超临界水中废塑料的化学回收

论述了近年来废塑料在超临界水作用下的化学回收过程。介绍了超临界水的特性以及用超临界水对废塑料（PE、PP、PS）进行热解和部分氧化的工艺，以回收单体、油和氧化。指出我国应大力加强对该领域的研究。     

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.     

Supercritical hydrothermal synthesis of organic-inorganic hybrid nanoparticles

We have developed supercritical hydrothermal synthesis method of metal oxide nanoparticles where metal salt aqueous solution is mixed with high temperature water to rapidly increase the temperature of the metal salt solution and thus reduce the reactions and crystallizations during the heating up period. By using this method, we succeeded in the continuous and rapid production of metal oxide nanocrystals. A new method proposes to synthesize organic-inorganic fused materials based on the methods of supercritical hydrothermal synthesis. By introducing organic materials in a reaction atmosphere of supercritical hydrothermal synthesis, we successfully synthesized metal oxide nanoparticles whose surface was modified with organic materials. In supercritical state, water and organic materials form a homogeneous phase, which provides an excellent reaction atmosphere for the organic modification of nanoparticles. Modification with bio-materials including amino acids was also possible. By changing organic modifiers, particle morphology and crystal structure were changed. This organic surface modification provides a various unique characteristics for the nanoparticles: Dispersion of nanoparticles in aqueous solutions, organic solvents or in liquid polymers can be controlled by selecting hydrophilic or hydrophobic modifiers.     

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.     

Synthesis of <Emphasis Type="Italic">N</Emphasis>-vinylpyrrolidone modified acrylic acid copolymer in supercritical fluids and its application in dental glass-ionomer cements

Compressed fluids such as supercritical CO(2) offer marvellous opportunities for the synthesis of polymers, particularly in applications in medicine and dentistry. It has several advantages in comparison to conventional polymerisation solvents, such as enhanced kinetics and simplified solvent removal process. In this study, poly(acrylic acid-co-itaconic acid-co-N-vinylpyrrolidone) (PAA-IA-NVP), a modified glass-ionomer polymer, was synthesised in supercritical CO(2) (sc-CO(2)) and methanol as a co-solvent. The synthesised polymer was characterized by (1)H-NMR, Raman and FT-IR spectroscopy and viscometry. The molecular weight of the final product was also measured using static light scattering method. The synthesised polymers were subsequently used in several glass ionomer cement formulations (Fuji II commercial GIC) in which mechanical strength (compressive strength (CS), diametral tensile strength (DTS) and biaxial flexural strength (BFS)) and handling properties (working and setting time) of the resulting cements were evaluated. The polymerisation reaction in sc-CO(2)/methanol was significantly faster than the corresponding polymerisation reaction in water and the purification procedures were simpler for the former. Furthermore, glass ionomer cement samples made from the terpolymer prepared in sc-CO(2)/methanol exhibited higher CS and DTS and comparable BFS compared to the same polymer synthesised in water. The working properties of glass ionomer formulations made in sc-CO(2)/methanol were comparable and in selected cases better than the values of those made from polymers synthesised in water.     

Advanced polymer-inorganic hybrid hard coatings utilizing in situ polymerization method

Hard coatings are frequently used to give plastics high scratch resistance. Coating hardness and adhesion to the substrate are considered to be key factors influencing scratch resistance, but it is difficult to produce coatings that have both properties. Hybridization of polymers and inorganic materials is a promising approach for solving this problem. We prepared polymer-silica hybrid coatings by using in situ polymerization to carry out radical polymerization of vinyl monomers in a sol-gel solution of alkoxysilanes, and measured the abrasion resistance of the coatings. However, the expected properties were not obtained because the sol-gel reaction did not perfectly proceed on the surface of the coatings under the N2 conditions. We found that curing the hybrid coatings by UV irradiation in air promoted the sol-gel reaction on the surface, resulting in coatings having excellent abrasion resistance.     

原位聚合聚酰亚胺改性尼龙树脂的制备与性能

塑料的高性能化已经成为当前研究的热点。选择耐水性优良的双酚A型二酐和双酚A型二胺作为反应单体,二步聚合得到分子量很高的端酸酐聚酰亚胺,利用酸酐的活性,接枝上酰基己内酰胺活性基团,聚合得到PI改性尼龙树脂,通过红外分析证明上述各步反应是成功的。聚酰亚胺(PI)改性尼龙的力学性能随着聚酰亚胺用量和分子量的增加而增加,明显优于一般工程塑料。微观分析聚酰亚胺分子并没有进入尼龙树脂的结晶相,而是形成致密的片晶存在尼龙基体中。     

聚丙烯在超临界水中的降解反应初探

超临界水由于具有许多独特的性质,用超临界水作为化学反应的介质已受到人们广泛的重视,尤其是它可以使废塑料发生降解或分解。本文以聚丙烯在超临界水中的降解作为模型反应．研究了温度、压力、时间及水／聚丙烯等条件对该反应的影响,为今后聚丙烯及其它塑料废弃物在超临界水中的降解提供实验指导。     

