膨胀型阻燃剂的研究进展

随着易燃高分子材料的广泛应用,阻燃剂也得到了广泛的应用,同时对阻燃剂的阻燃性、相容性等特性也有了更高的要求。膨胀型阻燃剂具有阻燃效率高、低烟、低毒等优点,因此成为阻燃剂的重要发展方向。简单介绍了膨胀型阻燃剂的阻燃机理,重点综述了近年来国内外膨胀型阻燃剂的最新研究进展和阻燃剂生产的新技术。最后指出了目前膨胀型阻燃剂研究存在的问题,也对该领域未来的研究方向提出了建议。     

无卤本质阻燃环氧树脂

本质阻燃高聚物阻燃效能持久,不存在挥发、溶出及迁移的问题,且可实现分子内协同阻燃效应,又为环境兼容,故近年日益崭露头角。文中论述无卤本质阻燃环氧树脂的一些制备方法及性能,且涉及的主要是分子中含DOPO侧基及含磷酸酯基的两类本质阻燃环氧树脂。     

环氧树脂/聚磷酸铵复合材料的阻燃性能与热降解行为

利用环氧树脂(EP)成炭能力,引入聚磷酸铵(APP)以提高其阻燃性能。当APP质量分数为9%时,EP/APP氧指数达30.5%,垂直燃烧性能通过V-0级。相比EP,EP/APP的热释放峰值与总热释放均有所下降。此外,利用热失重-红外联用设备研究了EP以及EP/APP的热降解行为并解释相关机理:EP在高温下会释放CO、甲醇等易燃性气体,剧烈燃烧并放出大量的热;APP在低温阶段的热裂解产物会催化EP的降解,但在高温下EP/APP却有热稳定性优异的炭层形成,在火灾中此炭层会覆盖在基体表面保护下部材料以免其遭到进一步的破坏。     

Effect of nano anhydrous magnesium carbonateon fire-retardant performance of polylactic acid/bamboo fibers composites

Polylactic acid/bamboo fibers (PLA/BF) composites, which are extremely flammable, must be carried out fire-retardant processing. However, traditional organic flame retardants release certain amount of pollutant to the environment, and inorganic flame retardants require more addition, which influenced the mechanical properties of composites. Therefore, nano inorganic flame retardants, which have some characteristics of small size, uniform shape and high specific surface area, can bring good flame-retardant effect with relatively few addition. Meanwhile, it can enhance the interaction of composites interface, and disperse more evenly in polylactic acid matrix. Furthermore, it has light influence on the physical mechanical properties. In this study, nano anhydrous magnesium carbonate (NAMC) is used as flame retardant, Cone Calorimeter and Dynamic Thermal Mechanical Analyzer are adopted for studying the fire-retardant properties and the dynamic thermodynamic parameters of the polylactic acid/bamboo fiber composites, respectively. Results show that nano anhydrous magnesium carbonate flame retardant have good fire-retardant performance for the polylactic acid/bamboo fiber composites, considering practicality and economy, its ideal addition is 5%.     

A Boron-Containing Ammonium Polyphosphate for Epoxy Resins with Enhanced Flame Retardancy and Reduced Smoke Release

Epoxy resin (EP) has been widely used in coatings, adhesives, and composites. However, EP is flammable with severe smoke production. The addition of flame retardant fillers into EP can effectively improve its flame retardancy, but often brings mechanical reduction to EP. Herein, a high-effective boron-containing flame-retardant (2-phenyl-1,3,2-dioxaborolan-4-yl) methanamine ammonium polyphosphate (PBMA-APP) is synthesized and introduced into EP to improve the fire resistance and the impact toughness. With the addition of 6% PBMA-APP, the fire performance of EP is significantly improved. The Underwriters Laboratories-94 rating is increased to V-0, the total heat release and total smoke production (TSP) are reduced by 30% and 32%, respectively. It is proposed that the synergistic effect among B, N, and P in PBMA-APP promoted the char formation of EP. The addition of 6% PBMA-APP into EP causes little effect on tensile strength but increases the impact strength of EP to 11.2 kJ m⁻². This work has proposed a possible strategy to develop a high-efficient flame retardant for thermosetting resins.     

无机阻燃剂的作用机理及研究现状

无机阻燃剂因无卤、低烟、无毒等特点已广泛应用于聚合物材料的阻燃.介绍了无机阻燃剂的阻燃机理,对各种无机阻燃剂及其复配协效体系的研究现状进行了详细阐述,并简要说明了目前无机阻燃剂的发展趋势.指出无机阻燃剂的多功能化,如抗菌、导电、防辐射等是近年来无机阻燃剂的重要发展方向之一.     

阻燃剂及其阻燃机理的研究现状

近来关于阻燃剂及其阻燃机理越来越受人们的关注.综述了卤系、磷系、氮系、铝镁系、粘土类和膨胀石墨阻燃剂在高分子材料中的阻燃机理及其研究现状,并提出了增加复合材料在燃烧过程中的成炭倾向是今后聚合物阻燃设计的新思路.     

