纳米Mg(OH)2阻燃聚丙烯复合材料研究

研究了纳米Mg(OH)2阻燃聚丙烯复合材料,包括纳米Mg(OH)2的表面偶联和60Co-γ辐照改性方法、改性Mg(OH)2与红磷复配的协同效应、复配体系填充量对复合材料力学性能和阻燃性能的影响。结果表明,Mg(OH)2在空气中经60Co-γ辐照后有硝基化合物和其它含N、O基团产生,使复合材料的力学性能提高,改性效果优于偶联剂KH-570改性;Mg(OH)2与红磷起协同阻燃的最佳配比为15∶4,当复配阻燃体系的填充量为30%时,复合材料的氧指数提高到31.1%。     

表面改性Mg(OH)_2/LDPE复合材料性能的研究

以硬脂酸钠为改性剂,将采用湿法表面改性后的氢氧化镁(Mg(OH)2)填充到低密度聚乙烯(LDPE)中。考察Mg(OH)2用量对Mg(OH)2/LDPE复合材料阻燃性能和力学性能的影响,并对比改性前后力学性能及阻燃性能的差异。结果表明:Mg(OH)2可提高Mg(OH)2/LDPE复合材料的阻燃性和耐热性,但降低了复合材料的力学性能;经硬脂酸钠表面改性的Mg(OH)2可使复合材料力学性能的减弱趋势变得平缓。     

聚丙烯酸酯/纳米二氧化硅复合乳液的制备及其在防水涂料中的应用

利用乳液聚合制备原位分散的聚丙烯酸酯/二氧化硅纳米复合材料,采用红外、透射电镜对试样进行了分析。采用该乳液制备的纳米二氧化硅改性聚丙烯酸酯防水涂料具有优良的耐洗刷性能。     

原位气泡拉伸法制备LDPE/纳米Mg(OH)2复合材料研究

用原位气泡拉伸(ISBS)法制备低密度聚乙烯(LDPE)/纳米Mg(OH)2复合材料。结果表明,ISBS法对LDPE基体中的纳米Mg(OH)2具有良好的分散能力,被分散的纳米粒子没有重新团聚。ISBS法制备的纳米复合材料的力学性能优于双螺杆剪切分散制备的复合材料的性能。复合材料的拉伸强度随着纳米Mg(OH)2添加量的增加而增大,在添加量为15份时达到最大值,然后随着添加量的增加而下降,但仍然远高于纯LDPE的拉伸强度。     

纳米氢氧化镁增强EPDM/PP的力学性能及形态结构研究

采用动态硫化法制备了聚丙烯/三元乙丙橡胶/纳米Mg(OH)2复合材料,通过力学性能测试、差示扫描量热仪(DSC)分析等手段,对纳米氢氧化镁填充EPDM/PP的力学性能以及结晶与熔融特征进行了研究,通过透射电镜考察了纳米Mg(OH)2在EPDM/PP体系中的微观结构.结果显示随着纳米Mg(OH)含量的增加,EPDM/PP的拉伸强度和断裂伸长率都呈先增加然后下降的趋势;与表面未处理的纳米Mg(OH)2相比,经KH560表面处理过的纳米Mg(OH)2在EPDM/PP基体中的分散更加均匀,对EPDM/PP的增强作用更加明显.当经KH560表面处理过的纳米Mg(OH)2质量含量为10%时,纳米复合材料的拉伸强度达到最大值18.5MPa;填充纳米Mg(OH)2后,纳米复合材料的结晶度以及熔融温度都有所下降.红外光谱表明KH560与纳米Mg(OH)2之间形成了化学键.     