Recent Advances in Direct Synthesis of Value‐Added Aromatic Chemicals from Syngas by Cascade Reactions over Bifunctional Catalysts

Value‐added aromatic monomers such as benzene, toluene, and xylenes (BTX) are very important building‐block chemicals for the production of plastics, polymers, solvents, pesticides, dyes, and adhesives. Syngas‐to‐aromatics (STA) is a very promising approach for the synthesis of aromatic monomers, and is catalyzed via bifunctional catalysts in a single reactor, wherein methanol/dimethyl ether and/or olefins intermediates formed from syngas on metal components are converted into aromatic monomers exclusively on the HZSM‐5 by cascade reactions. Since an optimal Fischer–Tropsch synthesis (FTS) temperature of Fe‐based catalysts is very close to an aromatization temperature of HZSM‐5, Fe‐based catalysts have been frequently used/modified for the synthesis of aromatic monomers from hydrogenation of carbon oxides (CO and CO₂). The nature of metal components and amounts of Brönsted acid sites on HZSM‐5, and their mesoporosity and intimacy, significantly alter the selectivity for aromatics by tuning BTX distibution and catalyst stability. Although many developments have been achieved regarding the STA process in recent years, no reviews have been published in this flourishing research area over the last two decades. Here, the recent advances and forthcoming challenges in the progress of syngas (CO+H₂) chemistry and hydrogenation of CO₂ toward the value‐added aromatic monomers through cascade reactions are highlighted.     

降冰片烯及其衍生物开环易位聚合的研究进展

环烯烃开环易位聚合(ROMP)是指在金属催化剂存在下,环烯烃中的碳碳双键断裂并重新结合形成新的分子,得到的聚合物中留有不饱和双键,具有活性聚合的特点。ROMP是改造碳碳双键最有效的手段之一,极具特色且广泛应用于高分子材料与有机分子的合成。关于环烯烃ROMP研究早在20世纪50年代就已开始,当时的研究主要集中在以Ti、Re、W、Mo等过渡金属配合物组成的Ziegler-Natta催化体系引发环烯烃ROMP。20世纪80年代中期以后,研究则以亚烷基类或卡宾型类催化剂为主,其引发环烯烃ROMP的机理更加清晰。随着结构明确、稳定高效的环烯烃ROMP催化剂的开发与完善,该领域的研究焦点开始转向环烯烃ROMP适用单体的拓展以及所得聚合物的应用。在环烯烃ROMP研究中,降冰片烯及其衍生物是研究最多和应用最广的一类单体,这是因为它们的反应活性较高,来源丰富,价格也不昂贵。除研究拓展ROMP适用单体外,研究者主要从降冰片烯基单体的空间位阻、化学构型、侧基极性以及与其他环烯烃或降冰片烯基单体共聚改性等方面不断进行尝试,同时充分发挥环烯烃ROMP优势,与其他聚合方法联用,不断改善所得聚合物的性能并将其应用于不同研究领域。降冰片烯及其衍生物ROMP在阻燃材料、交换膜、纳米材料、生物医药等领域已取得一系列研究成果,其中在阻燃材料领域研究最早且许多产品已经工业化。在交换膜领域,由于降冰片烯基聚合物膜的热稳定性、耐酸碱性和电导率均较好,目前的研究主要是探索如何在燃料电池中获得应用。纳米材料是近年来最热门的研究领域之一,降冰片烯基纳米金属聚合物材料和纳米磁性聚合物材料等已有初步应用。在生物医药领域,降冰片烯及其衍生物极具发展前景,目前的研究主要集中在药物传输材料,已有初步的研究成果,但要实现工业化尚待进一步研究。此外,基于降冰片烯及其衍生物的接枝聚合物、嵌段聚合物、液晶聚合物、导电聚合物等也获得人们越来越多的关注。本文简要介绍了降冰片烯及其衍生物ROMP的反应机理,以及ROMP催化剂从多组分到钼、钨系再到钌系等几个发展阶段,详细综述了降冰片烯及其衍生物ROMP在上述若干领域的研究进展,并在此基础上简要探讨了今后研究与开发应用的新方向。     

Synthesis and characterization of ionic charged water soluble arginine-based poly(ester amide)

A family of water soluble and positively charged l-arginine based poly(ester amide)s (Arg-PEAs) was synthesized and characterized. These biodegradable polymers consist of three nontoxic building blocks: l-arginine, diols, and dicarboxylic acids. The Arg-PEAs were prepared by solution polycondensation reaction of tetra-p-toluenesulfonic acids salts of bis-(l-arginine) α, ω-alkylene diesters and di-p-nitrophenyl esters of dicarboxylic acids. Optimal conditions of the monomers and polymers synthesis were investigated, and the monomers and Arg-PEAs were chemically characterized. Arg-PEAs were found to have good solubility in water and many other polar solvents. Structure–function relationship of the Arg-PEAs revealed that changing the number of methylene groups in the diol or/and diacid segment could finely tune the hydrophobic and cationic properties of the Arg-PEAs. MTT assay showed that all the prepared Arg-PEAs were non-toxic to the cell lines even at very large doses. Arg-PEAs with double bond functionality could be photo-crosslinked with polyethylene glycol diacrylate to form cationic hybrid hydrogels.     

