含羟基柔性链段纳米二氧化硅的制备及其对高速列车涂层性能的影响研究

采用两步法对纳米二氧化硅进行有机无机杂化改性,首先通过异氰酸酯的桥接作用,在纳米二氧化硅的表面引入环氧树脂分子,再利用环氧基团的碱式开环反应,形成可参与交联固化的羟基,制备了表面接枝含羟基柔性链段的纳米填料,研究了纳米二氧化硅不同用量对涂层材料力学性能与耐磨性能的影响。结果表明,有机无机杂化改性后的纳米二氧化硅能与有机树脂发生化学反应,改善了无机纳米二氧化硅在涂层中的分散性,提高了有机/无机的界面相容性,从而提高了涂层的韧性和致密性。当改性纳米二氧化硅的添加量为6%时,与添加未改性纳米填料的涂层相比,其耐磨性提高了24%,拉伸强度提高了25%,断裂伸长率提高了50%,涂层的饱和吸水率降低了40%。     

纳米二氧化硅-有机硅复合涂层防护性能的研究

利用电化学阻抗谱（EIS）技术对纳米二氧化硅含量为5％的有机硅复合涂层的防护性能进行了研究，试验结果与有机硅清漆涂层和微米二氧化硅含量为5％的有机硅复合涂层的实验结果进行了比较。结果表明，纳米氧化硅粒子的填加有效地阻挡侵蚀介质的渗透和腐蚀，纳米氧化硅．有机硅复合涂层比有机硅清漆涂层和微米二氧化硅一有机硅复合涂层具有更好的防护性能。     

纳米二氧化硅-有机硅复合涂层防护性能的研究

利用电化学阻抗谱(EIS)技术对纳米二氧化硅含量为5%的有机硅复合涂层的防护性能进行了研究,试验结果与有机硅清漆涂层和微米二氧化硅含量为5%的有机硅复合涂层的实验结果进行了比较。结果表明,纳米氧化硅粒子的填加有效的阻挡侵蚀介质的渗透和腐蚀,纳米氧化硅-有机硅复合涂层比有机硅清漆涂层和微米二氧化硅-有机硅复合涂层具有更好的防护性能。     

纳米二氧化硅的制备及其在环氧树脂中的应用

介绍了纳米二氧化硅（nano-SiO2）常用的制备方法,如化学沉淀法、溶胶-凝胶法和微乳液法等,对各种方法的优缺点进行了评述;简要论述了nano-SiO2在环氧树脂（EP）中的应用,并对其制备方法及其在EP中的应用前景作了展望。     

纳米二氧化硅的制备及其在环氧树脂中的应用

介绍了纳米二氧化硅(nano-SiO2)常用的制备方法,如化学沉淀法、溶胶-凝胶法和微乳液法等,对各种方法的优缺点进行了评述;简要论述了nano-SiO2在环氧树脂(EP)中的应用,并对其制备方法及其在EP中的应用前景作了展望。     

基于二氧化硅纳米粒子的抗冲击超双疏涂层的制备及其性能研究

随着超疏水涂层的成功制备及其在实际工业和生活中的应用,超双疏涂层的研究也取得了一定的突破。然而,抗冲击超双疏涂层的研究和制备仍存在一定的困难。因此,我们报道了一种抗冲击超双疏涂层。首先选择合适粒径的二氧化硅纳米粒子,然后在乙醇体系中,以氨为催化剂,以小分子有机硅烷为改性剂,与长链有机硅烷反应,形成均匀悬浮液。最后,采用简单的喷涂工艺制备超双疏涂层。该涂层具有良好的超双疏性能和抗冲击性能,同时具有优异的化学稳定性和热稳定性。     

纳米二氧化硅复合涂料的制备及其性能

通过表面改性技术制备了疏水性的纳米二氧化硅粒子,粒径约50 nm.在机械搅拌和超声场共同作用下,将纳米二氧化硅均匀分散到聚氨酯清漆中,制得纳米二氧化硅复合涂料,考察了纳米二氧化硅复合量对复合涂料性能的影响.直接腐蚀实验、阳极极化和交流阻抗测试结果表明,加入偶联剂改性的纳米二氧化硅后,复合聚氨酯清漆在氯化钠溶液中的抗腐蚀能力明显提高,浸泡腐蚀失重量减小约20％～70％,阳极腐蚀电流降低1个数量级以上,低频区涂层阻抗值增大2个数量级以上.油漆剪切强度和剥离强度实验显示,纳米复合漆膜的附着力增加.     

