改性海泡石与金属氧化物对膨胀阻燃PP燃烧性能的影响

采用极限氧指数、垂直燃烧、TGA、FTIR和SEM等方法研究了改性海泡石(SP)及金属氧化物(ZnO、Ni2O3)对聚丙烯(PP)/马来酸酐接枝三元乙丙橡胶(EPDM-g-MAH)/膨胀阻燃剂(IFR)体系燃烧性能的影响。极限氧指数和垂直燃烧结果表明:SP及金属氧化物均对IFR有一定的协效作用,能提高体系的极限氧指数和阻燃性能。TGA结果表明:SP可以提高燃烧残余炭层的稳定性和残炭率。SEM观察表明:SP与ZnO复配体系的燃烧残余炭层更致密和连续。FTIR测试发现SP、金属氧化物促进了IFR在PP体系中的交联成炭作用,较快生成连续的保护性炭层。     

膨胀型阻燃剂PEPA/MP阻燃聚丙烯的研究

用季戊四醇磷酸酯(PEPA)作成炭剂,与三聚氰胺磷酸盐(MP)和协效剂按一定比例复配成膨胀型阻燃剂(IFR),用于聚丙烯(PP)的阻燃。研究IFR含量对PP燃烧性能和力学性能的影响,结果表明:IFR添加量为23%时,阻燃PP的氧指数(LOI)为26.3%,阻燃等级达到UL94 V-0级。与PP相比,阻燃PP的拉伸强度、冲击强度降低,弯曲强度提高。采用差示扫描量热仪(DSC)、热失重(TG)、扫描电镜(SEM)等方法对阻燃PP的热性能、成炭性能等进行分析,结果表明:随IFR添加量增大,PP的结晶度增大,起始分解温度降低,高温成炭率提高。阻燃PP燃烧后形成表面致密,内部多孔的膨胀炭层结构。     

锡酸锌协效阻燃聚丙烯

通过水热法合成锡酸锌(Zn2Sn O4),将所得Zn2Sn O4作为协效剂加入聚丙烯(PP)/聚磷酸铵(APP)/季戊四醇(PER)膨胀阻燃(IFR)体系中,测试其阻燃和力学性能;并利用热重、热分析-质谱及扫描电镜等方法探索其协效阻燃机理。结果表明:添加1%锡酸锌的PP/IFR体系LOI达30.2%,并且对力学性能影响较小;热分析表明加入锡酸锌使PP/IFR体系热降解过程中最大分解温度提高,最大失重速率降低,成炭量增加,炭层致密结实,部分离子流强度也有所降低,与IFR有很好的阻燃协同作用。     

IFR/可膨胀石墨及协效剂氧化锌对PP阻燃性能影响的研究

制备了聚丙烯(PP)/有机膨胀型阻燃体系(IFR)、PP/IFR/可膨胀石墨(EG)和PP/IFR/可膨胀石墨(EG)/协效剂氧化锌(ZnO)三种体系,通过力学性能、氧指数(LOI)、垂直燃烧测试及热重分析(TG),探讨了复配膨胀型阻燃体系IFR/EG与协效阻燃剂ZnO之间的协同效应。结果表明,当IFR/EG/ZnO质量比为9.25/9.25/1.5时,阻燃PP的LOI值达到最高,同时阻燃PP的力学性能比不含ZnO的PP有所提高。TG结果表明,ZnO的加入使阻燃PP的热稳定性得到提高,形成了更稳定的保护层,从而提高了PP的阻燃效果。     

碱木质素/聚磷酸铵膨胀阻燃聚氨酯泡沫的制备及性能研究

采用一步发泡法制备出聚氨酯泡沫(PUF),将精制碱木质素与聚磷酸铵(APP)按不同比例组成膨胀阻燃剂(IFR)并添加到PUF中,制得碱木质素/聚磷酸铵膨胀阻燃聚氨酯泡沫(PUF/IFR)。通过极限氧指数(LOI)测试、热重分析(TG)、扫描电镜(SEM)考察了PUF/IFR材料的阻燃性能、热降解行为、成炭性能及残炭微观形貌。结果表明:当碱木质素与APP的复配比为1:6、IFR添加量为30%时,PUF/IFR的LOI值达到26.3%。IFR的加入形成了连续致密的炭层附着在材料表面,降低了材料的热降解速率,提高了残炭率,从而改善了材料的热稳定性和阻燃性能。     

