可膨胀石墨与含磷阻燃剂对聚氨酯硬泡性能影响研究

通过试验研究比较了可膨胀石墨(EG)、含磷阻燃聚醚多元醇(F-7190)和磷酸三乙酯(TEP)对硬质聚氨酯泡沫塑料(RPUF)氧指数和燃烧性能的影响,同时考察了这几种阻燃剂对RPUF的压缩强度、导热系数等物理性能的影响。结果表明,EG的阻燃效果最好,F-7190、TEP的添加对含EG的RPUF极限氧指数的提高有促进作用,不同膨胀倍率的EG对RPUF的阻燃效果和物理性能的影响不同。RPUF的压缩强度随F-7190含量的增加略有增加,随TEP、EG含量的增加而减小。RPUF的导热系数随F-7190、TEP和EG含量的增加而增大,但存在一定的差异,其中EG的影响最大。     

复配阻燃剂对硬质聚氨酯泡沫塑料阻燃性能的影响

研究了甲基膦酸二甲酯(DMMP)、尿素(UC)、磷酸三乙酯(TEP)单独添加及复配使用对硬质聚氨酯泡沫塑料(RPUF)阻燃性能的影响。结果表明,UC与DMMP及TEP复配是气相和凝聚相双相协同阻燃机理的复合阻燃剂;UC与DMMP,UC与TEP复配阻燃RPUF,可达到垂直燃烧分级V0级;UC／DMMP复配使用,UC和DMMP含量分别为15%和25%时,其阻燃RPUF的氧指数最高,为27.3%,阻燃性能优于UC／TEP复配阻燃RPUF;复配阻燃RPUF的压缩强度比单独填充UC体系高,呈现协同作用。     

珍珠岩填充硬质聚氨酯泡沫保温板的制备与性能

以珍珠岩为填料制备了聚醚型硬质聚氨酯泡沫材料(RPUF),研究了珍珠岩的填充量,珍珠岩粒径对RPUF板材的机械性能及导热性能的影响,确定了最佳的填料比例,珍珠岩的最佳填充量可达40%。通过加入阻燃剂TCPP和DMMP等,提高了珍珠岩填充RPUF保温板的阻燃性能,材料的最佳氧指数可达到34.1。     

两种磷杂菲/三嗪双基化合物在聚氨酯硬泡中的阻燃行为对比研究

通过箱式发泡制备了三（3DOPO2羟基丙基）1,3,5三嗪2,4,6三酮（TGD）/三（3DOPO丙基）1,3,5三嗪2,4,6三酮（TAD）单独添加和分别与可膨胀石墨（EG）复配阻燃的硬质聚氨酯泡沫（RPUFs）。利用极限氧指数仪（LOI）、锥形量热仪,热重气相色谱质谱联用仪和扫描电子显微镜研究了TAD和TGD在RPUF中的阻燃行为。结果表明,TAD和TGD均能提高RPUF的LOI值,降低RPUF的总热释放量,平均有效燃烧热和热释放速率峰值,并且TGD对这些数值的影响明显大于TAD;随着EG的加入,TGD/EG/RPUF体系表现出比TAD/EG/RPUF更高的LOI值和残炭产率。     

可膨胀石墨在硬质聚氨酯泡沫阻燃性能中的研究

对近年出现的一种新型膨胀阻燃剂———可膨胀石墨(EG)在硬质聚氨酯泡沫塑料(RPUF)中的阻燃性能与其它几种无卤阻燃剂作了比较。用氧指数(LOI)法研究了EG与聚磷酸铵(APP)、磷酸三乙酯(TEP)、三聚氰胺(MA)、三聚氰胺氰脲酸盐(MC)等无卤阻燃剂在RPUF中的协同阻燃作用。结果表明,EG阻燃RPUF的效果最好;并且EG与这些无卤阻燃剂之间存在着协同或反协同作用,其中EG与两种含磷阻燃剂APP和TEP的协同效果最好。     

反应型阻燃剂及全水发泡剂对硬质聚氨酯泡沫塑料阻燃性能的影响研究

以多元醇、异氰酸酯、发泡剂等添加剂为原料,并加入含卤结构型阻燃聚醚多元醇,制备出阻燃硬质聚氨酯泡沫塑料(RPUF),考察了配方中阻燃多元醇及发泡剂水的用量对RPUF的阻燃等性能的影响。研究结果表明,阻燃聚醚多元醇能显著提高RPUF的阻燃性能,氧指数随着其用量的增加而增大,水发泡剂的用量直接影响RPUF的密度、力学性能和阻燃性能。     

