PEO-LiClO<Subscript>4</Subscript>-ZSM5 composite polymer electrolyte (IV): Polarized optical microscopy study

Polarized optical microscopy (POM) results show that ZSM5 has great influence on both the nucleation stage and the growth stage of PEO spherulites. Part of ZSM5 particles can act as the nucleus of PEO spherulites and thus increase the amount of PEO spherulites. On the other hand, ZSM5 can restrain the recrystallization tendency of PEO chains through Lewis acid-base interaction and hence decrease the growth speed of PEO spherulites. The increasing amount of PEO spherulites, decreasing size of PEO spherulites, and the incomplete crystallization are all beneficial for creating more continuous amorphous phases of PEO, which is very important for the transporting of Li⁺ ions. An adequate amount of ZSM5 can enhance the room temperature ionic conductivity of PEO-LiClO₄ based polymer electrolyte for more than two magnitudes.     

Effect of poly(butylene succinate) crystals on spherulitic growth of poly(ethylene oxide) in binary blends of the two substances

The effects of the lamellar growth direction, extinction rings, and spherulitic boundaries of poly(butylene succinate) (PBSU) on the spherulitic growth of poly(ethylene oxide) (PEO) were investigated in miscible blends of the two crystalline polymers. In the crystallization process from a homogeneous melt, PBSU first developed volume‐filling spherulites, and then PEO spherulites nucleated and grew inside the PBSU spherulites. The lamellar growth direction of PEO was identical with that of PBSU even when the PBSU content was about 5 wt %. PEO, which intrinsically does not exhibit banded spherulites, showed apparent extinction rings inside the banded spherulites of PBSU. The growth rate of a PEO spherulite, G_PEO, was influenced not only by the blend composition and the crystallization temperature of PEO, but also by the growth direction with respect to PBSU lamellae, the boundaries of PBSU spherulites, and the crystallization temperature of PBSU, T_PBSU. The value of G_PEO first increased with decreasing T_PBSU when a PEO spherulite grew inside a single PBSU spherulite. Then, G_PEO decreased when T_PBSU was further decreased and a PEO spherulite grew through many tiny PBSU spherulites. This behavior was discussed based on the aforementioned factors affecting G_PEO. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 539–547, 2009     

聚环氧乙烷球晶中同心环形纹的形成

聚环氧乙烷 (PEO)是一种易结晶的柔性高聚物 ,它形成的球晶比较大 ,易于观察 ,是研究高聚物结晶的常用材料[1～ 3 ] .有人发现PEO球晶在正交偏振片观察下呈现有明暗相间的同心圆环 ,并指出PEO球晶中的此圆环结构不是普通的消光 ,因为在非偏振光下此结构仍然存在[4,5] ;并认为这种同心环形纹的出现与球晶阶梯式生长或螺旋式生长方式有关 .本文作者利用偏光显微镜在观察PEO单个球晶的生长过程中 ,并未发现有这种同心环形纹的出现 ;为了进一步认识环形纹的形成原因 ,本文作者对PEO的结晶过程进行了全程跟踪观察 ,对同心环形纹的形成给予…     

Spherulitic growth in block copolymers and blends of miscible crystalline polymers

Spherulitic morphology and growth rate of block copolymers comprised of miscible crystalline constituents, namely poly(ethylene succinate) (PES) and poly(ethylene oxide) (PEO), were investigated. The results of the copolymers were compared with those of the blends with the same composition and molecular weight. Interpenetrating spherulites, where spherulites of one component grow in those of the other component, were observed in the copolymers as in the blends. Copolymerization, namely the connectivity of the PES and PEO blocks, reduced the spherulitic growth rate in the melt for both components. The growth inside the spherulites of the other component was discussed based on the lamellar and fibrillar (or lamella‐stack) structures, which are influenced by the interblock connectivity. Suppression of molecular mobility in the interlamellar regions resulted in the reduced nucleation and growth rate of the component growing in the spherulites of the other constituent. PES of the copolymer showed dendrites around 60 °C or above. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012     

