共查询到19条相似文献,搜索用时 187 毫秒
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改性酚醛成炭剂的制备及其在氢氧化镁/聚酰胺6阻燃体系中的协效阻燃作用 总被引:1,自引:0,他引:1
氢氧化镁(MH)是一种重要环保型阻燃剂,针对MH阻燃效率低,添加量大,与树脂相容性差的特点,研制了硼改性酚醛基成炭剂(BPF)用于增强MH的凝聚相阻燃作用,以提高MH的阻燃效率.用XRD、红外、核磁等手段表征了BPF的化学结构.TGA研究表明BPF成炭性优异,750℃时残炭高达61%.阻燃PA6体系中,BPF与MH有显著的协效作用,材料能通过UL94-1.6 mm V0级别.BPF的阻燃增效机理分析表明,BPF燃烧时生成的B2O3可在燃烧材料表面富集形成玻璃态的有效阻隔层,使材料自熄.此外,BPF能显著提高材料加工流动性,具有较好增塑、润滑作用.BPF不会恶化材料力学性能,阻燃材料综合性能优良. 相似文献
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层状复合氢氧化物(LDHs)因其化学组成可调、比表面积大、生物相容性好等特点,目前在环境、能源和生物医药等领域广受关注.然而, LDHs在合成过程中由于其分子内作用力易发生团聚而导致其在基体中的分散不均匀,极大地限制了LDHs在实际中的应用.有机改性是改善LDHs分散性的有效方法,从表面改性和插层改性两个方面综述了近年来LDHs的有机改性方法,并介绍了其在阻燃、吸附、催化、气体阻隔、发光、储能和生物医药材料等领域的应用.最后对改性后LDHs未来的研究方向和应用领域进行了展望. 相似文献
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锡氟磷酸盐玻璃(Pglass)具有较低的玻璃化转变温度,在常规聚合物加工温度窗口内具有熔融流动性,是一种新型的无机类聚合物玻璃。本文采用双螺杆挤出机制备了聚丙烯(PP)/Pglass有机聚合物/无机玻璃复合材料,并对其相形貌、界面性能、流动性能、结晶性能、力学性能和热稳定性能进行了研究。结果表明:Pglass以微米级颗粒分散在PP基体中,且两相之间界面明显、相容性较差。Pglass的添加使复合材料的熔体剪切粘度降低。Pglass的存在促进了基体PP的结晶。复合材料的弹性模量随着Pglass含量的增加而增加。Pglass提高了复合材料的热稳定性。 相似文献
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Dehong Chen Huaiping Zhang Qiukai Zheng Feiyue Liu Kai Xu Mingcai Chen 《先进技术聚合物》2008,19(9):1353-1360
Rod‐like magnesium hydroxide (MH) particles were prepared via coprecipitation of the magnesium salt with foreign ions, such as copper(II), zinc(II), iron(III), and nickel(II). Flame retardant polypropylene (PP) composites were fabricated using these particles. The microstructure, flame retardation, mechanical properties, thermal behavior, and oxidation‐induced temperature were characterized. It was found that foreign ion compounds increased the flame retardancy. MH containing a zinc compound presented a similar performance as that of neat MH. The presence of a copper compound decreased the thermal behavior and mechanical properties of the flame retardant composite, while iron and nickel compounds brought some improvements. In addition, the thermal degradation mechanisms of the flame retardant composites were investigated by Fourier transform infrared (FTIR) spectroscopy at different temperatures. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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Fabienne Samyn Charafeddine Jama Shonali Nazare Alberto Fina Giovanni Camino 《European Polymer Journal》2008,44(6):1631-1641
Flame retardant nanocomposites have attracted many research efforts because they combine the advantages of a conventional flame retardant polymer with that of polymer nanocomposite. However the properties obtained depend on the dispersion of the nanoparticles. In this study, three types of polymer flame retarded nanocomposites based on different matrices (polypropylene (PP), polybutadiene terephtalate (PBT) and polyamide 6 (PA6)) have been prepared by extrusion. In order to investigate the dispersion of nanoparticles in the polymer containing flame retardant, conventional methods used to characterise the morphology of composites have been applied to FR composites containing nanoclays. XRD, TEM and melt rheology give useful information to describe the dispersion of the nanofiller in the flame retarded nanocomposite. In the PA6-OP1311 (phosphorus based flame retardant) materials, the clay is well dispersed unlike in PBT and PP materials where microcomposites are obtained with some intercalation. The poor dispersion is also highlighted by NMR measurements but the presence of flame retardant particles interferes in the quantitative evaluation of nanoclay dispersion and underestimations are made. 相似文献
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The influence of KH-550 on properties of ammonium polyphosphate and polypropylene flame retardant composites 总被引:2,自引:0,他引:2
Hongjiao Lin Hong Yan Bo Liu Liqiao Wei Bingshe Xu 《Polymer Degradation and Stability》2011,96(7):1382-1388
