EVA基膨胀型阻燃复合材料的制备与性能

以酚醛树脂(PF)为碳源,密胺甲醛树脂包覆的聚磷酸铵(MFAPP)为酸源,氢氧化镁(MH)为气源并增强固炭能力,配制成新型膨胀型阻燃体系(IFR),用于乙烯-醋酸乙烯酯共聚物(EVA)的阻燃.利用垂直燃烧仪(UL-94)、极限氧指数(LOI)、热重分析仪(TGA)、扫描电子显微镜(SEM)、万能试验机等对无卤阻燃EVA...     

硅酸镁对膨胀型阻燃PE/EVA炭层的影响

将超支化三嗪化合物与多聚磷酸铵构成的膨胀型阻燃剂,用于制备阻燃PE/EVA体系。通过锥形量热仪、TG、FTIR、SEM及X射线衍射能谱等分析,考察了硅酸镁对PE/EVA体系阻燃性能及炭层结构的影响。结果表明,2%的硅酸镁能有效促进成炭过程,提高阻燃性能且无熔滴。与未添加硅酸镁相比,燃烧过程延长,燃烧残余率增大,而且炭层更加致密,氧指数由35%提高到38.5%。此外,硅酸镁的加入对体系的力学性能没有明显影响。     

氢氧化镁对膨胀阻燃乙烯-醋酸乙烯酯共聚物性能的影响

考察了低添加量的氢氧化镁(MH)对乙烯-醋酸乙烯(EVA)、聚磷酸铵(APP)、双季戊四醇(DPER)复配组成膨胀型阻燃材料的力学性能、燃烧性能、加工性能的影响,通过以上研究,拓宽以APP为主的膨胀型阻燃剂用协效剂的选择范围,提高材料的阻燃效率、降低成本和添加量。结果表明:MH添加量为3份时,能够与膨胀阻燃体系形成良好协效作用,使氧指数提高,当添加量继续增加,产生了相反的作用,造成氧指数的急剧下降,而随着MH添加量的增加,阻燃材料的拉伸性能基本保持不变,硬度上升,熔体流动速率有小幅下降。     

膨胀型阻燃剂阻燃PP/SBS/POE共混物的性能研究

研究了聚磷酸胺类膨胀型阻燃剂（AP）和磷酸酯膨胀型阻燃剂(NP)的用量对聚丙烯（PP）/苯乙烯-丁二烯-苯乙烯共聚物（SBS）/乙烯-辛烯共聚物（POE）共混体系的力学性能、燃烧性能和遇水抗析出性能的影响。探讨了阻燃剂的析出机理,并从耐电压方面分析其在电线电缆领域应用的可行性。结果表明,NP具有更高的分解温度和残炭率。将AP与NP分别加入到PP/SBS/POE共混体系中,共混物的拉伸强度和断裂伸长率都降低,但阻燃性能提高。在相同添加量下,NP阻燃的共混物的拉伸强度和氧指数更高,而AP更能促进共混物成炭。AP和NP在热水浸泡过程中都会析出,析出过程是由表层向内部逐步析出的过程,析出量随着浸泡时间延长而增加。在相同的浸泡时间下,NP体系的析出量更小。浸泡后的共混物的力学性能和阻燃性能下降。     

MAPP阻燃EVA泡沫复合材料的制备及其性能

利用乙二胺（EDA）对聚磷酸铵（APP）进行改性,得到聚磷酸铵衍生物（MAPP）。采用MAPP、石墨（EG）和木粉（MF）复配的方式得到膨胀性阻燃剂,并与EVA复合得到泡沫复合材料。采用FT-IR、XRD、¹H NMR表征接枝效果,利用LOI和UL-94测试仪、锥形量热仪（CONE）、TG及SEM等分析材料的阻燃性能、残炭的形态及力学性能。结果表明：EDA已成功接枝在APP上,所形成的MAPP能够有效提高复合发泡材料的阻燃性能、减少热释放量;MAPP/EVA复合发泡材料的残炭层更加致密和完整,能够有效起到隔热、隔氧的作用;并且MAPP能够提高材料的耐水性及与EVA基体的相容性。当MAPP添加量为20%时,体系的LOI可达27.6%,且UL-94为V-0级别,拉伸强度、断裂伸长率分别可达1.282 MPa、236.40%,阻燃材料的综合性能达到最优。     

