纳米CaSiO3填料的制备及其性能表征

以乙醇为溶剂，正硅酸乙酯（TEOS）为胶溶剂，CaCO3为主要试剂，采用溶胶-凝胶（Sol-Gel）技术制备纳米偏硅酸钙（CaSiO3）填料，考察主要工艺参数——初始水凝胶pH值、R值（H2O/TEOS）对粉体形貌、颗粒大小等性质的影响。研究表明：采用溶胶-凝胶法能合成纳米级的CaSiO3填料。     

溶胶-凝胶法制备乙烯基改性SiO_2杂化玻璃

采用溶胶-凝胶法以乙烯基三乙氧基硅烷(ETES)作为有机改性剂,与正硅酸乙酯(TEOS)制备了乙烯基改性S iO2杂化玻璃。研究了乙醇作溶剂的一步溶胶-凝胶法、二步溶胶-凝胶法及丙酮作溶剂的三种方法对产物性能的影响。结果表明:采用乙醇作为溶剂的一步溶胶-凝胶法得不到完整透明致密的杂化玻璃;采用乙醇作为溶剂的二次水解法,透光率随ETES/TEOS摩尔比的增大而增加,可制备ETES/TEOS摩尔比较大(3∶1~6∶1)的透明均质完整杂化玻璃,透光率可达92.8%;采用丙酮作为溶剂的一次水解法透光率随ETES/TEOS摩尔比的增大而减小,可制备ETES/TEOS摩尔比较小(1∶8~2∶1)的透明均质完整杂化玻璃,透光率可达90.3%。红外光谱表明,乙烯基通过S i─C键接枝到S iO2网络中。     

乙醇对溶胶-凝胶法制备SiO_2溶胶性能的影响

以HNO3为催化剂,用正硅酸乙酯(TEOS)溶胶-凝胶工艺制备纳米多孔二氧化硅薄膜。较详细地研究了工艺参数乙醇/TEOS摩尔比对溶胶性能的影响.结果表明,随着乙醇/TEOS摩尔比的增大,溶胶粘度减小,凝胶时间变长,胶体粒径有变小趋势。     

HCl-NH3双组分催化正硅酸乙酯快速制备SiO2气凝胶

以正硅酸乙酯(TEOS)为原料,水和乙醇为溶剂,盐酸和氨水为催化剂,采用溶胶-凝胶法制备了SiO2气凝胶.研究了水和乙醇及催化剂对制备SiO2气凝胶反应速度、凝胶时间的影响.结果表明HCl和NH3·H2O作为催化剂大大加速了溶胶和凝胶反应速度,使凝胶时间减少至几分钟甚至更短,所制备的SiO2气凝胶具有纳米多孔结构(骨架颗粒为15～20nm,孔洞尺寸为10～30 nm).     

原位溶胶-凝胶法改性三元乙丙橡胶的制备及其表征

天津大学化工学院采用原位溶胶-凝胶反应制备了三元乙丙橡胶(EPDM)/SiO2纳米复合材料。分别以EPDM和γ-甲基丙烯酰氧丙基三甲氧基硅烷(KH570)接枝改性的乙丙橡胶(EPDM-g-KH570)在前驱体四乙氧基硅烷(TEOS)中溶胀,再浸入含有正丁胺的催化剂溶液中催化前驱体的原位溶胶-凝胶反应。考察了不同溶剂以及催化剂含量对TEOS转化率和原位生产的SiO2粒径的影响。采用FT-IR和SEM等测试手段对     

纳米二氧化硅制备工艺的研究

以正硅酸乙酯(TEOS)为前驱液、氨水为催化剂和去离子水、无水乙醇为溶剂,采用溶胶-凝胶法制备出了纳米二氧化硅。利用傅里叶变换红外光谱仪(FT-IR)、动态激光散射粒度分析仪(DLS)、透射电子显微镜(TEM)对纳米二氧化硅的元素组成结构、粒径范围及分布、颗粒形状结构等一系列的性能进行了表征。实验结果表明:产品微观形貌为规整的圆球状;当催化剂氨水浓度为0.4 mol/L,TEOS浓度为0.17 mol/L时,纳米二氧化硅颗粒的峰平均值为215.4 nm,平均粒径为299.6 nm。     

