磷钨酸在膨胀阻燃聚乳酸中的协效作用研究

利用磷钨酸(PWA)与膨胀阻燃剂(IFR)复配得到复合阻燃剂,并与聚乳酸(PLA)熔融共混制备阻燃复合材料PLA/IFR/PWA。通过氧指数测试(LOI)、垂直燃烧(UL-94)、扫描电子显微镜(SEM)、锥形量热测试(CONE)和热失重分析(TGA)对该复合材料的阻燃性能和热稳定性能进行研究。结果表明:PLA/IFR/PWA复合材料表现出优异的阻燃效果和明显的抑烟作用。当添加总质量分数为20%(IFR为18%,PWA为2%)时,复合材料的LOI达到41.7%,UL-94等级为V-0等级,高温残炭量显著提高,燃烧过程中烟释放量明显降低。     

聚乳酸/苯基次膦酸铈复合材料的制备及性能

采用简单方法合成苯基次膦酸铈(CeP),并将其作为阻燃剂加入聚乳酸(PLA)中,通过熔融共混技术制备聚乳酸/苯基次膦酸铈(PLA/CeP)复合材料。通过热重(TG)、极限氧指数(LOI)、UL-94垂直燃烧(UL-94)、微型量热(MCC)研究复合材料的热稳定性、阻燃性能和燃烧性能。通过阻燃测试发现,CeP能够提高复合材料阻燃性能,PLA/CeP20极限氧指数能达到24.3%并通过UL-94 V-2级别。热重分析的结果表明,CeP显著提高了PLA/CeP复合材料初始分解温度和成炭率。MCC测试结果表明,CeP能明显降低PLA/CeP复合材料火灾危险性。PLA/CeP20热释放速率峰值(PHRR)和总热释放(THR)分别为397 W/g和13.6 kJ/g,与纯聚乳酸相比,分别下降了13.9%和28.0%。因此,苯基次磷酸铈对聚乳酸具有良好的阻燃效果。     

不同膨胀型阻燃剂改性聚丙烯/聚乳酸复合材料

用两种不同的膨胀型氮磷阻燃剂(IFR1和IFR2)阻燃改性聚丙烯(PP)/聚乳酸(PLA)复合材料。结果表明:两种阻燃剂在PP/PLA基体中都具有良好的分散性和界面粘合性。阻燃剂的加入降低了材料的力学性能,而含有25%阻燃剂的PP/PLA复合材料就能到达垂直燃烧试验(UL-94)的V0等级。燃烧过程中阻燃剂通过在材料表面形成致密的炭层来提高材料的阻燃性,其中IFR1对PP/PLA体系的阻燃改性效果更好。从力学性能和阻燃效果的双重考虑,质量含量25%的阻燃剂适合于PP/PLA材料的阻燃改性。     

三嗪膨胀阻燃聚乳酸的制备及其性能

将实验室自制的三嗪大分子成炭发泡剂(CFA)、聚磷酸铵(APP)及硅树脂复配成膨胀阻燃剂(IFR)添加到聚乳酸(PLA)材料中制备阻燃PLA(IFR-PLA)材料,通过极限氧指数(LOI)和垂直燃烧(UL-94)测试研究了材料的阻燃性能。通过热重分析(TGA)测试研究了材料的热降解行为和成炭性能,通过锥形量热(CONE)测试研究了材料的燃烧行为,并对其燃烧后残炭的形貌进行研究。结果表明:当APP与CFA的质量比为5∶1,IFR的添加量为15%时,IFR-PLA材料通过UL-94 V-0级,LOI值达33.5%。IFR的加入促进了PLA材料的降解和成炭,从而提高了材料的阻燃性能。     

生物可降解聚乳酸的无卤阻燃与增韧改性研究

选用次磷酸铝(AHP)与聚乳酸(PLA)熔融挤出共混制备无卤阻燃PLA复合材料,采用氮系阻燃剂(MCA)与次磷酸铝进行复配,并通过添加增韧剂乙烯-甲基丙烯酸酯-甲基丙烯酸缩水甘油酯共聚物(EMA-GMA)改善阻燃PLA的冲击性能。研究结果表明,随着磷系阻燃剂AHP用量的增加,聚乳酸的阻燃性能提高;当AHP添加量为20%时,阻燃PLA复合材料的氧指数为29.0%,UL94测试达到V-0级,AHP与MCA有一定的阻燃协同作用。随增韧剂EMA-GMA用量的增大,阻燃聚乳酸复合材料的韧性较未改性的阻燃聚乳酸材料有明显增加。当EMA-GMA质量分数为15%时,改性聚乳酸复合材料的断裂伸长率比PLA阻燃复合材料提高5倍;缺口冲击强度增加了54.8%,无缺口冲击强度增加了230%。     

