Different effects of silane and carboxyled polypropylene on crystal morphology of polypropylene/molecular sieves type 5A composites

The silane KH‐550 and carboxyled polypropylene (EPP) were used as compatibilizers in this study. The effect of them on crystalline morphology of polypropylene/molecular sieves type 5A (PP/5A) composites was investigated. IR illustrated that 5A interacts with EPP by forming molecule interaction or hydrogen bonds, but interacts with silane by covalent bonds. Polarized optical microscopy (POM) and X‐ray diffraction (XRD) revealed that a suitable amount of silane can promote β‐crystal formation in PP, and the average size of spherulites in the PP/5A/silane is smaller than that of PP. EPP interacts with 5A by molecule interaction and cocrystallizes with PP, leading to the crystal morphology of PP/5A/EPP resembles to that of pure PP. Significant difference was detected in the effect of the two compatibilizers, which attributed to the different compatibility mechanisms. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

羧基化聚丙烯在聚丙烯／5A分子筛复合材料中的增容作用

利用扫描电镜、偏光显微镜、流变等手段探讨了羧基化聚丙烯（EPP）在聚丙烯／SA分子筛（PP／5A）共混物中的增容作用，以及对复合材料力学性能，形态结构和流变行为的影响。用红外光谱和X-射线衍射对EPP的增容机理进行了探讨。结果表明：EPP的加入改善了复合材料的相容性。在EPP含量为10％时，复合材料的综合性能最好，其拉伸强度、冲击强度分别较PP／SA提高了2．9％、31．8％。IR和XRD表明EPP是通过极性基团与5A之间以分子间作用力结合，另一端与基体PP产生共晶，从而发挥增容作用。     

Compatibilization of recycled poly(ethylene terephthalate) and polypropylene blends: Effect of polypropylene molecular weight on homogeneity and compatibility

The effectiveness of compatibilizers in enhancing the dispersion of polypropylene (PP) at various molecular weights in recycled polyethylene terephthalate (RPET) was elucidated. The idea of incorporating PP of different molecular weights evolved from the intention of simultaneously recycling the PET bottles together with the PP‐based bottle caps, which are often of low molecular weight (M_w). Three grades of PP with known molecular weights were blended with RPET at various loadings of compatibilizers. Morphological analyses suggest that the dispersion of the PP particles was more homogeneous, and the average particle size was smaller when low M_w PP was incorporated. This indicates that the interaction between the compatibilizer and PP particles was more intense with the presence of a large number but shorter PP molecular chains. Moreover, specimens containing low M_w PP were found to remain homogeneous regardless of compatibilizer and PP content in the RPET/PP blends. The homogeneity of the blends significantly affected their mechanical performance as well. Higher stiffness, yield strength, deformability, and toughness were observed when low M_w PP was incorporated, regardless of PP and compatibilizer loadings. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

13X分子筛对废水中锌离子的吸附性能研究

通过正交水平实验对13X分子筛吸附锌离子条件进行优化,考察了锌离子浓度、温度和溶液的pH值对锌离子吸附容量的影响。测定了锌离子在13X分子筛上的吸附平衡和动力学数据,吸附平衡符合Langmu ir方程,并得到了模型参数,说明Langmu ir模型能够描述本体系的特性。采用XRD对13X分子筛吸附锌离子的结构变化进行分析表明,其吸附过程中发生了锌离子与13X分子筛内钠离子的交换。这些结果为吸附过程处理含锌废水的设计提供一定的参考。     

载金属离子的13X分子筛对噻吩的吸附性能研究

采用Zn2+,Cu2+,N i2+,Ag+分别负载到13X分子筛制得吸附剂,考察了它们对噻吩的吸附能力,发现Ag+-13X吸附效果最好,与软硬酸碱理论解释的结果一致。测定了噻吩在Ag+-13X上的吸附动力学数据,并测定了其不同温度下的吸附平衡数据,采用Langmu ir模型进行拟合,与平衡数据吻合得很好,说明Langmu ir模型能够描述本体系的特征,从微观上探讨了其吸附机理,是分子尺寸和化学键的共同作用;考察了Ag+-13X对真实汽油的脱硫性能,结果表明对汽油中的噻吩类硫化物都有脱除效果,为其工业设计提供基础数据。     

