磷杂菲类阻燃剂的合成及其与聚磷酸铵复合膨胀体系对环氧树脂的阻燃性能研究

以9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)、五硫化二磷(P2S5)为原料合成9,10-二氢-9-氧杂-10-磷杂菲-10-硫化物(DOPS),并将DOPS与聚磷酸铵(APP)组成复合阻燃剂,用于环氧树脂(EP)的阻燃改性.通过氧指数(LOI)、垂直燃烧(UL-94)、热失重(TGA)、锥形量热(CONE)和扫描电镜(SEM)等方法对改性后的环氧树脂的阻燃性能和阻燃机理进行了测试和分析.实验结果表明,DOPS/APP阻燃体系对EP具有很好的阻燃性能,且复配阻燃剂的阻燃效果比单一的阻燃剂阻燃效果好;其中,当阻燃剂的总添加量达到30%时即W_(DOPS)=10%、W_(APP)=20%时,阻燃EP复合材料的LOI值可达到29.2%,垂直燃烧等级达到UL-94 V-0级,残炭量可达49.3%.     

苯酰亚胺结构对PET阻燃抗熔滴及抑烟的贡献

通过本体聚合方法合成了一系列侧链含苯酰亚胺结构的聚对苯二甲酸乙二酯(PET)共聚酯.研究发现,苯酰亚胺单元的引入不仅提高了共聚酯的玻璃化转变温度(T_g)和高温成炭性,并且大大降低了共聚酯高温下的热分解速率.随着苯酰亚胺含量的增加,共聚酯表现出更高的氧指数(LOI)值和更好的阻燃抗熔滴效果.锥形量热测试结果表明,苯酰亚胺结构的引入可以有效地降低共聚酯的峰值热释放速率(p-HRR)、峰值烟释放速率(p-RSR)和总烟释放量(TSR).通过对纯PET和共聚酯燃烧测试后残炭的结构和形貌分析,发现苯酰亚胺结构有助于共聚酯形成石墨化程度更高的致密炭层,这些炭层起到隔热隔氧和抑制有机可燃烟气挥发的作用,在不引入传统阻燃剂的情况下,赋予共聚酯很好的本征阻燃性及抑烟性.     

两步辐射接枝法制备抗熔滴涤纶织物

以涤纶(PET)为基材,利用两步γ辐射接枝法在PET织物表面依次引发甲基丙烯酸缩水甘油酯(GMA)/二乙烯苯(DVB)和乙烯基磷酸二甲酯(DMVP)接枝共聚,制备了新型抗熔滴PET织物.接枝率随吸收剂量和单体浓度的增加而增加,随剂量率增加而下降.傅里叶红外(FTIR)、X射线光电子能谱(XPS)和热重分析(TGA)的分析结果表明在PET织物上成功引入目标接枝聚合物.相比PET织物,辐射改性PET织物的拉伸强度以及断裂伸长率均有所提高.通过引入交联网状结构以及促进成炭的含磷接枝聚合物,PET织物的抗熔滴特性得到了明显改善,燃烧过程中平均产生一滴熔滴的时间:PET为3.0 s/n,PET接枝PGMA/DVB后延长为17.0 s/n,而进一步接枝PDMVP后在整个燃烧过程中均不产生熔滴.这种新型的方法有望用于PET织物防护服抗熔滴性能的改善.     

一种基于联苯二甲酸为介晶基元的含磷液晶共聚酯的合成与表征

以联苯二甲酸二甲酯、二甘醇和9,10-二氢-9-氧杂-10磷酰杂菲-对苯二酚二羟乙基醚(DOPO-HQ-HE)为单体,通过无规共聚合成了一种新型含磷液晶共聚酯(PDEBP).用1H-NMR对共聚酯的结构进行了表征,用TGA、DSC和POM对其热性能及液晶行为进行了研究.结果表明,阻燃单体DOPO-HQ-HE的引入不会降低共聚酯的热稳定性,含7.5 mol％ DOPO-HQ-HE的共聚酯PDEBP7.5在700℃的氮气氛中的残余物(Wt700R)可达31.9 wt％,并且具有很好的阻燃性.DOPO-HQ-HE含量的增加对共聚酯的结晶性有较大的破坏,5 mol％ DOPO-HQ-HE的共聚酯PDEBP5的清亮点温度为154.2℃,焓变为4.64 J/g,而PDEBP7.5在POM测试中在升温及降温过程中均难观察到液晶相的双折射现象.     