DOPS衍生物阻燃剂的合成及聚乳酸复合材料的性能（急）

以马来酸酐(MAH)和9,10-二氢-9-氧杂-10-磷杂菲-10-硫化物(DOPS)为原料,合成了马来酸酐-9,10-二氢-9-氧杂-10-磷杂菲-10-硫化物(MAH-DOPS),将MAH-DOPS应用于聚乳酸(PLA)的阻燃改性.采用TG、极限氧指数(LOI)、垂直燃烧(UL-94)、锥形量热、TG-FTIR和SEM-EDS测试了MAH-DOPS对PLA的热稳定性、阻燃性能和热降解行为的影响.结果表明,阻燃剂MAH-DOPS中的P、S元素产生的协同阻燃作用提高了阻燃效率,改善了PLA的阻燃性能.当阻燃剂质量分数为5％时,制备的PLA/MAH-DOPS-5％的LOI为28.1％,达到UL-94 V-0级,总热释放量和平均有效燃烧热降低.MAH-DOPS同时在气相和凝聚相发挥阻燃作用,并以气相阻燃机理为主.     

阻燃香蕉纤维增强聚乳酸复合材料的制备与表征

采用乙酰柠檬酸三丁酯(ATBC)作为增塑剂增塑聚乳酸,添加改性香蕉纤维和膨胀型阻燃剂(IFR)制备阻燃香蕉纤维增强聚乳酸复合材料.研究结果表明,偶联剂处理纤维的效果最好,使复合材料的拉伸、弯曲强度分别达到57.49MPa、101.80MPa,与扫描电子显微镜(SEM)的结果一致;IFR含量为5份(以聚乳酸为100份计)时综合性能最佳,材料的极限氧指数达到了 32.8%,垂直燃烧实验达到了 V-0 级(UL-94),材料的拉伸和弯曲强度分别为43.97 MPa 和87.95MPa,效果最好.热失重研究结果表明,阻燃香蕉纤维的加入能明显提高聚乳酸的热分解温度和残炭量.     

铁酸镍在膨胀阻燃聚乳酸复合材料中的作用

利用水热法制备了铁酸镍(NiFe_2O_4)纳米粒子,基于生物可降解材料聚乳酸(PLA)的易燃性,将NiFe_2O_4纳米粒子作为协效剂与膨胀型阻燃剂(IFR)复配,应用于PLA的阻燃改性。结果表明,所有的PLA复合材料均达到UL-94 V-0级别,LOI显著提高至39%以上;NiFe_2O_4纳米粒子有助于PLA膨胀阻燃体系形成更为膨胀和相对致密的炭层,明显提高炭渣中有序化炭的含量,有效提高PLA膨胀阻燃体系的初始降解温度,并显著提高其成炭量。因此,NiFe_2O_4纳米粒子在PLA膨胀阻燃体系中具有良好的协效作用,能够显著提高PLA膨胀阻燃体系的热稳定性和阻燃性能。     

EG与IFR复合阻燃ABS的动态燃烧性和协同效应

将可膨胀石墨(EG)与P-N型膨胀阻燃剂(IFR)复合阻燃丙烯腈-丁二烯-苯乙烯共聚物(ABS)树脂,阻燃剂添加量为20%(质量分数,下同),通过极限氧指数(LOI)仪、垂直燃烧测试(UL-94)仪、锥形量热(CONE)仪和扫描电镜(SEM)研究了EG与IFR复合阻燃ABS的协同效应。结果表明,EG/IFR质量比为1/1为最佳配比,阻燃ABS的LOI达到29%,UL-94为V-0级;EG与IFR复合阻燃ABS,表现出一定的协同作用;通过SEM观察ABS/EG/IFR试样燃烧后样品发现,EG与IFR起到协同阻燃作用。     

