氢氧化镁阻燃改性HDPE防水卷材性能研究

采用纳米氢氧化镁对高密度聚乙烯(HDPE)进行阻燃改性。通过氧指数法,垂直燃烧法和力学性能测试方法研究了改性材料相应性能的变化。结果显示改性后的HDPE氧指数比未改性前提高30%以上,燃烧等级提高到UL-94 V2级,拉伸强度有所增加,但拉伸应变下降较多。氢氧化镁对改善燃烧性能有帮助,同时也提高了HDPE的尺寸稳定性。     

油酸钠表面改性纳米氢氧化镁阻燃HDPE

通过油酸钠湿法表面处理纳米氢氧化镁(MH)共混改性阻燃HDPE.研究油酸钠表面改性机理及其用量对体系阻燃性、力学性能及流变性能的影响.得出结论:油酸钠可在MH表面形成包覆层,且改性后MH仍保持了纳米级粒径.油酸钠湿法改性MH可提高体系的阻燃性能和力学性能.在HDPE:MH=100:60时使用5%MH的油酸钠.体系拉伸强度、断裂伸长率和冲击强度分别提高约12%、10.5%和8%,而氧指数提高12.5%达到29.9%,垂直燃烧等级达FV-1级.MH加入将导致体系加工性恶化,表观黏度剧烈降低,油酸钠表面改性可一定程度改善流变性.     

氢氧化镁的表面改性及在聚丙烯中的应用研究

研制了用硅烷和钛酸酯偶联剂表面改性后的氢氧化镁和聚丙烯的复合材料,研究了用不同表面活性剂改性的阻燃剂氢氧化镁的用量对复合材料阻燃性能和力学性能的影响。结果表明,硅烷偶联剂表面改性后的氢氧化镁能更好改善复合材料的力学性能,显著提高聚丙烯的阻燃性能,在用量为65%时,氧指数达到31.9%,垂直燃烧特性可达UL94V-0级。     

HDPE/APP复合材料总体热稳定性作用与阻燃性能关系的研究

采用聚磷酸铵（APP）对高密度聚乙烯（HDPE）进行填充改性,制备出APP不同含量的HDPE阻燃复合材料。通过水平-垂直燃烧仪与氧指数测定仪测试材料的阻燃性能,热重分析实验与复合材料总体热稳定性作用（OSE）评价材料的热稳定性能,研究材料总体热稳定性作用与阻燃性能间的关系。结果表明：OSE法能较好地衡量添加剂用量对复合材料热稳定性能影响情况,增加APP填充量有利于提高HDPE复合材料总体热稳定性与阻燃性能,提高HDPE复合材料的总体热稳定性有利于改善其阻燃性能。     

PE-HD/APP复合材料总体热稳定性作用与阻燃性能关系

采用聚磷酸铵（APP）对高密度聚乙烯（HDPE）进行填充改性,制备出APP不同含量的HDPE阻燃复合材料。通过水平-垂直燃烧仪与氧指数测定仪测试材料的阻燃性能,热重分析实验与复合材料总体热稳定性作用（OSE）评价材料的热稳定性能,研究材料总体热稳定性作用与阻燃性能间的关系。结果表明：OSE法能较好地衡量添加剂用量对复合材料热稳定性能影响情况,增加APP填充量有利于提高HDPE复合材料总体热稳定性与阻燃性能,提高HDPE复合材料的总体热稳定性有利于改善其阻燃性能。     

环氧树脂-聚氨酯阻燃改性研究

以端异氰酸酯基聚氨酯为预聚体,环氧树脂CYD-011为原料,以氢氧化镁为阻燃剂对环氧树脂-聚氨酯进行了阻燃抑烟改性研究。测试结果表明,随着氢氧化镁的逐渐加入,环氧树脂-聚氨酯的热分解温度上升,氧指数提高。同时,燃烧过程中,氢氧化镁促使环氧树脂-聚氨酯表面形成致密薄膜,延缓热量和氧气的传递,提升了环氧树脂-聚氨酯的阻燃抑烟性能。     

纳米SiO_2对LLDPE/氢氧化镁的增效作用

用硅烷偶联剂对氢氧化镁(MH)进行表面处理,以MH和纳米二氧化硅(SiO_2)对线型低密度聚乙烯(LLDPE)进行阻燃改性。采用万能材料试验机测定了LLDPE/MH/SiO_2复合材料的力学性能,并用DSC表征了其结晶行为;用氧指数法、垂直燃烧试验和锥形量热仪对其阻燃性能和燃烧特性进行了测试。结果表明:少量纳米SiO_2的加入能抑制LLDPE的高温裂解,可提高其氧指数和垂直燃烧性能,降低火灾的危险性;而对其力学性能和结晶行为的影响不十分明显,是MH的有效协效剂。     