热重-质谱联用对膨胀型阻燃剂阻燃EVA的机理研究

采用极限氧指数仪和拉伸仪研究了膨胀阻燃剂阻燃乙烯醋酸乙烯共聚物（EVA）体系（APP/PER/MCA/ EVA）的阻燃及力学性能,并采用热重-质谱联用仪对该体系在空气中的热氧化降解进行了分析。结果表明,在APP/PER/MCA的配比为8/4/3、总添加量为40 % 时,阻燃EVA样品的阻燃和力学性能最好,其极限氧指数和拉伸强度分别为26 % 和6.62 MPa;与纯EVA相比,膨胀阻燃剂阻燃EVA的起始分解温度和失重率分别降低100 ℃和10 %,吸热量明显降低;阻燃EVA的热氧化降解过程中,H2O、CO2等小分子产物发生明显变化,且阻燃后苯环类化合物明显减少。     

微胶囊化膨胀阻燃剂及膨胀阻燃聚丙烯性能的研究

通过微胶囊化技术合成了新型磷氮体系无卤膨胀型阻燃剂(IFR),采用IFR提高聚丙烯(PP)的阻燃性能。运用扫描电子显微镜、氧指数仪和垂直燃烧仪等对IFR阻燃PP体系的表面形态和性能进行分析。结果表明,聚磷酸铵经包覆后粒度增大;当IFR的质量分数达到30%左右时,PP/IFR体系可以获得良好的阻燃效果,其氧指数达到32%,燃烧等级为FV-0级,抑烟效果较明显;力学性能下降不大;断裂面形态良好。     

ABS新型无卤膨胀型阻燃体系的研究

以聚磷酸铵（APP）为酸源,聚对苯二甲酰己二胺（PA6T）为炭源,探讨了不同比例的APP/PA6T复配对丙烯腈-苯乙烯-丁二烯共聚物（ABS）燃烧性能的影响以及ABS/APP/PA6T阻燃体系的降解成炭行为。结果表明,当APP含量为25 %,PA6T含量为5 %时,阻燃体系的极限氧指数达到29 %,通过UL-94测试V-1级,再添加2 %协效剂次磷酸铝,可通过V-0级。热失重分析表明,PA6T有较好的成炭作用,APP能极大改变PA6T的分解行为,使ABS/APP/PA6T阻燃体系的高温残炭率大大提高。SEM形貌分析表明,阻燃体系燃烧表面形成了膨胀、均匀、致密的炭层结构;此外,通过对残炭进行红外分析,发现存在化学键P-O-C,进一步验证了该膨胀阻燃体系的协效成炭行为。     

可膨胀石墨阻燃EVA燃烧性能及热失重行为的研究

用粒径为37、48及75μm的可膨胀石墨(EG)阻燃EVA,用锥形量热仪探讨了不同粒径的EG对EVA的阻燃作用,利用热失重分析仪研究了EVA/EG体系的热稳定性。结果表明:经过锥形量热仪测试表明,EVA/EG的热释放速率曲线呈现前单峰型,体现了典型的凝聚相阻燃机理;30 g EG的加入可以明显降低热释放速率,且粒径越大,阻燃效果越好;通过TG考察EG/EVA阻燃体系的热降解行为,在空气气氛下,EG膨胀炭层负载催化EVA交联成炭;相比于75μm EG,48μmEG形成炭层紧密,成炭量超过2.2%,形成的炭层稳定,在850℃也不会分解。     

多壁碳纳米管协效复合膨胀阻燃剂阻燃EVA的研究

以乙烯-乙酸乙烯酯共聚物(EVA)为基体树脂,大分子磷氮复合阻燃剂(NPS)为主阻燃剂,以多壁碳纳米管(MWCNTs)为协效剂,制备了低烟无卤阻燃EVA复合材料。采用极限氧指数(LOI)、热重分析(TGA)、扫描电镜(SEM)、力学性能和动态热力学性能(DMA)测试等手段对复合材料进行测定,重点考察了MWCNTs对膨胀阻燃EVA体系的影响,探讨了其作用机理。结果表明:MWCNTs对阻燃EVA体系具有很好的协同效应;MWCNTs的加入提高了膨胀炭层在高温时的热稳定性,增加了高温时的残炭量;MWCNTs可以改善膨胀炭层的形貌,提高炭层的隔热性能;0.5%的MWCNTs与29.5%的NPS复配,试样的LOI达到33.6%,拉伸强度达到12.37 MPa;MWCNTs用量在3%以内时,体系仍能保持较好的电绝缘性。     