IFR/OMMT协同阻燃长玻纤增强聚丙烯的阻燃性能和热稳定性能研究

以膨胀阻燃剂(IFR)和有机蒙脱土(OMMT)协效阻燃剂对长玻纤增强聚丙烯复合材料(LGFPP)进行阻燃改性,研究OMMT与IFR阻燃剂的协同效应对LGFPP阻燃性能和热稳定性能的影响。采用氧指数(LOI)和热失重分析(TGA)表征LGFPP的阻燃性能和热稳定性能,并通过扫描电镜(SEM)观察燃烧后的炭层形貌。结果表明,OMMT的加入提高了LGFPP/IFR体系的阻燃性能和热稳定性能;当OMMT添加量为2%时,体系的氧指数达到24.2%,燃烧后的残炭物形成致密的硅酸盐保护层。     

LGFPP/IFR/SP阻燃复合材料的协同阻燃机理

以海泡石(SP)作为协效剂,研究SP与膨胀型阻燃剂(IFR)协同阻燃LGFPP复合材料的性能。通过极限氧指数(LOI)、垂直燃烧(UL-94)、热重分析(TG)等表征LGFPP/IFR/SP复合材料的协同阻燃性能及协效机理。结果表明:随着SP协效剂用量增加,LGFPP/IFR/SP复合材料的LOI呈先增加后降低的趋势,当SP用量为1%时,复合材料的LOI为29.3%,燃烧等级达到V-0级;Ozawa法计算得到复合材料的活化能随着失重率的增大而增大;在LGFPP/IFR/SP阻燃协效体系中,海泡石主要为化学协效阻燃机理。     

改性赤泥协同膨胀型阻燃剂阻燃聚乙烯

以聚磷酸铵（APP）、季戊四醇（PER）和三聚氰胺（MEL）复配的膨胀型阻燃体系（IFR）为主要阻燃剂,表面改性后的赤泥（Ti-MRM）作为协效剂阻燃聚乙烯（PE）,采用熔融共混法制备PE基阻燃复合材料（PE/IFR-Ti-MRM）。通过热重分析仪（TGA）、垂直燃烧仪（UL-94）、极限氧指数测定仪（LOI）及扫描电镜（SEM）等对其热氧稳定性、燃烧等级、阻燃性能和残炭形貌进行了表征与分析。结果表明：加入改性赤泥的PE/IFR-Ti-MRM复合材料形成的炭层更加致密和连续,当最优配比时,复合材料的极限氧指数达到32.2,燃烧等级达到V-0级;而PE/IFR阻燃复合材料的极限氧指数只能达到27.5,燃烧等级为V-2级。     

透明膨胀型阻燃涂料的阻燃性和抑烟性研究

以三聚氰胺甲醛树脂（ MF）为基体,以苯基膦酸（ PPOA）、新戊二醇（ NPG）、 N,N-二甲基甲酰胺（ DMF）为膨胀阻燃剂（ IFR）制备透明膨胀型阻燃涂料,并通过添加聚乙二醇（PEG）进一步提高该涂料的性能。利用极限氧指数（ LOI）测试、建材烟密度测试和热重分析仪（ TG）研究了该涂料的阻燃性、生烟量和热稳定性,并使用扫描电子显微镜（SEM）观察涂料燃烧后的炭层形貌。结果表明： IFR能显著提高纯 MF的阻燃和抑烟性能;在此基础上添加 PEG可进一步提高该涂料的阻燃抑烟能力。当 IFR与 PEG的添加量分别为 40%、5%时,该涂料的阻燃、抑烟性最佳,其 LOI值达到 27.4%,烟密度等级为 27.15,且在该添加比例下可以使涂料在燃烧过程中具有较好的膨胀成炭能力。     

无卤膨胀阻燃剂在低密度聚乙烯中的应用研究

以干法合成的P-N无卤膨胀阻燃剂(IFR)为基础,配合聚磷酸胺(APP)并且将金属氧化物(ZnO)作为协效剂阻燃改性低密度聚乙烯(PE-LD)。采用扫描电子显微镜对该体系燃烧后的炭层结构进行了分析。通过红外光谱和X射线光电子能谱研究了该体系在不同温度热处理后的残炭组成,并分析了该膨胀型阻燃体系对PE-LD的阻燃机理。结果表明,PE-LD/IFR/APP/ZnO体系的极限氧指数可以达到27.9%,垂直燃烧性能达到UL 94V-0级。     

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.     

