Thermoplastic Polyurethane-Encapsulated Melamine Phosphate Flame Retardant Polyoxymethylene

Due to its “unzipping” degradation mode and poor compatibility with most other flame retardants, polyoxymethylene (POM) is the most difficult flame-retarded polymer among macromolecular materials. In this project, we took advantage of thermoplastic polyurethane (TPU) resin, which possesses good compatibility with POM, serving as an encapsulation layer, and the carrier resin of the nitrogen-phosphorus composite flame retardant melamine phosphate to achieve even and fine dispersion of the flame retardant particles in the POM matrix. The improved morphology of the dispersion phase can markedly modify the flame retardancy and good mechanical performance. Additionally, the encapsulation of TPU avoids direct contact of the flame retardant with POM, thus also advantageous to the enhancement of its material performance. Moreover, as an efficient formaldehyde absorbent and toughening agent, TPU itself can greatly improve the flame retardancy, thermal stability, and toughness of the flame retardant POM. Therefore, this method provides a simple and effective method to prepare flame retardant POM with good comprehensive performance.     

The synthesis of biphenyl ether/vanillin-based flame retardants for enhancing both the flame retardant properties and mechanical performance of epoxy resin

Imparting good flame retardancy and mechanical properties to epoxy resin (EP), while pursuing the sustainable and safe application of EP, we synthesized a novel reactive phosphorus/nitrogen flame retardant for biomass through nucleophilic addition reaction, which contains flexible ether bonds and rigid aromatic ring structure (DVD). Owing to the cooperative effect of aryl ether diamine, phosphorus phenanthrene, and biomass vanillin, the DVD exhibited excellent flame retardancy. EP/DVD-1 (0.4 wt% phosphorus content) achieved UL-94 V-0 rating, with an improvement in limiting oxygen index value from 26.5% (pure EP) to 32.5%. In the CCT, the modified DVD EP showed a 44.5% reduction in peak peak of heat release rate (PHRR) and a 38.0% reduction in total heat release compared to pure EPs. And flame retardant epoxy resin (FREP) still had good transparency after the addition of DVD, which indicated the nice compatibility between DVD andEP. What was noteworthiness was that at high levels of addition, the mechanical properties of modified EP for DVD was still improved compared to pure EP. These results demonstrate that DVD is an excellent and multifunctional bio-based flame retardant with broad application prospects in the field of EP material modification.     

改性凹凸棒土对PBAT阻燃性能的影响

用费托蜡（FTW）对凹凸棒土（ATP）进行表面改性制备了阻燃剂F-ATP，并对其形貌、结构及其热稳定性进行了表征。将阻燃剂F-ATP加入到聚己二酸/对苯二甲酸丁二醇酯（PBAT）基体中制备了PBAT/F-ATP复合材料。采用极限氧指数测定仪（LOI）、垂直燃烧测试（UL-94）、锥形量热仪（CCT）、TG-IR、拉曼光谱仪和SEM对复合材料的阻燃性能进行了分析。结果表明，改性后的ATP团聚现象消失且热稳定性明显提高。阻燃剂F-ATP质量分数为10%的PBAT/F-ATP复合材料（PBAT-3）阻燃效果最佳，其LOI值达到23.5%,UL-94等级达到V-1级，熔滴现象得到明显改善。与ATP质量分数为10%的PBAT/ATP复合材料相比，PBAT-3复合材料的峰值热释放速率值（PHRR）、总热释放量（THR）分别降低了4.99%和26.11%。PBAT-3复合材料气态产物的释放量在整个燃烧过程中均降低，起到了很好的气相阻燃效果，这主要归因于阻燃剂F-ATP的加入使PBAT/F-ATP复合材料形成致密且连续性好的炭层结构，有效地隔绝了复合材料内部与外界的热量/质量传递。     

Flame‐retardant and thermal degradation mechanism of low‐density polyethylene modified with aluminum hypophosphite and microencapsulated red phosphorus

Aluminum hypophosphite (AHP), a novel flame retardant, was used to improve the flame retardancy of low‐density polyethylene (LDPE) with microencapsulated red phosphorus (MRP). The synergistic effect between MRP and AHP was investigated by the limiting oxygen index (LOI), vertical burning test (UL‐94), and thermogravimetric analysis. When the contents of MRP and AHP were 10 and 30 phr, the LOI of LDPE/10MRP/30AHP composite was 25.5%, and it passed the UL‐94 V‐0 rating (the number before “MRP” and “AHP” is the loading of MRP and AHP, In LDPE/10MRP/30AHP, the content of the LDPE, MRP and AHP is 100phr, 10phr and 30phr, where phr refers to parts per hundreds of resin). The results of cone calorimetry testing show that the heat release rate of the composites was significantly reduced, and the strength of the char layer improved when the loading of AHP increased. The thermal stability of the LDPE/10MRP/30AHP composite was enhanced. The structure of the char was investigated by Fourier transform infrared spectrometry and scanning electron microscopy/energy‐dispersive spectrometry. The results indicate that AHP promoted the formation of stable char. This research provided a good way to prepare flame‐retardant materials with a halogen‐free flame retardant and contributed to environmental protection. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43225.     

