Preparation of Core-shell Structured Particles and Their Nucleation in Polyester:I. Preparation of Monodisperse SiO_2/PS Core-shell Composite Particles

1. Introduction At present, nanotechnology has been developed intoa new generation of techniques in providing advancedmaterials. This technology now has been applied toprepare and modify macromolecules or polymermaterials through blending, compositing,…     

Preparation and Characterization of Pyrotechnics Binder–Coated Nano-Aluminum Composite Particles

The aim of this article is to protect the activity of nano-aluminum (Al) particles in solid rocket propellants and pyrotechnics. The morphology, structure, active aluminum content, and thermal and catalytic properties of the coated samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetry–differential scanning calorimetry (TG-DSC), and oxidation–reduction titration methods. The results indicated that nano-Al particles could be effectively coated with phenolic resin (PF), fluororubber (Viton B), and shellac through a solvent/nonsolvent method. The energetic composite particles have core–shell structures and the thickness of the coating film is about 5–15 nm. Analysis of the active Al content revealed that Viton B coating had a much better protective effect. The TG-DSC results showed that the energy amount and energy release rate of PF-, Viton B–, and shellac-coated Al particles were larger than those of the raw nano-Al particles. The catalytic effects of coated Al particles on the thermal decomposition of ammonium perchlorate (AP) were better than those of raw nano-Al particles, and the effect of shellac-coated Al particles was significantly better than that of Viton B–coated Al particles.     

Preparation and Commercial Application of ZHC-01 Hydrocracking Catalyst

The ZHC-01 hydrocracking catalyst, characterized by high hydrogenation activity, good selectivity for middle distillates, strong resistance to nitrogen poisoning, was prepared by co-gelling. The catalyst is not only suited to the single-stage hydrocracking process, but also to the first stage of serial hydrocracking process. In parallel with the fully loaded operation of the 1.4 Mt/a hydrocracking unit at the SINOPEC Qilu Petrochemical Company, a pilot test of the ZHC-01 catalyst was also carried out on the hydrocracking unit. The test results indicated that the activity, the yield of major target products and quality of the ZHC-01 catalyst could comply with the design requirements for the hydrocracking unit, and this catalyst could be applied in the hydrocracking unit. The commercial test results showed that the ZHC-01 catalyst, featuring good activity, stability, and flexibility in production, not only could meet the demand for producing environmentally friendly middle distillates, but could also increase the resource of optimized steam cracking feedstock.     

Preparation of VPO Catalysts and Effect of Zirconium Promoter on the Selective Oxidation of Pentane

1. Introduction The C5 cut, a relatively low-cost hydrocarbon stream in oil refining, has not found adequate use in petrochemical industry (Weissermel and Arpe, 1978). If it is used as liquid-petroleum-gas (LPG) component, the C5 cut is too heavy; while if it is used as gasoline component, the C5 cut is relatively too light. On the contrary, the demand for phthalic and maleic anhydrides is expected to grow at a rate of about 5% per year (Gleaves and Centi, 1993) due to their increasing app…     

Preparation of hierarchical ZSM-5 zeolite and its application in synthesis of tributyl citrate

First,the hierarchical ZSM-5 zeolite was prepared by hydrothermal method using mesoporous template cetyltrimethylammonium bromide(CTAB).The physical and chemical properties of the hierarchical ZSM-5 zeolite were characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR)and N2 adsorption-desorption and Scanning electron microscope(SEM).Then,the as-prepared hierarchical ZSM-5 zeolite and ion exchange resin were used as catalysts to evaluate the reaction performance of the synthesis of tributyl citrate.Compared with the ion exchange resin,the as-prepared ZSM-5 has a microporous and mesoporous composite structure and a large specific surface area,so that significantly improving the catalytic performance of synthesizing tributyl citrate and increasing the esterification rate of the reaction 8.7%.     

Study on Preparation and Application of Ti／Si Complex Zeolite

A Ti/Si complex zeolite has been prepared. X-ray diffraction and infrared spectrometry study has shown that two structures, namely the ZSM-5 and MCM-41, exist in the sample. BET tests have revealed that the complex zeolite contains regular mesopores of 2.6 nm. Ultraviolet spectrometry analysis has shown that the Ti species exist in the zeolite skeleton in the form of tetra-coordinate valence. The Ti/Si complex zeolite (TS-1/Ti-MCM-41) has apparently improved catalytic activity with respect to the macromolecular organic compound oxidation as compared to individual components of either Ti or Si containing zeolites (TS-1 and Ti-MCM-41).     

Preparation of an SBS Latex–Modified Bitumen Emulsion and Performance Assessment

Abstract

For resolving the contradiction of the stability between styrene-butadiene-styrene (SBS)-modified bitumen emulsion and the concentration of SBS, a method of preparing SBS latex is provided in this article. Results showed that SBS latex had good stability properties and performance. The effect of emulsifier concentration on the storage stability showed that the maximum stability of SBS latex–modified bitumen emulsion (SBS-LMBE) was obtained at emulsifier weight concentration 1.0% and addition of SBS latex to bitumen emulsion enhanced the difficulty of emulsification. The effects of SBS latex on bitumen properties showed the penetration decreased, whereas the softening point and ductility at 5°C increased, which means that SBS latex plays a role in improving the properties of bitumen. Compared to the base bitumen, saturate and aromatic of evaporation residue of SBS-LMBE decreased. However, resin and asphaltene increased. Analysis of the relationship between the components and properties of bitumen showed that the components change caused by SBS latex was beneficial to the properties of bitumen. The colloidal index (CI) showed that SBS latex also made the colloidal system more stable.     