竹炭增强膨胀阻燃聚乳酸的制备及其热降解行为研究

将竹炭(BPC)与膨胀阻燃剂(IFR)复配得到协效增强膨胀阻燃体系(BPC/IFR)添加到聚乳酸(PLA)中,加工成阻燃改性PLA材料,并测试了材料的阻燃性能、热降解行为和燃烧行为。实验结果表明,PLA/10%IFR/5%BPC体系可通过UL 94V-0级测试,极限氧指数(LOI)值为31.6%。N_2气氛下,800℃时PLA/IFR/BPC体系残炭率增大了8.5%。锥形量热(CONE)实验结果表明,PLA/IFR/BPC的热释放速率(HRR)和总热释放量(THR)都明显降低,THR值由91.4 MJ/m~2降至60.1 MJ/m~2。     

A novel lanthanum-based phosphorus-containing flame retardant agent and its application in polylactic acid

Currently, intumescent flame retardants (IFR) are often used in the flame retardant modification of polylactic acid (PLA). Due to the high loading, it will weaken the mechanical properties of PLA. In this study, lamellar lanthanum-based DOPO derivative (La@DDP) is prepared by solution method, and it acts as a flame retardant agent was added into PLA with IFR. The results show that PLA composite passes the UL94 V-0 rating with a limiting oxygen index (LOI) of 32.0, in the addition of 4.5 wt% IFR and 1.5 wt% La@DDP. Moreover, the peak heat release rate (PHRR) and total heat release (THR) of the PLA composite reduces by 31.0% and 23.2% compared to pure PLA, respectively. IFR/La@DDP agents assign the PLA composite with excellent thermal stability and carbon-forming ability. Through the analysis of residual char, the synergistic flame retardant mechanism between IFR and La@DDP in PLA composite is discussed. Notably, the tensile strength and elongation at break of the PLA composites are only reduced by 4.03% and 9.51% compared to pure PLA. This work provides a novel lanthanum-based flame retardant agent for designing PLA composites with good fire safety and mechanical properties, and it will broaden the application range of PLA.     

Mechanical,thermal and combustion properties of intumescent flame retardant biodegradable poly (lactic acid) composites

ABSTRACT

Despite extraordinary mechanical properties and excellent biodegradability, poly (lactic acid) (PLA) still suffers from a highly inherent flammability, restricting its applications in the electric and automobile fields. Although a wide range of flame retardants have been developed to reduce the flammability, they normally compromise the mechanical strength of PLA. In this study, a series of composites based on PLA, have been prepared by melt-blending with intumescent flame retardants (IFRs). The morphology, thermal stability and burning behaviour of the composites were investigated using a scanning electron microscope–energy dispersive spectrometer (SEM–EDS), thermogravimetric analysis (TGA), the limiting oxygen index (LOI), vertical burning (UL-94) and the cone calorimeter test (CCT). The LOI value reached 38.5% and UL-94 could pass V-0 for the PLA/IFR composite containing only 12 wt-% IFR. The dispersion of IFR in PLA was observed using SEM–EDS. A significant improvement in fire retardant performance was observed for the PLA/IFR composite from the CCT (reducing the heat release rate and the total heat release). More importantly, compared to pure PLA, the addition of IFR did not seriously deteriorate the mechanical properties of the material.     

A novel bio-based charcoal-forming agent based on chitosan and phytate@Mg to improve the flame retardancy of poly(lactic acid)

A novel bio-based carbon forming agent (Mg@PA-CS) containing P and N elements was were synthesized using the complexation characteristics of chitosan (CS) and phytate (PA). The flame retardant behavior of poly(lactic acid) (PLA)/Mg@PA-CS/APP composites (addition of 20 wt% of different ratios of Mg@PA-CS and APP to polylactic acid composites) were investigated by the limiting oxygen index (LOI), vertical burning test (UL-94), cone calorimetry test (CCT), and thermogravimetric analysis (TGA). Due to the biphasic flame retardant and synergistic effect, since the 20 wt% flame retardant system (Mg@PA-CS:APP = 1:2), PLA composites passed the UL-94 test V-0 rating, reached 34% LOI value. The peak heat release rate (PHRR) and total heat release rate (THR) were reduced to 1/2 of the pure PLA, char residue could be as high as 11.49% at 800°C. Moreover, the flame-retardant mechanism of PLA composites during thermal decomposition was analyzed using a scanning electron microscope (SEM) and the coupling techniques of TGA linked with FT-IR (TG-FTIR).     

