含Eu和Tb聚合物的制备及荧光性质

从稀土氧化物出发制备了含稀土的单体或添加剂,通过与其他有机单体共聚或加入共聚体系,制备了固体含稀土聚合物。对所制备的单体或添加剂进行了元素分析及 IR,TG 和 DTA 测试。对含稀土聚合物进行了荧光性质的研究。     

无皂微乳液法制备热固性双亲聚合物

以自制可聚合大分子表面活性剂HTP与丙烯酸酯类单体进行无皂微乳液五元共聚,制备可热固化双亲聚合物。讨论了微孔液形成的条件、聚合温度和水溶性丙烯酸酯类单体含量对双亲聚合物形态和结构的影响。     

淀粉-丙烯酸类单体接枝共聚物的合成及应用

淀粉与丙烯酸类单体接枝共聚可以制备兼具天然与合成高分子性能的聚合物。分析了淀粉-丙烯酸类单体接枝共聚所采用的聚合方法、引发剂、溶剂、淀粉接枝前预处理等,总结了淀粉-丙烯酸类单体接枝共聚物在高吸水材料、生物降解塑料、废水处理、纺织浆料等方面的应用。     

无皂乳液聚合法合成含氟聚合物的研究进展

含氟聚合物由于其优异的物理和化学性能以及广阔的应用前景而受到关注,近年来成为研究的热点。基于含氟聚合物无皂乳液的最新研究进展,综述了含氟聚合物无皂乳液的制备方法,其中主要包括可聚合乳化剂共聚法、加入助溶剂法、水溶性单体共聚法、添加无机粉末法、加入两亲性聚合物法和采用两亲性结构RAFT试剂聚合法。系统地归纳了含氟聚合物无皂乳液在功能微球、表面施胶剂、皮革涂饰材料、织物整理剂和涂料粘合剂等方面的应用,并展望了其今后的发展方向。     

无皂乳液聚合法合成含氟聚合物的研究进展

含氟聚合物由于其优异的物理和化学性能以及广阔的应用前景而受到关注,近年来成为研究的热点。基于含氟聚合物无皂乳液的最新研究进展,综述了含氟聚合物无皂乳液的制备方法,其中主要包括可聚合乳化剂共聚法、加入助溶剂法、水溶性单体共聚法、添加无机粉末法、加入两亲性聚合物法和采用两亲性结构RAFT试剂聚合法。系统地归纳了含氟聚合物无皂乳液在功能微球、表面施胶剂、皮革涂饰材料、织物整理剂和涂料粘合剂等方面的应用,并展望了其今后的发展方向。     

含席夫碱生色团聚合物的合成及其光学性能

合成含席夫碱生色团的单体,并使之与丙烯酸酯类单体共聚制备了带有席夫碱生色团侧基的丙烯酸酯类聚合物.并利用傅立叶红外光谱、核磁共振氢谱及紫外可见光谱等测试手段,对所合成的席夫碱生色团单体及聚合物的结构进行了表征.此外,还探讨了含席夫碱生色团聚丙烯酸酯的全光开关特性及双折射性能.     

高分子量二元丙烯腈聚合物的合成及性能

设计合成了双功能共聚单体3-酰胺基-3-丁烯酸甲酯(MMPA),以二元共聚合代替传统的三元共聚合,采用水相悬浮聚合的方法制备超高分子量丙烯腈二元共聚物作为碳纤维前驱体。采用傅里叶红外变换光谱仪、差示扫描量热分析仪和热失重分析仪详细研究了单体配比对聚合物相对分子质量、结构及预氧化性能的影响,结果表明,共聚单体MMPA的加入使预氧化温度由240℃降低至213℃,且投料中随着MMPA含量的增加预氧化温度降低,预氧化程度加深,合成的共聚单体MMPA能够有效改善丙烯腈聚合物的预氧化性能,宽化放热峰,避免放热集中;水相悬浮制备得到的丙烯腈聚合物相对分子质量高达106.7×10~4,有利于提高碳纤维的力学性能。     