热致感应型形状记忆高分子材料的研究EI

主要探讨了热致感应型形状记忆高分子材料的记忆机理，并对几种形状记忆高聚物的实施方法进行了研究和探讨，认为该类材料集塑料－橡胶的特性于一体，在记忆温度下的行为与橡胶的弹性理论相一致。     

化学反应中聚合物流变动力学的研究进展

化学反应中聚合物流变动力学是联系化学反应动力学与聚合物流变学的交叉学科中的一类重要科学问题。文中从单体聚合、树脂固化、聚合物之间的反应以及聚合物接枝反应四方面综述了近年来聚合物流变动力学的研究进展,分析了尚存在的难点,并展望了其发展方向。     

具有光学活性高性能高分子材料的研究进展

旋光性聚合物可以使通过它的偏振光发生偏转,在手性识别和对映体拆分、手性催化剂、液晶、生物医药、光学开关和非线性光学等领域展现出良好的应用前景。本文综述了几种利用旋光性单体缩聚合成具有光学活性高分子材料的方法,对所得聚合物的热稳定性、可溶性、旋光性等主要性能进行分析比较,得到一系列重要的结论,并对其影响机理进行讨论。在此...     

氟化丙烯酸酯聚合物的制备及表面性能的研究进展

总结了近十年来通过在聚合物链中引入含氟基团，得到氟化丙烯酸酯聚合物的研制及表面性能的研究进展。     

New side-chain polyurethanes with highly conjugated push–pull chromophores for second order NLO applications

Six new side-chain polyurethanes with large molecular hyperpolarizabilities were synthesized by reaction of ethylenic and/or azo bridged push–pull chromophoric monomers with tolylene 2,4-diisocyanate. The NLO-phores show different conjugation pathway but analogous donor/withdrawing substituents. The chemical and thermal properties of the chromophores and of the polymers were examined. Evaluation of the second order NLO properties was performed by EFISH determination of μβ on the monomers, and by SHG measurements on some amorphous thin films obtained from polymers through spin-coating technique.     

超临界CO_2增强聚合物加工的研究与应用进展

对超临界CO2环境中聚合物加工方法的研究、应用现状与进展进行了综述。基于SC-CO2对聚合物的增塑作用,可开发出许多相关用途,如聚合物改性、聚合物共混、聚合物复合材料、多孔微泡沫材料、微粒化以及聚合物浸渍/灌注/插嵌等。在对研究现状和结果进行梳理总结后,认为SC-CO2对聚合物加工过程的增强作用机理可归结为:SC-CO2对聚合物的溶胀,导致增塑,进而降低了聚合物的玻璃化温度、黏度、表面张力,增强了小分子化合物在聚合基质中的扩散系数。此外,CO2作为绿色溶剂,是有机溶剂的良好替代品,因此具有广阔的应用前景。     

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。     

聚苯并咪唑树脂的合成与性能

聚苯并咪唑因其具有耐高温、耐腐蚀、阻燃、以及良好的力学性能、介电性能等多种优异性能而备受关注。我们合成了数种未见报道的新型聚苯并咪唑树脂,并用FT-IR、TGA、DSC进行了表征。在研究中我们对四胺合成路线进行了优化,改进了水解以及还原反应。实验以4,4’-二氨基联苯和邻硝基苯胺为原料合成了3,3’-二氨基联苯胺、3,3’,4,4’-四氨基二苯甲烷两种单体,通过两种单体与多种二元羧酸进行聚合制备了两个系列的聚苯并咪唑,在这些聚合物中我们选取了12种聚合物对它们的溶解性、耐热性进行了深入研究,多种数据显示这两类聚合物具有非常优异的热稳定性。     

Novel synthesis methods for new materials in solid state chemistry

The most common method used for synthesizing inorganic solids is the so-called ‘ceramic method’ which involves synthesizing at elevated temperatures and leads to thermodynamically stable phases. This method has a serious limitation because many inorganic solids of current interest are rather metastable and consequently their preparation requires low temperature methods. In this article, we have reported some methods of synthesis which also include methods that belong to soft-chemistry routes. The selected examples presented in this paper are: (i) the intercalation and or deintercalation of oxygen in oxides by electrochemical oxidation or reduction in aqueous or nonaqueous solutions, (ii) the use of chemical agents such as NO₂ or borohydrides for obtaining oxides with tunneled and lamellar structures, (iii) a multistage synthesis processing for intercalating, in layered oxygenated materials, anionic species and acrylic monomers and polymers, (iv) the supercritical fluid processing for preparing nitrides, carbon-nitrides, lamellar oxides and oxy-(hydroxy-) fluorides, and (v) the mechanical alloying for synthesizing new Mg-based binary intermetallics.