纳米氢氧化镁阻燃剂在软质PVC中的应用研究

采用不同改性剂对纳米氢氧化镁进行表面改性,通过切片的TEM电镜照片考察了改性前后的粉体在软质PVC体系中的分散情况。研究了纳米氢氧化镁粉体对该体系阻燃性能和机械力学性能的影响,并与微米氢氧化镁粉体进行了比较。实验结果表明：改性后的纳米氢氧化镁粉体在软质PVC体系中有较好分散性;在不同改性剂中,以硬脂酸锌的改性效果较好;改性纳米氢氧化镁的阻燃性能和机械力学性能要优于微米级氢氧化镁;添加量为40克(以100克PVC为基准)时体系的综合性能较好,氧指数可增加8．6％;加入阻燃协效剂,体系的阻燃性能有大幅度的提高,氧指数可增加19.6％。     

具有高效阻燃和抑烟性能的聚苯乙烯建筑塑料的制备与性能研究

将氢氧化镁(MH)通过十二烷基苯磺酸钠(SDBS)改性制备了改性氢氧化镁(MMH)阻燃剂,将其与聚苯乙烯(PS)进行混融得到阻燃PS复合板材。对阻燃PS复合板材的微观形貌、力学性能、热稳定性以及阻燃性能进行了分析。结果表明:MMH在PS基体中分散较好,且PS-MMH-3具有最佳的拉伸强度和断裂伸长率,极限氧指数(LOI)相比于纯PS提高44.3%,且燃烧速率较慢,说明PS-MMH-3具有较好的阻燃性能。     

聚苯乙烯/表面改性纳米氢氧化镁复合材料的加工和阻燃性能研究

用带有长链烷基的硅烷偶联剂对纳米氢氧化镁(n-MH)粉体进行表面改性,然后与聚苯乙烯(PS)树脂进行熔融复合制备了PS/表面改性n-MH复合材料,研究了复合材料的微观结构、加工流变行为和燃烧行为。结果表明:随着偶联剂用量增加,表面改性n-MH在PS树脂基体中的团聚程度显著减小,分散较均匀,复合材料的加工性能明显改善。表面改性n-MH的加入使复合材料的水平燃烧性能有所下降,但对材料的氧指数影响不大。     

A novel grafted polyethylene with diphenyl phosphoryl group: Improved flame retardancy and favorable compatibility

A novel phosphorous/benzene-containing flame-retardant diphenyl phosphoryl polyethylene (PEP) is synthesized from ethylene vinyl acetate (EVA) copolymer with two steps reactions and its chemical structure is characterized by Fourier transform infrared and nuclear magnetic resonance spectroscopies. The grafted molecular dispersion is calculated by gel permeation chromatography and the phase transition is analyzed by differential scanning calorimetry. And results show its promising processability potential. High density polyethylene (HDPE) composite containing 15 wt% PEP is prepared by melt blending, and its fire performance and thermal behaviors are investigated in terms of limiting oxygen index (LOI), vertical burning (UL-94) and thermogravimetric analysis. There is a 16% increase to 20.2 in the LOI value of PEP, while it fails the UL-94 test. The char morphology is characterized by scanning electronic microscopy and observed multi-layered intumescent residue char effectively reduces the transfer of heat and oxygen. The major degradation is quantitively analyzed by the Flynn-Wall-Ozawa method. The results demonstrate that there is a catalytic effect by the phosphorous substance in char formation. Finally, the mechanical properties tests show that the loss due to the addition is small, which signifies the good compatibility between the pure HDPE and the grafted addition.     

