超支化聚酰亚胺的应用研究进展北大核心CSCD

近年来,超支化聚合物在化学、材料以及生物等领域引起了广泛的关注。超支化聚酰亚胺(HBPI)是由超支化大分子和线性聚酰亚胺结合形成的一种新型聚合物,它有独特的三维体型分子结构,高度支化的分子链分布,以及高分布密度的表面端基官能团。其独特的结构、优异的理化性能和合成及改性方法上的多样性使HBPI在许多领域具有潜在的应用。本文综述了自1999年出现超支化聚酰亚胺以来国内外在HBPI应用领域的研究进展,包括在气体分离膜、质子交换膜、光敏、光波导、荧光、介电、复合材料领域的应用研究进展,总结概述了HBPI在上述各领域的应用机理,并对HBPI的应用发展前景进行了展望。     

壳聚糖改性技术的新进展Ⅰ．烷基化、酰化以及接枝化改性

壳聚糖是一种新型高分子功能材料,自身具有优良的生物性能.为克服其溶解性较差等缺陷,扩大其应用范围,常采用物理和化学的手段对壳聚糖改性,以改善其物理、化学性能,本文介绍了自2000年以来国内外关于壳聚糖物理和化学改性方面的最新研究进展,阐释了改性途径以及对改性后所得衍生物的相关表征.主要涉及到壳聚糖的烷基化、酰化以及接枝化改性等途径,并列表比较了以上各种手段的改性效果.本文的下篇<壳聚糖改性技术的新进展Ⅱ.交联化、季铵盐化、羧基化改性以及其低聚糖衍生物>将继续介绍基于壳聚糖的其它改性手段的最新进展.     

壳聚糖改性技术的新进展Ⅱ交联化、季铵盐化、羧基化改性及其低聚糖衍生物

壳聚糖是一种新型高分子功能材料,自身具有优良的生物性能。为克服其溶解性较差等缺陷,扩大其应用范围,常采用物理和化学的手段对壳聚糖改性,以改善其物理、化学性能。本文是"壳聚糖改性技术的新进展Ⅰ"的下篇,将继续介绍2000年以来国内外关于壳聚糖物理和化学改性方面的最新研究进展,阐释改性途径以及对改性后所得衍生物的相关表征。主要涉及到壳聚糖的交联化改性、季铵盐化改性、羧基化改性以及制备壳聚糖低聚糖衍生物等途径。     

Reinforced Modification of PEEK and its Applications

聚醚醚酮（PEEK）作为一种特种热塑性工程塑料,在许多工程领域有着广泛的应用。采用不同手段改性聚醚醚酮,改善其热学性能、力学性能、摩擦学性能和加工性能等,有利于降低生产成本和进一步拓展其应用范围。本文从化学改性和纤维增强、无机填充、表面改性、与有机共混等物理改性两个方面综述了近年来国内外聚醚醚酮改性研究进展情况,以及对其在工业领域、电子电器领域、航空领域、汽车领域和医学领域中的应用作了简单的概括,最后展望了聚醚醚酮改性研究开发问题及解决方法。     

乙烯-醋酸乙烯共聚物改性研究进展

乙烯-醋酸乙烯共聚物(EVA)具有优异的柔韧性、耐腐性、加工性、绿色环保,广泛应用于薄膜、热熔胶、黏合剂、电线电缆等领域。然而,EVA存在粘度低、热性能和力学性能差等缺点,限制了其发展和应用。因此,制备性能优良的新型改性EVA材料成为近年来的研究热点。本综述回顾了近年来关于EVA不同改性方法的研究进展,对化学改性和物理改性两方面进行了重点介绍,分析了不同改性方法的优势和短板,最后对EVA改性方法及研究方向进行展望。     

改性浇铸尼龙的研究进展

立足于浇铸尼龙的反应机理,结合对其在实际应用中的改性要求,阐述了改性浇铸尼龙的研究进展.尤其以聚合物改性浇铸尼龙为重点,从改性的机理和相形态等方面详细地介绍了其的研究情况,总结了最新的工作以及将来的发展方向,为尼龙材料的更加广泛应用提供一定的参考.     

