氧化镁阻燃剂的现状及展望

分析了氢氧化镁作为阻燃剂的性能及优点，并根据其作为阻燃剂产品的要求，对其制备方法进行了概述。总结了目前国内外镁资源的利用、研究、生产和使用状况，结合国内的实际情况，对阻燃剂氢氧化镁发展提出了建议，同时指出应加强对阻燃型氢氧化镁产品行业标准的制定工作，以促进该行业的进一步发展。     

氢氧化镁阻燃剂的开发应用

介绍了氢氧化镁阻燃剂的制备方法，并对氢氧化镁阻燃剂的开发应用提出了建议。     

Study on the flame retardancy of EVM/magnesium hydroxide composites optimized with a flame retardant containing phosphorus and silicon

A novel phosphorus‐silicon‐containing flame retardant, spirocyclic pentaerythritol bisphosphorate disphosphoryl chloride/9, 10‐dihydro‐9‐oxa‐10‐phosphaphanthrene‐10‐oxide/vinyl methyl dimethoxysilane (SPDV), was synthesized successfully and used for optimizing the flame retardancy of ethylene‐vinyl acetate copolymer (EVM) rubber/magnesium hydroxide (MDH) composites. The microstructure of SPDV was characterized and determined by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy. Thermogravimetric analysis (TGA) showed that SPDV had good charring effect in air even at high temperature (800°C). The flame retardancy of the optimized EVM/MDH composites by SPDV was investigated by limiting oxygen index (LOI), cone calorimeter, and UL‐94 vertical burning tests. A higher LOI value (29.4%) and better UL‐94 rating (V‐0) can be achieved for the optimized EVM/MDH composite (EVM‐7) than EVM/MDH composite without SPDV (EVM‐3) with the total loading of additives. The HRR decreased and residual mass increased gradually as the loading of SPDV increased for the optimized EVM/MDH composites. There existed distinct synergistic intumescent flame‐retardant effect between SPDV and MDH in EVM matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

磷化合物对氢氧化镁阻燃聚氨酯密封胶性能的影响

研究了磷化合物对氢氧化镁阻燃聚氨酯(PU)密封胶性能的影响。研究结果表明,聚磷酸铵(APP)与间苯二酚双-(二苯基磷酸酯)(RDP)复合磷系阻燃剂对氢氧化镁阻燃PU密封胶具有良好的协效作用;当m(APP)∶m(RDP)=6∶4时,阻燃PU密封胶的综合性能较好,此时该密封胶的氧指数由28.9提高到31.7、垂直燃烧级别也由FV-1级提升到FV-0级(3.2mm)、拉伸强度为2.7MPa、断裂伸长率为376%且邵A硬度为56。     

新型氢氧化物阻燃剂在胶粘剂领域中的应用进展

介绍了表面改性、超细化、以及与其他阻燃剂联用等途径对氢氧化物[Al(OH)3、Mg(OH)2]阻燃性能的影响,综述了新型阻燃剂在胶粘剂领域中的应用研究进展,比较了氢氧化物、改性氢氧化物、氢氧化物协同作用、氢氧化物和有机物协同作用等对各种胶粘剂阻燃性能和力学性能的改进效果,讨论了该领域研究中依然存在的一些不足,指出了今后的研究可能取得突破的几个方向。     

氢氧化镁阻燃剂的表面改性及其在聚丙烯中的应用

采用不同改性剂对氢氧化镁进行表面改性处理，通过实验发现采用4％的硬脂酸钠处理后的氢氧化镁阻燃剂在聚丙烯体系中分散均匀，当氢氧化镁在聚丙烯体系中的添加量达65％时，达到了理想的阻燃效果。     

水镁石及其在氢氧化镁阻燃剂生产中的应用

对水镁石及其在氢氧化镁阻燃剂生产中的应用作了评述。包括资源概况和矿石品位、生产企业、国内外研究开发近况。并展望了其发展前景。     

轻烧粉水化法制取阻燃级氢氧化镁新工艺

以轻烧粉为原料，采用直接水化、机械方法除铁、除杂，化学方法除铁、除钙、除硅等净化工艺，湿法表面处理、压滤、干燥、分级包装制取氢氧化镁阻燃剂，其产品达到HG／T3600-2000工业氢氧化镁阻燃剂质量要求。该法具有工艺流程短，操作简便，投资少，原料易得，产品成本低，经济效益好等特点。     

Combustion characteristics of halogen‐free flame‐retarded polyethylene containing magnesium hydroxide and some synergists

Halogen‐free flame‐retarded polyethylene materials have been prepared by using magnesium hydroxide (MH) as a flame retardant combined with red phosphorous (RP) and expandable graphite (EG) as synergists. The effects of these additives on the combustion behavior of the filled linear low density polyethylene (LLDPE), such as a limiting oxygen index (LOI), the rate of heat release (RHR), the specific extinction area (SEA), etc., have been studied by the LOI determination and the cone calorimeter test. The results show that RP and EG are good synergists for improving the flame retardancy of LLDPE/MH formulations. In addition, a suitable amount of ethylene and vinyl acetate copolymer (EVA) added in the formulations can increase the LOI values while promoting the char formation and showing almost no effect on the RHR and SEA values. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 206–214, 2001     