凹凸棒石复配膨胀阻燃剂阻燃HDPE的研究

以聚磷酸铵(APP)与三羟乙基异氰脲酸酯(THEIC)为膨胀阻燃剂(IFR),凹凸棒石(ATP)为协效剂,采用熔体共混法制备了阻燃高密度聚乙烯(HDPE),通过红外光谱、氧指数、热失重和锥形量热分析,研究了ATP对阻燃HDPE燃烧性能的影响。结果表明:添加少量的ATP能催化APP/THEIC间的酯化反应,提高了HDPE的阻燃性能;当ATP的用量为2%时,HDPE/28%IFR/2%ATP复合材料的氧指数达30%,阻燃等级提高为V-0,体系的热释放速率峰值和总热释放量分别比HDPE/30%IFR复合材料降低了22.7%和26.7%。     

Enhanced flame retardancy and mechanical properties of waterborne polyurethane based on the phosphorus and nitrogen containing polybutadiene acrylonitrile

To further improve fire resistance of waterborne polyurethane, the macromolecular intumescent flame retardant (APBDH) was designed and prepared from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), 4-aminothiophenol, benzaldehyde, and hydroxyl-terminated polybutadiene acrylonitrile (HTBN). Then, it was incorporated into waterborne polyurethane (WPU) to preparing flame retarded WPU (FR-WPU). TGA results suggested that the incorporation of APBDH into WPU increased thermal stability of FR-WPU. The fire resistance of FR-WPU were investigated by limiting oxygen index (LOI) test, the vertical burning test (UL-94), SEM-EDS analysis, the Laser Raman test, and cone calorimeter test. An LOI value of 28.82% and a UL-94 V-0 rating can be achieved when the WPU sample conjugated with 7.5 wt% APBDH. It indicated that the fire resistance of FR-WPU remarkably improved and displayed both gas and condensed phase mechanism. As the content of APBDH increased, the tensile strength and the elongation at break of FR-WPU increased firstly and then decreased. The thermo-mechanical behaviors indicated that the storage modulus increase at first and then descend with the addition of APBDH, while the T_gs firstly decreased and then increased. Additionally, the T_gh increased with the addition of APBDH.     

Effect of Nanoparticles on Mechanical and Flame-retardant Properties of Polyether-Block-Polyamide Polymer Nanocomposites

In this study, polyester elastomer-based thermoplastic (TPEE) nanocomposites were fabricated for flame-retardant applications. Small amounts of graphene and nanoclay were added to the nanocomposites to investigate their effects on the mechanical and thermal properties of the nanocomposites. The addition of a phosphorous flame-retardant additive resulted in a significant improvement of the Young’s modulus and thus yield stress in the synthesized nanocomposites as compared to those made with the virgin TPEE. There was no synergistic improvement in mechanical properties with the addition of graphene and nanoclay to the nanocomposites. However, thermal properties, mainly the heat deflection temperature and fire performance (UL-94 V0), were improved significantly by the addition of graphene and nanoclay and a synergistic effect was observed. Heat distortion temperature and thermogravimetric analysis were used to analyze the thermal properties of the nanocomposites. The UL-94 testing method was used to investigate the fire performance of the nanocomposites. Scanning electron microscopy was used to observe the polymer fracture surface morphology. The dispersion of the graphene and nanoclay particles was confirmed by transmission electron microscopy analysis.     

Improving the fire performance and smoke suppression of expandable polystyrene foams by coating with multi-dimensional carbon nanoparticles

Expandable graphite (EG) and modified multi-wall carbon nanotubes (ATH-MWNT) were introduced to expandable polystyrene (EPS) foams in order to improve its fire performance. The fire performance of EPS foams was evaluated by limiting the oxygen index (LOI), vertical burning (UL-94), and cone calorimetry tests. The results showed that the presence of 14.3% EG and 4.1% ATH-MWNT increased the LOI value from 18.0 to 30.3%, upgraded the UL-94 rating from no rating to V-0, completely eliminated melt dripping, and significantly decreased the peak heat release rate from 933 to 177 kW/m². Thermal analysis indicated that the thermal stability and char formation were improved by the presence of flame retardants. The char morphology was characterized by scanning electronic microscopy (SEM). It was suggested that the presence of EG and ATH-MWNT could form integrated char layers during combustion, which was beneficial to the formation of an intumescent protective char structure.     

Hydroxyethylidene diphosphonic acid-modified starch-based flame retardant in improving the flame retardancy of insulating paper

In order to improve the flame-retardant performance of insulating paper and reduce the fire risk, hydroxyethyl diphosphate and dicyandiamide were used to modify starch to prepare a new starch-based flame retardant (SHPD). The combustion, mechanical, and electrical properties of SHPD treated flame-retardant insulating paper were investigated. The results showed that when the impregnation concentration of SHPD was 25.0%, the limiting oxygen index of the insulating paper was increased from 18.3% to 38.3% and reached the level of UL-94 V-0. The tensile index and burst index of the flame-retardant insulating papers were only 10.17% and 12.5% lower than that of the control insulating paper. The ring crush strength and alternating current breakdown strength in air of the flame-retardant insulating papers were 63.3% and 1.8% higher than that of the control insulating paper. The SHPD flame retardant has a good application prospect in insulating paper.     