聚合物光接枝表面改性研究与应用

主要考察了近年来利用紫外光（ＵＶ）对聚合物进行表面接枝改性研究与应用的最新进展情况，从接枝实验体系与条件、接枝影响因素以及聚合物表面接枝改性的应用等几个方面对其进行了总结和介绍。     

有机硅弹性体表面生物相容性的研究进展

生物材料表面的生物相容性一直是生物材料研究领域倍受关注的问题.本文综述了对有机硅弹性体进行改性以提高其表面生物相容性的研究进展,介绍了各种常用的化学改性方法如本体接枝、等离子体处理、光化学诱导接枝、臭氧活化接枝以及硅氢加成反应、原子转移自由基聚合反应在有机硅弹性体表面改性中的应用.对改性后的有机硅弹性体表面抗非特异性蛋白质和血小板的能力等方面进行了评述,并进一步分析了有机硅弹性体表面化学改性的发展趋势和研究重点.     

聚乙二醇化壳聚糖的制备及其应用研究进展

聚乙二醇(PEG)是一种具有无毒、亲油亲水、高生物相容和无免疫原性等特点的化合物。将聚乙二醇结构引入壳聚糖(CTS)糖链中得到的聚乙二醇化壳聚糖,不但保持了CTS的天然性和优良生物降解等特性,还具有更好的水溶性和对有机化合物的结合能力。通过对CTS进行聚乙二醇化改性,可进一拓展其应用领域。本文结合近20年国内外PEG改性CTS的研究特点,围绕PEG改性CTS的制备及其在药物负载与控制释放、组织工程、抗菌材料、生物活性物传递和环境保护等领域的应用进行了总结,并展望其未来的发展趋势。     

蚕丝改性方法概述

天然的蚕丝具有独特的优良性能,但同时也存在性能缺陷,如力学性能（拉伸强度与韧性）差,使用时间短以及色牢度差等。科学家们发展了蚕丝的改性技术,改良蚕丝的性能以达到更好的应用目的。目前常用的蚕丝改性方法主要分为基因改性方法、物理改性法、化学改性法及添食育蚕法等。概述了蚕丝的结构与改性的原理,介绍了4类改性法及其近年来取得的重要进展,总结了目前蚕丝改性研究中的难点,展望了蚕丝改性研究的未来发展方向。     

Tunable memory performances of the porphyrin terminated hyperbranched polyimides

Herein, a functional hyperbranched polyimide, denoted as ATPP‐HBPI, was synthesized by termination of polyamic acid with 5‐(4‐aminophenyl)‐10, 15, 20‐triphenylporphyrin (ATPP) and chemical imidization. Subsequently, ATPP‐HBPI was coordinated with Zn ion to give Zn‐ATPP‐HBPI. In the HBPIs, the porphyrin terminals acted as the electron donor (D) and the 6FDA moieties acted as the electron acceptor (A) to promote the electron transition. Both ATPP‐HBPI and Zn‐ATPP‐HBPI exhibited good organo‐solubility and high thermal stability. They were used as the electroactive layer to fabricate the memory device with a configuration of indium tin oxide (ITO)/HBPI/Al to evaluate their bistability. The devices exhibited different memory behaviors, WORM for ATPP‐HBPI and SRAM for Zn‐ATPP‐HBPI, respectively. Optical and electrochemical experiments and molecular simulation were carried out to illustrate this phenomenon of performance transformation. The results show that the metallization of terminal of the HBPIs provides a strategy for tailoring the memory characteristics of the devices. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 1953–1961     

Thermal properties and toughness performance of hyperbranched‐polyimide‐modified epoxy resins

An amine‐terminated hyperbranched polyimide (HBPI) was prepared by the condensation polymerization of a commercially available triamine monomer with a dianhydride monomer. The effects of the HBPI content on the thermal and mechanical interfacial properties of diglycidyl ether of bisphenol A (DGEBA) epoxy resins were investigated with several techniques. The thermogravimetric analysis results showed that the thermal stability of the DGEBA/HBPI blends did not obviously change as the HBPI content increased. The glass‐transition temperature (T_g) of the DGEBA/HBPI blends increased with the addition of HBPI. Improvements in the critical stress intensity factor (K_IC) and impact strength of the blends were observed with the addition of HBPI. The K_IC value and impact strength were 2.5 and 2 times the values of the neat epoxy resins with only 4 wt % HBPI. The fractured surfaces were studied with scanning electron microscopy to investigate the morphology of the blends, and they showed that shear deformation occurred to prevent the propagation of cracks in the DGEBA/HBPI blends. These results indicated that a toughness improvement was achieved without a decrease in the thermal stability or T_g. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3348–3356, 2006     

