THE MORPHOLOGY OF BACTERIORHODOPSIN MEMBRANE AT AIR／WATER INTERFACE OBSERVED UNDER BREWSTER ANGLE MICROSCOPE

ＴＨＥＭＯＲＰＨＯＬＯＧＹＯＦＢＡＣＴＥＲＩＯＲＨＯＤＯＰＳＩＮＭＥＭＢＲＡＮＥＡＴＡＩＲ／ＷＡＴＥＲＩＮＴＥＲＦＡＣＥＯＢＳＥＲＶＥＤＵＮＤＥＲＢＲＥＷＳＴＥＲＡＮＧＬＥＭＩＣＲＯＳＣＯＰＥ￥ＢａｏＦａｎｇＬＩ；ＹｕＣｈｅｎｇＳＯＮＧ；ＪｉｎＲｕＬ...     

SYNTHESIS AND FLUORESCENCE STUDY OF St／DVB COPOLYMERS LABELLED WITH PYRENE GROUPS

ＳＹＮＴＨＥＳＩＳＡＮＤＦＬＵＯＲＥＳＣＥＮＣＥＳＴＵＤＹＯＦＳｔ／ＤＶＢＣＯＰＯＬＹＭＥＲＳＬＡＢＥＬＬＥＤＷＩＴＨＰＹＲＥＮＥＧＲＯＵＰＳＷａｎｇＧｕｏｃｈａｎｇ；ＬｉａｎｇＹｕａｎｆｏｎｇ；ＧａｏＨｕａｎ；ＬｉａｎｇＬｉｊｕｎ；ＨｅＢｉｎｇｌｉ...     

DETERMINATION OF FLAVONOID COMPOUNDS IN GINGKO BILOBA LEAVES SUPERCRITICAL FLUID EXTRACTION AND HIGH PERFORMANCE LIQUID CHROMATOGRAPHY （SFE／HPLC）

ＤＥＴＥＲＭＩＮＡＴＩＯＮＯＦＦＬＡＶＯＮＯＩＤＣＯＭＰＯＵＮＤＳＩＮＧＩＮＧＫＯＢＩＬＯＢＡＬＥＡＶＥＳＳＵＰＥＲＣＲＩＴＩＣＡＬＦＬＵＩＤＥＸＴＲＡＣＴＩＯＮＡＮＤＨＩＧＨＰＥＲＦＯＲＭＡＮＣＥＬＩＱＵＩＤＣＨＲＯＭＡＴＯＧＲＡＰＨＹ（ＳＦＥ／Ｈ...     

POM／EVA共混物的研究

用力学测试、扫描电镜（ＳＥＭ）、热分析（ＤＳＣ）等手段研究了聚甲醛（ＰＯＭ）与乙烯－醋酸乙烯酯共聚物（ＥＶＡ）共混物（ＰＯＭ／ＥＶＡ）的力学性能及其微同形态；用聚甲醛与马来酸二丁酯（ＤＢＭ）的接枝物（ＰＯＭ－ｇ－ＤＢＭ）作相溶剂，能改变共的两相间的粘结力，从而提出了共混物的力学性能，ＳＥＭ观察表明接枝物的加入改变了ＰＯＭ／ＥＶＡ共混物的断裂方式，微观形态及结晶性能，对其热性能影响不大；通过改变ＰＯ     

VAPOR PHASE CARBONYLATION OF ETHANOL OVER Ni－Pb／C CATALYST AT ATMOSPHERIC PRESSURE

ＶＡＰＯＲＰＨＡＳＥＣＡＲＢＯＮＹＬＡＴＩＯＮＯＦＥＴＨＡＮＯＬＯＶＥＲＮｉ－Ｐｂ／ＣＣＡＴＡＬＹＳＴＡＴＡＴＭＯＳＰＨＥＲＩＣＰＲＥＳＳＵＲＥ￥Ｗａｎｇ，Ｄａ－ｗｅｉ；Ｆｅｎｇ，Ｊｉｎｇ－ｘｉａｎａｎｄＨｕａｎｇ，Ｚｈｏｎｇ－ｔａｏ（Ｄｅｐａｒｔｍ...     