新型含偶氮苯生色团聚合物的制备和性能

合成了含手性碳原子的新型偶氮苯生色团,通过酰氯化反应制备出含偶氮苯生色团的单体,将所合成的单体与丙烯酸酯类单体进行自由基共聚得到以偶氮苯生色团为侧基的高分子.利用1H NMR、FTIR、UV-Vis吸收光谱,对所合成的单体及聚合物进行了结构表征.研究了所制备的聚合物的全光开关效应.结果表明,在激发光的照射下,通过聚合物中偶氮苯基团的顺-反-顺异构循环在聚合物材料中可形成光致各向异性;在较低驱动光功率(28.1 mW)下这种聚合物具有良好的全光开关效应.     

异戊二烯对苯乙烯-间戊二烯共聚合的影响

二烯烃-苯乙烯类单体序列结构极大程度上影响相关橡胶类产品（丁苯橡胶、多元集成橡胶）或树脂产品（丁苯树脂）的综合性能。活性阴离子聚合在共聚单体序列类型调控方面具有极大的优势，如严格嵌段序列、渐变嵌段序列、无规序列及交替序列等。新型间戊二烯（PD）单体可以通过阴离子共聚合实现其与苯乙烯类单体特殊交替序列共聚物的合成，异戊二烯（IP）阴离子聚合可以实现高顺式1,4-结构聚合物的定向合成。文中以PD、苯乙烯（ST）和IP为共聚单体，在环己烷中（含0.015%四氢呋喃）通过正丁基锂（n-BuLi）引发聚合合成了多元共聚物，重点考察了共聚动力学和共聚物的微观结构。实验结果表明：（1）聚合动力学显示均聚合速率ST>IP>>PD,ST/IP和PD/IP二元共聚显示经典“双S”转化率曲线，ST/PD二元共聚速率与IP均聚速率相当（；2）核磁氢谱和竞聚率数据显示ST/PD二元共聚符合经典交替共聚行为，结合红外数据表明，二元共聚产物1,4-结构含量高于90%，反1,4-结构含量高于85%;(3)三元共聚转化率与瞬时共聚单体组成关系表明，异戊二烯以高顺1,4-结构插入苯乙烯-间戊二烯序列中，...     

可降解功能性聚合物多孔材料的制备与表征EI北大核心CSCD

通过己内酯(CL)和甲基丙烯酸缩水甘油酯(GMA)共聚合成可降解大分子交联剂,将其应用于高内相乳液聚合制备可降解聚合物多孔材料。在此基础上,引入端双键的聚甲基丙烯酸二甲氨基乙酯(PDMAEMA)大分子单体共聚,制备含功能链段的可降解聚合物多孔材料。用核磁共振、傅里叶变换红外光谱和扫描电镜等对大分子交联剂、大分子单体及多孔材料进行分析和表征。结果表明,合成的大分子交联剂相对分子质量为8100,残留双键含量为GMA结构单元的20%。当大分子交联剂含量为单体质量的1/10时,体系可以形成稳定的高内相乳液,经聚合可得到内部孔洞丰富、泡孔直径为20~22μm的可降解聚合物多孔材料。引入端双键的PDMAEMA大分子单体后,所得聚合物多孔材料孔壁泡孔直径为10~15μm,微孔尺寸为5~8μm,其可在碱性溶液中水解。     

Supramolecular Nanotube Reactors for Production of Imine Polymers with Controlled Conformation,Size, and Chirality

A series of supramolecular nanotubes with inner diameters of 1, 4, 9, 12, 16, and 29 nm are prepared from amino acid lipids. The hydrophobic channels of the nanotubes act as reactors for the formation of imine polymers by not only effectively encapsulating the benzaldehyde and diacetyleneamine precursors of the imine monomers but also markedly accelerating imine formation. The nanotube inner diameter determines whether the imine monomers self‐assemble into nanoparticles, nanotapes, nanocoils, or twisted nanofibers in the channels. UV‐induced polymerization of the diacetylene units in the imine nanostructures followed by decomposition of the nanotubes into molecular dispersions of the constituent amino acid lipids results in expulsion of the polymerized imine nanostructures with retained conformation. The isolated nanocoils and twisted nanofibers retain the helicity and circular dichroism induced by the nanotubes, which exhibits supramolecular chirality, even though the components of the imine monomers are achiral. These supramolecular nanotubes with tunable diameters and functionalizable surfaces can be expected to be useful for the production of polymers with controlled conformation, size, and chirality without the need for rational design or chemical modification of the monomers or optimization of the polymerization conditions.     