多羟基结构三嗪成炭剂在膨胀阻燃PP中的应用

以二乙醇胺为侧链,三聚氯氰和哌嗪为主链,采用一锅法制备了一种多羟基三嗪成炭剂(CDP),将其与聚磷酸铵(APP)复配成膨胀阻燃剂(IFR)用于阻燃聚丙烯(PP)。采用垂直燃烧、极限氧指数、热失重分析等手段研究了阻燃PP的阻燃性能和热稳定性,并用扫描电子显微镜(SEM)对炭层形貌进行了研究。结果表明,APP和CDP具有良好的协同阻燃效果,当APP与CDP质量比为2∶1时,协同阻燃效果最优,仅添加20% IFR,即可使PP达到UL94 V–0级别,LOI为29.5%。热失重分析表明该复合材料在800℃具有最高的残炭量,SEM也显示形成了连续致密的炭层。     

分子筛在无卤膨胀阻燃体系中的协效催化作用

考察了分子筛在自制膨胀型阻燃体系(IFR)中的协效催化作用。利用添加分子筛的IFR对聚丙烯(PP)进行阻燃。运用扫描电子显微镜、垂直燃烧仪等对膨胀阻燃PP体系的表面形态和性能进行了研究。结果表明,阻燃PP加入不同的分子筛后,燃烧级数达到V-0级,氧指数最高增加17.86%,有明显的成炭效果,可获得良好的阻燃性能。     

Enhancement of wollastonite on flame retardancy and mechanical properties of PP/IFR composite

Wollastonite, a natural calcium metasilicate possessing acicular crystal habit structure, was used together with intumescent flame retardant (IFR) to flame retard polypropylene (PP). The synergistic effects between wollastonite and IFR were investigated using limiting oxygen index (LOI) test, cone calorimeter test, thermogravimetric analysis, scanning electron microscope‐energy dispersive spectrometer (SEM‐EDS), etc. The results revealed that wollastonite could effectively improve mechanical properties and flame retardancy of the PP/IFR composite. When 2.0 wt% wollastonite substituted for the same amount of IFR in the composite, the impact strength was enhanced from 4.6 kJ/m² to 6.8 kJ/m², which was increased by 47.1%. Meanwhile, the LOI was increased from 33.0% to 35.5%, a UL‐94V‐0 rating was achieved and the peak heat release rate decreased substantially from 314.4 kW/m² to 262.8 kW/m². Furthermore, the SEM‐EDS results provided positive evidence that the quality of char layer of the PP/IFR/wollastonite was superior to that of the PP/IFR composite due to synergism between wollastonite and IFR. POLYM. COMPOS., 35:158–166, 2014. © 2013 Society of Plastics Engineers     

Effect of a novel intumescent retardant for ABS with synergist Al(H<Subscript>2</Subscript>PO<Subscript>2</Subscript>)<Subscript>3</Subscript>

A novel intumescent flame retardant (IFR), containing ammonium polyphosphate (APP) and poly(hexamethylene terephthalamide) (PA6T), was prepared for acrylonitrile–butadiene–styrene (ABS). Limiting oxygen index (LOI), vertical burning test (UL-94), thermogravimetric analysis (TGA) were used to investigate the flammability property and thermal stability of the IFR/ABS systems. It was found that the flame retardancy of the IFR/ABS systems was improved significantly. When the components of the IFR were 25% APP and 5% PA6T, the LOI value of IFR/ABS system reached to the maximum of 29, but only UL-94V-1 rating was passed. Thus, Al(H₂PO₂)₃ was incorporated into ABS/APP/PA6T system as a synergistic agent, it was found 2% addition of Al(H₂PO₂)₃ caused PA6T/APP/PA6T/Al(H₂PO₂)₃ (70/23.3/4.7/2) to pass V-0 rating of UL-94 test. Meanwhile, the TGA curves indicated that PA6T could be effective as a charring agent and there was a synergistic reaction between PA6T and APP, which effectively promoted the char formation of IFR/ABS composites. Moreover, the residual char obtained after the LOI test of the IFR/ABS was characterized by Fourier transform infrared spectra (FTIR). Results indicated that P–O–C chemical bond was formed in the residual char, which could indicate the cross-linking reaction between PA6T and APP could occur. Furthermore, scanning electron microscopy (SEM) was used to investigate the morphology of the residual char formed in the LOI tests. It was revealed that both ABS/APP/PA6T (70/25/5) and PA6T/APP/PA6T/Al(H₂PO₂)₃ (70/23.3/4.7/2) formed uniform and compact intumescent charred layers.     