高速列车橡胶外风挡表面涂层的制备及性能

采用正交试验法考察了基材粗糙度、固化剂配比、固化温度、固化时间等工艺参数对高速列车橡胶外风挡涂层性能的影响。确定了最佳工艺方案为:基材打磨选择150目加240目的砂纸,主剂与固化剂的配比为6∶1,在100°C下固化60 min。按此工艺方案制备的涂层具有以下性能:附着强度0级,光泽21.6 Gs,出现裂纹的最大拉伸量181%,拉伸疲劳寿命4 832次。     

纳米二氧化硅改性环氧防腐底漆的研究

以纳米二氧化硅改性环氧树脂为主要成膜物,制备了一种防腐底漆。研究了纳米二氧化硅用量,固化剂、功能性颜料和助剂的选择及配比对涂料性能的影响。试验结果表明:与改性前相比,纳米二氧化硅改性环氧涂层的附着力、柔韧性明显提高;涂层湿附着力提高300%,柔韧性从30 cm提高到70 cm;采用改性树脂制备的防腐涂层的耐盐雾性和耐湿热性均达3 000 h以上;涂料施工固体分达75%以上;涂层的综合性能良好。     

光固化纳米二氧化硅/环氧丙烯酸酯杂化涂料的制备与表征

通过在纳米SiO2粒子表面锚固热引发剂,然后在活性稀释单体中对纳米SiO2进行原位接枝聚合改性.将改性纳米SiO2和活性稀释单体的混合物直接与其他原料共混,制备了光固化纳米SiO2/环氧丙烯酸酯(EA)杂化涂料.采用傅立叶变换红外光谱(FTIR)、扫描电镜(SEM)、热重分析(TG)和涂膜性能试验等对杂化涂料的结构与性能进行了研究.结果表明,聚合物链段通过化学键接枝到了纳米SiO2粒子表面;改性后的纳米SiO2在杂化膜中分散良好;在引入改性纳米SiO2后,涂膜的耐热性、抗冲击性、硬度、附着力等性能得到显著改善.     

石墨烯的制备及其电化学性能分析

以大鳞片石墨制备的膨胀石墨(EG)为原料,采用改进的Hummers法制备氧化石墨,采用Na BH4化学还原制备石墨烯。采用扫描电镜和X射线衍射仪对化学还原后的石墨烯进行形貌和结构表征,应用电池测试系统对样品进行循环伏安(CV)、恒流充放电等电化学性能测试。结果表明:石墨烯电极在电流密度100m A·g-1时的首次放电比容量达1900m Ah·g-1;经100个循环周期后石墨烯电极比容量为450m Ah·g-1;在不同电流密度下循环50次,再回到100m A·g-1时,仍保持首次循环92%的比容量。     

Preparation and coating properties of an acrylic melamine resin containing silicone segments

The aim of this study was the preparation of novel water repellent UV curable materials using acrylic modified melamine (AM) and poly-dimethylsiloxane (PDMS). UV curable acrylic melamines containing silicone segments (SiAMs) were synthesized by condensation of methylolmelamine, 2-hydroxyethyl acrylate, and carbinol-modified PDMS. The SiAM films with a 0.3 wt% PDMS segment that were cured by UV irradiation had higher transparency than that of a blended sample. Examination with a scanning electron microscope revealed that the blend sample has cohesion of the silicone segments, while such a phenomenon was not observed in the composite samples (SiAMs). From these results, it was confirmed that aggregation of the silicone segments was prevented by introducing the silicone segments into the acrylic melamine. By introducing 0.3 wt% of PDMS segments into AM, good water-shedding properties were confirmed, while several of the most attractive features of AM, such as hardness, adhesion, and refractive index, were maintained.     