Reactions of polymers in supercritical fluids for chemical recycling of waste plastics

Sub- or supercritical fluids have been focused as reaction media for environmental applications from a view point of green chemistry. Chemical recycling of waste plastics is important issue. We have applied reaction in water or organic solvent in sub- or supercritical condition to convert polymers into its monomers. Condensed polymers such as polyethylene terephthalate or nylon 6 were depolymerized to its monomers by hydrolysis of alcoholysis in supercritical water or alcohol. The other polymers such as phenol resin and fiber reinforced plastics (FRP) were also decomposed to small molecules by solvolysis. In this paper, the degradation of polymers studied in our group was reviewed.     

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.     

Metals Supported Water Monomers:the Bonding Nature Revisited

A single water monomer is known as a hard-to-observe molecule even in the presence of metal surfaces as supporting matrix. This review highlights effort in experimental characterizations and theoretical modeling of transition metals supported water monomers with attention given to its structure and bonding, together with the insights that we have provided into the bonding nature of the water-interactions by the newly employed projected PDOS (partial density of states) difference analysis, which is proved to be an effective tool to be elucidate such bonding nature. The general s-d hybridization and d-shell effect are summarized, and how these effects can be tuned by tailoring local surface configurations is discussed.     

Synthesis and polymerization of substituted ammonium sulfonate monomers for advanced materials applications

Sulfonated polymers have found use as ion-exchange membranes for use in fuel cells, water purification, electroactive devices, and inorganic materials templating and synthesis. Improving the materials for these applications and opening up new applications requires the ability to synthesis targeted or more complex sulfonated polymers, which includes tailoring the chemistry (copolymerization across a wider range of solubility) and/or polymer architecture (block, graft, nanoparticle). This article will summarize the recent work using sulfonated monomers with substituted ammonium counterions as a versatile route for enabling this goal. Two main benefits of these monomers are as follows. First, they are useful for preparing amphiphilic copolymers, which is a challenge using traditional acidic or alkali salt forms of sulfonated monomers. Second, sulfonated polymers with substituted ammonium counterions are useful polymers for obtaining unique material properties, such as organo-gelation of low polarity solvents or obtaining ionic liquid polymers for the fabrication of solid polymer electrolytes.     

基于氢键作用的超分子弹性体材料的研究进展

超分子弹性体是指在分子(包括小分子和大分子)间通过氢键、离子键、配位键等非共价键结合的,在常温下具有与传统弹性体材料类似高弹性和流变特性的一类新型材料,同时由于其特殊的分子键作用方式,超分子弹性体还具有与传统弹性体不同的特性,如可逆热塑性、自修补性、热敏性和良好的加工性等。文中综述了近年来国内外在氢键型超分子弹性体的合成、制备与表征等方面的研究进展,并指出其发展趋势。     

Carbon Dots as Fillers Inducing Healing/Self‐Healing and Anticorrosion Properties in Polymers

Self‐healing is the way by which nature repairs damage and prolongs the life of bio entities. A variety of practical applications require self‐healing materials in general and self‐healing polymers in particular. Different (complex) methods provide the rebonding of broken bonds, suppressing crack, or local damage propagation. Here, a simple, versatile, and cost‐effective methodology is reported for initiating healing in bulk polymers and self‐healing and anticorrosion properties in polymer coatings: introduction of carbon dots (CDs), 5 nm sized carbon nanocrystallites, into the polymer matrix forming a composite. The CDs are blended into polymethacrylate, polyurethane, and other common polymers. The healing/self‐healing process is initiated by interfacial bonding (covalent, hydrogen, and van der Waals bonding) between the CDs and the polymer matrix and can be optimized by modifying the functional groups which terminate the CDs. The healing properties of the bulk polymer–CD composites are evaluated by comparing the tensile strength of pristine (bulk and coatings) composites to those of fractured composites that are healed and by following the self‐healing of scratches intentionally introduced to polymer–CD composite coatings. The composite coatings not only possess self‐healing properties but also have superior anticorrosion properties compared to those of the pure polymer coatings.     