High-efficiency ammonium polyphosphate intumescent encapsulated polypropylene flame retardant

The flame retardant polypropylene containing the micro-envelope core-shell structure flame retardant, which encapsulated ammonium polyphosphate into melamine-formaldehyde resin and sodium silicate through in situ polymerization was prepared with polyamide 6, added as a carbon-forming agent. The composition of ammonium polyphosphate, encapsulated ammonium polyphosphate with melamine-formaldehyde resin and the micro-envelope core-shell structure flame retardant were characterized. The fire safety and thermal stability were investigated and showed an improvement including limiting oxygen index, thermogravimetric analysis, vertical burning tests, and microscale combustion calorimeter. The burned compounds were also studied to confirm the burning mechanism. The results showed the flame retardant performance had been greatly improved, while polyamide 6 had better char-forming effect. Besides, the water solubility of flame retardants and their influence on the mechanical properties of polypropylene were also investigated. The results on the effects of additives demonstrated a high efficiency flame retardant to polypropylene. A core-shell flame retardant that sodium silicate and melamine-formaldehyde resin-coated ammonium polyphosphate had been constructed. The effect of the built flame retardant system on the combustion performance of polypropylene was studied from the mechanism and performance. The LOI of the most flame retardant polypropylene reached 28.6%, and UL-94 reached the V-0 level.     

Studies on intumescent flame retardant polypropylene composites based on biodegradable wheat straw

Wheat straw (WS) has numerous advantages compared with traditional bioadditives such as starch and lignin. So in this work, based on WS and silica microencapsulated ammonium polyphosphate, flame retardant polypropylene/wheat straw (WSP) composites were prepared by melted blend method. Flame retardant and thermal properties of WSP composites have been investigated. The results of cone calorimeter show that peaks of heat release rate and total heat release of the flame retardant WSP composite decrease substantially compared with those of pure polypropylene. The peak of heat release rate value of the flame retardant WSP composite decreases from 1290.5 to 247.9 kW/m², and the total heat release value decreases from 119.4 to 46.3 MJ/m². Meanwhile, thermal degradation and gas products of the flame retardant WSP composite were monitored by thermogravimetric analysis and thermogravimetric analysis‐infrared spectrometry. The result of thermal analysis shows that the flame retardant WSP composite has a high thermal stability and has a 30.0 wt% residual char at 600°C. From this work, we hope to provide a method to prepare flame retardant polymer composites with a biodegradable natural material‐WS.     

含磷硅高分子阻燃剂与聚磷酸铵对EVA的协效阻燃作用

研究了聚酯型磷-硅无卤阻燃剂(EMPZR)与聚磷酸铵(APP)对乙烯-醋酸乙烯酯共聚物(EVA)阻燃及力学性能的影响。结果表明,添加为40 %（质量分数,下同）的由EMPZR和APP所组成的复合阻燃剂得到的阻燃EVA材料,其极限氧指数达到28.6 %,垂直燃烧测试达到V-0级,拉伸强度为6.4 MPa,断裂伸长率达592 %。热失重分析测试表明,阻燃EVA材料的热失重速率较纯EVA有明显下降;成炭率显著提高,阻燃EVA在800 ℃时残炭量为15 % ,纯EVA仅为0.2 %。通过扫描电子显微镜对残炭形貌进行表征,以及对氧指数测试前后的阻燃EVA材料的红外图谱分析,表明EMPZR与APP在EVA中具有协效阻燃作用。     

Synthesis and characterization of bio-based intumescent flame retardant and its application in polyurethane