Preparation and Application of Silica-based Perfusion Packing of Size Exclusion Chromatography for Quantitation of Polyacrylamide in Enhanced Oil Recovery Systems

The synthesis and characterization of a novel macroporous silica derived size exclusion chromatography (SEC) packing for quantitative analysis of high molecular weight (MW) polyacrylamide (PAM) are presented. Using this packing, a fast, sensitive and reproducible approach for quantitation of super high-MW PAM in demanding enhanced oil recovery (EOR) waters was developed and the effect of synthesis parameters on the properties of resultant materials was investigated. These parameters include salt addition, reaction temperature and duration, activation condition of functional groups on the silica surface, as well as the reaction cycles required for optimal silica modification. Moreover, SEC analysis conditions, such as mobile phase composition, flow rate, detection and sample preparation, were also explored and an optimal analysis protocol was developed. Under this optimized SEC analysis conditions, the synthesized macroporous materials proved satisfactory for quantification of PAM with average MW up to 22 million Daltons. An SEC analysis required less than few minutes with a detection limit of 1 ng, a linear response range of 0.1 to 75 mg/L with squared R value of 0.99 and reproducibility better than 9.2% RSD (relative standard deviation). The analysis of PAM in highly saline oilfield production water containing interfering high MW polymeric surfactants indicated the recovery ranges from 92.5% to 110.1% for 1.0 mg/L PAM and 94.2% to 103.8% for 50 mg/L PAM solution. This study presented for the first time that the reliable quantization of high MW PAM in highly demanding EOR waters can be achieved by SEC.     

Preparation of microencapsulated α-olefin drag reducing polymer used in oil pipeline transportation

Microcapsules containing oil drag-reducing polymer particles were prepared by melting-scattering and condensing of polyethylene wax,in-situ polymerization of urea and formaldehyde,and interfacial polymerization of styrene respectively.The related processes were studied by a molecular dynamics simulation method,and molecular design of microcapsule isolation agent was carried out on the basis of the simulation.The technologies for preparing microencapsulated oil drag-reducing polymer particles were compared and the circulation drag reducing efficiency of the microencapsulated polymer particles was evaluated based on the characterization results and their dissolution properties.Molecular design of a microcapsule isolation agent suggests that a-olefin polymer particles can be stably dispersed in water by using long-chain alkyl sodium salt surfactant which can prevent the agglomeration ofα-olefin polymer particles.The results of simulation of the adsorption process shows that the amount of alkyl sodium salt surfactant can directly affect the stability of microencapsulatedα-olefin polymer particles, and there must be a minimum critical amount of it.After characterization of the morphology by Scanning Electron Microscopy(SEM) and comparison of the static pressure stability,especially the conditions of reaction and technological control of microcapsules with different shell materials,microencapsulation of a-olefin polymer particles with poly-(urea-formaldehyde) as shell material was selected as the optimum scheme,because it can react under mild conditions and its technological process can be controlled in a large range.The relationship of drag reducing rate and dissolving time of microcapsules showed that the formation of microcapsules did not affect the maximum drag reducing rate,and the drag reducing rate of each sample can reach about 35%along with the dissolving time,i.e.microencapsulation did not affect the drag reducing property ofα-olefin polymer.     

核壳结构PS/PU纳米复合物的合成及其性能的研究

采用种子乳液聚合法 ,合成出以聚氨酯 (PU)为壳、聚苯乙烯 (PS)为核的核壳结构聚苯乙烯 /聚氨酯 (PS/PU)纳米复合乳液。采用动态光散射、透射电镜、红外光谱等测试手段对其结构特征及粒子形态进行了研究 ,其核 /壳质量比对纳米复合乳液的性能有一定影响 ,随着核 /壳质量比的增加 ,复合乳液的粒径和紫外吸光度增大 ,电导率下降 ,乳液粘度先下降而后上升     

核壳型复合粒子的合成及表征

以丙烯酸丁酯（BA）为第一单体,甲基丙烯酸甲酯（MMA）为第二单体,二乙烯苯（DVB）为交联剂,经分步乳液聚合,对表面偶联化处理的滑石粉微粒进行包覆,制得了以滑石粉粒子为核、PBA—co—DVB为弹性芯层、PBA—co—PMMA无规共聚物为过渡层、PMMA为壳层结构的多层复合粒子。通过FT—IR、DSC及DMA等检测表征,确认了其核壳聚合物包覆的形态结构。     