Synthesis of alkaline‐developable,photosensitive hyperbranched polyimides through the reaction of carboxylic acid dianhydrides and trisamines

Hyperbranched polyimides (HBPI)s with high glass‐transition temperatures and excellent thermal stability were synthesized through the reaction of commercially available carboxylic acid dianhydrides with tris[4‐(4‐aminophenoxy)phenyl]ethane (TAPE). In particular, hyperbranched polyimide HBPI(TAPE‐DSDA), prepared through the reaction of TAPE with 3,3′,4,4′‐diphenylsulfonetetracarboxylic dianhydride (DSDA), showed higher thermal stability and good solubility. Furthermore, alkaline‐developable, photosensitive HBPI(TAPE‐DSDA)‐MA‐CA was prepared through the reaction of HBPI(TAPE‐DSDA) with glycidyl methacrylate with tetrabutylammonium bromide as a catalyst in N‐methyl‐2‐pyrrolidinone (NMP) followed by the addition reaction of cis‐1,2,3,6‐tetrahydrophthalic anhydride with triphenylphosphine as a catalyst in NMP. The glass‐transition temperatures of HBPI(TAPE‐DSDA)‐MA‐CA were greater than 300 °C. A resist composed of 74 wt % HBPI(TAPE‐DSDA)‐MA‐CA, 22.2 wt % trimethylpropane triacrylate, and 3.8 wt % Irgacure 907 as a photoinitiator achieved a resolution of a 55‐μm line pattern and a 275‐μm space pattern by UV irradiation (1000 mJ/cm²). © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3697–3707, 2004     

Nonvolatile resistive memory devices based on ferrocene‐terminated hyperbranched polyimide derived from different dianhydrides

A series of ferrocene‐terminated hyperbranched polyimides (HBPI‐Fcs) were synthesized from a tetra‐amine, bis(4‐(3,5‐bis (4‐amino‐2‐(trifluoromethyl) phenoxy) phenoxy) phenyl) methanon, and various dianhydrides, followed by termination with (4‐amino) phenyl ferrocene. All the HBPI‐Fcs possessed good organo‐solubility and high thermal stability. The devices based on HBPI‐Fcs exhibited bipolar and nonvolatile write‐once‐read‐many times (WORM) memory performance with various threshold voltages and the same ON/OFF current ratio of 10⁴. Moreover, the devices possessed excellent bistability under a constant bias of −1.00 V during a test period of 10⁴ s. The different charge trapping ability of the electron‐accepting moiety endowed the devices with different the threshold voltages. Mechanism analysis showed that the switching behavior was dominated by the charge trapping effect and the charge transfer was well fitted with the space‐current‐limited‐current (SCLC) and ohmic model. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 505–513     

Fluorinated Hyperbranched Polyimide for Optical Waveguides

A novel fluorinated hyperbranched polyimide (HBPI) is synthesized by using a new triamine monomer, 1,3,5‐tris(2‐trifluoromethyl‐4‐aminophenoxy)benzene (TFAPOB) (A₃), as a ‘core’ molecule, 4,4‐(hexafluoroisopropylidene)diphthalic anhydride (6FDA) as a B₂ monomer, and 3,5‐ditrifuoromethylphenyl as an endcapping reagent. The polymer shows a glass transition temperature of 232 °C and a temperature of 10% weight loss at 535 °C. The HBPI presents a birefringence as low as 0.002 at 650 nm. Near‐IR results indicate that HBPI exhibits desirable properties for low loss optical waveguide applications.

