电光高分子研究进展

电光高分子是二阶非线性光学材料的重要组成部分,目前的研究重点主要在于合成具有高二阶非线性光学效应和取向稳定性以及低光学损耗的电光高分子,以满足高性能光学器件的制作要求。最近,电光高分子的设计与合成已经取得了很大的进展,例如结合"位分离"原理,利用高分子良好的加工性,获得了一些具有较好综合性能的高分子,可以较为有效地将小分子发色团的高β值转换为高分子大的宏观电光效应。本文综述了近几年来电光高分子的研究进展,主要包括线型电光高分子、树枝状电光高分子和超支化高分子。     

聚类肽高分子材料及其结构与性能的研究

聚类肽又称为氮取代聚甘氨酸(N-聚甘氨酸),是一类具有优良生物相容性以及生物活性的可降解高分子材料.由于酰胺键的活泼氢被取代,聚类肽主链结构中消除了聚肽固有的多重氢键相互作用,其主链柔性较好,聚合物性质主要由侧链基团的种类及其物理化学性质决定.基于这种链结构特征,可以通过设计不同的侧基结构,有效地调节聚类肽高分子的热力学性能、降解性能和自组装行为等物理化学性质.合成聚类肽的方法主要有2种——开环聚合和固相合成.本文主要介绍了聚类肽高分子的本体与溶液自组装行为,系统阐明了如何通过调控聚类肽高分子的侧链结构,研究链结构与自组装行为之间的相互关系,进一步构筑具有独特相分离行为以及自组装结构的新型生物高分子,同时探讨了这些材料在生物医用和能源等领域的潜在应用.     

结构用自修复型高分子材料的制备

自修复型高分子材料属于智能材料的一类,仿照生物体损伤自愈合的功能,通过材料内部的自诊断和自响应机制,及时修复材料在成型加工或使用过程产生的微小裂纹,避免其进一步扩展.近年来本课题组针对结构用自修复型高分子材料的强度恢复问题,综合利用高分子化学、高分子物理、材料力学等学科的理论和方法,设计、合成了一系列外植型和本征型自修复高分子材料,提出的自修复策略适用于典型热固性和热塑性高分子材料.此外,深入研究了相关的合成路线、配方优化、制备工艺、材料结构与性能、自修复的微观机制、使用稳定性等,为此类材料的实际应用提供依据.     

发光液晶高分子:分子构筑、结构与性能及其应用

发光液晶高分子结合了液晶高分子的有序性、稳定性、力学性能和发光分子的发光特性,有着广阔的应用前景。为了获得高效的发光液晶高分子,不同结构的发光液晶高分子被成功地设计与合成,包括主链型、侧链型、“甲壳”型发光液晶高分子、发光液晶高分子网络等。同时,分子结构、液晶相结构与光物理性质的关系也得到了相应的深入研究。本文总结了发光液晶高分子的最新研究进展,详细介绍了不同类型发光液晶高分子的分子结构设计合成、结构与性能、相关应用,并对其发展前景进行了展望。     

一种光交联电光聚合物的合成及其外部电光测量

合成了一种新的带有光交联基团的电光聚合物,其高分子基体是双酚A环氧树脂,二阶非线性生色团对硝基苯胺和光交联基团肉桂酰氯都键接在高分子链上.将聚合物溶解后旋涂成膜,对薄膜进行电晕极化.极化的后阶段用紫外光照射,使聚合物体系交联成网络结构,形成生色团取向长时间稳定的聚合物电光薄膜.用这种聚合物电光薄膜构成外部电光调制系统,测量了共面波导上的电信号.     

无柔性间隔基侧链型液晶高分子复合定形相变材料的制备与性能研究

设计合成了一系列具有不同烷氧基尾链长度的单体4′-烷氧基-4-联苯酚甲基丙烯酸酯Mbi Cm(m=1,2,4,6,8,10,12,14,16,18),通过自由基聚合方法合成了相应的具有不同烷氧基尾链长度的无柔性间隔基侧链型液晶高分子PMbi Cm,将所得的侧链型液晶高分子和相变材料石蜡按一定质量比混合,通过"加热-冷却法"成功制备了定形相变材料.通过凝胶测试发现当尾链长度为m=12,14,16,18时,高分子对固体石蜡具有良好的凝胶定形效果,且随着烷氧基尾链的增长,聚合物和石蜡的相容性增加,最低凝胶浓度降低,得到定形相变材料的凝胶解缔温度也相应下降.通过示差扫描量热法(DSC)、热重分析法(TG)、流变(Rheology)等测试考察了定形相变材料的相变储能性能、热稳定性和流变性能,实验结果表明该定形相变材料具有相变焓值高、热稳定性好、凝胶强度高等优点.通过红外光谱(FTIR)、偏光显微镜(POM)和扫描电镜(SEM)等测试发现PMbi Cm通过非共价键作用力自聚集形成三维凝胶网络结构,对石蜡起固定支撑作用.     

