有机硅偶联剂改性SiO_2作用机理研究

采用有机硅偶联剂对SiO2进行改性,并用红外光谱进行了表征。结果表明:硅烷偶联剂与SiO2表面的大部分羟基发生了化学反应,经改性后的SiO2,活化指数大大提高,且偶联剂占SiO2的最佳用量为7%。结合红外光谱分析结果和偶联剂分子结构,推断出在无水和有水条件下,偶联剂改性SiO2化学反应机理;结合改性过程中可能发生的化学反应,建立改性SiO2的结构模型。     

A Study on Composites from Casein Modified Melamine-Formaldehyde Resin

Amino resins are used for various applications such as decorative plastic plates, decorative wood boards, particle boards, leather tanning, foam, coating, and molding materials. In the present work, it was planned to prepare modified melamine-formaldehyde resin by incorporating casein. The intended melamine-formaldehyde-casein (MFC) resin samples were prepared under alkaline condition with an 1:3 melamine: formaldehyde ratio. Casein was incorporated in varying proportions (up to 25% w/w of melamine content) at 85–90°C. The samples were characterized by viscosity measurement and vapor pressure osmometry (VPO). The resin samples were cured isothermally at 60°C using ammonium chloride as well as hydroxylamine hydrochloride and at 120°C using hexamine as the curing agents. Jute fabric (JFRC) and glass fabric reinforced composites (GFRC) were produced by maintaining 60:40 and 40:60 proportion of resin to reinforcement materials, respectively. The laminates thus formed were characterized for their mechanical properties and chemical resistance.     

The solvent-free modification of butyl rubber in the medium of NaH

A novel improved butyl rubber (PMIIR) was prepared in a solvent free process, using sodium hydride (NaH) as activating agent and maleic anhydride (MAH) as modifier by processing modification technology in a conventional polymer processing equipment of an internal mixer. The structure of products was characterized by ¹H NMR and FT-IR. In this process, polar sodium carboxylate functional group and unsaturated carbon–carbon double bonds were successfully introduced onto the chains of IIR on one step. The reaction mechanism was investigated in detail. It was found that the functionalization experienced two modified mechanisms: addition and substitution modified mechanisms. The reaction efficiency and content of MAH were evaluated. Polymer isolation and purification operations were reduced out due to the result of solvent free. Curing and mechanical properties of products were investigated. It was found that PMIIR has greatly increased curing rate due to the incorporation of polar group and carbon–carbon double bond.     

变质处理及热处理对泡沫铝合金压缩吸能性的影响

采用可溶石膏型预制块,通过加压渗流的方法制备了高孔隙率的ZL101开孔泡沫铝合金,并对泡沫铝合金进行变质处理和T6热处理.通过压缩试验研究了变质处理和固溶热处理对泡沫铝合金的压缩吸能性能的影响.结果表明,通过石膏型渗流法制备的开孔泡沫铝合金的孔隙率可以达到89.3%～90.7%,采用变质处理和热处理能够有效提高开孔泡沫铝合金的强度,获得高比强度的开孔泡沫铝合金,其比强度达到0.82,理想吸能效率可达85%.     

钾长石与磷矿共酸浸制NPK复合肥研究

用磷酸浸取钾长石与磷矿混合物,经水浸取酸浸产物后再用氨水中和制备NPK复合肥和长效磷肥,或制备速效和长效性能兼有的复合肥料.重点研究了钾长石与磷矿共酸浸产物水浸工艺、浸取液氨化工艺.结果表明:水浸适宜条件为温度70℃,浸取时间100min,浸取水量10mL/g原料.氨化终点pH值在6左右时,整个过程钾总收率在84%以上,磷总收率在85%以上.该工艺流程简单,产品缓释效能具有可控性,具有良好的发展前景.     

漫渗燃烧合成TiAl金属间化合物的物化过程探讨

漫渗燃烧合成可分为两个主要过程，即漫渗和燃烧合成。影响漫渗的主要因素是Ａｌ对Ｔｉ的润湿性，它主要与温度有关。提高温度有利于漫渗。燃烧合成主要存在两次反应，其中生成ＴｉＡｌ３的反应瞬间即可完成，是一剧烈的化学过程，属于非扩散控制；由ＴｉＡｌ３转变成ＴｉＡｌ的过程相应要慢得多，是一个扩散控制。整个反应受二次反应控制，即受扩散控制。     

粉煤灰-赤泥复合絮凝剂PAFC的除磷性能

为了确定粉煤灰和赤泥经HCl改性制得的复合絮凝剂PAFC处理含磷废水的合适工艺技术条件,对浓度为50.0 μg/mL的模拟含磷废水进行了适宜除磷pH值和PAFC用量试验,并对反应过程中的水力条件进行了研究。结果表明：在pH=8、PAFC投加量为180 mg/L、快速搅拌速度为200 r/min、快速搅拌时间为60 s、慢速搅拌速度为50 r/min、慢速搅拌时间为15 min情况下,取得了97.55%的磷去除率。除磷机理分析表明：①PAFC结构杂乱无章、参差不齐,表面积极大,孔隙度极高,这十分有利于对磷的吸附。②PAFC通过自身携带的Fe-OH、Al-OH、H-OH羟基基团,以及Al3+和Fe3+水解形成的氢氧化铝（铁）等羟基络合物吸附磷;PAFC中的Al3+和Fe3+除了与水中溶解的正磷酸盐反应生成不溶性磷酸盐沉淀,还通过电性中和作用,降低或消除污水中胶体的ζ电位,从而令水中胶体消除静电斥力,使悬浮物快速脱稳并沉降到水底,表现出良好的絮凝除磷效果。粉煤灰和赤泥可制备优质除磷絮凝剂PAFC,实现了这些工业固体废弃物的资源化利用,且达到了以废治废效果。     

CFG桩复合地基的基本原理及工程应用

阐述了CFG桩复合地基的原理，介绍了CFG桩复合地基桩、桩周土以及褥垫层的作用，以工程实例说明了CFG桩复合地基在工程中的应用及参数的合理选取。     

聚丙烯/蒙脱石纳米复合材料的制备

用有机改性剂对蒙脱石进行改性后，以改性蒙脱石和聚丙烯为原料，采用熔融插层法制备聚丙烯／蒙脱石纳米复合材料。研究了改性剂种类和用量对蒙脱石有机改性效果的影响，考察了所制备纳米复合材料的力学性能与改性蒙脱石加入量之间的关系。结果表明：十六烷基三甲基溴化铵对蒙脱石的改性效果较好，其用茸为蒙脱石质鼍的20％时，蒙脱石的d（001）值由1．236nm增大到1．955nm；复合材料中改性蒙脱石的适寅质量分数为3％，在此条件下，复合材料的各种力学性能均比纯聚丙烯明显提高，其中抗弯强度提高15．46％。     

不同变质剂对铝合金组织及性能的影响

在合金熔炼的过程中分别加入RE(镧铈混合稀土)、Al-Ti-B和铝钪合金对合金进行变质处理,研究不同变质剂对合金组织及力学性能的影响。结果表明,RE、Al-Ti-B和铝钪都是通过改变合金中硅相的颗粒大小来改变合金的铸态组织,从而提高合金的综合力学性能。