聚苯乙烯-SiO2杂化材料的合成与表征

以苯乙烯(ST)、正硅酸乙酯(TEOS)为原料,丙烯酸-β-羟丙酯(β-HPA)为交联剂,乙醇为溶剂,采用溶胶凝胶法制备了聚苯乙烯-SiO2杂化材料.通过FT-IR、SEM、TG-DTA、溶剂抽提等方法对杂化材料进行了测试.结果表明:聚苯乙烯通过β-HPA接枝到SiO2上,杂化材料具有良好的热稳定性和耐溶剂性能,杂化材料的溶胶分数随着水量和pH值的增加而增加.     

SiO2气凝胶/纤维复合材料热稳定性的研究

本文以正硅酸乙酯(TEOS)为前驱体;乙醇和水为溶剂;采用HCl和NH3.H2O两步催化法;以莫来石纤维为增强材料,在溶胶-凝胶过程后,经过表面改性;采用常压干燥工艺、真空干燥工艺,制备了轻质纳米SiO2气凝胶/莫来石纤维复合材料。采用STA 449 C型热重分析仪,对复合材料的热稳定性进行了测试,并分析了纤维填入后对复合材料热稳定性的影响。     

纳米二氧化硅制备工艺的研究

以TEOS(正硅酸乙酯)为前驱体、氨水为催化剂和无水乙醇为溶剂,采用溶胶-凝胶法制备了纳米二氧化硅。利用傅里叶变换红外光谱(FT-IR)仪和纳米激光粒度分布仪对纳米二氧化硅的结构、粒径及其分布进行了表征,并着重探讨了反应温度、催化剂浓度和反应时间等对纳米二氧化硅粒径的影响。研究结果表明:当反应温度为60℃、催化剂浓度为0.82 mol/L和反应时间为3~4 h时,制得的纳米二氧化硅平均粒径为300 nm左右。     

KH-570原位改性纳米二氧化硅的制备与表征

以正硅酸乙酯(TEOS)为原料,采用溶胶-凝胶法制备纳米二氧化硅溶胶,再用γ-(甲基丙烯酰氧基)丙基三甲氧基硅烷(KH-570)对其进行改性,得到KH-570改性的纳米二氧化硅。采用红外光谱(FT-IR)、粒径分析、透射电镜(TEM)以及热重分析(TG)等对原料及产物进行表征。结果表明:KH-570能够成功改性纳米二氧化硅,改性后的纳米二氧化硅尺寸主要分布在30～115nm。     

Synthesis and Structural Characterizations of “Core–Shell”-Type Nickel-Coated Polymeric Particles

A polystyrene seed with a narrow size distribution was synthesized by the dispersion polymerization method first, then uniformly “swollen up” and cross-linked with divinylbenzene (DVB) utilizing the dynamic swelling polymerization technique. The surface of hollow poly(styrene-co-DVB) particles was coated with nickel by the electroless plating method. The density of the synthesized “core–shell”-type conductive particle was 3.06 g/cm³, significantly lower than the density of pure metallurgical nickel of 8.91 g/cm³. Hence, the sedimentation problem, which often occurs in the blend of high-density metal fillers with a relatively low density polymer matrix, could be overcome as the metal fillers were replaced by the synthesized core–shell-type conductive particles.     