含磷阻燃共聚酯的结构与性能研究

通过利用NMR，SEM，DSC，DTA／TGA，LOI等测试方法对合成的磷系共聚型阻燃聚对苯二甲酸乙二酯（PET）切片的结构以及热性能，燃烧性能，成炭性能等进行研究。结果表明，阻燃剂与EG，TPA聚合在一直,恰PET聚酯切片热降解温度变宽，具有良好的阻燃性能（LOI＞28）和成炭性能。     

本质阻燃高聚物

本质阻燃高聚物由于其自身特殊的化学结构。不需进行阻燃处理即具有本质阻燃性,在新世纪,它们有可能取代一部分以阻燃剂处理的阻燃高聚物而获得工业应用。本文叙述３类本质阻燃高聚物的合成,性能、特征和应用,它们是（１）多乙炔苯聚合物;（２）无机－有机杂化共聚物;（３）含稠杂环的聚合物（芳香族酰胺－酰亚胺聚合物）。     

杨木胶合板阻燃性能研究

通过热释放速率(HRR)、总热释放量(THR)、有效燃烧热(EHC)、CO产率、CO2产率以及烟释放总量等指标,研究了杨木胶合板的阻燃性能。实验结果表明:磷酸氢镁和二氧化锆阻燃剂单独使用时,都能够在杨木胶合板燃烧过程中降低热释放速率、总热释放量、有效燃烧热、CO2产率以及烟释放总量,增大CO产生速率,但阻燃效果不理想;而磷酸氢镁与纳米二氧化锆复合阻燃剂,可以在杨木胶合板燃烧过程中产生协同效应,并且使用此复合阻燃剂的杨木胶合板在点燃190 s后即停止燃烧,其阻燃效果最佳。     

纳米技术在材料阻燃改性中的应用

介绍了纳米技术在阻燃材料中的应用进展。层状硅酸盐、层状双氢氧化物、碳纳米管等制备的聚合物／纳米复合材料，其热稳定性有所提高，但要和阻燃剂协同使用才能达到最佳的阻燃效果。常规阻燃剂的纳米化不仅可以提高阻燃效率，还可降低阻燃剂的添加量，改善阻燃材料的物理机械性能。     

Performance of epoxy filled with nano- and micro-sized Magnesium hydroxide

Magnesium hydroxide (MDH) particles are often used as fillers to improve the flame retardancy of polymers. However, achieving the balance between the enhanced fire resistance and reduced mechanical properties, especially toughness, is still a challenge to the composite community. In this study, the effect of the particle size and silane surface modification of MDH particles on the flame retardant, thermal, and mechanical properties of epoxy was studied. Both nano- and micro-sized MDH particles were modified by a silanization reaction with γ-aminopropyltrietoxysilane in an aqueous solution and filled into epoxy matrix by a high-shear mixer and a three-roll mill. Results show that nano-MDH filled epoxy composites yielded better mechanical properties than their micro-MDH filled counterparts. Furthermore, the adhesion between nano-sized MDH and the matrix was improved by the silane surface modification. When comparing the flame retardant properties, enhancements in heat release rates and total heat released were observed for MDH filled epoxy composites.     

含硅阻燃剂的研究进展

通过介绍有机硅系阻燃剂、无机硅系阻燃剂、含硅本质阻燃高聚物技术以及含硅化合物的协效阻燃技术和阻燃机理等内容,概括了含硅阻燃剂的研究进展情况.阐述了硅系阻燃剂不但具有高效、低毒、抑烟和促进成炭等优异的阻燃性能,而且相对于传统阻燃剂,聚合物的加工性能和力学性能等方面也有显著的提升作用.     

铝酸钴对软聚氯乙烯阻燃热降解性影响

通过活性炭模板法制备出尖晶石型铝酸钴阻燃剂。将其应用于软聚氯乙烯(PVC)的阻燃研究。当添加10 g铝酸钴时,软PVC的阻燃、消烟和力学性能最佳。通过热重-红外和扫描电镜对阻燃前后的热降解过程进行研究,表明,阻燃处理后,软PVC样品的初始降解温度提前,高温时的剩炭量增加;降解过程中释放HCl和-CH_3气体碎片的最大释放峰温度提前,并且气体的释放量减少,降解过程中形成稳定的炭层,阻止了内部可燃气体与外部的氧气接触,达到良好的阻燃消烟性能。     

Effects of milling on the thermal stability of synthetic hydromagnesite

Hydromagnesite is a basic magnesium carbonate that undergoes an endothermic decomposition with water and carbon dioxide release in the temperature range of 200-550 °C. Due to this thermal behaviour it has been studied as flame retardant filler for polymers in cable applications. For this purpose the particle size distribution should be optimized, as it is in most cases responsible for decrease in final composite mechanical properties. This work describes the variations found in the thermal behaviour of hydromagnesite associated with the process of particle size reduction. Air jet micronization was compared with mechanical milling. Thermogravimetry and differential scanning calorimetry were used to study thermal decomposition. FTIR spectroscopy and XRD analysis of the solid residue after heating were used to follow structural changes. Decomposition behaviour of synthetic hydromagnesite was shown to be dependent of the applied particle size reduction process. A remarkable increase in the decomposition rate was observed for the milled sample, which was attributed to the introduction of defects in the crystalline structure during the mechanical milling. Therefore, it was concluded that the mechanical milling process may affect the thermal decomposition of hydromagnesite and therefore its characteristics as flame retardant.     