膨胀石墨填充硬质聚氨酯泡沫塑料的研究

对膨胀石墨(EG)填充硬质聚氨酯泡沫塑料(RPUF)泡孔结构和填料分散情况进行了分析，研究了EG对RPUF的微观结构形态、泡孔平均直径和泡孔直径分布的影响；同时研究了EG对RPUF的压缩力学性能和电学性能的影响，并分析其压缩破坏的机理。结果表明：EG使RPUF泡孔平均直径减小，泡孔尺寸分布减小，EG在反应体系中充当泡孔成核剂，石墨片层间距离小，并未形成插层复合结构。随EG用量的增加，RPUF的压缩强度和压缩模量轻微下降。不同膨胀倍率的EG对其压缩强度和压缩模量没有影响；EG填充RPUF的体积电阻没有变化，对其导电性能没有影响。     

线性富磷化阻燃剂在聚氨酯泡沫中的应用研究

通过界面聚合法合成了一种线性富磷化阻燃剂（LPRFR）,将LPRFR与可膨胀石墨（EG）复配制备了阻燃聚氨酯泡沫（RPUF）,使用红外光谱分析仪、核磁共振分析仪对阻燃剂LPRFR的化学结构进行了表征,并通过极限氧指数仪、锥形量热仪、扫描电子显微镜和红外光谱分析仪对RPUF的燃烧性能、微观形貌和化学结构进行了分析。结果表明,仅10 %（质量分数,下同）的LPRFR 与8 %EG复配后,RPUF的极限氧指数（LOI）便达到26.1 %;LPRFR和EG能大幅降低RPUF的热释放速率,并提高基体的成炭能力; LPRFR参与了燃烧过程中的成炭反应,形成了含P—O—C及P=O结构的高质量炭层,有效隔绝了氧气和热量;LPRFR是一种对于聚氨酯泡沫阻燃性能优异的新型阻燃剂。     

匀泡剂对阻燃硬质聚氨酯泡沫塑料燃烧性能的影响

利用氧指数仪测定了全磷阻燃剂（DMMP、DEEP、V6）、卤代磷酸酯阻燃剂（TCEP、TCPP、TDCP）及两类阻燃剂复配对硬质聚氨酯泡沫塑料(RPUF)氧指数的影响。结果表明,全磷阻燃剂的阻燃效果优于卤代磷酸酯类阻燃剂;磷卤复配阻燃效果优于单一阻燃剂;单独使用DMMP或DMMP与TCEP复配使用阻燃效果最佳,这句话跟上一句不是矛盾吗？氧指数分别为23.0 %和24.5 %。利用锥形量热仪进一步研究了7种不同硅烷匀泡剂对RPUF阻燃性能的影响。结果表明,硅烷匀泡剂AK8803在提高RPUF的点燃时间以及降低RPUF燃烧释放热危害方面,优于其他6种匀泡剂;而硅烷匀泡剂L580则在降低RPUF燃烧烟气量方面优于其他6种匀泡剂。     

EG与BHAPE对RPUF燃烧及成炭作用的影响

制备了可膨胀石墨(EG)和N,N-[双(2-羟乙基)氨甲基]磷酸二乙酯(BHAPE)单独添加及复配使用阻燃的硬质聚氨酯泡沫塑料(RPUF),通过万能拉伸试验机、组合冲击试验机、氧指数仪、综合热分析仪、锥形量热仪和扫描电镜(SEM)等测试,对力学性能、阻燃性、热稳定性、燃烧性能及炭层形貌等进行了分析。结果表明,BHAPE的添加能够改善RPUF的比冲击强度,减少EG对体系力学性能的损害;氧指数(LOI)的实际值明显高于计算值,复配组分的LOI由20.3%提高到29.2%,EG/BHAPE具有显著的协同效应;EG/BHAPE复配使阻燃体系的初始分解温度、最大热解速率、热释放速率、总热及总烟释放量降低,残炭率提高,燃烧后形成厚且致密的炭层。     

Flame retardancy of different‐sized expandable graphite particles for high‐density rigid polyurethane foams

The effects of expandable graphite (EG) of different particle sizes, on the fire‐retardant properties of high‐density rigid polyurethane foam (RPUF) (0.45 g cm^?3) were studied. Samples of EG with different particle sizes were obtained by pulverization in an ultra‐high‐speed mixer for 4 and 13 min, respectively. It was shown that as received (EG0) and 4 min pulverized EG (EG4) efficiently improved the fire‐retardant properties of RPUF composites, while 13 min pulverized EG (EG13) did not. The char of the burned composites filled with EG0 and EG4 covered the whole surface of the samples and formed a complete physical barrier. This barrier material prevented combustible gases from feeding the flame and also isolated oxygen efficiently from the burning material. EG13 did not produce enough char to cover the whole surface of the burning sample, resulting in poor fire‐retardant property of the RPUF composites. Thermal degradation tests of the foams by thermogravimetric analysis indicated that EG showed negligible effects on the thermal stability of the RPUFs. Copyright © 2006 Society of Chemical Industry     