聚磷酸酯阻燃剂复配蒙脱土及聚磷酸铵对环氧树脂阻燃性能的影响

本文以二氯化磷酸对甲基苯酯和10-(2,5-二羟基苯基)-10-氢-9-氧杂-10-磷杂菲-10-氧化物(ODOPB)为原料,合成了一种新型聚磷酸酯阻燃剂聚磷酸-2-10-氢-9-氧杂-10-磷杂菲-10-氧化物基对苯二酚对甲苯酯(POTP),并采用傅里叶变换红外光谱(FTIR)和核磁共振(~(31)P-NMR,~1H-NMR和~(13)C-NMR)对其结构进行表征.将POTP与蒙脱土(MMT)及聚磷酸铵(APP)组成复合阻燃剂对环氧树脂(EP)进行阻燃改性,通过垂直燃烧(UL-94)、氧指数(LOI)、热失重(TGA)、锥形量热(CONE)和扫描电镜(SEM)等方法研究其对EP的热性能和阻燃性能的影响.结果表明,当阻燃剂添加量为7%时, EP复合材料UL-94测试等级可达V-0级;当添加阻燃剂为9%时,其LOI值可达到27.6%,最大热释放速率(Pk-HRR)下降了50.1%,热释放总量(THR)下降了27.4%,其残炭量高达29%. CONE测试后的残炭形貌研究显示阻燃EP在高温下形成较稳定的致密膨胀炭层,能有效抑制烟毒性气体释放,隔绝可燃气体与空气的交换,从而提高阻燃EP在高温下的热稳定性和阻燃性能.     

聚苯氧基磷酸联苯二酚酯/聚磷酸铵膨胀阻燃剂对环氧树脂阻燃性能影响研究

以聚苯氧基磷酸联苯二酚酯(PBPP)与聚磷酸铵(APP)组成复合阻燃剂,对环氧树脂(EP)进行阻燃改性.通过氧指数(LOI)、垂直燃烧(UL-94)、热失重(TGA)、锥形量热(CONE)和扫描电镜(SEM)等方法研究改性环氧树脂的阻燃性能和阻燃机理.结果表明,PBPP/APP体系对EP具有较好的阻燃性能,阻燃剂添加量为10%时能使环氧树脂的氧指数提高到29.6%,垂直燃烧等级达到UL94 V-0级,残炭量大大增加;平均热释放速率下降45.7%,热释放速率峰值下降51.0%,有效燃烧热平均值下降21.1%;TGA、CONE、SEM等综合分析显示了PBPP/APP改性后的环氧树脂比纯环氧树脂具有更高的热稳定性,燃烧后能够形成连续、致密、封闭、坚硬的焦化炭层,在聚合物表面产生有效覆盖、隔绝了氧气,改善了环氧树脂的燃烧性能.     

SDS-LDH与CTAB-MMT协同APP阻燃P(BA-VAc)的对比分析

通过极限氧指数(LOI)和垂直燃烧(UL-94),对比分析了十二烷基硫酸钠改性双羟基氧化物(SDS-LDH)和十六烷基三甲基溴化铵改性蒙脱土(CTAB-MMT)协同聚磷酸铵(APP)对聚(丙烯酸丁酯-醋酸乙烯酯)(P(BA-VAc))胶膜阻燃效果的异同.当APP添加量为14.5 wt%,层状无机粒子引入量为0.5 wt%时,P(BA-VAc)/APP/SDS-LDH和P(BA-VAc)/APP/CTAB-MMT的最佳LOI值分别为30.5和30.1.通过热分析法(TGA)探讨了阻燃型复合材料的热降解行为.700℃时,P(BA-VAc)/14.5%APP/0.5%SDS-LDH比P(BA-VAc)/14.5%APP/0.5%CTAB-MMT的残留量高2.7%.采用扫描电镜(SEM)观察复合材料LOI测试后炭层微观形貌.与P(BA-VAc)/15%APP复合材料相比,P(BA-VAc)/14.5%APP/0.5%SDS-LDH和P(BA-VAc)/14.5%APP/0.5%CTAB-MMT燃烧后炭层的外表面更加致密,并且连续性更好.通过傅里叶变化红外(FTIR)和X-射线光电子能谱(XPS)对阻燃材料500℃热氧化炭层进行了分析.SDS-LDH和CTAB-MMT均可促进更多酯化反应和脱水反应发生;相比而言,SDS-LDH具有较好的催化协同成炭效果.     