甲壳型液晶高分子的构筑、自组装及其功能化

甲壳型液晶高分子的发展很大程度上依赖于聚合物自组装的发展,而各种可设计、可预测、可调控的自组装策略的涌现,将甲壳型液晶高分子研究推向前所未有的高度,同时也极大地丰富了高分子化学与物理的内容,提升了研究水准.研究表明,侧链"甲壳效应"在调控甲壳型液晶高分子有序结构等方面有着重要作用.本综述从甲壳型液晶高分子设计合成、液晶相态调控、嵌段共聚物自组装和功能化应用等方面,总结和评述了近年来该领域国内的最新研究进展.最后,本综述总结了甲壳型液晶高分子在发展中所面临的主要问题,并对其发展趋势进行了展望.     

树枝状电光材料研究进展

电光材料是以光子为载体的新一代信息材料. 目前, 研究的焦点主要集中在树枝状电光材料. 综述了近几年树枝状电光材料的研究进展, 主要包括树枝状电光大分子、树枝状电光高分子以及超分子自组装电光聚合物.     

若干新型有机光电功能材料的分子设计、合成与性能 研究

介绍本研究组得到国家自然科学基金资助的四个方面工作的进展。研究了金属有机化合物的结构与非线性光学性质的关系,总结了从分子几何构型着手,根据不同用途,对金属有机非线性光学材料进行分子设计的经验规律;提出了利用“组合式共轭桥”进行有机非线性光学发色团分子设计的新思路,所合成的几个有机化合物既有很大的光学非线性,又有紫移的最大吸收峰;通过化学键将有机发色团分子张到各种高分子的侧链上,合成和表征了潜在的电光高分子和光折变高分子材料;采用无机-有机夹层复合的思路对兼有导电性和强磁性的分子材料进行了探索,将一些有机小分子和导电高分子分别插入了层状无机物MPS3的层间,得到了8个新的分子磁体,而另一夹层化合物则表现了较高的电导率。     

含磷全芳族热致液晶共聚酯的合成及热性能

全芳族热致液晶聚酯因其优良的力学性能、热稳定性及较低的熔融粘度而倍受关注 ,是当今最有前途的特种高分子材料之一 .但是 ,全芳族聚酯的刚性结构使其熔点较高 ,难以加工 ,因而通过分子设计制备熔点较低的热致全芳香族聚酯液晶成为研究的热点 .在主链型热致液晶高分子的分子设计中 ,通常采用共聚或在高分子链中引入取代基、柔性链段、扭结成分等方法来达到降低聚合物相转变温度的目的[1～ 6 ] .本文以对羟基苯甲酸、对苯二甲酸、间苯二甲酸和含磷二元酚化合物为单体 ,合成了一类具有较低熔点或流动温度的新型全芳族热致共聚酯液晶 ,其分子…     

高分子电光材料在THz辐射源领域的研究进展

THz辐射以其独特的性质和广阔的应用前景正吸引着科学家们广泛的关注,选择综合性能优良的辐射源材料是THz科学技术发展的关键,高分子电光材料相对传统晶体具有许多无法比拟的优势,如电光系数高、相干长度大、无声子吸收带隙、设计灵活多样等,能获得响应强、频带宽、平坦连续的THz谱图,是一类极具研究价值的THz辐射源材料。本文在简要介绍THz辐射的基础上,综述了近年来高分子电光材料在THz辐射源领域的研究进展,对影响THz辐射信号的因素作了相应分析,并指出了目前存在的主要问题。     

Preparation and characterization of the soluble NLO polyarylates with enhanced electro-optic properties

Three novel nonlinear optical polyarylate polymers were prepared containing one main-chain polymer (mPAR-chr1) and two side-chain polymers (sPAR-chr1, sPAR-chr2) with different kinds of chromophores. The obtained polymers were characterized and evaluated by UV-Vis, ¹H NMR, DSC and TGA. All the polymers exhibited excellent thermal stability, film forming ability and good electro-optic (EO) activity. The relationship between EO coefficients (r ₃₃) and the chromophore concentration of the three polymers had been also characterized and discussed. There were no obvious differences found in EO activity between main-chain and side-chain polyarylates with the same chromophore (chr1). Due to the stronger electron-withdrawing tricyanopyrroline acceptor and the steric effect of the large dendritic groups of chromophore 2 (chr2), polymer sPAR-chr2 showed the largest EO cofficients (64 pm V^?1) in these new polymers.     