Synergistic flame retardancy of ZnO and piperazine pyrophosphate/melamine cyanurate in polypropylene

In order to improve the flame retardant efficiency and smoke-suppression of piperazine pyrophosphate/melamine cyanurate (PPAP/MCA) in PP, the synergism of ZnO and PPAP/MCA was investigated by limiting oxygen index (LOI) determination, UL-94 test, and cone calorimetry test (CCT). It is found that ZnO performs an exceptional synergism in flame retardant effect and inhibition on the flame propagation. Besides, ZnO can significantly inhibit the production of the smoke and CO. The TGA of the PP composites, the component and structure analysis of the heated composites and CCT residues reveal that ZnO performs the synergism primarily by the following modes: ZnO promotes obviously the charring of the composite, and improves the thermal stability as well as the strength of the intumescent layer, which brings about an improved flame retardant property and inhibiting ability on the flame propagation.     

Fabrication of Fly Ash‐Based Mesoporous Aluminosilicate Oxides Loaded with Zinc and its Synergistic Fire Resistancy in Polypropylene

A kind of mesoporous aluminosilicate oxides (MAOs) were fabricated from industrial waste, coal fly ash. After loaded with zinc on MAO, the product MAO‐Zn was characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, and scanning electron microscopy (SEM). MAO‐Zn was incorporated with intumescent flame retardant (IFR) together and used in polypropylene (PP). Basic characterization including limiting oxygen index (LOI), vertical burning test (UL‐94), and cone calorimeter test (CCT) were finished. The result showed the LOI value of PP was only 17.7 and cannot pass UL‐94 grade; however, 25 wt% IFR in PP help the composite obtained LOI value of 27.6 and passed UL‐94V‐1 grade. Surprisingly, with only 2 wt% MAO‐Zn substitution of IFR, the LOI of PP/IFR composite sharply went up to 37.2 and passed V‐0 grade. CCT results documented that heat, smoke, and fatal gas release were obviously suppressed by IFR/MAO‐Zn combination. By SEM observation and quantitative analysis of TGA results, the contribution of MAO‐Zn was summarized as adsorption of heat/smoke and promotion on charring. It was worth mentioning that the low dose of MAO‐Zn (≤ 3 wt%) did not bring further deterioration on mechanical properties. J. VINYL ADDIT. TECHNOL., 26:135–143, 2020. © 2019 Society of Plastics Engineers     

Effect of charring agent THEIC on flame retardant properties of polypropylene

Tris(2‐hydroxyethyl) isocyanurate (THEIC) was used as charring agent and combined with ammonium polyphosphate (APP) to form an intumescent flame retardant (IFR) for polypropylene (PP). The flame retardancy and combustion performance of PP/IFR composite was tested by limiting oxygen index (LOI), UL‐94 vertical burning test and cone calorimeter. The results showed that PP/IFR composite had highest LOI of 34.8 and obtained V‐0 rating when 30 wt % IFR was loaded and mass ratio APP/THEIC was 2 : 1. The peak heat release (PHRR) and total heat release (THR) values of PP composite containing FRs were remarkably reduced compared with that of pure PP. However, water resistant test demonstrated the PP/IFR composite had poor flame retardant durability, both the LOI value and UL‐94 V‐rating decreased when PP/IFR composite was soaked in water at 70°C after 36 h. The degradation process and the char morphology of IFR and PP/IFR composite were investigated by TGA and SEM images. The possible reaction path between APP and THEIC in the swollen process was proposed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41214.     

超支化三嗪成炭剂阻燃聚丙烯

将自制的超支化三嗪成炭剂（CFA）与聚磷酸铵（APP）以1∶1的比例复配成膨胀型阻燃剂（IFR）,用于聚丙烯（PP）的阻燃。采用冲击实验、拉伸实验、极限氧指数仪、垂直燃烧（UL 94）和扫描电子显微镜 (SEM)等方法表征了PP阻燃复合材料的力学性能、阻燃性能,分析了断面形貌。结果表明,添加阻燃剂后,冲击强度呈先增加后降低的趋势,拉伸强度则随着阻燃剂含量的增加不断下降,但降幅不明显;含有15 % IFR的阻燃复合材料,其垂直燃烧等级即可通过UL 94 V-0级测试,显示出复合IFR具有优秀的阻燃效果。