聚对苯二甲酸二甲酯/聚2,5-呋喃二甲酸二甲酯嵌段聚酯的合成与表征

以生物基单体2,5-呋喃二甲酸、乙二醇为原料合成聚2,5-呋喃二甲酸乙二醇酯(PEF)。采用熔融酯交换法以PEF聚酯部分取代聚对苯二甲酸乙二醇酯(PET),制备了系列PET-b-PEF嵌段共聚酯。通过核磁共振仪(NMR)、差示扫描量热仪(DSC)、热失重仪(TGA)、X射线衍射仪(XRD)等技术手段表征了共聚酯的结构和性能。结果表明,该系列共聚酯的玻璃化转变温度(Tg)在75.8~80.3℃之间,且随着PEF链段质量分数的增加,PET-b-PEF嵌段共聚酯的Tg先降低后升高,结晶度和熔融温度逐渐降低。当PEF链段含量高于15%时,共聚酯没有结晶峰。该系列共聚酯具有良好的热稳定性,起始分解温度在392.2~407.9℃之间,与所制备的PET起始分解温度403.3℃接近。且当共聚酯中PEF链段含量低于15%时,起始分解温度均在407℃左右,优于PET的热稳定性。     

改性PHB/PET液晶共聚酯的合成

精选八种具有不同结构特征的第三单体,以熔融缩聚法合成了八种改性PHB/PET共聚酯。发现含香草酸第三单体的PHB/PET/VA三元共聚酯具有较快共聚反应速率、较低熔融温度、典型热致液晶行为和良好成纤性。香草酸是最适合于PHB/PET体系共聚改性的第三单体。     

超支化聚磷酸酯阻燃剂对尼龙6的成炭促进作用

以三氯氧磷和双酚A为原料制备了具有超支化结构的聚磷酸酯阻燃剂(HPPEA),通过红外(FTIR),核磁(1H-NMR,31P-NMR)及热重分析表征了产物的结构和热稳定性.将HPPEA与三聚氰胺聚磷酸盐(MPP)进行复配,通过熔融共混法制备阻燃尼龙6,通过氧指数法和垂直燃烧法测试了其阻燃性能,采用热重分析(TGA)研究...     

Thermal stability and flame retardancy of PET/magnesium salt composites

Nano-Mg(OH)₂ (nanometre magnesium hydroxide, nano-MH) was successfully introduced into the esterification and polycondensation system by in situ polymerization to obtain PET/magnesium salt composites (PETMS). The thermal properties and flame retardancy of PETMS were investigated by differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), UL-94 vertical burning and limited oxygen index (LOI) test. The DSC and TGA results show that magnesium salts in the PET matrix have little effect on the thermal properties of PET, but a significant effect on the thermal stabilities of the composites. The results of LOI and UL-94 test show PETMS have higher LOI values (≥25%) and V-0 rating without melt dripping in the UL-94 test, indicating that PETMS have good flame retardancy and anti-dripping property. Moreover, the residues of magnesium salts and composites after TGA test were also studied by Fourier transform infrared spectroscopy (FTIR) to better understand the mechanism of flame retardancy, which reveals that magnesium salts accelerate the degradation of PET and catalyze the formation of char. The SEM results show the morphological structures of the char effectively protect the composites’ internal structures and inhibit the heat, smoke transmission and reduce the fuel gases when the fire contacts them.     