丙烯酰基苯并三氮唑的光引发聚合及产物光化学反应

研究了丙烯酰基苯并三氮唑(ABT)、甲基丙烯酰基苯并三氮唑(MABT)的光自引发聚合行为及均聚物、共聚物的光化学反应。通过红外光谱、核磁共振谱和元素分析确定了单体、产物的结构,用紫外光谱和自由基捕捉剂探讨了光化学反应机理。     

Synthesis of Polymerizable Cyclodextrin Derivatives for Use in Adhesion-Promoting Monomer Formulations

The synthesis of the cyclodextrin derivatives reported herein was assisted by extensive literature research together with structure-property relationships derived from three-dimensional molecular modeling. These studies led to the hypothesis that many of the 21 hydroxyl groups on beta-cyclodextrin molecules could be derivatized to form a closely related family of analogous chemical compounds containing both polymerizable groups and hydrophilic ionizable ligand (substrate-binding) groups, each attached via hydrolytically-stable ether-linkages. The vinylbenzylether polymerizable groups should readily homopolymerize and also copolymerize with methacrylates. This could be highly useful for dental applications because substantially all contemporary dental resins and composites are based on methacrylate monomers. Due to hydrophilic ligands and residual hydroxyl groups, these cyclodextrin derivatives should penetrate hydrated layers of dentin and enamel to interact with collagen and tooth mineral. Analyses indicated that the diverse reaction products resulting from the method of synthesis reported herein should comprise a family of copolymerizable molecules that collectively contain about 30 different combinations of vinylbenzyl and hexanoate groups on the various molecules, with up to approximately seven of such groups combined on some of the molecules. Although the hypothesis was supported, and adhesive bonding to dentin is expected to be significantly improved by the use of these polymerizable cyclodextrin derivatives, other efforts are planned for improved synthetic methods to ensure that each of the reaction-product molecules will contain at least one copolymerizable moiety. The long-term objective is to enable stronger and more durable attachments of densely cross-linked polymers to hydrated hydrophilic substrates. Capabilities for bonding of hydrolytically stable polymers to dental and perhaps other hydrous biological tissues could provide widespread benefits.     

Effect of surface charge on osteoblastic proliferation and differentiation on a poly(ethylene glycol)-diacrylate hydrogel

Two charge monomers, namely 2-(methacryloyloxy)ethyl-trimethylammonium chloride (MAETAC) and sodium methacrylate (SMA), were incorporated into poly(ethylene glycol)-diacrylate (PEGDA) hydrogels to investigate the effects of surface charge on the proliferation and differentiation of osteoblasts. The physicochemical properties of the polymers were characterized, and MC3T3-E1 cells were seeded on the hydrogels to evaluate the effect of charge polarity and density on osteoblastic proliferation and differentiation. FTIR results revealed that the two charged monomers were successfully incorporated into PEGDA. The zeta potential of the hydrogels became more positive or negative with increasing concentration of MAETAC or SMA. The zeta potential of the charged hydrogels remained constant after immersion in culture medium for different time points. Other physicochemical properties such as surface morphology, swelling ratio in PBS, contact angle, and elastic modulus were not significantly different among each group with different concentrations of charge monomers incorporated into PEGDA. The modification of hydrogels with charge monomers not only improved osteoblastic proliferation but also upregulated alkaline phosphatase activity and the expression of osteogenic marker genes and relative growth factors. These findings indicate that, in contrast to charge polarity, the charge density would be more important to improve osteoblast-like cells proliferation and differentiation on the poly(ethylene glycol)-diacrylate hydrogel. The hydrogel can be designed by controlling the incorporation of charge monomers. This study provides a model to study the effect of charge on cell behavior.