A novel bio-based P-N containing intumescent flame retardant melamine starch phytate (PSTM) was prepared via the reaction of phytic acid starch ester with melamine and characterized by Fourier transform infrared, scanning electron microscopy and thermogravimetric analysis (TGA). The effects of PSTM on thermal properties and flammability of rigid polyurethane (PU) foams were analyzed by TGA, limit oxygen index (LOI), vertical burning tests (UL-94) and cone calorimeter measurement. The TGA results demonstrated that the thermal stabilities of PU/PSTM foam at high temperature was enhanced with the increasing additive amount of PSTM. The results showed that PU foam with 30 php PSTM (PU/PSTM-30%) observed an LOI value of 25.9 and a UL-94 rating of V-0. Cone calorimetry data showed that peak heat release rate, total heat release and smoke production rate of PU/PSTM-30% were distinctly lower than that of pure PU. Further experimental results demonstrated that PSTM promotes well charring of PU which could protect the foam from combustion. This work developed a novel bio-based intumescent flame retardant by suing phytic acid and starch as the acid source and carbon source, respectively, which is of great significance to the preparation of environmental-friendly flame retardants.     

硼酸锌在膨胀型无卤阻燃ABS中的协同作用

采用熔融共混法制备了丙烯腈-丁二烯-苯乙烯共聚物(ABS)/膨胀型阻燃剂(IFR)/硼酸锌(ZB)无卤阻燃复合材料。利用热重分析仪、氧指数测定仪、扫描电子显微镜等研究了ZB对复合材料热失重行为、阻燃性能、微观结构及力学、加工性能的影响。较低含量的ZB与IFR存在较好的阻燃协同作用,且ZB可促进IFR成炭,使ABS/IFR复合材料的氧指数及其残炭量分别由未加ZB时的27.4%、21.29%提高到30.1%和23.05%。ZB的加入能够提高ABS/IFR复合材料的弯曲性能和加工性能,但对复合材料的冲击、拉伸性能产生了不利影响。     

膨胀型阻燃剂在橡胶中的应用

介绍了膨胀型阻燃剂的组成及功能改进,总结了膨胀型阻燃剂在天然橡胶、三元乙丙橡胶、丁苯橡胶及氯丁橡胶中的应用进展,并对膨胀型阻燃剂的发展方向做了展望。     

EVA阻燃材料的制备与性能研究

通过极限氧指数、垂直燃烧、烟密度、锥形量热、扫描电子显微镜等表征方法,研究了不同用量自制哌嗪类膨胀阻燃剂（IFR）对乙烯醋酸乙烯共聚物（EVA）的阻燃作用。结果表明,添加30 %（质量分数,下同）IFR的EVA材料极限氧指数能达到37 %,UL 94垂直燃烧达到V-0级,有焰、无焰烟密度均很低,热释放速率峰值降至156 kW/m2,仅仅只有纯EVA的21.8 %,燃烧后形成了致密的膨胀炭层;该阻燃材料具有很低的吸湿率,力学性能保持较好,且能满足RoHS环保要求。     

膨胀型阻燃剂在聚丙烯中的应用研究

使用磷酸、季戊四醇、三聚氰胺合成了一种膨胀型阻燃剂。采用热重分析（TGA）、红外光谱分析（FTIR）、氧指数晨6定和垂直燃烧实验，研究了所合成的膨胀型阻燃剂对聚丙烯的阻燃作用。与普通的膨胀型阻燃剂和包覆型膨胀阻燃剂的对比研究表明，该阻燃剂对聚．丙烯的阻燃性能优良，达到相同的阻燃效果（聚丙烯氧指数达到34％）时，用量较其它两种膨胀型阻燃剂明显减少。抗析出和防湖性能较其它两种膨胀型阻燃剂也有明显改善。     

Synthesis of a novel intumescent flame retardant and its application in EVM

A novel phosphorous-nitrogen structure containing intumescent flame retardant, 4,4-diaminodiphenyl methane bi(2,2-dimethyl-1,3-propanediol) phosphoramidate (DBDPP) was synthesized and characterized. Thermal stability and flammability properties of ethylene vinyl-acetate copolymer rubber(EVM)/DBDPP composites were investigated by thermogravimetric analysis (TGA), limiting oxygen index (LOI) test and UL-94 measurement, respectively. The results showed that the addition of DBDPP enhanced the thermal stability and flame retardancy of EVM significantly. The weight of residues improved greatly with the addition of DBDPP. SEM investigations revealed that a strong charred layer was formed from EVM/DBDPP composites during combustion. It is confirmed that the char structure was a critical factor for flame retardancy of EVM rubber. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012