聚烯烃无卤阻燃剂研究进展与发展趋势

初步概括了无机阻燃剂和膨胀型阻燃剂的阻燃机理,综述了近10年聚烯烃无机阻燃剂和膨胀型阻燃剂的研究进展及发展趋势。     

新型无卤阻燃剂开发成功

乙二醇丁醚(EGEB)又称丁基溶纤剂，曾被列入有害空气污染物的名单。美国环保署(EPA)最近已批准将EGEB从”清洁空气法案”中的危险空气污染物(即有毒气体物质)名单中剔除，但仍保留其在挥发性有机化合物(VOC)名单中，其生产和使用必须符合有毒释放物清单(TRI)的要求。     

无卤阻燃剂的应用现状

简要介绍了当前几种常见无卤阻燃剂的应用现状。     

新型无卤阻燃剂的研究与应用

介绍了纳米型、膨胀型和磷系三种新型无卤阻燃剂的研究与应用进展。该系列阻燃剂是无卤阻燃剂中的典型代表，其热稳定好、高效、抑烟、阻滴、安全、无毒，对环境基本无污染，在阻燃材料中得到广泛的应用，并将逐渐代替含卤阻燃剂。     

复合阻燃剂FR602对丁苯橡胶阻燃性能的影响

研究复合阻燃剂FR602替代三氧化二锑物对丁苯橡胶（SBR）阻燃性能、硫化特性和物理性能的影响。结果表明,阻燃剂FR602可以完全替代三氧化二锑与十溴二苯醚组成协效阻燃体系,胶料具有较大的氧指数及较高的垂直燃烧等级,阴燃现象显著减少,硫化特性和物理性能变化不大。     

EG与IFR复合阻燃ABS协同效应及热失重行为研究

将可膨胀石墨(EG)、P-N型膨胀阻燃(剂IFR)与ABS树脂共混,制作复合阻燃材料。用氧指数(OI)、UL 94测试和锥形量热仪(CONE)探讨了EG与IFR复合阻燃ABS的协同效应。通过热失重分析(TG)研究了阻燃ABS体系的热失重行为。结果表明:EG与IFR协同阻燃ABS,OI达到29%,UL 94为V-0级,热释放速率大幅度降低,EG与IFR复合阻燃ABS具有一定的协同效应;在空气气氛下,EG与IFR可以相互促进成炭,且形成的炭层稳定在,850℃也不会分解。     

无卤阻燃剂的开发与应用研究进展

综述了无卤阻燃剂的种类和开发研究进展,重点介绍了无机物阻燃剂、含硅阻燃体系、无卤膨胀型阻燃剂、含磷无卤阻燃剂等无卤阻燃剂的开发,以及在聚合物中的应用研究进展,并对阻燃剂的发展方向进行了展望。     

无卤膨胀型阻燃聚丙烯的性能研究

利用微胶囊化技术合成的新型磷氮体系无卤膨胀型阻燃剂IFR对聚丙烯（PP）进行阻燃。考察了阻燃剂IFR中聚磷酸铵（APP）的微胶囊包覆效果以及阻燃剂IFR对PP的阻燃性能、力学性能、热稳定性以及表面形态等的影响。结果发现包覆后的APP粒度均匀致密，效果比较良好；在PP中添加的IFR阻燃剂质量分数达到30％左右时，有明显的成炭效果，氧指数达到32％，阻燃性能提高；力学性能下降也趋于平缓；且IFR与PP的界面相容性比较良好；阻燃PP材料的热稳定性也得到了提高。     

无卤膨胀型阻燃剂在聚丙烯中的应用研究

通过对比实验研究了两种新型氮磷体系膨胀型阻燃剂(PN-201、ANTI-6)对聚丙烯(PP)阻燃性能及力学性能的影响。结果表明:在PP中添加PN-201型阻燃剂23%有明显的成炭作用,可以获得良好的阻燃效果,又使PP具有优越的综合性能,阻燃PP材料的热稳定性也得到了提高。     

无卤阻燃剂的研究现状

综述了磷系阻燃剂、氮系阻燃剂、硅系阻燃剂、金属氢氧化物阻燃剂及膨胀型阻燃剂的研究状况及阻燃机理。     

用反相悬浮聚合法制备膨胀型阻燃剂及其在丁苯橡胶中的应用

采用反相悬浮法聚合丙烯酸钠,同时将化学膨胀阻燃体系(IFR)三组分聚磷酸铵、季戊四醇和三聚氰胺加入到聚合体系中进行原位包裹,用傅里叶变换红外光谱对聚合产物的结构进行了表征,研究了三聚氰胺用量和聚磷酸铵与季戊四醇配比对丁苯橡胶硫化胶阻燃效果的影响,采用热重法分析了阻燃丁苯橡胶的热性能,并通过扫描电镜观察了添加IFR的丁苯橡胶在燃烧后表面的微观形态。结果表明,三聚氰胺的质量分数为IFR体系的3.0%、聚磷酸铵与季戊四醇的质量比为4.00～5.67时IFR体系的剩炭率最高,阻燃性能较好;添加IFR后丁苯橡胶的阻燃性能得到相应改善,当IFR质量分数为30%时丁苯橡胶硫化胶的极限氧指数可达27.5%;添加了IFR的丁苯橡胶硫化胶在燃烧时形成了较为致密的泡沫炭层,表明IFR对丁苯橡胶具有较好的膨胀阻燃效果。     