Influence of iron carbide filler in carbon matrix on the adhesive properties of acrylic pressure-sensitive adhesives

Inorganic fillers can improve coating properties, such as scratch resistance and UV stability and can significantly enhance the fillers usability in coatings and realize new market opportunities. In the pressure-sensitive adhesive (PSA) technology the inorganic fillers are used to change the very important properties of pressure-sensitive adhesives, such as tack, peel adhesion and shear strength. In the current study, the above mentioned properties of synthesized acrylic PSA using iron carbide filler in carbon matrix were investigated. The acrylic PSA containing iron carbide filler (Fe₃C,C) was examined with SEM/EDX technique and the PSA adhesive and cohesive properties were examined by using a special strength machine according to AFERA tests. The conclusion is that the application of this kind of fillers allows the manufacturing of self-adhesive materials with moderate adhesiveness and very good removability.     

不同无机填料在聚氨酯弹性体中的性能对比

以聚醚N-204、甲苯二异氰酸酯为原料,用1,4-丁二醇为扩链剂,填充经超声波分散、偶联处理的不同无机填料,分别合成填充型聚氨酯(PUR)弹性体。研究了填充型PUR弹性体的耐磨性、力学性能以及填料在弹性体中的分布状况。结果表明,不同无机填料在PUR弹性体中所表现出的性质不同,碳化硅主要提高了弹性体的耐磨性,而陶瓷微珠、玻璃微珠在增强增韧方面发挥了作用。     

Modification of ion-exchange membranes

Heterogeneous ion-exchange membranes with various active polymeric fibrous fillers were synthesized. The possibility of replacing polyethylene as a traditional inert polymeric carrier by poly(vinyl chloride) was analyzed.     

Functional lignin-SiO2 hybrids as potential fillers for phenolic binders

Functional lignin-SiO₂ hybrid fillers were synthesized and characterized with a view to their potential application in binders for phenolic resins. The properties of these fillers and of composites obtained from them with phenolic resin were compared with those of systems with lignin or silica alone. The chemical structure of the materials was investigated by Fourier transform infrared spectroscopy. Surface properties of lignin-SiO₂ fillers were tested using inverse gas chromatography (IGC). IGC was used for determination of surface energy and surface heterogeneity of the studied fillers. IGC made it possible to assess the adhesion between the tested fillers and phenolic resins. Interactions of functional fillers with phenolic resins were also evaluated by IGC. The results indicated that lignin-SiO₂ interacted strongly with the phenolic resin, more strongly than pure lignin. This was proved by SEM observations: thanks to the stronger interactions of lignin-SiO₂ hybrid with phenolic resins, a more homogeneous composite was obtained. Thermo-mechanical properties of lignin–silica and resin systems were investigated by DMTA. DMTA results showed that phenolic binders with lignin-SiO₂ fillers have better thermo-mechanical properties than systems with lignin or silica alone: higher glass transition temperature and a smaller decrease in storage modulus. Lignin fillers can thus provide new, promising properties for a phenolic binder combining the good properties of lignin as a plasticizer and of silica as a filler improving mechanical properties.     

环氧树脂-有机硅复合改性水性聚氨酯耐温防腐涂料的研究

以异氟尔酮二异氰酸酯(IPDI),聚丙二醇(PPG),二甲基硅油及环氧树脂等为主要原料合成了环氧树脂-有机硅复合改性水性聚氨酯,通过添加无机填料和助剂制备了水性聚氨酯涂料。利用红外光谱和热分析仪对乳液、涂料的结构和性能进行表征。探讨了乳液、镇水粉和铁红的用量对涂膜力学性能、耐水性能和防腐性能的影响。当乳液含量为65%,镇水粉含量为10%,铁粉含量为6%时,其热稳定性能提高了50℃,吸水率降低了3倍,冲击强度增加到80 kg/cm,附着力达到0级,自腐蚀电位提高至450 mV。结果表明,无机填料的加入,可极大改善水性聚氨酯涂层的综合性能。     

不同无机填料对聚氨酯弹性体性能的影响

以聚醚多元醇和TDI-80为原料,MOCA为扩链剂,填充不同无机填料,分别合成填充型聚氨酯弹性体,研究了不同无机填料对聚氨酯弹性体性能的影响。采用差示扫描量热分析（DSC）、热重分析（TG）、X射线衍射（XRD）、红外光谱（FT-IR）及力学性能等测试方法对填充型聚氨酯弹性体的结构与性能进行了表征和分析。结果表明,3种...     