EVA及PS膨胀阻燃体系LOI值随温度变化规律的研究

利用高温氧指数仪结合新一代燃烧测定仪锥形量热仪CONE研究了EVA18及PS膨胀阻燃体纱的LOI值随温度变化的规律，以及一种膨胀阻燃促进剂ZEO对典型的膨胀燃添加体系APP／PER在高温下LOI下降趋势的抑制作用，也即对提高阻燃体系实际阻燃能力的作用。     

过氧化氢氧化制备羧基再生亚麻纤维素及其膨胀阻燃环氧树脂

采用过氧化氢制备羧基再生亚麻纤维素,通过红外光谱、核磁共振、X射线衍射和热重分析表征产物的结构与性能,研究表明再生亚麻纤维素上的C6伯羟基被选择性地氧化为羧基,而且氧化再生亚麻纤维素随着羧基含量的增加,其热稳定性下降。将其作为成炭剂,并与酸源、气源复配组成膨胀型阻燃剂(IFR)用于阻燃环氧树脂,通过极限氧指数测试(LOI)和垂直燃烧测试(UL-94)表征阻燃性能。研究表明,膨胀型阻燃剂的加入能有效地提高环氧树脂的阻燃性能。与EP/MFAPP/PER复合材料的LOI相比,EP/MFAPP/OLF27.4和EP/MFAPP/OLF34.5复合材料的LOI更高,MFAPP/OLF体系的阻燃效果比MFAPP/PER体系要好,这是因为MFAPP/OLF体系的催化成炭效果更好,样品表面生成的防护性炭层,起到了阻隔热量和氧气的作用并抑制了可燃性气体的释放。     

水滑石/红磷协同阻燃EVA材料的热分解特性

采用熔融共混方法制备了EVA/水滑石(LDH)/微胶囊化红磷(MRP)无卤阻燃材料,研究了LDH和MRP在乙烯与醋酸乙烯共聚物(EVA)中的阻燃协同作用,发现在EVA/LDH阻燃体系中添加适量的MRP可以显著提高体系阻燃性能,而且燃烧过程中不再有熔滴现象发生。采用TG和实时傅立叶变换红外光谱(RT-FT-IR)研究了EVA及其复合阻燃材料的热分解特性,实验发现,与EVA/LDH体系相比,EVA/LDH//MRP体系的热稳定性有所提高,MRP对EVA/LDH体系中的EVA热氧化降解具有一定的抑制作用。     

介孔分子筛和Cr_2O_3协同膨胀阻燃体系对阻燃天然橡胶性能的影响

用介孔分子筛(MCM-41)和Cr_2O_3协同膨胀型阻燃体系(IFR)对天然橡胶(NR)进行阻燃。为研究MCM-41和Cr_2O_3的阻燃协同作用,使用不同组分的两种协效剂协同IFR阻燃天然橡胶。对阻燃体系分别进行氧指数测试、热重分析、锥形量热分析、拉伸测试和残炭扫描分析。研究结果表明:天然橡胶单纯添加IFR时,其力学性能大幅下降,热学性能也没有显著提升。然而随着Cr_2O_3和MCM-41添加量的增加,橡胶基体的拉伸强度和断裂伸长率均有所改善,在IFR添加量为36%(与天然橡胶的质量比)、MCM-41添加量为1%,Cr_2O_3为3%时,IFR-MCM-41-Cr_2O_3复合阻燃剂的阻燃效果最好,热释放速率峰值和热释放总量均明显下降,IFR-MCM-41-Cr_2O_3/NR复合材料燃烧后,炭层发泡均匀且致密,极限氧指数(LOI)可以达到26.5%,垂直燃烧(UL-94)为V-0级。     

膨胀蛭石/酚醛阻燃保温复合材料的制备及性能

以膨胀蛭石为阻燃剂,采用中温发泡方法与酚醛树脂复合制备膨胀蛭石/酚醛阻燃保温复合材料。阻燃保温复合材料通过极限氧指数、锥形量热、导热系数和表观密度分析了发泡温度、固化剂含量、发泡剂含量、表面活性剂含量、固化时间以及蛭石含量对膨胀蛭石/酚醛阻燃保温复合材料阻燃及保温性能的影响。结果表明:以膨胀蛭石为阻燃剂制备的膨胀蛭石/酚醛阻燃保温复合材料的阻燃保温性能优越、表观密度低。单因素实验结果表明,膨胀蛭石/酚醛阻燃保温复合材料的最优条件为发泡温度80℃、固化剂含量10wt%、发泡剂含量10wt%、表面活性剂含量5wt%、固化时间2 h以及蛭石含量60wt%。最优条件下的膨胀蛭石/酚醛阻燃保温复合材料表观密度为190.08 kg/m3、压缩强度为0.32 MPa、导热系数为0.054 9 W/（m·K）、极限氧指数为71.1%、平均热释放速率为15 kW/m2。