Synthesis of a novel cross‐linked organophosphorus‐nitrogen containing polymer and its application in flame retardant epoxy resins

A novel cross‐linked organophosphorus–nitrogen polymetric flame retardant additive poly(urea tetramethylene phosphonium sulfate) defined as PUTMPS was synthesized by the condensation polymerization between urea and tetrahydroxymethyl phosphonium sulfate. Its chemical structure was well characterized by Fourier transform infrared (FTIR) spectroscopy, ¹³C and ³¹P solid‐state nuclear magnetic resonance. The synthesized PUTMPS and curing agent m‐phenylenediamine were blended into epoxy resins to prepare flame retardant epoxy resin thermosets. The effects of PUTMPS on fire retardancy and thermal degradation behavior of EP/PUTMPS thermosets were investigated by limiting oxygen index (LOI), vertical burning test (UL‐94), cone calorimeter measurement, and thermalgravimetric analysis (TGA) tests. The surface morphologies and chemical compositions of char residues for cured epoxy resins were investigated by scanning electron microscopy and X‐ray photoelectron spectroscopy (XPS), respectively. Water resistant properties of epoxy resin thermosets were evaluated by putting the samples into distilled water at 70°C for 168 h. The results demonstrated that the EP/12 wt% PUTMPS thermosets successfully passed UL‐94 V‐0 flammability rating and the LOI value reached 31.3%. The TGA results indicated that the incorporation of PUTMPS promoted epoxy resin matrix decomposed and char forming ahead of time, which led to a higher char yield and thermal stability for epoxy resin thermosets at high temperature. The morphological structures and analysis of XPS for the char residues of the epoxy resin thermosets shown that PUTMPS benefited to the formation of a sufficient, more compact, and homogeneous char layer with rich flame retardant elements on the materials surface during burning, which prevented the heat transmission and diffusion, limited the production of combustible gases, inhibited the emission of smoke, and then led to the reduction of the heat release rate and smoke produce rate. After water resistance tests, EP/12 wt% PUTMPS thermosets still remained excellent flame retardancy. Copyright © 2015 John Wiley & Sons, Ltd.     

A DOPO-based reactive flame retardant containing benzimidazole groups: Synthesis and its flame-retardation on epoxy resin

DOPO based flame retardants demonstrate exceptional flame retardancy efficiency when applied to epoxy resins. However, the crosslinking degree of epoxy resin may decrease due to the addition of DOPO, leading to a deterioration in flame retardancy and mechanical properties. Herein, a reactive DOPO derivative flame retardant 6-((1H-benzo[d]imidazol-2-yl) amino) dibenzo oxaphosphinine 6-oxide (BADO) was successfully synthesized, which contains multiple reactive sites, thus ensuring a higher degree of crosslinking in the system. As a result, the modified epoxy resin exhibits excellent flame retardancy. The limiting oxygen index value of the modified epoxy resins increased from 19.8% to 29.7% by adding 7.5 wt% BADO, and its UL-94 test passed V-0. Flame retardancy mechanism analysis reveals that BADO exhibits both gas-phase and condensed-phase flame retardant effects. In particular, the formation of a porous inside-char layer is a significant factor in reducing smoke release. The 7.5% BADO/EP composite exhibited a 43.2% reduction in total smoke production and a 43.6% reduction in total smoke rate compared to neat epoxy resins (EP). Furthermore, the addition of BADO slightly deteriorates the mechanical properties of the modified epoxy resin.     

含锌阻燃剂对NER/OMMT-TPP体系阻燃聚丙烯的影响

将硼酸锌和氧化锌加入到酚醛环氧树酯/有机蒙脱土纳米复合材料(NER/OMMT)与磷酸三苯酯(TPP)阻燃聚丙烯(PP)体系,考察了硼酸锌和氧化锌用量对PP阻燃、抑烟性能和力学性能的影响.在NER/OMMT与TPP总用量仅为10wt%的情况下加入4wt%的硼酸锌后,制得了氧指数高达31.5%的阻燃聚丙烯,并且烟雾产生总量比加入前下降了46.6%,在降低了材料的毒害性的同时很好地提高了其综合性能.     