Electrical,thermal, and mechanical properties of silicone foam composites filled with carbon-based nanofillers

It is critical to develop a new method to prepare engineered carbon-based fillers for high-performance applications. In this article, the functional nanocarbon-based fillers (FG-M) composed of multiwalled carbon nanotubes (MWNTs) and graphene oxide (GO) was synthesized by a simple self-assembly reaction under the existence of triethoxyvinylsilane. Based on the FG-M fillers, the silicone foam composites (FG-M/SF) were prepared, and the electrical, thermal, and mechanical properties of the composites were studied. Results showed that the FG-M could effectively improve the electrical, thermal, and mechanical properties of the composites compared with the single-filler system (GO/SF and MWNTs/SF). Especially, the composites exhibited the best synergistic effect on electrically, thermal and mechanical enhancement while the ratio of MWNTs and GO was close to 1:1. Moreover, the effect of type and content of fillers on the rheological properties and density of the composites was also studied. The result showed that the FG-M/SF system has good thixotropic and foaming performance. The FG-M filler will have a good application prospect in the preparation of high-performance SF composites.     

Synthesis and properties of novel macromolecular coupling agents prepared by ATRP

Novel block and graft macromolecular coupling agents with well‐defined structures have been synthesized successfully by atom transfer radical polymerization (ATRP). The molecular weights and molecular weight distributions of those functional copolymers can be controlled because of the living/controlled ATRP. The structures and composition of block and graft copolymers with the monomers of butyl acrylate (BA), styrene (St), and 3‐methacryloxyl‐propyltrimethoxyl silicon (KH‐570) have been characterized by mean of ¹H NMR, IR, GPC, and UV. Because the KH‐570 of macromolecular coupling agents owns strong affinity to surface hydroxyl of fillers, inorganic fillers that were treated by the macromolecular coupling agents possess some new properties, for example increasing the effect between matrix and fillers of composites. The mechanical properties and morphology of composites with macromolecular coupling agents have been investigated by the dynamic mechanical spectra and SEM. The results showed that the damping value and compatibility of composites with macromolecular coupling agents were improved greatly when compared with that of composite with small molecular coupling agent. Furthermore with different contents of BA, St, and KH‐570 in the macromolecular coupling agents, the damping value of the composites are different. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3919–3926, 2006     

Raw and chemically treated bio-waste filled (Limonia acidissima shell powder) vinyl ester composites: Physical,mechanical, moisture absorption properties,and microstructure analysis

The rapid growth of environmentally sustainable and eco-friendly materials tends to the utilization of biowastes as filler in polymer matrix composites. The particulate composite with improved wettability of fillers and advanced approach can evolve polymer composites that exhibit promising applications in packaging, automobile, marine, construction, and aerospace. In the present work, one of the biowaste fillers were synthesized from Limonia acidissima shells via a top-down approach (pulverizing) and the surfaces were chemically modified using sodium hydroxide (NaOH) before they were used as fillers in vinyl ester polymer composites by different weight percentage (0, 5, 10, 15, and 20 wt%). The prepared particulate composites were characterized by mechanical properties, moisture absorption behavior, and morphology. At different filler loading the tensile strength, tensile modulus, flexural strength, flexural modulus, impact strength, hardness, density, and moisture intake tests were performed. The results reveal that the properties increased for composites filled with alkaline treated fillers for the same filler loading and found to be higher at filler loading of 15 wt%. The morphological analysis confirms the better interfacial bonding between alkali-treated particles and matrix due to the removal of non-cellulose materials from the surface of the particles.