Preparation of a chitosan‐based flame‐retardant synergist and its application in flame‐retardant polypropylene

A novel flame‐retardant synergist, chitosan/urea compound based phosphonic acid melamine salt (HUMCS), was synthesized and characterized by Fourier transform infrared spectroscopy and ³¹P‐NMR. Subsequently, HUMCS was added to a fire‐retardant polypropylene (PP) compound containing an intumescent flame‐retardant (IFR) system to improve its flame‐retardant properties. The PP/IFR/HUMCS composites were characterized by limiting oxygen index (LOI) tests, vertical burning tests (UL‐94 tests), microscale combustion calorimetry tests, and thermogravimetric analysis to study the combustion behavior and thermal stability. The addition of 3 wt % HUMCS increased the LOI from 31.4 to 33.0. The addition of HUMCS at a low additive amount reduced the peak heat‐release rate, total heat release, and heat‐release capacity obviously. Furthermore, scanning electron micrographs of char residues revealed that HUMCS could prevent the IFR–PP composites from forming a dense and compact multicell char, which could effectively protect the substrate material from combusting. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40845.     

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。     

Study on flame‐retardancy and thermal degradation behaviors of intumescent flame‐retardant polylactide systems

Two intumescent flame‐retardant (IFR) additives, IFR‐I and IFR‐II, were synthesized and their structure was confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance. Polylactide (PLA) was modified by the two IFRs to obtain flame‐retardant composites. The flammability of the PLA/IFR composites was characterized by the vertical burning test UL‐94 and limiting oxygen index. The limiting oxygen index values of the PLA composites increased with increase of IFR content. The PLA composite with 20 wt% IFR‐I could pass the UL‐94 V0 rating, while the composite with 30 wt% IFR‐II could not. The results of pyrolysis combustion flow calorimetry showed that the heat release capacity of PLA composites with 30 wt% IFR‐I decreased 43.1% compared with that of pure PLA. The thermal degradation and gas products of PLA/IFR‐I systems were monitored by thermogravimetric analysis and thermogravimetric analysis infrared spectrometry. Scanning electron microscopy was used to investigate the surface morphology of the char residue. Copyright © 2011 Society of Chemical Industry     

Synergistic effect of MXene on the flame retardancy and thermal degradation of intumescent flame retardant biodegradable poly (lactic acid) composites

The effect of Ti₃C₂ MXene nanosheets on the intumescent flame retardant (IFR) poly (lactic acid) (PLA) composites was investigated among a series of PLA/IFR/MXene, which were prepared by melt blending 0-2.0 wt% MXene, 10.0 wt%-12.0 wt% IFR and PLA together. The results of limiting oxygen index (LOI) and vertical burning (UL-94) discover that the combination of 0.5 wt% MXene and 11.5 wt% IFR synergistically improves the fire safety of PLA to reach UL-94 V-0 rating with LOI value of 33.0%. The PLA/IFR/MXene composites perform an obvious reduction in peak of heat release rate (HRR) in cone calorimeter tests (CCTs). Furthermore, the carbon residues after CCTs were characterized by scanning electron microscope (SEM), laser Raman spectroscopy (LRS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It is demonstrated that both the titanium composition of the MXene structure and the characteristics of the two-dimensional material enhance the PLA/IFR/ MXene composite materials' ability to produce a dense barrier layer to resist burnout during thermal degradation.     

新型磷-氮膨胀阻燃剂在改性聚丙烯中的应用研究

采用自制干法合成的磷-氮膨胀型阻燃剂(磷酸酯三聚氰胺盐,IFR)复配聚磷酸胺(APP)和聚四氟乙烯(PT-FE)阻燃改性聚丙烯(PP),利用极限氧指数法、垂直燃烧法分析了阻燃PP的燃烧性能,通过热重分析仪、傅里叶变换红外光谱仪、扫描电子显微镜和X射线光电子能谱对阻燃PP的热降解过程、燃烧性能、残炭结构进行了分析,并研究了燃烧过程中复配阻燃体系对PP的阻燃机理。结果发现,IFR、APP和PTFE之间具有明显的阻燃协效作用;当阻燃剂总添加量为24%(APP为6%、IFR为17.5%、PTFE为0.5%)(质量分数)时,阻燃PP的极限氧指数达到30.1%,垂直燃烧测试达UL 94V-0级;加入阻燃剂还能提高PP的热稳定性。