激光粒度仪测试阻燃剂级氢氧化镁粒度分布

建立了实用、准确和快速的阻燃剂级氢氧化镁粉体粒度分布的测试方法。采用MS2000激光粒度分析仪研究了待测样品质量、泵转速、分散时间、分散介质、分散剂种类以及分散剂质量浓度等因素对阻燃剂级氢氧化镁粉体粒度分布测试结果的影响。适宜条件:以700 mL水为分散介质,洗洁精为分散剂,分散剂质量浓度控制在0.1~0.3 g/L,氢氧化镁粉体样品质量范围为0.020~0.035 g,泵转速为1 400~2 000 r/min,超声波分散时间为2~5 min,超声波分散后立即测量。     

Poly(trimethylene terephthalate)/magnesium hydroxide composites with on‐demand thickening at high temperatures

Magnesium hydroxide, when melt extruded with poly(trimethylene terephthalate) (PTT) at low concentrations (1–3 wt.%), can be melt processed during extrusion and injection molding. When the polymer is heated in the melt to 295°C, the viscosity of the composite behaves similarly to control samples and the viscosity decreases as a function of temperature. When the temperature of the composite is raised above 295°C (above the normal processing conditions for PTT), a significant change in the melt rheology of the composite is observed relative to unfilled compositions. This change in melt rheology coincides with the decomposition temperature of magnesium hydroxide and formation of magnesium oxide, a common thickening agent employed in unsaturated polyester resins. Lower processing temperature polyesters, including PTT, enable processing of the polymer in the presence of magnesium hydroxide under normal conditions. The viscosity modifier ‘turns on’ when the composite sees elevated temperature where magnesium oxide is known to form. The magnesium oxide is hypothesized to interact with PTT carboxyl end groups, providing the observed increase in viscosity. The rheological response observed in the composites is dependent on the concentration of magnesium hydroxide. During burning, the viscosity modifier results in a non‐dripping formulation of PTT. Copyright © 2012 John Wiley & Sons, Ltd.     

Remarkable effects of silicone rubber on flame retardant property and mechanical properties of crosslinked high-density polyethylene/bio-based magnesium phosphate flame retardant (MHPA) composite

In this paper, a new bio-based flame retardant MHPA was prepared by the reaction of magnesium hydroxide (MH) and phytic acid (PA). Then the crosslinked high-density polyethylene (HDPE) flame-retardant composite was prepared by adding it and silicone rubber (SR) into HDPE and using electron beam irradiation. The test results of limiting oxygen index (LOI) and cone calorimeter test (CCT) show that the combination of MHPA and SR can increase the flame retardancy and smoke suppression performance of HDPE. The LOI of HDPE composite with 10 parts of SR is 28.3%, and its pHRR, THR and TSP values are reduced to 454.1 kW/m², 99.7 MJ/m² and 8.3 m², respectively, which is because MHPA and SR jointly promote the formation of continuous and high-density carbon slag in the combustion process of HDPE and inhibit the penetration of flame. In addition, the HDPE composite with 10 parts of SR has significant tensile strength, elongation breaking strength and tear strength, because SR can produce continuous stable structure with HDPE after irradiation and crosslinking. Therefore, this study verified that MHPA and SR together can effectively improve the flame retardancy, smoke suppression and mechanical properties of HDPE composite.     

阻燃型氢氧化镁的制备及其应用

为制备高分散性氢氧化镁阻燃剂,以氯化镁为原料,氢氧化钠为沉淀剂,采用直接水热法制备了超细氢氧化镁微晶。采用扫描电子显微镜和X射线衍射仪对其形貌和晶体结构进行了表征;同时将其填充到乙烯-醋酸乙烯酯共聚物(EVA)树脂中,采用转矩流变仪、拉力试验机和氧指数仪对EVA/氢氧化镁混合物的流变性能、力学性能和阻燃性能进行了研究。结果显示,所制备的氢氧化镁产品为六方晶型,分散性高,与EVA树脂的相容性好。氢氧化镁填充量为60%(质量分数)的EVA混合物的转矩流变性能、力学性能和阻燃性能均优秀,平衡扭矩为13.8 N.m,拉伸强度为9.1 MPa,断裂伸长率达到1 200%,氧指数达到45。     

氢氧化镁阻燃剂在聚合物改性中的应用研究进展

综述了氢氧化镁（MH）的阻燃机理及超细化、表面改性处理和与其他阻燃剂协同阻燃在聚合物改性中的应用。展望了氢氧化镁阻燃研究的发展前景。     

不同氢氧化镁对LLDPE性能的影响

采用气泡液膜法制备了疏松型纳米氢氧化镁（LN-MH）,将其和不同氢氧化镁分别填充到线型低密度聚乙烯（LLDPE）中制得复合材料。通过常规力学性能测试、TG、极限氧指数（LOI）和锥形量热仪（CONE）研究了疏松型氢氧化镁（LN-MH）和普通氢氧化镁（C-MH）对LI。DPE性能的影响。结果表明：LN-MH／LLDPE复合材料的拉伸强度、弯曲强度和氧指数均比C-MH／LLDPE有显著的提高;与C-MH相比,LN-MH对LLDPE有更好的阻燃效果和成炭作用,但热稳定性稍差。     

Synergistic flame retardant effect of cerium oxide in ethylene‐vinyl acetate/aluminum hydroxide blends

The flammability characterization and synergistic flame retardant effect of cerium oxide (CeO₂) in the ethylene‐vinyl acetate/aluminum hydroxide blends were studied using limiting oxygen index (LOI), UL‐94 test, and cone calorimeter test (CCT). The results showed that the addition of a given amount of CeO₂ apparently increased the LOI value and UL‐94 rating. The data obtained from the CCT indicated that the addition of CeO₂ greatly decreased the heat release rate and prolonged the combustion time. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010