α,β-不饱和缩醛的氢化研究

对α,β-不饱和缩醛的氢化反应进行了研究。用雷尼镍对α,β-不饱和缩醛进行催化氢化制得2-乙基己醛环乙二缩醛,双键氢化的选择性可达75%左右,此法中催化剂成本较低,适用于工业生产。     

AlPO_4催化剂的制备和表征及其在缩醛化反应中的催化性能

利用水热及溶胶-凝胶两种方法制备不同组成的AlPO4催化剂。应用XRD、NH3-TPD等手段对催化剂进行了表征。试验表明催化剂结构及表面酸性与其制备方法、焙烧温度及n(P)/n(Al)比密切相关。乙醛和丙二醇的缩醛化反应表明丙二醇的转化率主要受催化剂表面弱酸度的影响。当n(P)/n(Al)为1.0,焙烧温度为400℃,用溶胶-凝胶法制备的AlPO4催化剂活性最高。     

AlPO_4催化剂的制备和表征及其在缩醛化反应中的催化性能

利用水热及溶胶-凝胶两种方法制备不同组成的AlPO4催化剂。应用XRD、NH3-TPD等手段对催化剂进行了表征。试验表明催化剂结构及表面酸性与其制备方法、焙烧温度及n（P）/n（Al）比密切相关。乙醛和丙二醇的缩醛化反应表明丙二醇的转化率主要受催化剂表面弱酸度的影响。当n（P）/n（Al）为1.0,焙烧温度为400℃,用溶胶-凝胶法制备的AlPO4催化剂活性最高。     

日用香料环己烯基丙醛环缩醛的制备

德国Celanese Chemical sEurope公司取得的欧洲专利Eur．Pat．Appl．EP1，481，974(2004．12．1)介绍日用香料环己烯基丙醛环缩醛(I)的制备。     

可化学回收的生物基环氧玻璃体

采用生物基缩水甘油醚季戊四醇双缩香草醛环氧树脂（DEPVD）为原料，经商用二苯二硫醚胺固化剂（AFD）固化得到生物基环氧玻璃体（DEPVD-AFD）。利用核磁共振氢谱（1H-NMR）对DEPVD的结构进行了表征。通过红外光谱（FTIR）、示差扫描量热仪（DSC）、热重分析仪（TGA）、拉伸测试机、降解回收实验等手段对环氧树脂的固化过程和综合性能进行了表征。结果表明，树脂材料具有较好的力学性能、热稳定性及降解性能，其玻璃化转变温度为143℃，拉伸强度为87.0 MPa，杨氏模量约为2 300 MPa,10%热失重温度为323℃。降解回收实验的结果表明，固化剂中含有的螺环缩醛结构赋予了环氧树脂可降解的特性。DEPVD-AFD能在H+浓度为0.1 mol/L的1,4-二氧六环溶液中完全降解（处理温度75℃，时间4 h），由于降解产物具有显著的溶解度差异，含有二苯二硫醚结构的高价值中间产物（DSS）可以通过水洗的方式进行简单高效的回收，DSS的FTIR和1H-NMR结果表明此中间产物具有明确的化学结构和较高的纯度，这种简单高效的回收方式有望为环氧玻璃体的化学回收铺平道路。     

固载杂多酸催化缩醛反应的研究

将固载杂多酸(PW12/C)应用于缩醛反应。以糠醛与乙二醇的缩合为探针反应,详细探讨了影响缩醛反应的各种因素,得出糠醛与乙二醇反应的最佳条件,并成功地应用于糠醛与正己硫醇的缩合反应。糠醛乙二醇缩醛的收率为93.4%,糠醛正己硫醇缩醛的收率为85.6%。     

HAlMSU-W-Y介分子筛催化合成新型七元环缩醛(酮)的研究

研究了HAlMSU-S-Y分子筛催化1,4-丁二醇与环己酮、丁酮、丙醛、丁醛、异丁醛、戊醛、异戊醛、正辛醛、苯甲醛等醛(酮)的缩合反应.考察了反应时间、醛(酮)与醇的配比、HAlMSU-S-Y分子筛用量等因素对醛(酮)与醇缩合反应的影响.结果表明,当醛(酮)与1,4-丁二醇摩尔比为1:1.5,催化剂用量为2 g/mol醛(酮),反应2 h,选择性一般在97%以上,转化率也一般在95%以上,表明HAlMSU-S-Y分子筛对醛(酮)与醇的缩合反应有较好的催化性能.     

氨基磺酸催化合成苯甲醛乙二醇缩醛

以氨基磺酸为催化剂合成了苯甲醛乙二醇缩醛,考察了醛醇摩尔比,反应时间,催化剂用量,带水剂用量等因素对苯甲醛乙二醇缩醛收率的影响。结果表明：最适宜的工艺条件是：n（苯甲醛）：n（乙二醇）=1：1．5,催化剂用量占反应物总质量的1．5％,带水剂环己烷用量为16mL（占反应物总质量的2．18％）,反应时间1．5h,上述条件下,苯甲醛L--醇缩醛收率可达到83．73％。     

聚乙烯醇在乙醇水溶液中缩醛化的研究

聚乙烯醇（ＰＶＡ）在乙醇水溶液中在酸性条件下与醛类缩醛化制成ＰＶＡ缩醛的乙醇水溶液。缩醛化度可由乙醇的浓度来控制。ＰＶＡ缩醛的乙醇水溶液经氧化降解后可直接用作配制胶粘剂和涂料的胶料。     