MODELS FOR π－π INTERACroNS IN “MOLECULARMETALS” IONIZATION ENERGIES，ELECTRONIC STRUCTURE AND THROVGH－SPACE／THROUGH－BOND INTERACTIONS IN ［2，2］ PARACYCLOPHANE

ＭＯＤＥＬＳ　ＦＯＲ　π－π　ＩＮＴＥＲＡＣｒｏＮＳ　ＩＮ　“ＭＯＬＥＣＵＬＡＲＭＥＴＡＬＳ”　ＩＯＮＩＺＡＴＩＯＮ　ＥＮＥＲＧＩＥＳ，ＥＬＥＣＴＲＯＮＩＣ　ＳＴＲＵＣＴＵＲＥ　ＡＮＤ　ＴＨＲＯＶＧＨ－ＳＰＡＣＥ／ＴＨＲＯＵＧＨ－ＢＯＮＤ　ＩＮＴＥＲ...     

新型液晶／高聚物复合富氧膜的富氧性能及结构表征Ⅰ．液晶／高聚物复合膜的富氧性能研究

研究用烃橡胶（ＳＢＲ、ＰＢ）和聚二甲基硅氧烷（ＰＤＭＳ）分散α，ω－对乙氧羰氧基苯甲酸聚乙二醇酯（ＰＥＥＣＢ）而得到聚合物分散液晶复合膜（ＰＤＬＣＭ）．用这种复合膜进行富氧分离，当ＰＥＥＣＢ－４．０５（４．０５为聚醚软段的数均聚合度ＤＰ）的含量超过某一临界值（约２３．０％ｗｔ）时，室温下ＳＢＲ／ＰＥＥＣＢ－４．０５／ＰＤＭＳ体系膜的氧气透过系数Ｐｏ２值达７０～６３４ｂａｒｒｅｒ），增加约６０倍，分离系数仍较高（αｏ２／Ｎ２＝３．４７～２．５９）．考察了各种影响因素对膜透气性能的影响．     

MICROCALORIMETRIC STUDIES OF SURFACE ACID/BASE PROPERTIES OF REDUCED IRON／MAGNESIUM CATALYSTS

ＭＩＣＲＯＣＡＬＯＲＩＭＥＴＲＩＣＳＴＵＤＩＥＳＯＦＳＵＲＦＡＣＥＡＣＩＤ／ＢＡＳＥＰＲＯＰＥＲＴＩＥＳＯＦＲＥＤＵＣＥＤＩＲＯＮ／ＭＡＧＮＥＳＩＵＭＣＡＴＡＬＹＳＴＳ＊ＴｕＭａｉ，ＳｈｅｎＪｉａｎｙｉ＊＊，ＣｈｅｎＹｉ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈ...     

新型液晶／高聚物复合膜的富氧性能及结构表征 Ⅱ．液晶／高聚物复合膜的结构表征

用ＩＲ、ＤＳＣ、ＷＡＸＤ、正交偏光显微镜、ＳＥＭ、ＴＥＭ等手段，表征了所合成的液晶／烃橡胶、硅橡胶三元共混复合膜的织态结构及液晶态转变，结果发现，液晶ＰＥＥＣＢ－４．０５由于与ＳＢＲ和ＰＤＭＳ共混，Ｔｋ－ｓ转变温度下降了３７．５℃，体系存在不完全的相分离，液晶ＰＥＥＣＢ－４．０５在体系中形成液晶富集区（ＬＣ－ｒｉｃｈ ｄｏｍａｉｎ），大小约０．２－２．２μｍ，在压力的作用下，连续的液晶富集区形成宽     

聚β—羟基丁酸酯／聚醋酸乙烯酯共温物结晶行为的研究

以ＤＳＣ，ＰＯＭ，ＷＡＸＤ实验方法研究了聚β－羟基丁酸酯／聚醋酯乙稀酯（ＰＨＢ／ＰＶＡｃ）共混体系的结晶行为。结果表明：随共混物中非晶组份ＰＶＡｃ含量的增加，ＰＨＢ结晶的活化能增大。用Ａｖｒａｍｉ方程处理实验数据，结果表明ＰＶＡｃ的加入对ＰＢＨ结晶的生长方式影响不大，但结晶速率却明显下降。ＷＡＸＤ实验表明，ＰＶＡｃ的加入入不影响ＰＨＢ的结晶结构，但微晶尺寸和结晶度却明显变小。偏光显微镜观察结果与Ｄ     