针状微胶囊Mg(OH)_2/EVA纳米复合材料的制备及性能研究

将自制针状微胶囊纳米氢氧化(镁Mg(OH)2)与乙烯-乙酸乙烯共聚(物EVA)经双螺杆挤出机熔融共混挤出造粒,然后利用注射机制成针状微胶囊Mg(OH)2/EVA纳米复合材料,对其力学性能、热稳定性和流变性能进行了研究。结果表明:纳米Mg(OH)2用量为4%时,复合材料的拉伸强度最大,加工流动性较好;在低温区时,纳米Mg(OH)2含量对复合材料的热稳定性能几乎没有影响,在高温区时,纳米Mg(OH)2的加入使其热稳定性略有提高。     

LDPE/LLDPE/纳米Mg(OH)2阻燃体系的研究

以LDPE/LLDPE(60:40)共混体系为基础,添加阻燃剂纳米Mg(OH)2,考察聚乙烯/纳米Mg(OH)2共混复合体系的阻燃性能、力学性能以及加工工艺条件.实验表明:随着Mg(OH):份量的增加,发烟量逐渐减少,纳米Mg(OH),添加量大于40%以后,发烟量逐渐趋近于零,说明纳米氢氧化镁在PE阻燃系统中具有优异的抑烟作用;随着阻燃剂纳米Mg(OH),的增加,燃烧级别最后升高至FV-O级.阻燃体系的力学性能随着纳米Mg(OH)2的增加而下降,当纳米氢氧化锾质量含量达到50%时,材料转为脆性.流动性随纳米Mg(OH)2含量的增加而下降.     

纳米二氧化硅/聚丙烯酸酯复合乳液的合成及其涂膜性能

以改性硅溶胶与丙烯酸酯类单体原位聚合,采用单体预乳化、半连续滴加法制备了高硅含量纳米SiO2/聚丙烯酸酯复合乳液,研究了纳米SiO2和甲基丙烯酸(MAA)的用量、乳化剂配比和乳液固含量对乳液性能的影响,利用红外光谱、热重分析等方法对乳液结构和热稳定性进行了表征,测试了乳胶膜的性能。当SiO2用量为20%,乳化剂中m(OP-10):m(DNS-86)=1:3,功能性单体MAA用量为5%,乳液固含量为40%时,可制得稳定性良好的纳米SiO2/聚丙烯酸酯复合乳液,其涂膜硬度为6H,附着力1级,耐磨性达2500r,且具有良好的耐水性和耐热性。     

低密度聚乙烯/改性锂皂石纳米复合材料的制备及其性能

采用水热法制备出锂皂石,通过阳离子交换法对其改性制备出改性锂皂石(LAP-CTAB)。以LAP-CTAB为填料,通过熔融插层法制备了LDPE/LAP-CTAB纳米复合材料,并对其进行表征与测试。结果表明:当LAPCTAB的添加量为1%时,LDPE/LAP-CTAB纳米复合材料的力学性能达到最优,其拉伸强度、断裂伸长率和冲击强度分别提高了9.4%、54.4%和38.4%。此外,LAP-CTAB的加入提高了LDPE基纳米复合材料的热稳定性、流变性、紫外吸收性和阻燃性能。     

聚氨酯弹性体/Mg(OH)2纳米复合材料的制备与表征

将预分散的纳米氢氧化镁[Mg(OH)2]加入聚氨酯弹性体(PUE)反应体系进行原位聚合。由于预聚物粘度的影响,纳米粒子的最大添加量为5%(质量分数)。力学测试表明,所得Mg(OH)2/聚氨酯弹性体纳米复合材料的力学性能较纯PU有较大提高。复合材料置于60℃的水中3周后,拉伸强度保留93%。XRD测试显示复合材料中无明显结晶。氧指数(IO)测定显示,纳米Mg(OH)2的加入,可明显提高复合材料的难燃性能、当其质量分数为5%时,氧指数可达31。     

Electrical,Mechanical, and Thermal Properties of Mg(OH)<Subscript>2</Subscript>/PI Nanocomposite Films