13X沸石分子筛对低浓度CO2动态吸附

目前对于吸附分离技术应用于高压、低浓度CO₂脱除的研究还较少,在进行相应吸附脱碳工艺设计时也缺少相关的参考数据。为探究13X沸石分子筛对低浓度CO₂的动态吸附性能,本文利用动态吸附实验的方法,探究不同条件下低浓度（摩尔分数3%）CO₂气体在13X分子筛上的动态吸附性能,得到不同压力、温度、气体流量、填料高度及分子筛规格（尺寸、形状）等因素影响下的13X分子筛对于CO₂气体的动态吸附规律及相应的性能指标参数。结果表明：随着吸附压力的升高,13X分子筛的CO₂吸附量增加但增量逐渐减小;降低吸附温度、减小气体流量和增加填料高度均有利于增强13X分子筛的动态CO₂吸附性能,提高吸附脱碳效果,其中温度及填料高度的变化对于CO₂吸附的影响程度最大;实验还发现小尺寸及条状13X分子筛的动态吸附脱碳性能优于其他规格,并根据其特定条件下的出口CO₂浓度为50mL/m³时的CO₂吸附量指标,给出吸附剂用量与液化天然气（LNG）脱碳工艺处理量的关系系数。     

Polymerization of N-vinylcarbazole over cobalt (II) exchanged 13X molecular sieves

Polymerization of N-vinylcarbazole over Co(II)-13X molecular sieves in toluene solution has been studied. The rate of polymerization has been observed to be second order both in monomer concentration and in the exchange level of Co(II), and linearly dependent on catalyst loading. An apparent activation energy of 8.71 kcal mol^?1 (36.41 kJ mol^?1) has been found for the polymerization. The effect of different parameters on molecular weight has also been studied. The general kinetic features of the reaction are somewhat different from those reported for monomers like isobutyl vinyl ether, styrene etc. on simple and rare earth exchanged 13X molecular sieves.     

PP-g-AA对PP/云母增容作用的研究

研究了聚丙烯(PP)与云母共混时,添加第3组分PP—g—AA对PP/云母共混体系的影响。用扫描电镜观察共混体系中云母的分布状况。研究结果表明,加入第3组分增加了共混体系的相容性,使拉伸强度和抗冲击强度均明显提高。     

载铜13X的制备及其对噻吩的吸附动力学

研究了载铜13X的制备以及吸附噻吩的动力学性能.实验考察了负载溶液、还原时间、还原温度以及预处理等方面对吸附剂制备的影响,得到了制备载铜13X吸附剂所需要的最优化条件.采用Crank单孔模型对测定的吸附动力学数据进行拟合,确定了不同温度下的噻吩在载铜13X上的扩散系数.实验结果表明,Crank单孔模型可很好地描述噻吩在载铜13X分子筛上的吸附过程.     

磷化氢在改性13X分子筛上的吸附行为

为回收工业废气中的磷化氢(PH3)并资源化,采用浸渍法制备了一种CaCl2改性13X分子筛吸附剂,通过容积法研究了25—70℃PH3气体在改性13X分子筛上的等温吸附行为。结果表明,在实验条件范围内25,40,55,70℃下PH3的饱和吸附量(质量分数)分别为2.528,1.901,1.591,0.925mg/g。Freundlich吸附等温方程很好地模拟了改性13X分子筛对PH3的等温吸附,Langmuir和Henry吸附等温方程对吸附平衡数据的拟合效果不佳表明了改性13X分子筛表面吸附位的不均匀分布。当初始吸附量为0.10mg/g时,等量吸附热值最大,为17.81353kJ/mol,即等量吸附热不超过18kJ/mol,过程为物理吸附,便于PH3气体的解吸。     

PP-g-Si对PP／GF的增容作用

制备了硅烷接枝聚丙烯(PP-g-Si)，研究了PP-g-Si作为聚丙烯／玻纤(PP／GF)复合体系的界面相容剂对界面结合和力学性能的影响，并与马来酸酐接枝聚丙烯(PP-g-MAH)的增容效果进行了比较。结果表明，PP-g-Si对PP／GF体系有增容作用，不仅可以改善PP／GF复合体系的拉伸强度，而且可以改善其韧性。硅烷接枝聚丙烯可以降低PP／GF复合体系的最大扭矩。玻纤的加入可以提高聚丙烯的热变形温度，硅烷接枝聚丙烯对PP／GF复合体系的热变形温度有稍微改善。扫描电镜观察表明，玻纤与基体间具有强有力的界面结合，硅烷接枝聚丙烯的增容效果优于马来酸酐接枝聚丙烯。     

Compatibilization of styrene–butadiene–styrene block copolymer in polypropylene/polystyrene blends by analysis of phase morphology