Ammonium polyphosphate (APP)/polypropylene (PP) composites were prepared by melt blending and extrusion in a twin-screw extruder. APP was first modified by a silane coupling agent KH-550 then added to polypropylene. The surface modification of APP by the coupling agent decreased its water solubility and its interface compatibility with the PP matrix. Limiting oxygen index (LOI) and thermogravimetric analysis (TGA) were used to characterize the flame retardant property and the thermal stability of the composites. The addition of APP improved the flame retardancy of PP remarkably. The crystal structures of APP/PP composites were characterized by X-ray diffraction (XRD). The results indicated that β-crystal phase PP may be formed. The structures and morphologies of APP, KH-550/APP and APP/PP composites were characterized by field-emission scanning electron microscope (FESEM). The mechanical property tests showed good mechanical properties of composite materials. Compared with unmodified one, the impact strength, tensile strength and elongation of modified APP/PP were all improved. 相似文献
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Congrui Qi Bihe Yuan Haoran Dong Kaiyuan Li Sheng Shang Yaru Sun Gongqing Chen Yuanyuan Zhan 《先进技术聚合物》2020,31(5):1099-1109
In order to improve its water resistance and compatibility with polymer matrix, ammonium polyphosphate (APP) is modified with melamine‐trimesic acid (MEL‐TA) aggregates by supramolecular self‐assembly technology. Chemical structure and morphology of APP@MEL‐TA are investigated by Fourier transform infrared spectroscopy and scanning electron microscopy (SEM), respectively. Intumescent flame retardant system of APP@MEL‐TA and charring‐foaming agent is introduced into polypropylene (PP) matrix. The flammability and combustion behavior of PP composites are investigated by limiting oxygen index (LOI), UL‐94 vertical burning, and cone calorimetry tests. In terms of LOI values and cone combustion results, APP@MEL‐TA performs better than pristine APP. Char residue of PP composites is investigated by SEM and Raman spectra. Flame retardant mechanisms are proposed based on thermal decomposition, combustion results, and analysis on char residue. 相似文献
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《Surface and interface analysis : SIA》2018,50(3):277-283
In order to improve the dispersion and compatibility of magnesium hydroxide (MH) when added in the polymer matrix as fillers, the surface of MH was modified by dry process using vinyltrimethoxysilane (VTMS), and the interfacial interaction between MH and VTMS was also studied. Scanning electronic microscopy, transmission electron microscopy, and X‐ray powder diffraction analyses showed that the agglomerations of MH particles were effectively relieved, and a thin layer was formed on the surface of modified MH. Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy analyses showed that the VTMS molecules bound strongly to the surface of MH particles and chemical bond (Si―O―Mg) was formed after modification. The effect of surface modification was evaluated by contact angle, the settlement curve, and thermogravimetric analysis. The results showed that the surface of MH particles was transformed from hydrophilic to hydrophobic, with the dispersibility and the compatibility of MH particles significantly improved in the organic phase. Additionally, the thermal stability of the VTMS modified MH particles had improved significantly. 相似文献
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Yang Xu Man Chen Xin Ning Xiaolang Chen Zhidan Sun Yonghong Ma Jie Yu Zhibin Zhang Xiaojin Bo Le Yang Zining Chen 《Journal of Thermal Analysis and Calorimetry》2014,115(1):689-695
In this study, polypropylene (PP)/thermoplastic polyurethanes (TPU) filled with inorganic intumescent flame retardant expanded graphite (EG) was prepared by melt blending in a twin-screw extruder. The thermal stability, fire retardancy, mechanical properties, and fracture morphology of PP/TPU composites with treated and untreated EG were investigated by thermogravimetric analysis, cone calorimeter, and scanning electron microscope. The results showed that both untreated and treated EG can greatly enhance the thermal stability and fire resistance of polymer matrix materials. Compared with untreated EG, treated EG can further improve the flame retardancy of the composites. For example, treated EG can further reduce the heat release rate, total heat release, and CO emissions of the composites in the combustion. Surface treatment of EG could significantly improve elongation at break and impact strength of PP/TPU/EG composites due to its enhanced interfacial adhesion and the good dispersion of EG particles in the polymer matrix. 相似文献