Purification of protein and recycling of polymers in a new aqueous two-phase system using two thermoseparating polymers

In this study we present a new aqueous two-phase system where both polymers are thermoseparating. In this system it is possible to recycle both polymers by temperature induced phase separation, which is an improvement of the aqueous two-phase system previously reported where one of the polymers was thermoseparating and the other polymer was dextran or a starch derivative. The polymers used in this work are EO50PO50, a random copolymer of 50% ethylene oxide (EO) and 50% propylene oxide (PO), and a hydrophobically modified random copolymer of EO and PO with aliphatic C14H29-groups coupled to each end of the polymer (HM-EOPO). In water solution both polymers will phase separate above a critical temperature (cloud point for EO50PO50 50 degrees C, HM-EOPO, 14 degrees C) and this will for both polymers lead to formation of an upper water phase and a lower polymer enriched phase. When EO50PO50 and HM-EOPO are mixed in water, the solution will separate in two phases above a certain concentration i.e. an aqueous two-phase system is formed analogous to poly(ethylene glycol) (PEG)/dextran system. The partitioning of three proteins, bovine serum albumin, lysozyme and apolipoprotein A-1, has been studied in the EO50PO50/HM-EOPO system and how the partitioning is affected by salt additions. Protein partitioning is affected by salts in similar way as in traditional PEG/dextran system. Recombinant apolipoprotein A-1 has been purified from a cell free E. coli fermentation solution. Protein concentrations of 20 and 63 mg/ml were used, and the target protein could be concentrated in the HM-EOPO phase with purification factors of 6.6 and 7.3 giving the yields 66 and 45%, respectively. Recycling of both copolymers by thermoseparation was investigated. In protein free systems 73 and 97.5% of the EO50PO50 and HM-EOPO polymer could be recycled respectively. Both polymers were recycled after aqueous two-phase extraction of apolipoprotein A-1 from a cell free E. coli fermentation solution. Apolipoprotein A-1 was extracted to the HM-EOPO phase with contaminating proteins in the EO50PO50 phase. The yield (78%) and purification factor (5.5) of apolipoprotein A-1 was constant during three polymer recyclings. This new phase system based on two thermoseparating polymers is of great interest in large scale extractions where polymer recycling is of increasing importance.     

Synthesis and evaluation of demulsifiers with polyethyleneimine as accepter for treating crude oil emulsions

Demulsifiers provide an important means of breaking water‐in‐crude oil, which are formed during crude oil exploitation. In present work, twenty polyether copolymers based on polyethyleneimine (PEI) were synthesized. The interfacial properties of the PEI polyethers at the water‐crude oil interface were described by interfacial tension (IFT) and interfacial dilational modulus. The effects of position isomerism, size of intermediate and ratio of ethylene oxide (EO)/propylene oxide (PO) on the demulsification efficiency of these polyethers were studied. The results show that different positions of the EO and PO in copolymers lead to huge difference in both interfacial properties and demulsification performance. Polymers with hydrophilic core and hydrophobic tails (Ex‐mn series) are not efficient on demulsification of water‐in‐oil emulsion whereas polymers with hydrophobic core and hydrophilic tails (Px‐mn series) are. Meanwhile, Px‐mn series show higher IFT and lower interfacial dilational modulus than Ex‐mn series. In the same series, the IFT and interfacial dilational modulus decrease with decreasing EO/PO ratio. In the series with best demulsification performance (P199‐mn series), 60 min water removal rates of the polymers increase with decreasing EO/PO ratio at 65°C. In other words, the longer the hydrophobic blocks of polymers, the stronger the demulsification capacity. The effect of concentration of demulsifier on the demulsification efficiency was also investigated. Copyright © 2015 John Wiley & Sons, Ltd.     

Large electro‐optic activity and enhanced temporal stability of methacrylate‐based crosslinking hyperbranched nonlinear optical polymer