Nano-Mg(OH)₂ particles were prepared by reverse precipitation. Nano-Mg(OH)₂/PI composite films with varying contents of Mg(OH)₂ were successfully prepared by in situ polymerization and thermal imidization. The surface morphology, thermal stability, and the mechanical and dielectric properties of the films were characterized. Results indicated the following: the nanoparticles were homogeneously dispersed in the matrix, thermal stability was reduced, and the Young’s modulus of PI-3% was 2851.6 N/mm² and increased by 155% relative to that of neat PI. The real and imaginary parts of relative permittivity increased, and electric modulus formalism was introduced to determine the dielectric relaxation behavior of the composites in the study. The result from the Cole–Davidson semicircle showed that the increase in nano-Mg(OH)₂ concentration led to an increase in the inhomogeneous distribution of relaxation time. Direct current illustrates that the activation energy of the hopping process exhibits an increasing trend. The aging threshold increased in accordance with the theory of space-charge limited current. Breakdown increased to 323 kV/mm, whereas the pure film was is 292 kV/mm, and the electric property of polyimide improved.     

Effect of Nano–Magnesium Hydroxide on Mechanical and Flame-Retarding Properties of SBR and PBR: A Comparative Study

Magnesium hydroxide [Mg(OH)₂] is one of the potential inorganic fillers. In this work, nanoparticles (37±5 nm) of the magnesium hydroxide were prepared using matrix-mediated growth and control technique, and their size was confirmed by X-ray diffraction technique. Nano-Mg(OH)₂-SBR and nano-Mg(OH)₂-PBR composites with 2–10% (w/w) filler loading were prepared by compounding on laboratory-scale two-roll mill and a compression molding machine. These composites were tested for tensile and physical properties, and the properties were compared with the composites of commercial Mg(OH)₂. The incorporation of nanofiller improved the properties of nanocomposites.     

Comparative Study of the Mechanical and Thermal Properties of Polyamide-66 Filled with Commercial and Nano-Mg(OH)2 Particles

In the present work, polyamide-Mg(OH)₂ nanocomposites were prepared via melt intercalation on a twin-screw extruder. Different particle sizes (24, 20, 11 nm) of Mg(OH)₂ were synthesized by in-situ deposition technique and its shape and sizes was confirmed on transmission electron microscope (TEM). Nano-Mg(OH)₂ was added from 1 to 4 wt% in the polyamide. Properties such as tensile strength, elongation at break, hardness, and flame retardency were studied. These results were then compared with commercial Mg(OH)₂-filled composites. There was propounding effect to be observed on properties of polyamide nanocomposites due to uniform dispersion of nano-Mg(OH)₂ and commercial Mg(OH)₂. Moreover, thermal property like thermal degradation was studied on TGA. Extent of dispersion of nano-Mg(OH)₂ was studied along with microcracks generated during tensile testing using AFM. It was found that nano-Mg(OH)₂ is thermally more stable compared to that of commercial Mg(OH)₂. Besides that, T_g and M.T. are studied on DSC.     

纳米氢氧化镁的制备及其在LDPE中的应用

以MgCl2为原料,采用氨水作主沉淀剂,氢氧化钠作辅沉淀剂,在有机分散剂PEG的存在下,以溶剂置换后处理工艺制备了PEG包覆的纳米Mg(OH)2(N-PMH)。采用正交设计法考察了沉淀剂的滴加速度、反应时间和反应温度对N-PMH粒径的影响,并对LDPE/N-PMH复合材料的阻燃性能和力学性能进行了研究。     

纳米Mg/PP复合材料的制备及结构研究

分别采用高能球磨法和电阻加热蒸发法制备了纳米Mg，并对其物相及结构进行了表征。再将经活化处理的纳米Mg与PP熔融共混制得复合材料，并测试其力学性能。结果表明：在一定用量范围内，蒸发法制备的纳米Mg能大大提高复合材料的韧性，由脆性断裂转变为韧性断裂；同时能保持复合材料原有的强度。     