可膨胀石墨与含磷阻燃剂在聚氨酯硬泡材料中的应用

通过氧指数仪与锥形量热仪研究了可膨胀石墨（EG）与低聚磷酸酯多元醇（OP550）、二乙基N,N二(2羟乙基)胺基甲基膦酸酯（WSFR 6）2种反应型含磷阻燃剂对聚氨酯硬泡材料（RPUF）阻燃性能的影响。结果表明,在OP550与WSFR 6的存在下,RPUF具有较好的成炭性,且炭层较为致密;添加EG后,体系的阻燃性能进一步提高,当其含量为14 %（质量分数,下同）时,RPUF体系的极限氧指数达到33.6 %,热释放速率峰值降低到106.93 kW/m2。     

Effects of expandable graphite and ammonium polyphosphate on the flame‐retardant and mechanical properties of rigid polyurethane foams

In this work, the effect of expandable graphite (EG) and ammonium polyphosphate (APP) on the flame retardancy and mechanical properties of the rigid polyurethane foam (RPUF) was studied. The results indicated that both EG and APP could effectively improve the flame retardancy of RPUF, while the retardancy of EG was better than APP. When the flame‐retardant loading was 15 wt %, the limited oxygen index (LOI) values of APP‐ and EG‐filled RPUF were 24.5 and 32 vol %, respectively. According to the LOI test, the optimal ratio of APP to EG in RPUF composites was 1 : 1 by weight, at which the LOI value of 15 wt % (APP + EG)/RPUF was 30.5 vol %. Thermal degradation test of RPUF composites by thermogravimetric analysis indicated that the addition of APP and EG to RPUF could lead to an increase in the amount of high‐temperature residue. Under the same conditions, the residue amount of EG/RPUF was less than that of APP/RPUF at the same temperature. Compression test and dynamic thermal mechanical analysis indicated that both the compressive strength and modulus decreased at a certain extent with the EG‐ or APP‐filled into RPUF, respectively, but with the mixture of EG and APP added into RPUF, the mechanical properties of these materials increased. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Expandable Graphite For Halogen-Free Flame-Retardant of High-Density Rigid Polyurethane Foams

We obtained the high-density rigid polyurethane foam (RPUF) filled with expandable graphite (EG) by airtight cast molding, and its fire performance was evaluated. The results show that the LOI values increase linearly with EG content, especially the LOI value of the 20 wt% EG-filled RPUF composites increases rapidly to 39.5% from 22.5% of pure RPUF. When the pure RPUF was burned, no clear transition process between burning spots and virgin material is observed. But when the EG/RPUF composite was burned, EG produced high-volume expanded graphite and covered the surfaces of the materials, which can prevent combustible gases from feeding the flame, and it also separates oxygen from the burning material efficiently. The thermal degradation of foam was investigated using thermogravimetric analysis (TGA). The result shows that the thermo-oxidative degradation of pure RPUF takes place in the range of 220–350°C and 450–650°C, respectively. The thermal stability of RPUF composites increased slightly when it contained 20 wt% EG. The mechanical and electrical properties of EG/RPUF were also discussed. Generally, addition of EG resulted in a slight decrease in the mechanical properties and no influence on the electrical conductivity.     

Dependence of flame‐retardant properties on density of expandable graphite filled rigid polyurethane foam

Different density rigid polyurethane foams (RPUF) filled with various expandable graphite loadings were fabricated by cast molding. The flame retardant properties of these composites were assessed by limiting oxygen index and horizontal and vertical burning tests. The results showed that the flame retardant efficiency got better with increase in the foam density at the fixed EG weight percent or with increase in the EG weight percent at the fixed foam density. After burning, the low density (0.065 g/cm³) pure burned RPUF produced the highly collapsed and carbonized material, while the high density (0.510 g/cm³) pure RPUF had little change in size and had reduced destruction of the material. Moreover, the scanning electronic microscope (SEM) observation showed that the higher density EG/RPUF composites had a more compact outer layer (burned layer) after burned, in which more wormlike materials composed of expanded graphite particles appeared. In addition, higher foam density led to less plastic deformation in the interface layer between the burned and the inside layers. These results indicated that a weight percent of a flame retardant additive that achieves satisfactory flame retardancy for a certain density foam cannot effectively be applied for another density foam. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Synergistic effect of expandable graphite and aluminum hypophosphite on flame‐retardant properties of rigid polyurethane foam

