高分子长链结构在“高分子物理学”中的特殊性

高分子的长链结构决定高分子材料的特殊性质。长链结构的显著特征是熵弹性,使高分子材料在强度、弹性模量、形变响应方面不同于金属材料和无机材料,从而导致高分子材料的独具的橡胶态。"高分子物理学"研究的主要对象是长链分子,文中以高分子长链结构和凝聚态结构为逻辑起点,根据长链结构的存在状态与高分子特殊的链段运动单元之间的关系,阐述了高分子独有的橡胶态、松弛特性及流动中明显的粘弹特性,体现出高分子长链结构在研究"高分子物理学"中的主线作用。     

侧链高分子液晶的合成与应用

侧链高分子液晶是近年来出现的新型液晶材料，可以用加聚、聚合物改性、缩聚、开环聚合等方法合成，是优良的信息材料和气相色谱固定液。本文对侧链高分子液晶研究的历史、国际与国内的发展现状作了综合评述。     

侧链液晶高分子的分子工程研究进展

综述了近几年侧链液晶高分子（ＳＬＣＰ）的分子工程研究的最新进展，从ＳＬＣＰ的分子设计与液晶行为和材料性能的关系、ＳＬＣＰ及基于ＳＬＣＰ的新型材料的应用前景、ＳＬＣＰ的合成方法等几个方面进行探讨。     

高分子材料导电性能改善研究进展

提高高分子材料导电性能的方法,主要有掺杂、与其它材料复合、改变导电高分子的结构等方式。掺杂能够改变高分子材料中已有电子能带的能级,使得高分子中能带间的能量差减小,载流子迁移的阻力随之减小。与其它材料复合多为材料能提供载流子迁移的通道、与导电高分子材料形成大的共轭体系、改善链与链之间的有序性或增加复合物的紧密度,从而提高复合材料的导电性,与导电高分子复合的材料多为金属或金属氧化物、无机非金属纳米材料以及一些普通的有机高分子。改变导电高分子的结构能改善聚合物的规整度,提高其结晶度。导电高分子材料具有广泛的应用前景,今后需要在提高导电高分子电导率的同时改善其溶解性、加工性以及稳定性等综合性能,以实现导电高分子的实用化。     

肝素化/类肝素化高分子膜材料的研究进展

一般的高分子材料与血液接触时,在材料表面会形成血栓,无法满足抗凝血的要求。将肝素或类肝素物质通过适当的方法固定在高分子材料上,可以提高材料的抗凝血性能。对改善高分子材料血液相容性的方法进行了总结,叙述了肝素化/类肝素化高分子膜材料的特征与优势,重点介绍了肝素化/类肝素化抗凝血高分子膜材料的制备方法研究进展,并对类肝素化高分子膜材料的发展方向进行了展望。     

彩色C_（60）

彩色Ｃ_（６０）近几年，国际上对球状碳分子（也称布基球）Ｃ_（６０）的研究不断扩展和深入，形成了一股布基球研究热。原因是Ｃ_（６０）这种材料具有许多特珠性能，其潜在的应用领域十分广阔。现在，已知布基球不仅可以制造半导体、超导材料，还可以制造发光的彩色材?..     

分形理论与高分子科学

综述了分形(Fractal)理论在高分子科学中的应用,着重讨论了在高分子链结构、高分子溶液、凝胶化反应、固体高分子材料和生物高分子等领域中的分形问题。     

液晶嵌段共聚的对PC／TLCP共混体系相容作用的研究

利用热致液晶高分子ＰＥＴ／６０ＰＨＢ与聚碳酸酯的多嵌段共聚物作为相容剂,研究了ＰＣ与该ＴＬＣＰ共混体系的力学性能,热性能,形貌及织构。研究表明,ＰＣ／ＴＬＣＰ二元共混物的相容性很差,ＴＬＣＰ在加工条件下不能形成分散于基体中的具有一定长径比的微纤,得到材料的力学性能较ＰＣ基体有所下降。     

高分子PTC材料在微电机自保中的应用

本文研究了高分子ＰＴＣ材料的性能，并利用高分子ＰＴＣ材料将传统的微电机改造成了具有自保结构的新型微电机。实测数据与理论设计吻合较好。     

高分子材料粘温敏感性和粘切敏感性的串讲

高分子材料的剪切黏度是其流变性质中最重要的材料函数之一,粘温敏感性和粘切敏感性是指温度和剪切速率变化所造成高分子材料剪切黏度变化的剧烈程度。对高分子材料粘温敏感性和粘切敏感性的串讲不仅可以使学生深入理解高分子材料流变性质,更可以帮助学生掌握高分子结构与性能的密切联系,融会贯通专业基础知识。粘流活化能(Eη)和非牛顿指数(n)是分别衡量高分子材料粘温、粘切敏感性大小的主要参数,它们的大小与高分子材料的链结构密不可分。     

Charge Transfer in Fullerene-Conducting Polymer Compositex: Electronic and Excitonic Properties

C₆₀ doping into conducting polymer with highly extended π-electron system in the main chain induces remarkable quenching of photoluminescence in conducting polymer and drastic enhancement of photoconductivity. These results can be explained in terms of photo-induced charge transfer between conducting polymer and C₆₀. That is, photoexcited excitons or exciton-polarons on conducting polymer are effectively dissociated at C₆₀ molecules transferring electrons to C₆₀. Photoexcitation of C₆₀ results in the transfer of hole from C₆₀ to conducting polymer. These novel C₆₀ doping effects have been observed not only in conducting polymers with non-degenerated ground state structures but also those with degenerated ground state structure such as di-substituted acetylene polymers with solitonic electronic systems.