硼酸锌在膨胀型无卤阻燃ABS中的协同作用

采用熔融共混法制备了丙烯腈-丁二烯-苯乙烯共聚物(ABS)/膨胀型阻燃剂(IFR)/硼酸锌(ZB)无卤阻燃复合材料。利用热重分析仪、氧指数测定仪、扫描电子显微镜等研究了ZB对复合材料热失重行为、阻燃性能、微观结构及力学、加工性能的影响。较低含量的ZB与IFR存在较好的阻燃协同作用,且ZB可促进IFR成炭,使ABS/IFR复合材料的氧指数及其残炭量分别由未加ZB时的27.4%、21.29%提高到30.1%和23.05%。ZB的加入能够提高ABS/IFR复合材料的弯曲性能和加工性能,但对复合材料的冲击、拉伸性能产生了不利影响。     

硅橡胶阻燃开发研究进展

简单介绍了硅橡胶的燃烧过程及其自身的燃烧特性,并确立了硅橡胶的阻燃研究方向。综述了铝-镁系、磷氮系、硼硅铂系、膨胀型等不同类型阻燃剂在硅橡胶中的实际应用,并对未来阻燃技术进行了展望。     

膨胀型阻燃剂在橡胶中的应用

介绍了膨胀型阻燃剂的组成及功能改进,总结了膨胀型阻燃剂在天然橡胶、三元乙丙橡胶、丁苯橡胶及氯丁橡胶中的应用进展,并对膨胀型阻燃剂的发展方向做了展望。     

Synergistic flame‐retardant effect of halloysite nanotubes on intumescent flame retardant in LDPE

Synergistic flame‐retardant effect of halloysite nanotubes (HNTs) on an intumescent flame retardant (IFR) in low‐density polyethylene (LDPE) was investigated by limited oxygen index (LOI), vertical burning test (UL‐94), thermogravimetric analysis (TGA), cone calorimeter (CC) test, and scanning electronic microscopy (SEM). The results of LOI and UL‐94 tests indicated that the addition of HNTs could dramatically increase the LOI value of LDPE/IFR in the case that the mass ratio of HNTs to IFR was 2/28 at 30 wt % of total flame retardant. Moreover, in this case the prepared samples could pass the V‐0 rating in UL‐94 tests. CC tests results showed that, for LDPE/IFR, both the heat release rate and the total heat release significantly decreased because of the incorporation of 2 wt % of HNTs. SEM observations directly approved that HNTs could promote the formation of more continuous and compact intumescent char layer in LDPE/IFR. TGA results demonstrated that the residue of LDPE/IFR containing 2 wt % of HNTs was obviously more than that of LDPE/IFR at the same total flame retardant of 30 wt % at 700°C under an air atmosphere, and its maximum decomposing rate was also lower than that of LDPE/IFR, suggesting that HNTs facilitated the charring of LDPE/IFR and its thermal stability at high temperature in this case. Both TGA and SEM results interpreted the mechanism on the synergistic effect of HNTs on IFR in LDPE, which is that the migration of HNTs to the surface during the combustion process led to the formation of a more compact barrier, resulting in the promotion of flame retardancy of LDPE/IFR. In addition, the mechanical properties of LDPE/IFR/HNTs systems were studied, the results showed that the addition of 0.5–2 wt % of HNTs could increase the tensile strength and the elongation at break of LDPE/IFR simultaneously. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40065.     

Application of chlorinated waste rubber as a flame retardant of low density polyethylene

For the reuse of the abundant waste rubber (WR), chlorinated waste rubber (Cl‐WR) was prepared by a water‐based chlorination method using chlorine gas as the chlorinating reagent. The resultant Cl‐WR was used as a flame retardant of low density polyethylene (LDPE) matrix. The properties of WR and Cl‐WR were characterized by thermogravimetric (TG) and Fourier transform infrared (FTIR) spectrometer. The results indicated that the Cl‐WR with a 42% chlorine content had a higher char residue than WR. The limiting oxygen index (LOI) value can be increased up to 27.2 and the flame retardancy reached to the maximum (V‐0) grade for the LDPE/Cl‐WR‐Sb blends with mass ratios of Cl‐WR/LDPE and Cl‐WR/Sb₂O₃ being 80/100 and 1.5/1, respectively. The improvement of the flame retardancy and thermal properties of the LDPE/Cl‐WR‐Sb blends were attributed to the char formation and synergistic effect between Cl‐WR and Sb₂O₃ in a high temperature region, although the mechanical properties of the said blend decreased in comparison with that of the neat LDPE. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparation of a novel synergistic flame retardant and its application in silicone rubber composites