A methacrylate‐based crosslinking hyperbranced polymers have been synthesized through initiator‐fragment incorporation radical polymerization and used for the temperature stable electro‐optic (EO) polymer application. This polymer consists of methyl methacrylate, 2‐metacryloxyethyl isocyanate, and ethylene glycol dimethacrylate (EGDMA) monomers. The use of EGDMA as a bifunctional unit resulted in the solvent‐soluble crosslinking hyperbranched chain, so that the EO polymer enhanced glass transition temperatures. A phenyl vinylene thiophene vinylene bridge nonlinear optical chromophore was attached to the polymer backbone as the side‐chain by a post‐functionalization reaction. The loading concentration of the chromophore was varied between 30 and 50 wt % by simply changing the mixing ratio of the precursor polymer to the chromophore. The synthesized EO polymers produced optical quality films with a light propagation loss of 0.61 dB/cm in a slab waveguide at 1.31 μm. The electrically poled film had an EO coefficient (r₃₃) of 139 pm/V at 1.31 μm. The EO crosslinking hyperbranced polymer had a high‐glass transition temperature of 170 °C, and exhibited excellent temporal stability of the EO activity at 85 °C for 500 h. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Effect of chain blockiness on the phase behavior of ethylene‐octene copolymer blends

New challenges and opportunities for polyolefin blends arise from the recent introduction of olefin block copolymers (OBCs). In this study, the effect of chain blockiness on the miscibility and phase behavior of ethylene‐octene (EO) copolymer blends was studied. Binary blends of two statistical copolymers (EO/EO blends) that differed in comonomer content were compared with blends of an EO with a blocky EO copolymer (EO/OBC blends). The blends were rapidly quenched to retain the phase morphology in the melt and the phase volumes were obtained by atomic force microscopy (AFM). Two EOs of molecular weight about 100 kg/mol were miscible if the difference in octene content was less than about 10 mol % and immiscible if the octene content difference was greater than about 13 mol %. The blocky nature of the OBCs reduced the miscibility and broadened the partial miscibility window of the EO/OBC blends compared with the EO/EO blends. The EO/OBC blends were miscible if the octene content difference was less than 7 mol % and immiscible above 13 mol % octene content difference. It was also found that the phase behavior of EO/OBC blends strongly depended on blend composition even for constituent polymers of about the same molecular weight. Significantly more demixing was observed in an OBC‐rich blend (EO/OBC 30/70 v/v) than in an OBC‐poor blend (EO/OBC 70/30 v/v). An interpretation based on extractable fractions of the OBC described the major features of the EO/OBC (30/70 v/v) blends. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1554–1572, 2009     

^13C—NMR研究环氧乙烷—环氧丙烷无规共聚物的序列结构

利用高分辨核磁共振谱仪研究了环氧乙烷－环氧丙烷均聚物和无规共聚物的核磁共振主链碳谱。在对其链结构进行有效归属的基础上，讨论了不同配比聚合物的僚共振主链碳谱特点及其可能的单元链节排列顺序。     

一种梳状高分子固体电解质的分子运动和离子导电性

用交流复阻抗谱和动态粘弹谱等对交替马来酸酐共聚物多缩乙二醇酯衍生物及其ＬｉＣｌＯ４盐复合物进行了研究．结果表明，在Ｌｉ／ＥＯ＝０．０７—０．０４２范围内，从１７３Ｋ到３７３Ｋ，本聚合物一高氯酸锂复合体系的动态粘弹谱存在着两个明显的转变，其中β转变归属于ＰＥＯ的侧链玻璃化转变，转变温度随ＬｉＣｌＯ４盐浓度的增加而增加。α转变归属于主链玻璃化转变，在Ｌｉ／ＥＯ＝０．０２８时有极大值。盐浓度与电导率的关系与通常不一样，在所研究盐浓度范围内观察到两个峰，其一在Ｌｉ／ＥＯ＜０．０１４，另一峰在Ｌｉ／ＥＯ＝０．０２８．电导率与温度的依赖关系不符合Ａｒｒｈｅｎｉｕｓ行为；以ｌｇσ对１／Ｔ－Ｔ０作图，用侧链玻璃化转变温度Ｔβ作Ｔ０时，呈典型的ＶＴＦ行为。该体系室温电导率最高可达６×１０－６ｓ／ｃｍ．     

Interactions and Temperature Transitions of Ethylene Oxide – Propylene Oxide – Ethylene Oxide tri-block Copolymers in Water Media

Summary: ATR FTIR spectra of two ethylene oxide – propylene oxide – ethylene oxide (EO)_n-(PO)_m-(EO)_n tri-block copolymers (Pluronics) with different lengths of the EO blocks were investigated in water media at various temperatures. The observed wavenumber shifts and intensity changes of the bands of different chemical groups of polymers and of water molecules served as a basis for the estimation of structural changes and interactions of polymers with the surrounding water molecules. Two types of such interactions, i.e. hydrophilic (ether group – water) and a hydrophobic (methyl group – water) are detected. In the copolymer with shorter length of the EO blocks, an interchain H₂O bridge in a liquid crystalline phase was discovered and confirmed by ab initio calculations. A model for the structural changes during the temperature transitions is specified.