含羟基聚酰亚胺改性环氧胶的制备及性能研究

将3,3'-二氨基-4,4'-二羟基联苯(DADHBP)、2,2-双(3-氨基-4-羟基苯基)六氟丙烷(BAH-PFP)和3,3',4,4'-四羧酸二苯醚二酐(ODPA)、3,3',4,4'-四羧酸二苯甲酮二酐(BTDA)单体聚合,再经亚胺化得到含羟基聚酰亚胺(HPI)粉末,采用傅里叶红外光谱对其进行了表征。由HPI、烯丙基双酚A、双马来酰亚胺、2-乙基-4-甲基咪唑与N,N,N',N'-四缩水甘油基-4,4'-二氨基二苯甲烷(TGDDM)共聚反应制得胶粘剂,并对胶粘剂的热性能、力学性能及吸水性进行了研究,结果表明:该胶拉伸剪切强度为21.1 MPa,固化后吸水率为0.49%。通过凝胶化时间法计算胶粘剂的表观活化能为64.5 kJ/mol。     

Preparation and properties of segmented thermoplastic polyurethane elastomers with two different soft segments

Thermoplastic polyurethane elastomers were prepared from 4,4‐diphenylmethane diisocyanate (MDI)/1,4‐butanediol (BD)/poly(propylene glycol) (PPG) and MDI/BD/poly(oxytetramethylene glycol) (PTMG). The MDI/BD‐based hard‐segment content of polyurethane prepared in this study was of 39–65 wt %. These polyurethane elastomers had a constant soft‐segment molecular weight (M_n , 2000), but a variable hard‐segment block length (n, 3.0–10.1; M_n , 1020–3434). The effects of the hard‐segment content on the thermal properties and elastic behavior were investigated. These properties of the PPG‐based MPP samples and the PTMG‐based MPT samples were compared. The polyurethane prepared in this study had a hard‐segment crystalline melting temperature in the range of 185.5–236.5°C. With increasing hard‐segment content, the dynamic storage modulus and glass transition temperature increased in both the MPP and MPT samples. The permanent set (%) increased with increasing hard‐segment content and successive maximum elongation. The permanent set (%) of the MPP samples was higher than that of MPT samples at the same hard‐segment content. The value of K (area of the hydrogen‐bonded carbonyl group/area of the free carbonyl group) increased with increasing hard‐segment content in both the MPP and MPT samples, and the K value of the MPT samples was higher than that of the MPP samples at the same hard‐segment content. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 345–352, 1999     

溶剂挥发速率对涂层表观的影响

本文通过不同挥发速率的溶剂及其组合对涂层表观影响的研究,解决了紫外光固化体系喷涂工艺中经常出现的针孔、点子等涂布弊病。     

纳米氧化铈的制备及其催化性能

纳米氧化铈是新兴的催化材料,在化学工业和环境污染控制方面有着广泛的应用前景。对近年来国内外制备纳米氧化铈材料的不同方法进行了阐述和比较。其中溶胶-凝胶法和沉淀法工艺已经较为成熟,而其他方法,如共沸精馏法、冰冻脱水法、水解法、气相法、微乳液法、表面修饰法、液-液两相法、熔融法、固相反应法等,都还需要进一步完善。对纳米氧化铈的催化性能进行了研究,研究表明,纳米氧化铈的催化性能大大优于传统的非纳米氧化铈粉体。     

Thermoplastic polyurethane nanocomposites of reactive silicate clays: effects of soft segments on properties

This paper addresses the effects of soft-segment on clay particle exfoliation and resultant mechanical and thermal properties of nanocomposites of reactive layered silicate clay and thermoplastic polyurethanes (TPU). The composites were synthesized via a two-step bulk polymerization scheme from polyether- and polyesterpolyols of molecular weight 2000, diphenylmethanediisocyanate, butanediol, and up to 5 wt% reactive layered silicate clay. It was found that the extent of tethering reactions between polymer chains carrying residual -NCO groups and reactive clay particles was significant, although did not depend on the nature of polyol used. Nanocomposites were obtained only in the case of polyesterpolyol, which can be attributed to both clay-polymer reactions and higher viscosity in the clay-polymer mixing step. These nanocomposites showed 125% increase in tensile stress, 100% increase in elongation, and 78% increase in tensile modulus along with 130% increase in tear strength and a 60% reduction in volume loss in abrasion test. It was observed that hydrogen bonding did not influence the properties and the extent of hydrogen bonding was not affected by the clay particles.