以水热法于ZSM-5分子筛中分散MoO3的研究

热扩散法的ＭｏＯ３最高分散量为每克ＺＳＭ－５上０．０８克ＭｏＯ３．而本文采用水热分散法可使ＭｏＯ３在ＺＳＭ－５分子筛中的分散量大大提高．当分散量高达每克ＺＳＭ－５上０．３克ＭｏＯ３时，通过ＸＲＤ，ＩＲ，ＤＴＡ谱测试和吸附测定，都证实了ＭｏＯ３在ＺＳＭ－５中仍然是以非晶相分散态存在．此时，样品有吸附自重６％的水的吸附能力和相应的孔道．     

聚β—羟基丁酯酯／超高分子量聚氧化乙烯共混体系相容性和结晶行为

为了解决废弃塑料引起的“白色污染”问题,世界各国竞相研制开发可生物降解高分子材料,其中,有关聚β羟基丁酸酯［ｐｏｌｙ（βｈｙｄｒｏｘｙｂｕｔｙｒａｔｅ）（ＰＨＢ）］的研究尤其活跃．然而,由于商品价格较高,材料本身抗冲击性能较差、加工窗口较窄等限制...     

聚β-羟基丁酸酯/超高分子量聚氧化乙烯共混体系相容性和结晶行为

为了解决废弃塑料引起的“白色污染”问题,世界各国竞相研制开发可生物降解高分子材料,其中,有关聚β 羟基丁酸酯［ｐｏｌｙ（β ｈｙｄｒｏｘｙｂｕｔｙｒａｔｅ）（ＰＨＢ）］的研究尤其活跃．然而,由于商品价格较高,材料本身抗冲击性能较差、加工窗口较窄等限制...     

Crystallization kinetics in shearing‐induced oriented and stretched poly(ethylene oxide)

Isothermal crystallization kinetics in the melting of poly(ethylene oxide) (PEO) were investigated as a function of the shear rate and crystallization temperature by optical microscopy. The radial growth rates of the spherulites are described by a kinetics equation including shearing and relaxation combined effects and the free energy for the formation of a secondary crystal nucleus. The free‐energy difference between the liquid and crystalline phases increased slightly with rising shearing rates. The experimental findings showed that the influence of the relaxation of PEO, which is related to the shear‐induced orientation and stretch in a PEO melt, on the rate of crystallization predominated over the influence of the shearing. This indicated that the relaxation of PEO should be more important so that the growth rates increase with shearing, but it was nearly independent of the shear rate within the measured experimental range. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 656–665, 2004     

聚氧乙烯球晶上彩色环状条纹的形成

用自然白光代替偏振光在显微镜下观察聚氧乙烯球晶的生长过程, 可以更清晰地看到彩色环形条纹的形成. 当成长中的二维球晶相互碰撞后, 被挤出的熔体改变球晶的原有结晶方向, 流向饼形球晶中央而在其表面上逆向结晶, 由于被挤出的熔体数量有限, 晶层的厚度逐渐减小, 在盖玻片下方形成一个盘状的楔形真空间隙. 此间隙导致彩色环状干涉条纹的形成. 实验用肉眼直接观察到二维球晶在生长过程中结晶方式的变化, 为二次结晶理论的发展提供了实验依据.     

Effects of top confinement and diluents on morphology in crystallization of poly(l‐lactic acid) interacting with poly(ethylene oxide)

Effects of top confinement and diluent poly(ethylene oxide) (PEO) on poly(l ‐lactic acid) (PLLA) crystal morphology have been investigated. When crystallized at 120 °C, uncovered neat PLLA sample exhibits higher growth rate ringless spherulites; while the covered sample exhibits lower growth rate ring‐banded spherulites. As PEO is introduced into PLLA, the morphology also undergoes significant changes. For the same T_c,PLLA = 120 °C, the PEO/PLLA blend with PEO composition greater than 25% exhibits ring‐banded patterns even in uncovered sample. However, in much greater PEO composition (>80 wt %), uncovered samples exhibit ring bands diverging into dendritic patterns, while top covered samples tend to maintain the spiral ring‐band patterns. Both PEO inclusion in PLLA and top cover on films impose growth kinetic alterations. Additionally, the top glass cover tends to prevent the lower surface tension PLLA to be accumulated on the surface, resulting in the formation of ring‐band pattern. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 1160–1170     