聚硅氧烷核壳粒子的制备与应用进展

综述了近几年聚硅氧烷核壳粒子的研究进展。分别介绍了以聚硅氧烷为核、为壳及为核壳的核壳粒子,重点阐述了以一步乳液聚合法和种子乳液聚合法制备聚硅氧烷核壳粒子及聚硅氧烷核壳粒子在增韧改性剂、涂料等领域的应用。     

双亲粒子聚合物随钻堵漏剂的合成与性能评价

首次将双亲粒子应用于随钻堵漏的研究。用浓乳液聚合界面引发制备疏水性核/亲水性壳双亲粒子。首先,通过浓乳液聚合得到聚苯乙烯胶体粒子,作为疏水性的核;然后通过界面引发使丙烯酰胺在核的表面聚合包覆,形成亲水性的聚丙烯酰胺壳层。该双亲粒子呈微粒状,并存在轻微的相互粘连或串状结构,平均粒径21.36μm。双亲粒子在淡水基浆中抗温可达180℃。含1%双亲粒子基浆的堵漏效果明显,并随粒子加量的增加,基浆漏失量减少,堵漏能力提高。随着挤注量的增加,挤注压力逐渐增大,挤注量为700 mL时的挤注压力可达14 MPa。双亲粒子可降低体系API滤失量。在加量不高于2%时,基浆流变性变化不大,可用于高温地层的随钻堵漏。     

Synthesis of monodisperse crosslinked polystyrene microspheres

Monodisperse crosslinked polystyrene （CPS） particles were prepared through the normal emulsion polymerization method by adding crosslinker--divinylbenzene （DVB） into the reaction system after polystyrene （PS） particles grew to -80% of the final size. When the amount of crosslinker DVB added was less than 6.17 wt% based on styrene, the prepared CPS particles were spherical and uniform and the size of the CPS particles could be predicted through the normal emulsion method. The glass transition temperature （Tg） of the prepared CPS particles was higher than that of un-crosslinked PS particles and, the more crosslinker that was added, the higher the Tg of CPS Particles. The prepared CPS particles had strong resistance to organic solvents.     

二氧化硅空心球的制备

在乙醇/水的混合溶液中,采用聚乙烯吡咯烷酮(PVP)为分散剂,偶氮二异丁腈(AIBN)为引发剂,通过分散聚合法制备出聚苯乙烯(PS)微球,然后以微球为模板,将产生的PS粒子作为核,SiO_2作为壳。SiO_2空心球通过在600℃时的热分解可得到。对制得的空心球通过热分析仪、扫描电子显微镜进行表征。对图进行分析,并讨论影响因素。     

单分散阳离子聚苯乙烯微球的制备及表征

通过分散聚合制备了单分散性好的阳离子聚苯乙烯(PS)微球,考察了聚合过程中苯乙烯(St)、引发剂偶氮二异丁腈(AIBN)、分散剂聚乙烯基吡咯烷酮(PVP)、共聚单体甲基丙烯酰氧乙基三甲基氯化铵(DMC)的含量及反应介质的组成等因素对微球的粒径及其分散系数的影响;采用FTIR、NMR、FESEM、Zeta电位及激光粒度分布仪等分析手段对微球的结构、粒径分布及表位电位等进行了表征。实验结果表明,当反应体系中St质量分数为10%、AIBN质量分数为0.2%、PVP质量分数为1.5%、DMC质量分数为0.3%时,在聚合温度为70℃、乙醇与水的体积比为9∶1条件下,制备出了平均粒径为1.38μm、分散系数为0.005、Zeta电位约为+40 mV的阳离子PS微球。     

分散聚合法制备大粒径窄分布单分散聚苯乙烯微球

采用分散聚合法成功制备出粒径2.05～9.03μm的单分散聚苯乙烯(PS)微球。考察了单体质量分数、分散介质极性、引发剂用量和稳定剂用量对PS微球粒径和分布的影响,得出适宜的合成条件:单体苯乙烯(St)质量分数28%～37%、分散介质(乙醇水溶液)极性4.5～5.2、引发剂偶氮二异丁腈与St的质量比0.03～0.05、稳定剂聚乙烯吡咯烷酮与St的质量比0.3～0.8、75℃下反应24 h,在此条件下,可合成出单分散性好、分散系数低(在0.05以下)、大粒径的PS微球。     

分散聚合法制备聚丙烯酰胺降滤失剂的研究

以丙烯酰胺为单体,通过分散聚合法制备了一种聚丙烯酰胺微球降滤失剂,并与水溶液聚合法、反相乳液聚合法分别合成的聚丙烯酰胺降滤失剂进行了对比。通过优化引发剂加量等方法,合成了可溶解的聚丙烯酰胺微球降滤失剂FA-25。该方法合成过程无毒、环保,无需进行后处理。通过透射电镜分析、热重分析、粒径分析、凝胶色谱法分子量分析等手段,对FA-25进行了结构表征研究,结果表明FA-25为球形,尺寸在40～200 nm范围内,分子量可以达到104 928,初始热分解温度200 ℃。在膨润土浆中加入1% FA-25后能够将中压滤失量降至13.8 mL,优于水溶液合成的产品及反相乳液法制备的产品。此外,产品抗温性能良好,可以抵抗200 ℃的高温,具有良好的应用前景。