Highly effective photo-induced charge transfer has been also observed in conducting polymer/C₆₀ heterojunctions, which are interpreted as donor (D)-acceptor (A) photocell. Based on this finding we have demonstrated an organic photovoltaic cell with D-A double heterojunction, Al/C₆₀/OEP/conducting polymer/TTO, in which OEP is octaethylporphine as an light absorbing antenna molecule. Novel characteristics have also been observed in various other junction devices utilizing C₆₀ doped conducting polymer.

Granular and multiphase superconductivity has been found in C₆₀-conducting polymer-alkali metal composites.

Effect of other type of fullerenes such as C₇₀, modified C₆₀ and C₆₀ polymers, and also effect of C₆₀ doping in polysilanes and their derivatives have also been studied.     

Worm-like morphology of semi-rigid substituted poly(<Emphasis Type="Italic">p</Emphasis>-phenylene)

The rheological and dynamic mechanical properties of a semi-rigid substituted poly(p-phenylene) were investigated. At temperatures below the glass transition temperature of 152 °C the amorphous polymer is very stiff compared with flexible chain polymers. Although the material can be processed in the melt, the melt is unusually elastic. Atomic force and transmission electron microscopy revealed a worm-like morphology. Blends with polycarbonate yield transparent materials. Microscopy and X-ray diffraction of these blends indicated that the flexible chain polymer is located in between the worm-like structures of the semi-rigid polymer.     

Electronic spectra of the crystalline polymers of C60: photoluminescence study at high pressure

Specific details of the electronic spectra of perfect crystalline polymers of C60 were studied by means of the photoluminescence spectra measurements at normal conditions and at high pressure up to 4 GPa. The structure of the photoluminescence spectra, the intensity distribution between the principal bands and the pressure-induced shift of the bands differ considerably among the pristine C60, linear orthorhombic and planar tetragonal and rhombohedral polymeric phases of C60. Unlike the planar polymers of C60, the linear orthorhombic polymer exhibits irreversible changes in the photoluminescence spectrum under simultaneous application of high pressure and laser irradiation. The changes observed in the photoluminescence spectra of the planar polymeric phases of C60, as compared to the pristine material, are discussed in relation to the corresponding changes in the calculated electronic structure of the pristine C60 and its polymeric phases. The observed photoluminescence spectral structure along with the pressure behavior of the photoluminescence spectra are very sensitive to the structure of the polymers as well as to the C60 cage deformations and can be used to effectively characterize the various polymeric phases of C60.     

High Pressuee Synthesis of Alkali Metal Doped C60 Polymers

Alkali metal doped fullerenes, AC₆₀ (A = Li, Na) were polymerized under a pressure of 5 GPa at 573 K. the X-ray diffraction patterns of the products were very similar to that of the rhombohedral two-dimensional C₆₀ polymer, the basal spacings being slightly increased by the intercalation of the alkali atoms between the two-dimensional polymer layers. the alkali metal doped C60 polymers were insoluble in toluene and found to be semiconductors over a temperature range of 200 - 300     

Migration of Acrylic Monomers from Methacrylate Polymers – Establishing Parameters for Migration Modelling

Acrylic acid‐based and methacrylic acid‐based monomers are widely used for the manufacture of polymers, for polymer dispersions or for other specialty resins. Some of these applications cause interactions between the polymer and contact medium such as food contact materials, eyeglasses, contact lenses or toys. More specifically, migration of monomers from the polymer into the contact medium may occur, which needs to be evaluated for safety purposes. The objective of this study was to investigate the basic diffusion properties of acrylic polymers with respect to representative monomers in order to establish a scientific basis for migration modelling simulating the mass transport of monomers from the polymers when they are in contact with foods, human skin or body fluids such as sweat and saliva. For this purpose, 11 representative acrylic polymers containing five different acrylic monomers (MA, EA, BA, MMA and nBMA) were studied in extensive kinetic migrations experiments in contact with five different contact media (simulants) at three different temperatures (20°C, 40°C and 60°C). The simulants were selected according to the applications: toys were simulated by saliva simulant and articles coming in contact with human skin by sweat simulant. For food contact applications, water (aqueous foods), Miglyol 840 (Sasol, Witten, Germany) (fatty food) and Tenax® (Sigma‐Aldrich Corporation, Munich, Germany) (an adsorbent simulating dry foods) were selected. The diffusion coefficients (D) of the monomers in the polymer as well as partition coefficients between polymer and contact media were derived. It was found that those acrylic polymer materials used for rigid plastics applications exhibit extremely low diffusion behaviour, whereas acrylic polymer resins used for coating applications showed somewhat higher diffusion behaviour but this still at very low rates in comparison with other typical polymers used for the manufacture of food packaging materials. As a result, conservative polymer‐specific constants in support of migration modelling were established, and the specifications for the model general applicability were determined and specified. The parameter related to the polymers' intrinsic mobility is applicable to model migration of any other organic chemical substances, which may be present in acrylic polymers as potential migrants when they have comparable or higher molecular weights than the studied monomers. Copyright © 2012 John Wiley & Sons, Ltd.     