Effect of compatibilization of styrene–butadiene–styrene (SBS) block copolymer in polypropylene/polystyrene (PP/PS) blends was studied by means of small angle X‐ray scattering (SAXS) and scanning electron microscope (SEM). According to SAXS, a certain amount of SBS was located at the interface in all the analyzed samples, forming the relatively thicker interface layer penetrating into homopolymers, and the thickness of the interface layer was quantified in terms of Porod light scattering theory. The incorporation of SBS into PP/PS blends resulted in a decrease in domain size following an emulsification curve as well as an uniform size distribution, and consequently, a fine dispersion of PP domains in the PS matrix. This effect was more pronounced when the concentration of SBS was higher. A critical concentration of SBS of 15% above which the interface layer approaches to saturation and domain size attains a steady‐state was observed. Further, the morphology fluctuation of unetched fracture surface of umcompatibilized and compatibilized blends was analyzed using an integral constant Q based on Debye‐Bueche light scattering theories. Variation of Q as a function of the concentration of SBS showed that, due to the penetrating interface layer, adhesion between phases was improved, making it possible for applied stress to transfer between phases and leading to more uniform stress distribution when blends were broken; accordingly, a more complicated morphology fluctuation of fracture surface appeared. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:365–370, 2007     

羧基化聚丙烯对聚丙烯／极性聚合物的增容作用

探讨了一种全新方法制备的羧基化聚丙烯(EPP)在聚丙烯／聚酰胺(PP／PA6)，聚丙烯／聚乙烯醇(PP／PVA)共混物制备过程中的增容作用。实验结果表明，EPP的加入，使共混物的拉伸强度显著提高；扫描电镜及偏光显微形态分析表明，EPP改善了共混物的相容性，是一种性能优良、价廉、易得且环境友好的偶联剂。     

High resolution,quasi-equilibrium sorption studies of molecular sieves

Argon, nitrogen, and neopentane adsorption isotherms from molecular sieves are recorded at 87 K, 77 K, and 273 K, respectively, by a quasi-equilibrium, high resolution gas sorption technique. The molecular sieves used in this study are alkali exchanged zeolite X, AlPO₄-11, AlPO₄-5, VPI-5, KL, CaA, ZSM-5, and ZSM-11. Little relation is observed between the transition pressure for microporous nitrogen adsorption and pore size. Small changes in the effective pore size resulting from variations in cation size are detected in the transition pressure for argon adsorption. Large shifts in the transition pressure for argon adsorption are found for the 10-, 12-, and 18-membered ring pores of AlPO₄-11, AlPO₄-5, and VPI-5, respectively. Argon adsorption combined with neopentane adsorption on microporous materials provides additional information regarding transitions in the isotherm that result from dual pore systems and effects that may be due to adsorbate packing. The step in the nitrogen isotherm atP/P ₀> 0.1 from ZSM-5 is not observed in the nitrogen isotherm from ZSM-11.     

13X分子筛耦合四丁基溴化铵促进剂作用下CO2/H2水合物形成动力学

水合物法捕集CO₂技术因其清洁环保、工艺简单等优点成为研究热点。但气液传热传质速度慢导致的形成速率慢、储气能力低等关键问题亟待解决。利用13X分子筛耦合四丁基溴化铵（TBAB）促进剂在279.15～280.65K、3.0～6.0MPa研究了CO₂/H₂（39.8% CO₂/60.2% H₂）水合物的形成过程的压降曲线和气体消耗量,并对比分析了TBAB浓度、压力对其促进效果的影响。实验结果表明,与采用搅拌方式的TBAB/CO₂/H₂水合物形成过程相比,13X分子筛可显著提高TBAB/CO₂/H₂水合物的压降速率和气体消耗量。在279.15K、3.0MPa,随着TBAB溶液浓度增大,CO₂/H₂水合物形成过程的气体消耗量先增大后减小;而当温压条件为280.65K、3.0MPa时,气体消耗量随耦合促进剂中TBAB浓度变化仍遵循类似规律。此外,13X分子筛耦合TBAB促进剂对CO₂/H₂水合物压降速率和气体消耗量的影响随着实验压力升高而升高。     

微孔-中孔复合分子筛的合成研究进展

概述了最近几年引起人们广泛关注的微孔-中孔复合分子筛的合成情况,重点介绍了不同复合模式的微孔-中孔复合分子筛的合成方法,包括单模板剂法、双模板剂法、附晶生长法、孔壁晶化法、碱处理法、微孔沸石硅源法等一系列方法,分析了各种合成方法的优点。从目前已取得的研究结果看,附晶生长法和碱处理法值得进一步关注。     