阻燃抑烟环氧树脂的合成及其性质

以磷酸、三聚氰胺、尿素为原料制备阻燃抑烟剂聚磷酰氰胺脲,然后将其应用于TDE-85#环氧树脂中,以顺丁烯二酸酐为固化剂制备了阻燃抑烟环氧树脂。研究了阻燃抑烟剂聚磷酰氰胺脲的吸湿性,纯环氧树脂和阻燃抑烟环氧树脂的极限氧指数、UL-94阻燃性、隔热性能、烧蚀速率和透光率等。研究结果表明,聚磷酰氰胺脲对环氧树脂具有非常优异的阻燃、抑烟功效。     

电缆用高阻燃耐热软质PVC的制备及性能研究

以软质PVC为基体,选用氢氧化铝-氢氧化镁(ATH/MDH)为复配阻燃剂、硼酸锌(ZB)为阻燃协效剂及钙锌材料为复合热稳定剂(Ca-Zn),通过共混法对PVC进行改性,制备PVC/ATH/MDH、PVC/ATH/MDH/ZB及PVC/ATH/MDH/ZB/Ca-Zn等软质PVC复合电缆料。分析3种电缆料的阻燃性能、拉伸性能及热稳定性。结果表明:相较纯软质PVC,PVC/ATH/MDH与PVC/ATH/MDH/ZB的阻燃性能提高,拉伸性能显著下降,且热稳定性改善不明显。而PVC/ATH/MDH/ZB/Ca-Zn的阻燃性能显著提升,与纯软质PVC相比,其极限氧指数(LOI)增加34.90%,烟密度等级下降29.50%,复合材料的炭层更连续且致密;PVC/ATH/MDH/ZB/Ca-Zn的拉伸强度和断裂伸长率分别提高1.78%和2.48%。Ca-Zn的添加提高软质PVC的残炭率,热稳定性增强。PVC/ATH/MDH/ZB/Ca-Zn的综合性能最佳。     

Novel phosphorus-containing polyhedral Oligomeric Silsesquioxane functionalized Graphene oxide: preparation and its performance on the mechanical and flame-retardant properties of Bismaleimide composite

A novel phosphorus-containing polyhedral oligomeric silsesquioxane functionized graphene oxide(P-POSS-GO) were achieved and the resultant functionized GO combined with 4 wt% P-POSS were incorporated into bismaleimide resin to prepare flame-retardant P-POSS-GO/P-POSS/DBMI composite. Fourier-transform infrared spectra, transmission electron spectroscopy and X-ray diffraction were employed to examine the efficiency of surface functionalization of GO. The composite containing P-POSS and modified GO exhibited excellent flame-retardant property and better thermal stability as well as high mechanical property. With the incorporation of 0.6 wt% P-POSS-GO and 4 wt% P-POSS to DBMI, satisfied flame retardant grade V-0 and LOI as high as 39.4 were obtained. The increase of degradation activation energy could be internal reason for the improvement of flame retardancy. Besides, P-POSS-GO can facilitate the growth of oxygen insulation and heat insulation char layer, which could be outer reason for the improvement of flame retardancy.     

A P/N synergistic flame retardant containing flexible nitrile group for enhancing the mechanical properties and fire safety of epoxy resins

To further enhance the fire safety of epoxy resins, a phosphorus–nitrogen synergistic flame retardant (DPVHD) with a flexible chain segment and a nitrile group was synthesized. In addition to the traditional flame retardant elements P and N, the flame retardancy of the epoxy composites is further enhanced by the cross-linking effect of the nitrile groups introduced to form an interpenetrating network with the epoxy matrix. The results showed that the sample with 10 wt% DPVHD-10/EP had a LOI of 32.3% and passed the UL-94 V-0 rating, with PHRR and THR reduced by 15.4% and 47%, respectively, compared to pure EP. It is worth noting that the introduction of flexible chain segments improves the flexural properties of the epoxy resin matrix. Compared with pure epoxy, the flexural properties of epoxy-cured compounds with DPVHD addition show a rising trend with the increase of flame-retardant additive. And the rise of DPVHD-10/EP reaches 33.6%, which greatly reduces the negative effect of flame-retardant additives on the mechanical properties of the epoxy resin matrix. This work therefore provides new ideas for exploiting the advantages of phosphorus-nitrogen synergy and nitrile-based cross-linking for flame retardancy in epoxy resins.     