A series of flame retarding rigid polyurethane foam (RPUF) composites based on expandable graphite (EG) and aluminum hypophosphite (AHP) were prepared by the one‐pot method. The properties were characterized by limiting oxygen index (LOI) test, cone calorimeter test, thermogravimetric analysis (TGA), real‐time Fourier transform‐infrared spectra (RT‐FT‐IR), X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), etc. The results indicate that both EG and AHP could enhance the flame retardency of RPUF composites. Besides, the flame retardant effect of EG was better than that of AHP. The results also show that partial substitution of EG with AHP could improve the flame retardency of RPUF, and EG and AHP presented an excellent synergistic effect on flame retardancy. What is more, compared with RPUF/20EG and RPUF/20AHP, the heat release rate (HRR) and total heat release (THR) of RPUF/15EG/5AHP were lower.TGA results indicate that partial substitution of EG with AHP could improve the char residue which provided better flame retardancy for RPUF composites. The thermal degradation process of RPUF composites and the chemical component of the char residue were investigated by RT‐FT‐IR and XPS. And the results prove that RPUF/15EG/5AHP had higher heat resistance in the later stage. Compared with the RPUF composites filled with EG, a better cell structure and mechanical properties were observed with the substitution of AHP for part of EG. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42842.     

Flame‐retardant and mechanical properties of high‐density rigid polyurethane foams filled with decabrominated dipheny ethane and expandable graphite

The article reported the flame‐retardant and the mechanical properties of expandable graphite (EG), an intumescent type, and decabrominated dipheny ethane (DBDPE), a gas‐phase type of flame‐retardant‐containing high‐density rigid polyurethane foams (RPUF) with a constant density of 0.5g/cm³. The results indicated that both EG and DBDPE could effectively interdict the burning of RPUF, besides, the EG exhibited more effective flame retardancy than the DBDPE. When the flame‐retardant loadings were 20 wt %, the LOI value of DBDPE‐filled RPUF increased to 33 vol %, while, surprisingly, the EG‐filled RPUF reached 41 vol %. Unfortunately, when they were both simultaneously added into RPUF, there was not any flame‐retardant synergistic effect. Although EG had outstanding flame retardancy, the compressive strength and modulus of 20 wt % EG‐filled RPUF dropped to only 9.1MPa and 229.7MPa respectively, which were lower than those of DBDPE (12.4 MPa and 246.8 MPa). The phenomena were ascribed to the different flame‐retardant mechanisms of EG and DBDPE, which were verified by scanning electronic microscope (SEM) observation of the burned surfaces. Besides, the dynamical mechanical analysis (DMA) demonstrated that the additions of EG and DBDPE made the glass transition temperature shift to the high temperatures, and the EG‐filled RPUF had the higher storage modulus. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of expandable graphite on the properties of intumescent flame‐retardant polyurethane foam

Water‐blown rigid polyurethane foam (PUF) with two different particle sizes (180 and 300 μm) of expandable graphite (EG) as a flame‐retardant additive were prepared, and the effects on the mechanical, morphological, water absorption, thermal conductivity, thermal, and flame‐retardant properties were studied. In this investigation, EG content was varied from 5 to 50 php by weight. The mechanical properties of PUF decreased with increasing EG loading in both cases. The water absorption of the PUF increased with an increase in the EG loading mainly because of the collapse of foam cells, as evidenced from the scanning electron microscopy pictures. The thermal conductivity of the EG‐filled PUF showed that the insulation properties decreased with EG loading. The flame‐retardant properties (limiting oxygen index and char yield measurement) of the PUF improved with increasing EG loading. PUF filled with the higher particle size EG showed better mechanical properties and fire‐retardant properties than the PUF filled with the lower particle size EG. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

新型硬质聚氨酯泡沫的热分解行为及动力学

利用热重分析法比较研究了新型硬质聚氨酯泡沫[超支化聚氨酯多元醇型(HBPU型)]和硬质聚氨酯泡沫(RPUF)在氮气中的热分解行为,探讨了HBPU型RPUF在不同升温速率下的热分解动力学,运用Kissinger最大失重率法和Flynn-Wall-Ozawa等失重百分率法计算获得了其热分解过程的活化能。研究结果表明,HBPU型RPUF的初始分解温度(T5%)为205℃,半寿温度(T50%)为361℃,略低于传统的RPUF。Kissinger法得到的HBPU型RPUF的热分解表观活化能为159.8 kJ/mol;Flynn-Wall-Ozawa法得到的热分解过程分为三个阶段:第一阶段的平均活化能为82.8 kJ/mol,第二阶段的平均活化能为140.7 kJ/mol,第三阶段的平均活化能为111.3 kJ/mol,HBPU型RPUF具有较好的热稳定性。