Synthesis of a silicon-containing flame retardant and its synergistic effect with potassium-4-(phenylsulfonyl)benzenesulfonate (KSS) in polycarbonate (PC)

A novel flame retardant (DAPSiO), containing silicon and nitrogen, was synthesized by using dichlorodiphenylsilane, γ-chloropropyl methyl dimethoxysilane and 1,2-ethanediamine. DAPSiO was used together with potassium-4-(phenylsulfonyl)benzenesulfonate (KSS) to prepare a flame-retardant system for polycarbonate (PC). The structure of DAPSiO was characterized by Fourier transform infrared spectroscopy (FTIR), and ¹H-NMR tests. Flammability and thermal behaviors of PC/KSS/DAPSiO systems were estimated by limited oxygen index (LOI), vertical burning test (UL-94) and thermogravimetric analysis (TGA) tests. The results showed that the flame retardancy and thermal stability of PC/KSS system were improved with the addition of DAPSiO. When 1 wt% DAPSiO and 0.5 wt% KSS were incorporated, the LOI value of PC was found to be 44, and class V-0 of UL-94 test was passed. The scanning electron microscopy (SEM) and FTIR indicated that PC/KSS/DAPSiO system held a more cohesive and denser char structure when compared with pure PC and PC/KSS system.     

An efficient halogen-free flame retardant for glass-fibre-reinforced poly(butylene terephthalate)

Compared with poly(butylene terephthalate) (PBT), glass-fibre-reinforced poly(butylene terephthalate) (GF-PBT) is difficult to flame retard with halogen-free flame retardants. In the present study, the aluminium salt of hypophosphorous acid (AP) was used as a flame retardant for GF-PBT. A series of flame-retardant GF-PBT composites was prepared via melt compounding. The flame retardance and combustion behaviour of the composites were studied by limiting oxygen index (LOI), vertical burning test (UL-94) and cone calorimetric test. Thermal behaviours and thermal decomposition kinetics were investigated by thermogravimetric analysis (TGA) under N₂ atmosphere. The addition of AP to the composites could result in an increased LOI value, a UL-94 V-0 (1.6 mm) classification and a better fire performance in cone calorimetric tests. The char morphology observation after flame-retardant tests, calculation of decomposition kinetics, X-ray photoelectron spectroscopy (XPS) and infra-red spectral analysis of the char residue confirmed the condensed-phase flame-retardant mechanism. Furthermore, the mechanical properties of the flame-retardant composites were not deteriorated, retaining an acceptable level.     

Inherent flame retardation of bio-based poly(lactic acid) by incorporating phosphorus linked pendent group into the backbone

The molecular design for inherently flame-retardant poly(lactic acid) (IFR-PLA) was outlined and achieved by chemically incorporating an effective organophophorus-type flame retardant (FR) into the PLA backbone via the chain extension of the dihydroxyl-terminated prepolymer with 1, 6-hexamethylene diisocyanate (HDI). The structure of IFR-PLA was characterized by ¹H- and ³¹P-nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy. IFR-PLA was further blended with the commercial PLA to prepare flame retardant PLA blends (PLA-FR blend). The relevant properties of IFR-PLA and PLA-FR blends were evaluated by differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), limiting oxygen index (LOI) measurements and UL-94 tests. The thermal analysis revealed that the char yield of IFR-PLA and PLA-FR blend above 400 °C was greatly enhanced compared to that of pure PLA. The LOI value was significantly improved from 19 for pure PLA to 29 when 1 wt% of phosphorus content was introduced and all IFR-PLA samples achieved V-0 rating in the UL-94 tests. PLA-FR blends had an LOI value of 25-26 and UL-94 V-2 rating at 20 wt% of IFR-PLA content. The tensile strength of all the FR PLA systems was ca. 60 MPa. The method used in this study provided a novel route to permanently flame retard PLA.     

A novel halogen-free flame retardant for glass-fiber-reinforced poly(ethylene terephthalate)

In order to prepare halogen-free flame-retardant glass-fiber-reinforced poly(ethylene terephthalate) (FR-GF-PET), a novel flame retardant containing three flame-retardant elements, P, N and S, was synthesized by melt condensation reaction. Its chemical structure was characterized by FT-IR and ¹H NMR spectra. FR-GF-PET was prepared by melt-mixing the flame retardant with GF-PET. The effects of the flame retardant on the flammability and thermally decomposing behaviors of GF-PET were studied via LOI, UL-94 and TGA tests. The results showed that despite a negative effect on the thermal stability of GF-PET, the incorporation of the flame retardant improved the flame retardancy of GF-PET largely. The LOI values of GF-PET increase linearly with the increase of flame retardant content. The GF-PET passed the V-0 rating in UL-94 tests when 15 wt% of the flame retardant was added to GF-PET. An interesting phenomenon was found, that is, with the increase of flame retardant content, the flame retardancy of the system increased but the char yield decreased, which was explained according to the evidences of XPS tests and the kinetics of thermally decomposing reaction.     