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Fubin Luo Kun Wu Mangeng Lu Liu Yang Jun Shi 《Journal of Thermal Analysis and Calorimetry》2017,129(2):767-775
Aluminum hypophosphite (AHP) is surface modified by melamine derivative to fabricate reactive solid flame retardant (MCAHP) for polyurethane foam. MCAHP is successfully prepared and characterized by FTIR and SEM. The flame-retarded efficiency of MCAHP in PU is higher than that of AHP. It demonstrated that MCAHP has better compatibility in PU matrix compared with AHP based on the SEM observation. After surface modification, due to the reaction between MCAHP and PU matrix, crosslinking might be formed between MCAHP and PU matrix, which contributes to the excellent compatibility of MCAHP in PU matrix, and as a result, the glass transition temperature of PU/MCAHP is 4 °C higher than that of PU/AHP. The thermal behavior of PU composites is characterized by TG and TG-FTIR, and results suggest the sublimation of melamine at about 320 °C because of the decomposition of the melamine derivative. The sublimation of melamine can consume abundant heat and dilute the oxygen concentration, which is benefit for the improvement of flame retardancy. 相似文献
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Magnesium hydroxide (MH) flame retardant dynamic vulcanized ethylene‐propylene‐diene terpolymer (EPDM)/polypropylene (PP) thermoplastic vulcanizates (TPVs) were prepared by a twin‐screw extruder. Influences of MH on their morphology, mechanical properties, flammability, and crystallization behavior have been investigated. Static tensile measurements exhibited that TPVs have higher mechanical properties than un‐vulcanized EPDM/PP/MH blends (UVBs). Scanning electron microscopy (SEM) studies showed that the formation of the larger‐size “micro‐encapsulated structure” where the MH aggregates were covered with a cross‐linked rubber phase improved the interaction between MH and polymer matrix. Results of limiting oxygen index (LOI) and microscale combustion calorimetry (MCC) confirmed that TPVs had superior fire‐resistant properties to UVBs. SEM images showed that more uniform and compact charred layers were generated in TPVs. The differential scanning calorimetry (DSC) results indicated that the crystallization behavior of the flame retardant TPVs changed marginally with increase in MH content. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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《先进技术聚合物》2018,29(1):433-441
A method was elaborated to prepare flame retarded self‐reinforced polypropylene composites by injection moulding. The effect of intumescent flame retardant (FR) loading was comprehensively investigated on the morphology, flammability, and mechanical properties of the self‐reinforced polypropylene composites and compared with non‐reinforced counterparts of identical additive contents. Homogeneous distribution of both the reinforcing polypropylene fibres and the FR additive was achieved endowing significantly improved strength and stiffness accompanied with increased fire resistance. At 10% FR content, 37% reduction of peak of heat release rate, UL94 V‐2 rating, and LOI of 24.5 vol% were achieved without compromising the improved mechanical performance of the injection moulded self‐reinforced composites, ie, a 4‐fold increase of tensile strength and a 7‐fold increase of tensile modulus were reached compared with the non‐reinforced counterpart. At higher loading (15% FR), the FR properties improved further (LOI of 29.5 vol% was reached); however, due to the abrasive effect of the FR particles in the matrix, the structure of the reinforcing fibres tends to get damaged during the thermo‐mechanical processing, and thus their reinforcing efficacy deteriorated. It is demonstrated that the combination of polymer fibre reinforcement with other fillers (such as FRs) is advantageous and feasible even by injection moulding, but the balance between the individual attributed properties needs to be found. 相似文献