反应型磷氮阻燃剂/可膨胀石墨复配阻燃聚氨酯泡沫

将反应型阻燃剂六(4-磷酸二乙酯羟甲基苯氧基)环三磷腈(HPHPCP)和可膨胀石墨(EG)复配,制备了阻燃聚氨酯泡沫,详细研究了复配阻燃剂对聚氨酯泡沫的物理力学性能、热稳定性以及阻燃性能的影响。结果表明,阻燃聚氨酯泡沫的密度和热导率随着复配阻燃剂中EG含量的增加而升高;压缩强度随着EG含量的增加呈现先增加后降低的趋势。热失重表明复配阻燃剂大大提高了聚氨酯泡沫的热稳定性。聚氨酯泡沫的初始分解温度(T_10%)从212.9℃,分别提高到222.0、231.2和243.2℃;700℃残炭量从7.6%分别提高到26.3%、31.6%和37.9%。聚氨酯泡沫的阻燃性能随着复配阻燃剂中EG含量的增加而提高。阻燃聚氨酯泡沫的极限氧指数从19%提高到29%,均能通过UL-94水平燃烧HF-1等级和垂直燃烧V-0等级。     

甲基含氢硅油表面改性无卤膨胀阻燃剂研究

甲基含氢硅油与无卤膨胀型阻燃剂混合处理后,对聚丙烯材料进行阻燃改性,通过测试材料的拉伸强度,悬臂梁缺口冲击强度,氧指数,燃烧级数,热重分析和疏水保持率,并且利用方差分析和多重比较方法处理测试数据,研究甲基含氢硅油的加入对阻燃剂及阻燃改性材料性能的影响。结果表明:甲基含氢硅油的加入可以增加材料的韧性,降低材料的拉伸强度,显著提高处理后阻燃剂的疏水性。     

有机化坡缕石黏土-膨胀型阻燃聚丙烯复合材料的制备及性能

制备了优异阻燃性能(LOI36%)兼具良好力学性能的膨胀型阻燃聚丙烯复合材料OPGS/PA-APP/PP。将有机化坡缕石黏土引入到哌嗪-多聚磷酸铵(PA-APP)膨胀型阻燃(IFR)聚丙烯(PP)复合材料中,通过极限氧指数(LOI)、垂直燃烧(UL-94)、热重分析法(TGA)、扫描电子显微镜(SEM)、通用电子万能试验机研究了有机化坡缕石黏土添加量对PA-APP阻燃聚丙烯复合材料阻燃性能和力学性能的影响。结果表明,添加质量分数为2%的有机化坡缕石黏土提高了该复合材料的阻燃性能和力学性能。此外,所制备样品经垂直燃烧测试可达到阻燃V-0级别。实验证明,有机化坡缕石黏土在膨胀型阻燃聚丙烯复合材料中具有明显的协效阻燃作用。     

Development of ductile green flame retardant poly(lactic acid) composites using hydromagnesite&huntite and bio-based plasticizer

Turning brittle poly(lactic acid) (PLA) to ductile form via plasticizer inclusion is an effective option in the case of processing with high amounts of additives. Additionally, the integration of natural flame retardants to PLA involving bio-based plasticizer enables to use of environmentally friendly composites in conditions where fire resistance performance is required. In the current study, ductile green fire retardant PLA composites were manufactured using hydromagnesite&huntite (HH) as a natural fire retardant additive and acetyl tributyl citrate as a bio-based plasticizer. The influences of plasticizer and HH contents on the fire retardant, thermal and mechanical performances of the composites were explored. According to test results, the limiting oxygen index (LOI) value of PLA reduced from 29.2 to 28.0 and the UL-94 V rating changed from V2 to BC with the addition of 20 wt% plasticizer owing to the reduction in melt viscosity. The peak heat release rate (pHRR) and average heat release rate (avHRR) values increased steadily as the concentration of plasticizer increased due to the formation of a more porous residue structure stemming from the increased transportation rate of gases. In order to produce ductile flame retardant material, the plasticizer content was required to 20 wt% of HH. The highest LOI value (36.2) and UL-94 rating of V0 were achieved with the inclusion of 70 wt% HH in the presence of 20 wt% plasticizer. Improvement in impact resistance and reduction in tensile strength were observed as the added amount of plasticizer increased.