PEO-LiClO4-ZSM5复合聚合物电解质 I. 电化学研究

首次以“择形”分子筛ZSM5为填料, 通过溶液浇铸法制得PEO-LiClO₄-ZSM5全固态复合聚合物电解质(CPE)膜. 交流阻抗实验表明ZSM5的引入可以显著地提高CPE的离子电导率. 利用交流阻抗-稳态电流相结合的方法对CPE的锂离子迁移数进行了测定, 结果表明掺入ZSM5后锂离子迁移数明显升高. ZSM5的含量为10%时, CPE同时具有最高离子电导率1.4×10^－5 S•cm^－1(25 ℃)和最大锂离子迁移数0.353. PEO-LiClO₄-ZSM5/Li电极界面稳定性实验表明PEO-LiClO₄-ZSM5复合聚合物电解质在全固态锂离子电池领域具有良好的应用前景.     

聚氧乙烯-镧系金属盐(Ln3+)的络合对聚氧乙烯形态结构的影响

采用偏光显微镜(POM)、差示扫描量热(DSC)和X 射线衍射,对聚氧乙烯(PEO)的形态结构和热物理行为随6种镧系盐对PEO的摩尔比变化的规律进行了系统的探讨.结果表明,随六合水氯化镧系盐摩尔比的增加,PEO球晶行为、熔点和熔融热均逐渐减弱,当盐对PEO的摩尔比达到一定值时(如YbCl3·6H2 O :PEO =2 0 ) ,则PEO完全不结晶.不同的镧系盐对PEO结晶的影响程度不同.X 射线衍射分析的结果也表明PEO晶面衍射峰随Ln3+ 盐摩尔比的增加而下降,与POM和DSC结果一致的.结果还表明较高的干燥温度(6 0℃)对PEO与Ln3+ 的相互作用有促进作用.对比二次降温的试样与原始试样的结晶行为,降温后结晶试样的特征表明络合在降温结晶后还存在.红外结果表明PEO与Ln3+ 的相互作用是络合作用.     

Poly(ethylene oxide) blends with crosslinking polyester resin

The miscibility of polyethylene oxide (PEO) with oligoester and polyester resin, the morphology of the blends and the kinetics of PEO crystallization in the blends were studied by optical microscopy and differential scanning calorimetry. The blends were found to be miscible with uncured resin at 60°C. After isothermal crystallization of PEO from liquid oligoester or UV cured polyester about 20% of the PEO material is still dissolved in the resin and it is incorporated between lamellae or in the interspherulitic regions. It was observed that the growth rate of PEO spherulites and the degree of crystallinity of PEO in the blends decreases very fast together with a decrease of the PEO content and the progress of the resin crosslinking.     

PEO／PVP共混体系结晶行为

本文用WAXD、PLM、DSC方法研究了聚氧化乙烯(PEO)/聚乙烯基吡咯烷酮(PVP)共混体系的结晶行为,探索了两组分聚合物间相互作用及体系结晶度与非晶组分含量的关系。DSC研究表明PEO/PVP共混体系具有两个玻璃化转变温度,分别是纯组分的T_g,无相容性。应用Avrami和LH方程对其动力学参数进行了研究。偏光显微镜观察了共混物结构形态。     

Dispersion and Orientation of Zeolite ZSM‐5 Crystallites within a Fluid Catalytic Cracking Catalyst Particle

Confocal fluorescence microscopy was employed to selectively visualize the dispersion and orientation of zeolite ZSM‐5 domains inside a single industrially applied fluid catalytic cracking (FCC) catalyst particle. Large ZSM‐5 crystals served as a model system together with the acid‐catalyzed fluorostyrene oligomerization reaction to study the interaction of plane‐polarized light with these anisotropic zeolite crystals. The distinction between zeolite and binder material, such as alumina, silica, and clay, within an individual FCC particle was achieved by utilizing the anisotropic nature of emitted fluorescence light arising from the entrapped fluorostyrene‐derived carbocations inside the zeolite channels. This characterization approach provides a non‐invasive way for post‐synthesis characterization of an individual FCC catalyst particle in which the size, distribution, orientation, and amount of zeolite ZSM‐5 aggregates can be determined. It was found that the amount of detected fluorescence light originating from the stained ZSM‐5 aggregates corresponds to about 15 wt %. Furthermore, a statistical analysis of the emitted fluorescence light indicated that a large number of the ZSM‐5 domains appeared in small sizes of about 0.015–0.25 μm², representing single zeolite crystallites or small aggregates thereof. This observation illustrated a fairly high degree of zeolite dispersion within the FCC binder material. However, the highest amount of crystalline material was aggregated into larger domains (ca. 1–5 μm²) with more or less similarly oriented zeolite crystallites. It is clear that this visualization approach may serve as a post‐synthesis quality control on the dispersion of zeolite ZSM‐5 crystallites within FCC particles.     