反应型和添加型含磷阻燃剂阻燃环氧树脂的性能研究

研究了不同填充量的反应型和添加型含磷阻燃剂对阻燃环氧树脂力学性能和阻燃性能的影响,并对比研究了2种类型阻燃环氧树脂的热稳定性。结果表明,反应型阻燃剂中9,10-二氢-9-氧-10-磷杂菲-10-氧化物（DOPO）阻燃环氧树脂的力学性能和阻燃性能好于6-氢-二苯并[c,e][1,2]氧磷酰杂-6-甲醇,6-氧化物（DOPO-CH2OH）,添加型阻燃剂中三聚氰胺磷酸盐（MP）阻燃环氧树脂的性能好于聚磷酸铵（APP）;2种类型阻燃剂相比,2种反应型阻燃剂阻燃环氧树脂的力学性能、阻燃性能和热稳定性均好于添加型的MP和APP阻燃剂。     

包覆态和共混态磷酸酯/无机体系阻燃性能研究

研究了氢氧化镁、氢氧化铝或二氧化硅包覆笼状磷酸酯微胶囊以及上述3种无机阻燃剂和笼状磷酸酯复配共混用于阻燃环氧树脂的性能。采用极限氧指数,垂直燃烧（UL94）以及热分析（TG/DTG）对比了各阻燃体系的阻燃协效性能和热行为。结果表明,3种无机物在复配共混体系中都和笼状磷酸酯有较好的协同阻燃作用,而在包覆体系中阻燃性能都较差。添加量都为20 %（17 %笼状磷酸酯和3 %无机阻燃剂）,复配共混体系阻燃环氧树脂的极限氧指数可达32 %,且都可以达到UL94 V0级;而相应包覆微胶囊体系阻燃环氧树脂的极限氧指数约为24 %,阻燃级别仅达UL94 V2级。     

新型磷／氮协同阻燃环氧树脂的合成与性能

以双酚A环氧树脂E－51与DOPO（9,10-dihydrooxa-20－phosph henanthrene－10-oxide）合成含磷环氧树脂（ED）,以三聚氰胺与苯酚反应制备含氮的酚醛固化剂MFP。采用红外光谱对产物进行分析表征,采用热失重分析和UL94V垂直燃烧测试考查树脂的热性能和阻燃性能,同时探讨了阻燃环氧树脂的力学性能。结果表明,随着含磷量的增加,环氧树脂的热稳定性和阻燃性能得到改善,当含磷量为3％时,环氧树脂的初始分解温度高达330℃以上,在700℃下的残炭率达到30％以上,阻燃性能均达到了UL－94 V—0级。而试样的力学性能则随含磷量的增加而降低。     

阻燃热固性树脂及其材料国外研究进展

综述了2001—2005年阻燃热固性树脂及其组成物的研究进展。值得提出的是,前5年美国化学文摘报道的“阻燃树脂”的文献共有786篇(CA134~CA141前1/3部分)其中有关“阻燃热固性树脂及其组成物”的就有362篇。占所有阻燃材料的46·1%,阻燃环氧树脂的报道量为188篇,排在热固性树脂之首,占阻燃性树脂的51·9%;阻燃酚醛树脂(包括苯并恶嗪)的报道量为35(5)篇,排在第2位,占阻燃热固性树脂的9·7%;随后依次是聚苯醚、热固性/热塑性复合材料、氰酸脂、不饱和聚酯树脂(含乙烯基酯树脂)、丙烯酸树脂、聚氨酯树脂、有机硅树脂、聚酰亚胺(含双马来酰亚胺),其报道量和所占比例分别为20(5·5%)、16(4·4%)、15(4·1%)、12(4)(3·3%)、11(3·0%)、9(2·4%)、8(2·2%)、7(2)(1·9%)。研究的焦点在于无卤阻燃剂、无卤无锑阻燃剂、无卤无磷无金属氧化物阻燃剂;阻燃树脂组成物聚焦在覆铜板和电子封装上;阻燃热固性树脂/热塑性树脂复合材料成为新的研究热点。特别值得提出的是,聚有机硅氧烷作为无卤、无磷、无金属氧化物的新型阻燃剂得到世界同仁的注意。自阻燃有机硅涂料成为船舶涂料的热点。氰酸酯作为阻燃、耐热材料成为研究热点。聚芳醚作为耐高温、阻燃材料已经成为工业化的新型材料。本文介绍了11种热固性树脂阻燃技术的研究进展。     

Grafting multi-elements hybrid polymer brushes on graphene oxide for epoxy composite with excellent flame retardancy