基于一步法制备含羧基环氧树脂/纳米二氧化锆复合材料

选用乙烯基三乙氧基硅烷改性纳米二氧化锆,与烯丙基缩水甘油醚、甲基丙烯酸通过自由基共聚法制备了含羧基环氧树脂/纳米二氧化锆复合材料。采用傅里叶红外光谱、X射线衍射分别对改性纳米二氧化锆和含羧基环氧树脂/纳米二氧化锆复合材料进行了表征。结果表明:纳米二氧化锆表面引入了双键;纳米二氧化锆较为均匀地分散在聚合物基体中,其表面灰色部分可能是聚合物形成的包裹。将含羧基环氧树脂/纳米二氧化锆复合材料应用于制革鞣制工艺中,应用结果表明:含羧基环氧树脂/纳米二氧化锆复合材料配合酸皮质量3%的铬粉鞣制坯革收缩温度为102.6℃,增厚率为67.26%,与酸皮质量8%的铬粉鞣制坯革相比,柔软度明显提高,鞣制后废液中的Cr_2O_3含量降低了73.2%。     

Preparation of surface modified nano-Mg(OH)2 via precipitation method

Nano-magnesium hydroxide was prepared via wet precipitation by using the mixture of sodium dodecyl sulfate (SDS) and monoalcohol ether phosphate (MAP) as surface modifiers. The yield of the surface modified nano-Mg(OH)₂ was about 98%. The usage and dosage of surface modifiers were optimized by means of the measurements of suspension volume of the nano-particles in liquid paraffin. As the mass ratio of SDS to MAP was 2:1 and the total of 0.2 wt.% of Mg(OH)₂ theoretical weight (4.35 g) was used, the nano-Mg(OH)₂ with optimized dispersibility was obtained. The volume percent of the surface modified nano-particles suspension in liquid paraffin could reach 96% after 11 h while that of the nano-Mg(OH)₂ without modification would be 62%. The as-prepared samples were characterized through N₂ adsorption, X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetry-differential scanning calorimetry (TGA-DSC). The results show that hexagonal crystal nano-particles with both SDS and MAP molecules on the surfaces were obtained. The LOI value of PP composites is 35.0 at 150 phr (50% by weight) of surface modified nano-Mg(OH)₂.     

原位生成纳米SiO_2/丙烯酸树脂皮革涂饰剂的研究

该研究用乳液聚合法原位合成了纳米S iO2/丙烯酸树脂复合涂饰剂。考察了单体配比,体系pH,引发剂、乳化剂及正硅酸乙酯(TEOS)用量等因素对乳液性能的影响,并分析表征了纳米复合涂饰剂的宏观、微观结构,测试了聚合物膜的物理机械性能以及用于皮革涂饰后革样的各项性能。结果为:透射电镜(TEM)观察发现,粒径小于100 nm的S iO2颗粒均匀分散于纳米复合涂饰剂乳液内,且无明显团聚现象;差示扫描量热(DSC)分析得出,纳米S iO2的加入使丙烯酸树脂的玻璃化温度(Tg)提高了12.2℃;傅里叶红外光谱(FTIR)分析表明,纳米复合涂饰剂中形成了—S i—O—S i—结构。纳米S iO2/丙烯酸树脂复合涂饰剂应用于皮革涂饰后,其各项性能较丙烯酸树脂涂饰有明显提高,如透水汽性提高了7.42%,透气性提高了7.33%,耐干、湿擦性能均提高一级。     

Nano-Mg(OH)2 platelets coated flexible polyurethane foam for fast and environment-friendly removal of Cu2+ from aqueous solution

In this study, flexible polyurethane foam (FPUF) was successfully coated with nano-Mg(OH)₂ platelets. Due to the strong interaction between chitosan and nano-Mg(OH)₂, it was possible to yield modified foam with a weight-gain of up to 15 wt% by depositing one chitosan layer and one nano-Mg(OH)₂ layer. Meanwhile, the adsorption isotherms of Cu²⁺ on FPUF covered with 10 wt% coating (FPUF-10) shows the Langmuir behavior. It was found that for the FPUF-10, the removal % for Cu²⁺ after 30 min and 50 min treatment were 86% and 90%, respectively. Moreover, the maximum removal % could reach up to 95%.