Synthesis of organo-modified α-zirconium phosphate and its effect on the flame retardancy of IFR poly(lactic acid) systems

Novel intumescent flame-retardant poly(lactic acid) (PLA/IFR)/organo-modified α-zirconium phosphate(OZrP) nanocomposites were prepared via incorporation of charring agent (CA), ammonium polyphosphate (APP) and OZrP into PLA. OZrP was synthesized directly by a solvent thermal method. The morphological characterization of PLA/IFR/OZrP nanocomposites was conducted by wide angle X-ray diffraction (WXRD) and transmission electron microscopy (TEM). The effect of the OZrP on flame retardancy and the thermal stability of PLA/IFR composites were studied by thermogravimetric analysis (TGA), limiting oxygen index (LOI), vertical burning test (UL-94) and cone calorimeter test. The TGA data illustrated that the OZrP could increase the residue and significantly improve the flame retardancy of PLA/IFR/OZrP nanocomposites showing an excellent synergistic effect. The addition of OZrP to the flame-retardant PLA increases the LOI and enhances the UL-94 rating. Cone calorimeter tests gave clear evidence that the incorporation of OZrP into PLA/IFR composites resulted in the significant reduction of the heat release rate (HRR), low total heat release (THR) and high amount of char residues during combustion. The flame-retardant mechanism of PLA/IFR/OZrP nanocomposites may correspond to the intumescent flame-retardant mechanism and catalyzed carbonization mechanism caused by OZrP.     

Combustion properties and thermal degradation behavior of polylactide with an effective intumescent flame retardant

An intumescent flame retardant spirocyclic pentaerythritol bisphosphorate disphosphoryl melamine (SPDPM) has been synthesized and its structure was characterized by Fourier transformed infrared spectrometry (FTIR), ¹H and ³¹P nuclear magnetic resonances (NMR). A series of polylactide (PLA)-based flame retardant composites containing SPDPM were prepared by melt blending method. The combustion properties of PLA/SPDPM composites were evaluated through UL-94, limiting oxygen index (LOI) tests and microscale combustion calorimetry (MCC) experiments. It is found that SPDPM integrating acid, char and gas sources significantly improved the flame retardancy and anti-dripping performance of PLA. When 25 wt% flame retardant was added, the composites achieved UL-94 V0, and the LOI value was increased to 38. Thermogravimetric analysis (TGA) showed that the weight loss rate of PLA was decreased by introduction of SPDPM. In addition, the thermal degradation process and possible flame retardant mechanism of PLA composites with SPDPM were analyzed by in situ FTIR.     

A NEW SYNERGIST FOR INTUMESCENT FLAME RETARDANT POLYPROPYLENE

The synergistic effects of silicotungstic acid (SiW_(12)) as a carelyst in the phosphorus-nitrogen compounds AM-based intumescent flame-retardant (IFR) polypropylene (PP) were studied using the limiting oxygen index(LOI), the UL-94test, thermogravimetric analysis (TGA), real time Fourier transform infrared (FTIR), laser Raman spectroscopy (LRS). TheLOI data show that SiW_(12) added to PP/IFR systems has a synergistic FR effect with an IFR additive named AM. The TGAdata show that SiW_(12) apparently increases the thermal stability of the PP/IFR systems at high temperature (T>500℃). TheFTIR results provide the positive evidence that IFR can improve the thermal stability of PP and SiW_(12) can induce a higherrate of formation of phosphoric acid and its derivatives. The LRS measurements provide useful information on thecarbonaceous microstructures. In short, a suitable amount of SiW_(12) (1.5 wt%) exerts synergistic effects with the IFR byincreasing the LOI value and the thermal stability at high temperature and promoting the formation of charred structures onthe burning PP surface.     

磷化淀粉的合成及其与聚磷酸铵协效阻燃聚乳酸的性能研究

利用9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)和马来酸酐(MA)对淀粉进行改性得到磷化淀粉(DOPOMASt),通过红外光谱(FTIR)、核磁共振谱(1H-NMR)和X射线光电子能谱(XPS)确定其结构.利用DOPOMASt作为碳源,与聚磷酸铵(APP)复配后通过熔融共混制备了阻燃聚乳酸(PLA)...