In this paper, a silicon-oxygen coupling agent (MPS) with a double bond is hydrolyzed with graphene oxide (GO) to obtain MPS-GO. The polymerization of MPS-GO with the phosphorus-containing monomer (HEPO) is initiated with 2,2′-Azobis(2-methylpropionitrile) (AIBN) to obtain multi-elements hybrid polymer brushes grafting graphene oxide (HM-GO). As a flame retardant, different amounts of HM-GO are added to obtain EP composites. In this system, the properties of composite flame retardant obviously increase with the increasing of HM-GO. The limiting oxygen index (LOI) value of composites with 4 wt% addition of HM-GO is 31.0%, while the LOI value of EP-0 is only 23.9%. And the peak heat release rate (PHRR) value is reduced from 515.8 W g⁻¹ of pure epoxy resin to 376.9 W g⁻¹. In addition, with the increase of HM-GO addition, the T_g value, flexural strength and flexural modulus of EP composites are improved. Through calculation, it is proved that the rising of T_g was due to the increase of crosslink density of the system. The flame retardant performance and mechanical properties of the composite materials are steadily improved, indicating that such flame retardants are dispersed well in the epoxy resin. HM-GO is an efficient macromolecular modified graphene oxide halogen-free flame retardant, which can improve both flame retardant properties and mechanical properties.     

双层包覆次磷酸铝及其阻燃PBT

将密胺树脂-硼酸锌作为囊材,对次磷酸铝(AHP)进行双层包覆,形成一种具有核壳结构的双层包覆阻燃剂DE-AHP。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、红外光谱(FT-IR)、热重(DTG)等方法对产物进行表征。将DE-AHP与聚对苯二甲酸丁二醇酯(PBT)进行熔融共混,采用锥形量热仪、氧指数仪等设备研究了DE-AHP的加入量对PBT复合材料阻燃性能的影响。结果表明,双层包覆提高了AHP的热稳定性,热分解温度由纯AHP的327℃升高到378℃,且700℃时的残炭量也明显提高。在PBT中添加20%的DE-AHP,复合材料的极限氧指数为27.6%,能够达到UL-94 V-0阻燃等级,且其热释放速率峰值、总热释放量、总烟释放量显著降低。     

树脂改性对玻璃纤维增强聚合物筋材物理力学性能的影响

在基体树脂中加入阻燃剂和抗静电剂可以改善复合材料的阻燃和抗静电性能,同时也会影响复合材料的力学性能。本文通过在不饱和聚酯树脂中加入阻燃剂和抗静电剂,研究了树脂改性对玻璃纤维增强聚合物（GFRP）筋材拉伸性能、压缩性能、剪切性能、抗静电性能和阻燃性能的影响,分析了改性树脂的阻燃和抗静电机理。试验发现,树脂改性对GFRP筋阻燃和抗静电性能有明显提高,压缩强度有所增加,但GFRP筋拉伸性能和剪切性能有不同程度的降低。     

硬脂酸钠表面改性复合阻燃材料及在PE-LD上应用

以废弃的浓海水为原料,通过一步沉淀法制备无机复合阻燃材料。采用改性剂硬脂酸钠对无机复合阻燃材料进行表面改性处理,考察了改性剂的用量、改性时间和改性温度对其分散性的影响,同时通过扫描电子显微镜(SEM)、傅立叶变换红外光谱(FTIR)、X射线衍线(XRD)、比表面积(BET)测试、热重(TG)分析和差示扫描量热(DSC)对改性后的复合材料进行表征。结果表明,当改性剂用量为0.04 g,改性时间为6 h,改性温度为160℃时,改性后的无机复合阻燃材料分散性最佳,与有机材料的相容性最好。将改性后的无机复合阻燃材料填充到低密度聚乙烯(PELD)中进行了应用研究。通过DSC结果表明,添加了改性无机复合阻燃材料的PE-LD与纯PE-LD相比,最大分解温度推迟10℃左右,说明在提高了PE-LD的热稳定性的同时可增加其阻燃性。     

含磷阻燃环氧树脂体系研究进展

简要介绍了磷系阻燃剂作为一类新型无卤阻燃剂的特点和阻燃机理,重点综述了含磷阻燃环氧树脂体系的含磷固化剂、含磷环氧化合物及含磷环氧半固化物和添加磷型阻燃的进展,并通过热稳定性、成炭率和极限氧指数（LOI）等阻燃性能参数揭示了各类方法的阻燃效果,最后对含磷阻燃环氧树脂体系研究的未来进行了展望。