FT-IR microspectroscopic study of shot formation in melt-blown webs

We used Fourier transform infrared (FT-IR) microspectroscopy to investigate the chemical nature of fibers and defects called "shot" in melt-blown webs. Spectral differences were observed and evaluated in light of known thermal and oxidative degradation reactions for conditions comparable to those we used for melt blowing. Three different isotactic polypropylene polymers were evaluated in terms of the amount of shot produced and the amount of oxidative degradation exhibited by fibers and shot particles from each polymer. Little oxidative degradation was observed in fibers and the amount of degradation in fibers varied little for the three polymers we evaluated. Substantially more degradation was observed in shot particles, and the amount of degradation varied among the three polymers. Compared to polymer bound for fibers, we concluded that high temperature and mechanical shear in the extruder may introduce more chain scission in polymer bound for shot particles. Autoxidation reactions may occur after melt exits the die, and our data indicated that more oxidative degradation occurred in polymer that became shot particles than polymer that became fibers. The most favorable site for oxidation seemed to be tertiary rather than methylene hydrogen. Overall, the thermal history of polymer that becomes shot particles may be significantly different than the thermal history of polymer that becomes fibers, and this difference may have influenced shot formation.     

C60和苯乙炔共聚物荧光性能研究

合成表征了Ｃ６０和苯乙炔共聚物。详细地测试了聚合物溶液的荧光性能。研究结果表明溶液浓度为０．５ｇ／Ｌ时,聚合物呈出现了荧光浓度自猝灭效应。对于Ｃ６０含量为５％的聚合物在３５０ｎｍ被激发时,荧光光谱除在４４０ｎｍ有一个聚苯乙炔的荧光发射峰之外,在４０４ｎｍ呈现出了一个新的弱荧光峰,聚合物中Ｃ６０对这个荧光具有猝灭效应,聚合物发光机制被分析。     

Rational design of phosphonate/quaternary amine block polymer as an high-efficiency antibacterial coating for metallic substrates

Developing advanced technologies to address the bacterial associated infections is an urgent requirement for metallic implants and devices.Here,we report a novel phosphonate/quaternary amine block polymer as the high-efficiency antibacterial coating for metallic substrates.Three pDEMMP-b-pTMAEMA block polymers that bearing identical phosphonate segments(repeat units of 15)but varied cationic segments(repeat units of 8,45,and 70)were precisely prepared.Stable cationic polymer coatings were constructed on TC4 substrates based on the strong covalent binding between phosphonate group and metallic substrate.Robust relationship between the segment chain length of the polymer coating and the antibacterial property endowed to the substrates have been established based on quantitative and qualitative evaluations.Results showed that the antibacterial rate of the modified TC4 surface were 95.8%of S.aureus and 92.9%of E.coli cells attached.Interestingly,unlike the cationic free polymer or cationic hydrogels,the surface anchored cationic polymers do compromise the viability of the attached C2C12 cells but without significant cytotoxicity.In addition,the phosphonate/quate rnary amine block polymers can be easily constructed on titanium,stainless steel,and Ni/Cr alloy with significantly improved antibacterial property,indicating the generality of the block polymer for surface antibacterial modification of bio-metals.     

High Pressuee Synthesis of Alkali Metal Doped C60 Polymers

Abstract

Alkali metal doped fullerenes, AC₆₀ (A = Li, Na) were polymerized under a pressure of 5 GPa at 573 K. the X-ray diffraction patterns of the products were very similar to that of the rhombohedral two-dimensional C₆₀ polymer, the basal spacings being slightly increased by the intercalation of the alkali atoms between the two-dimensional polymer layers. the alkali metal doped C60 polymers were insoluble in toluene and found to be semiconductors over a temperature range of 200 - 300     

具有光学活性的3,5-二(烷基羰基-胆固醇)苯乙烯螺旋聚合物的奇偶效应

根据胆固醇含多个手性中心,将其引入到聚苯乙烯的侧链中,合成了一系列侧基含有手性链胆固醇基团的螺旋聚合物。这些无定形聚合物都有良好的热稳定性,随着柔性链上碳原子个数的增加,玻璃化转变温度逐渐降低。表征发现所有聚合物都为手性的螺旋结构聚合物,且随着柔性链的增长,所有的CD图上的科顿效应转变为同时含有正负科顿效应,最后转变为几乎只含有负科顿效应的现象,证明了手性胆固醇上的柔性链对聚合物分子的螺旋排列有着较大的影响。