介孔分子筛集砷材料的制备与表征

通过浸渍法在介孔分子筛上负载亲砷活性组分,制备了介孔分子筛集砷材料。用XRD、SEM、N2吸附和脱附进行了表征,并针对液态烃常温脱砷体系,对该材料的吸附集砷性能进行了进一步的测定。研究结果表明介孔分子筛集砷材料具有比常规脱砷剂更为优良的集砷性能。     

Compatibilization effects of styrenic/rubber block copolymers in polypropylene/polystyrene blends

Compatibilizing effects of styrene/rubber block copolymers poly(styrene‐b‐butadiene‐b‐styrene) (SBS), poly(styrene‐b‐ethylene‐co‐propylene) (SEP), and two types of poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene) (SEBS), which differ in their molecular weights on morphology and selected mechanical properties of immiscible polypropylene/polystyrene (PP/PS) 70/30 blend were investigated. Three different concentrations of styrene/rubber block copolymers were used (2.5, 5, and 10 wt %). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the phase morphology of blends. The SEM analysis revealed that the size of the dispersed particles decreases as the content of the compatibilizer increases. Reduction of the dispersed particles sizes of blends compatibilized with SEP, SBS, and low‐molecular weight SEBS agrees well with the theoretical predictions based on interaction energy densities determined by the binary interaction model of Paul and Barlow. The SEM analysis confirmed improved interfacial adhesion between matrix and dispersed phase. The TEM micrographs showed that SBS, SEP, and low‐molecular weight SEBS enveloped and joined pure PS particles into complex dispersed aggregates. Bimodal particle size distribution was observed in the case of SEP and low‐molecular weight SEBS addition. Notched impact strength (a_k), elongation at yield (ε_y), and Young's modulus (E) were measured as a function of weight percent of different types of styrene/rubber block copolymers. The a_k and ε_y were improved whereas E gradually decreased with increasing amount of the compatibilizer. The a_k was improved significantly by the addition of SEP. It was found that the compatibilizing efficiency of block copolymer used is strongly dependent on the chemical structure of rubber block, molecular weight of block copolymer molecule, and its concentration. The SEP diblock copolymer proved to be a superior compatibilizer over SBS and SEBS triblock copolymers. Low‐molecular weight SEBS appeared to be a more efficient compatibilizer in PP/PS blend than high‐molecular weight SEBS. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 291–307, 1999     

Compatibilization of polypropylene/polystyrene blends with poly(styrene-b-butadiene-b-styrene) block copolymer

The compatibilizing effect of the triblock copolymer poly(styrene-b-butadiene-b-styrene) (SBS) on the morphology and mechanical properties of immiscible polypropylene/polystyrene (PP/PS) blends were studied. Blends with three different weight ratios of PP and PS were prepared and three different concentrations of SBS were used for investigations of its compatibilizing effects. Scanning electron microscopy (SEM) showed that SBS reduced the diameter of the PS-dispersed particles as well as improved the adhesion between the matrix and the dispersed phase. Transmission electron microscopy (TEM) revealed that in the PP matrix dispersed particles were complex “honeycomblike” aggregates of PS particles enveloped and joined together with the SBS compatibilizer. Wide-angle X-ray diffraction (WAXD) analysis showed that the degree of crystallinity of PP/PS/SBS slightly exceeded the values given by the addition rule. At the same time, addition of SBS to pure PP and to PP/PS blends changed the orientation parameters A₁₁₀ and C significantly, indicating an obvious SBS influence on the crystallization process in the PP matrix. SBS interactions with PP and PS influenced the mechanical properties of the compatibilized PP/PS/SBS blends. Addition of SBS decreased the yield stress and the Young's modulus and improved the elongation at yield as well as the notched impact strength in comparison to the binary PP/PS blends. Some theoretical models for the determination of the Young's modulus of binary PP/PS blends were used for comparison with the experimental results. The experimental line was closest to the series model line. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 69: 2625–2639, 1998     

杂原子AlPO-n分子筛的制备及应用研究进展

通过在AlPO-n分子筛中掺杂不同的金属或非金属元素制备杂原子AlPO-n分子筛,不仅具有AlPO-n分子筛的规整结构、良好热稳定和水热稳定性,还具有可调控的酸性质、离子交换位点、催化活性中心和择形性,使杂原子AlPO-n分子筛在催化、气体吸附和化学分离等方面展现巨大潜力。综述近年来杂原子AlPO-n分子筛的研究进展,介绍杂原子掺杂的制备方法、模板剂效应和取代性能变化,描述杂原子AlPO-n分子筛的应用前景。