The influence of arrangement of St in MBS on the properties of PVC/MBS blends

Three series of MBS core-shell impact modifiers were prepared by grafting styrene and methyl methacrylate onto PB or SBR seed latex in emulsion polymerization. All the MBS modifiers were designed to have the same total chemical composition, and MMA/Bd/St equals 30/42/28, which is a prerequisite for producing transparent blends with PVC. Under this composition, there were three different ways of arrangement for styrene in MBS, which led to the different structure of MBS modifier. The concentration of MBS in PVC/MBS blends was kept at a constant value of 20 wt.%. The effects of arrangement of St in MBS on the mechanical and optical properties of PVC/MBS blends were studied. The notched Izod impact test results showed that the MBS with a PB homopolymer core grafted with St had a lowest brittle-ductile transition (BDT) temperature and BDT temperature increased with the amount of St copolymerized with Bd in the core of MBS. The transparency of blends also increased with the amount of St copolymerized with Bd in the core. TEM results showed that the arrangement of St in MBS influenced the deformation behavior. Two deformation modes were observed in the blends: cavitation and shear yielding. When all St was grafted onto the PB rubber, both cavitation and debonding were observed, which relieve the triaxial tension and promote the shear yielding of the PVC matrix. When all St was copolymerized with Bd in MBS, no cavitation could be observed and only the shear yielding of the PVC matrix took place.     

The influence of the arrangement of styrene in methyl methacrylate/butadiene/styrene on the properties of PMMA/SAN/MBS blends

A series of methyl methacrylate‐butadiene‐styrene (MBS) core–shell impact modifiers were prepared by grafting styrene (St) and methyl methacrylate (MMA) onto polybutadiene (PB) or styrene‐butadiene rubber (SBR) seed latex in emulsion polymerization. All the MBS modifiers were designed to have the same total chemical composition, and Bd/St/MMA equaled 39/31/30, which was a prerequisite for producing transparent blends with poly(MMA)/styrene‐acrylonitrile (PMMA/SAN) matrix copolymers. Under this composition, different ways of arrangement for styrene in MBS led to the different structure of MBS modifier. The concentration of PB or SBR rubber of MBS in PMMA/SAN/MBS blends was kept at a constant value of 15 wt.%. The effects of arrangement of St in MBS on the mechanical and optical properties of PMMA/SAN/MBS blends were investigated. The results indicated that Izod impact strength of PMMMA/SAN/MBS blend with the amount of St grafted on core in MBS was higher than that of blend with the amount of St copolymerized with Bd in core of MBS, while the transparency of blend is opposite. From transmission electron microscopy, it was found that the arrangement of St in MBS influenced the dispersion of blend, which led to different toughness. Copyright © 2013 John Wiley & Sons, Ltd.     

二次电子衬度曲线法研究PVC/MBS共混物断面的分形特征

利用二次电子衬度曲线法测定了聚氯乙烯甲基丙烯酸甲酯丁二烯苯乙烯共聚物(PVCMBS)共混物冲击断面的形貌特征及对应的分形维数值.结果表明,材料的断口或微观结构并不是严格的分形结构,这种自相似性仅存在于一定尺码范围内,不同断面形貌特征所对应的分形维数测量值不同,随着MBS用量增加,PVCMBS共混物缺口冲击强度随满足自相似原理的形貌特征所对应的分形维数值增大而增大.本文从理论上讨论了材料断裂韧性与分形维数的关系.     

PVC/MBS共混物的紫外光交联及光氧化反应

PVC及其共混物应用广泛,MBS作为PVC制品的透明抗冲改性剂,在提高PVC抗冲性能的同时,必然影响PVC在紫外光照下发生的光化学反应过程,我们用紫外可见光研究了MBS对PVC紫外光解脱HCl动力学,发现MBS对PVC光解脱HCl有抑制作用,本文利用FTIR光谱研究PVC／MBS共混体系中,MBS对PVC光氧化、光交联及光降解过程的影响。     

The toughness amplification map of poly(vinyl chloride) and its cellulose acetate‐compatibilized starch alloys containing core/shell rubber particles: Possible transition to super‐toughening

Toughening amplification of the neat poly(vinyl chloride) (PVC) and its reinforced version containing 25 phr of the cellulose acetate (CA)‐compatibilized starch using methyl methacrylate‐butadiene‐styrene (MBS) core–shell particles was studied. The room temperature measured impact strength of the PVC showed mild increase up to 10 wt % with the addition of MBS particles. Then, the toughness enhanced discontinuously to super‐tough plateau regime. The room temperature measured impact strength of PVC containing 20 phr of MBS particles, however, was reduced by as much as 95% when it was filled with 25 phr of the CA‐compatibilized starch. In addition, the brittle–ductile transition (BDT) of the toughened PVC increased from 0 to 60 °C because of its reinforcement, even though the matrix number density of the core/shell particles remained almost constant. The decline in the impact strength and the rise in the BDT of the hybrid PVC system were attributed to the decrease in the shear deformable matrix and shear deformation propagation rate despite the increase in the process zone size. Maximum impact strength of the hybrid system at 60 °C (its BDT) increased to about 25% of the toughened PVC at its BDT (0 °C). The toughness amplification correlation of the toughened and hybrid PVC systems with their process zones fractional stress volumes under the impact load showed three regimes: quasi‐tough, transition, and super‐tough, which were superimposable on literature data regarding hybrid nylon 66 systems. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010     