Dehydration condensation product (DHCP) was prepared by addition and dehydration condensation reactions of 9,10-dihydro-9-oxa-10-phenanthrene-10-oxide (DOPO), vinyl trimethoxysilane, and (3-aminopropyl) triethoxysilane. DHCP-PA with high phosphorus content was prepared by reaction between DHCP and phytic acid (PA). It was then compounded with oxidized multi-walled carbon nanotubes (OMWCNTs) to prepare silicone rubber (SR) flame retardant composites. The results showed that the SR with a small amount of DHCP-PA owned good flame retardant effect. The heat release rate (HRR) was decreased from 436 kW/m² for pure SR to 288 kW/m² for the SR with 5 phr DHCP-PA, and the decreasing degree was 33.9%. After mixing 5 phr DHCP-PA with 1 phr OMWCNTs, the HRR of SR composite was decreased from 436 to 251 kW/m², the smoke production rate was decreased from 0.161 to 0.087 m²/s, the limited oxygen index value was increased from 20.4% to 28.4%, and the flame retardant grade can reach UL94 V-0. In addition, the synergistic flame retardant mechanism was researched and analyzed.     

膨胀阻燃协效剂研究进展

综述了近年膨胀阻燃剂阻燃协效系统研究进展,协效剂主要有晶体硅铝酸盐类阻燃协效剂、金属盐与金属化合物、尼龙6等成炭剂和无机纳米粒子,根据存在的问题提出和展望了今后发展方向。     

Synergistic effects of fumed silica on intumescent flame‐retardant polypropylene

The synergistic effects of fumed silica on the thermal and flame‐retardant properties of intumescent flame retardant (IFR) polypropylene based on the NP phosphorus‐nitrogen compound have been studied by Fourier transfer infrared (FTIR) spectroscopy, cone calorimeter test (CCT), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), limiting oxygen index (LOI), and UL‐94 tests. The LOI and UL‐94 data show that when ≤1 wt % fumed silica substituted for the IFR additive NP can increase 2 to 4% LOI values of the PP blends and keep the V‐0 rating. The data obtained from the CCT tests indicate the heat release rates (HRR) reduce by about 23% for the PP/NP sample with 0.5 wt % fumed silica, whereas the mass loss rates (MLR) and total heat release (THR) values are much lower than those of the PP/NP samples without fume silica. The TGA data demonstrate that a suitable amount of fumed silica can increase the thermal stability and charred residue of the PP/IFR/SiO₂ blends after 500°C. The morphological structures of charred residues observed by SEM give positive evidence that a suitable amount of fumed silica can promote the formation of compact intumescent charred layers and prevent the charred layers from cracking, which effectively protects the underlying polymer from burning. The dynamic FTIR spectra reveal that the synergistic flame‐retardant mechanism of a suitable amount of fumed silica with IFR additive is due to its physical process in the condensed phases. However, a high loading of fumed silica restricts the formation of charred layers with P? O? P and P? O? C complexes formed from burning of polymer materials and destroys the swelling behavior of intumescent charred layers, which deteriorates the flame retardant and thermal properties of the PP/IFR blends. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synergistic effect of mesoporous silica SBA‐15 on intumescent flame‐retardant polypropylene

Mesoporous silica SBA‐15 synthesized from Pluronic P123 and tetraethoxysilane was used as a synergistic agent on the flame retardancy of polypropylene (PP)/intumescent flame‐retardant (IFR) system. Limiting oxygen index (LOI), UL‐94 rating and thermogravimetric analysis were used to evaluate the synergistic effect of SBA‐15 on PP/IFR system. It showed that PP/IFR system could reach V‐0 with loading of SBA‐15 ranging from 0.5 to 3 wt%, while without SBA‐15 it had no rating at UL‐94 test. The LOI value increased from 25.5 to 32.2 when the loading of SBA‐15 was 1 wt%. The thermal stability of PP/IFR was improved in the presence of SBA‐15 and the amount of the char residue at 600° C was increased from 8.96 to 16.42 wt% when loading of SBA‐15 varied from 0.5 to 5 wt%. Laser Raman spectroscopy (LRS) and scanning electron microscopy were employed to study the morphology of the char residue of PP/IFR system with and without SBA‐15. Copyright © 2010 John Wiley & Sons, Ltd.