     

微波辐射合成含三苯基吡啶结构超支化聚酰亚胺及其光学性能的研究

利用自己合成的含三苯基吡啶结构的BB′2型芳香三胺TAPP与A2型的二酐3,3′,4,4′-二苯酮四羧酸二酐(BTDA)在微波辐射下经"两步法"分别合成了氨基封端和酐基封端的新型超支化聚酰亚胺(AM-HBPI和AD-HBPI).通过FTIR、1H-NMR、XRD、TGA、溶解性试验以及UV-Vis和荧光光谱等对产物进行了一系列的结构表征和性能测试.结果表明,两种新型的含三苯基吡啶结构超支化聚酰亚胺(HBPI)在强极性非质子溶剂中均显示出良好的溶解性,对无机稀酸也具有一定的抗腐蚀性;它们还体现出优异的耐高温性,在N2中的10%热失重温度(T10%)分别高达573℃和568℃.除此之外,AM-HBPI和AD-HBPI还分别在200～400nm和200～350nm具有良好的紫外光吸收性能,以及紫、蓝色荧光发射性能.而且它们被HCl质子化后的紫外光吸收谱带均扩宽至425nm,荧光发射峰的强度也大大增强.     

Synthesis and gas transport properties of ODPA-TAP-ODA hyperbranched polyimides with various comonomer ratios

A series of hyperbranched copolyimides (HBPI)s based on commercially available monomers 4,4′-oxydiphthalic anhydride (ODPA), 2,4,6-triaminopyrimidine (TAP) and 4,4′-oxydianiline (ODA) were prepared. The synthesis involved the formation of hyperbranched polyamic acid (PAA) precursors in the first step and the thermal imidization of cast thin PAA films in the second step. Two basic types of HBPIs were prepared by controlling the molar ratio of ODPA and an amine mixture of TAP and ODA. When the molar ratio was 1:1, the amine-terminated HBPIs were obtained; with the molar ratio of 2:1 anhydride-terminated HBPIs were prepared. Degree of branching was estimated by ¹H and ¹³C NMR analysis. It was found that approximately 48% of TAP units presented in ODPA:TAP:ODA = 1:0.75:0.25 HBPI macromolecules create the branching unit. Amine-terminated HBPIs showed moderate weight-average molecular weights and these values rather higher than for the anhydride-terminated HBPIs. With increasing ODA comonomer content in amine-terminated HBPIs increased their molecular weight and thermal and mechanical stability, whereas in anhydride-terminated HBPIs these trends were opposite. Amine-terminated HBPIs generally exhibited higher thermal stability than the anhydride-terminated ones. Gas permeability coefficients of both HBPIs types increased with increasing content of ODA comonomer. Prepared membranes exhibited high separation performance and have a potential to be utilized in industrial gas separation applications.     

喜树碱及其衍生物的聚乙二醇化学修饰药物研究进展

目的：喜树碱及其衍生物药物是一类重要的抗肿瘤药物,但其存在水溶性差、生物利用度低、毒副作用大等问题,喜树碱及其衍生物的聚乙二醇化学修饰具有十分诱人的前景,但目前国内研究较少,本文综述近年来喜树碱及其衍生物药物的聚乙二醇化学修饰研究进展。方法：以喜树碱（Camptothecin, CPT）、伊立替康（Irinotecan, CPT-11）、7-乙基-10-羟基喜树碱（7-ethyl-10-hydroxycamptothecin, SN38）、聚乙二醇（Polyethylene glycol, PEG）、聚乙二醇化喜树碱（PEG-CPT）等为关键词,查阅近几年国内外相关研究文献。结果与结论：综述了喜树碱及其衍生物的聚乙二醇化学修饰药物的研究进展与临床研究报道,为发掘结构明确、组成稳定的新型化学修饰药物提供理论基础和技术支撑。     

A potential flower-like coating consisting of calcium-phosphate nanosheets on titanium surface

A potential calcium-phosphate fl ower-like nanocoating were coated onto the titanium surface in an easy approach. It has high surface area, low cytotoxicity as well as promising cell affi nity, which makes it a potential alternative modifi cation method for titanium surface.     

生物催化剂酶在高分子改性中的应用

生物催化剂酶用于高分子合成及改性的研究正在成为国外学者的一个新的研究热点，酶催化反应的专一性，高效性，高选择性及反应条件的相对温和性，使酶催化反应在高分子改性领域更具吸引力，为高分子改性开辟了一条更为清洁，更高效的途径。本文综述了近年来酶催化反应在高分子改性方面的研究进展。