Isothermal Degradation of PVC/MBS Blends

The process of thermal degradation of poly(vinyl chloride)/poly(methyl methacrylate-butadiene-styrene) (PVC/MBS) blends was investigated by means of isothermal thermogravimetry in nitrogen. The total mass loss was determined after 120 min. The kinetic parameters of the degradation process were determined by applying two kinetic models: the model which assumes autocatalytic degradation (Prout-Tompkins) and the model of two-dimensional diffusion. It was established that the thermal degradation at lower degrees of conversion (α<0.20) was well described by the former model, but the latter model was applicable at higher degrees of conversion. The thermal stability of blends at a certain temperature of isothermal degradation depends on the blend composition and the shell/core ratio in MBS, and on the adhesion in the boundary layer in PVC/MBS blends. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effect of polyvinylchloride on the properties of rubber vulcanizates

Natural rubber (NR) and styrene-butadiene rubber (SBR) were compounded with polyvinylchloride (PVC). Some physico-mechanical and dielectric properties of resulting rubber vulcanizates were measured. It was found that the addition of PVC to both NR and SBR results in slight decreases in tensile strength and elongation at break but a marked increase in oil-resistance of the vulcanizates. Moreover, the addition of PVC to NR slightly increases both dielectric constant and dielectric losses while the addition of PVC to SBR loaded with 50 phr carbon black (HAF) lowers these parameters. Both rubber blends, especially NR, show a reasonable stability with ageing.     

PVC/CPE/POE热塑性弹性体特性研究

研究了氯化聚乙烯（CPE）增容PVC／POE热塑性弹性体的结构与性能,通过对比使用增容剂CPE前后体系的力学性能,确证CPE对PVC／POE体系具有良好的增容效果。用DSC,SEM对热塑性弹性体的结构特性进行了研究,采用动态硫化的方法,提高了热塑性弹性体的性能。     

无水AlCl_3催化PVC/PS反应性增容的研究

以无水AlCl3为催化剂,通过聚氯乙烯(PVC)与聚苯乙烯(PS)之间Friedel-Crafts反应,实现了PVC/PS共混体系的反应性增容,使PVC与PS熔融共混温度由160℃降为140℃;通过预碾磨和加入苯乙烯(St)的方法,提高材料韧性,制备了综合力学性能良好的PVC/PS合金材料.应用FTIR、DSC、SEM和力学性能测试等手段表征了合金材料的结构与性能.结果表明,FTIR出现了1943和838 cm-12个苯环对位被取代的特征吸收峰;DSC在89℃出现了玻璃化转变;SEM证明PVC/PS两相界面粘接性随AlCl3、St的加入越来越好.在PS、AlCl3和St的质量分数分别为6%,0.6%和9%时,实现了对PVC的增强增韧.合金拉伸强度达到60.54MPa,比PVC的49.35 MPa提高了22.7%;缺口冲击强度达到5.3 kJ/m2,比PVC的3.9 kJ/m2提高了35.9%.     

Toughening of polyvinylchloride by core-shell rubber particles: Influence of the internal structure of core-shell particles

The work focused on the influence of the internal structure of MBS core-shell impact modifiers on the properties of PVC/MBS blends. MBS was synthesized by grafting styrene and methyl methacrylate onto PB seed latex by emulsion polymerization. Different monomer feeding manners and initiators were employed to control the internal structure of core-shell particles. The investigation of the morphology of MBS showed that when styrene monomer was fed in a semicontinuous feeding manner and redox initiator was used, core-shell particles with rarely sub-inclusions could be obtained. When preswollen manner of styrene monomer and redox initiator were employed, there were a large number of small sub-inclusions in the core of MBS. When AIBN was used as initiator, large sub-inclusions could be found in the core of MBS. The results of the Izod impact tests showed that PVC/MBS blend with MBS prepared by preswollen manner had the lowest brittle-ductile transition temperature. And TEM showed that the different internal structures of core-shell particles could lead to different deformation mechanisms. While the results of transparency tests showed that the presence of the sub-inclusions in the MBS impaired the transparency of the blends.