聚氧乙烯／聚酚氧共混体系的结晶行为及相容性研究

对聚氧化乙烯/聚酚氧(PEO/PH)共混体系的研究表明,随共混体系中非晶组份PH含量的增加,Avrami指数n值由2.0～2.3变为1.5～2.0,体系的结晶由盘状生长转化为纤维状生长;成核方式由方式Ⅰ转化为方式Ⅱ.PEO/PH共混体系的平衡熔点随PH含量的增加而降低,相互作用能量密度B=-1.46cal/mol,说明体系是互容的。     

Catalytic Combustion of Ethyl Acetate over Nanostructure Cobalt Supported ZSM-5 Zeolite Catalysts

Gas phase catalytic combustion of ethyl acetate, as one of volatile organic compounds (VOC), was studied on nanostructure ZSM-5, HZSM-5 and Co-ZSM-5 with different cobalt loadings. Nanostructure of ZSM-5 was determined by XRD, SEM and TEM. Catalytic studies were carried out under atmospheric pressure in a fixed bed reactor. Results showed that the Co-ZSM-5 catalysts had better activity than others and at temperatures below 350 ℃, amount of Co loading was more effective on catalytic activity. The order of conversion of ethyl acetate over different Co loading is as follows: Co-ZSM-5 (0.75 wt%)＜Co-ZSM-5 (1.5 wt%)＜Co-ZSM-5 (15 wt%)＜Co-ZSM-5 (2.8 wt%). Besides the higher the inlet concentration of ethyl acetate, the lower the conversion yield, and oxygen concentration in catalytic oxidation conditions has not so large influence on conversion. Furthermore, the presence of water vapor in inlet gaseous feed has an inhibitive effect on ethyl acetate conversion and at the temperatures above 400˚C, the effect decreases.     

分散法制备的CuCl/ZSM-5分子筛催化剂上C3H6选择性催化还原NO反应的研究

研究了由分散法制备的CuCl/ZSM-5分子筛催化剂上丙烯在过量氧存在下选择催化还原NO反应,发现该法能使活性组份高度分散于载体上,且所制备的高负载量CuCl/H-ZSM-5与离子交换法制备的Cu-ZSM-5相比在较低反应温度下具有更高的反应活性.     

聚环氧乙烷球晶的带状结构与球晶内部的环形裂纹

聚环氧乙烷球晶的带状结构与球晶内部的环形裂纹丁建东，朱军祥，杨玉良（复旦大学高分子科学系、国家教委聚合物分子工程开放实验室，上海，２００４３３）关键词聚合物，带状球晶，裂纹聚环氧乙烷（ＰＥＯ）具有高度的柔顺性，易于结晶，因而被人们选作研究聚合物结晶的...     

Thermoswitching property in TCNQ salts of ionenes containing poly(ethylene oxide) segments

Ionene polymers characterized by the alternating structure of ionene and crystalline poly(ethylene oxide) (PEO) segments were prepared as a function of PEO segment size. A microstructure of these ionenes and their 7,7,8,8-tetracyanoquinodimethane (TCNQ) salts were investigated with x-ray diffraction patterns, thermal scanning behavior, and polarizing micrographs. On the basis of this microstructure, the change in resistivity with temperature was studied. In Arrhenius' plots of the resistivity the simple salts in which the spherulites consisting of the PEO segments were observed showed a sharp decrease in resistivity with a rise in temperature [critical temperature resistor (CTR)] at about the melting point of the PEO segments, whereas the other simple salts in which the spherulites were not observed showed linear temperature dependence. The switching properties were confirmed similarly in repetitive heating/cooling cycles. This CTR characteristic was attributed to an increase in continuity in the conduction paths by melting spherulites. The apparent switching properties were not observed in the complex salts.