氯化锡催化合成苯甲醛乙二醇缩醛

以环境友好试剂氯化锡为催化剂,对苯甲醛与乙二醇的缩合反应进行了研究,考察了该绿色催化剂的用量、醛醇摩尔比、带水剂等因素对苯甲醛乙二醇缩醛收率的影响。实验结果表明,氯化锡有较好的催化活性。在回流条件下,催化剂用量约占醛用量的2.83%质量分数,醛醇物质的量的比为1：1.5,带水剂环己烷的用量为5mL时,反应90min,苯甲醛与乙二醇缩醛收率达77.3%。     

淀粉改性聚乙烯醇缩甲醛树脂的工艺研究

由于传统的PVA缩醛树脂是由PVA和甲醛制备的,所以树脂中的游离甲醛含量高。通过改变合成工艺,用淀粉对聚乙烯醇缩甲醛树脂进行改性,制得了游离甲醛含量低的树脂。考察了淀粉用量、体系pH值、反应时间、反应温度对树脂性能的影响,并采用了红外光谱对树脂结构进行了表征。根据此合成方法生产的产品具有工艺简单、游离甲醛含量低、耐水性能好、成本低等优点。     

Preparation of abamectin-loaded porous acrylic resin and controlled release studies

A polyacrylic high oil-adsorption resin was prepared by a suspension polymerization method with butyl acrylate and methyl methacrylate as monomers, benzoyl peroxide as an initiator, poly(vinyl alcohol) (PVA-1788) as a dispersing agent, and divinyl benzene as a cross-linking agent. The effects of dispersing agent, pore-forming agent and cross-linking agent on resins structures were revealed. The maximum specific surface areas and pore volumes of the resulting resins were 853.8?m²/g and 1.188?cm³/g, respectively. These structural parameters endowed excellent adsorbability to the resins. Abamectin, a macrolide insecticide, was selected as a model pesticide, and cyclohexanone was investigated as solvent in adsorption tests. The adsorption isotherms illustrated that adsorption was an endothermic process, and the optimum adsorption temperature was 293?K. Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction results suggested that abamectin-loaded resins were prepared. The sustained release data indicated that the pesticide-loaded resins exhibited a sustained pesticide release pattern, and the releasing process continued over 15?days in an alcohol medium with the final release rate of over 90?%. These studies established a theory and experimental foundation for the actual application of this method. Meanwhile, the pesticide-loaded resins could be applied to actual production process by adding proper adjuvants in their compositions.     

Metallization of cross-linked polyurethane resins by reduction of polymer-incorporated metal ion

Polyurethane (PU) resins having different degree of cross-linking were prepared by the reaction of 4,4′-methylenebis(phenyl isocyanate) (MDI) with various molar ratio of two kind of pentaerythritol ethoxylates (PEE15, ratio of ethyleneoxy (EO) unit/hydroxyl (OH) unit=15/4; PEE3, EO/OH=3/4) in the presence of cobalt(II) chloride at 100 °C for 48 h. Metallization behavior of the CoCl₂-containing PU resins by reduction with aqueous sodium tetrahydroborate solution was investigated by means of infra-red (IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA). It was confirmed by the measurement of degree of swelling and glass transition temperature that the PU resin having a higher molar ratio of PEE15/PEE3 has a lower degree of cross-linking. When the PU films were reduced at 20 °C, the PU resins with PEE15/PEE3=10/0, 8/2, and 6/4 afforded the films with a metallic luster, whose surface resistance increased in this order. The formation of cobalt metal on both the sides of the PU film was revealed from the results of the XPS and EPMA measurements. The PU resin having a lower degree of cross-linking could be more easily metallized by this reduction treatment.     

Hydroxyl Functionalized Methacrylic Terpolymers as Supports for Mn(III) Salen Catalysts and Their Application in Asymmetric Epoxidation

Hydroxyl functionalized gel type resins derived from 2-hydroxyethyl, 2-hydroxypropyl and 2-hydroxy-3-phenoxypropyl methacrylates were applied to covalent immobilization of Mn(salen) complexes via glutarate and carbonate linkers. The obtained catalysts were characterized by FTIR and DR UV–Vis methods and elemental analysis. It was found that the activity of polymeric catalysts obtained in this way depended on both the nature of the functional and cross-linking monomers and the degree of the cross-linking of polymer matrices and the way of complex immobilization. The highest activity was observed for the complexes immobilized on the HEMA resins cross-linked with 3%-mol of diethylene glycol dimethacrylate. For instance, in the presence of the catalysts with (S,S)-salen ligand S-epoxystyrene and (1S, 2R)-epoxyindene could be obtained with 46% and 69% ee, respectively. Attempts have also been made to recycle the selected catalyst. However, a rapid fall off in the activity was observed, although the selectivity was similar in which three cycles.     

Preparation and characterization of heat-resistant interpenetrating polymer network (IPN)

Interpenetrating polymer network (IPN) is a novel type of polymer hybrids, which possess physicochemical properties suitable for high performance coatings. Heat-resistant IPN have been prepared from immiscible resins, epoxy and silicones using a cross-linking agent and a catalyst. The products were analyzed by GPC, FT-IR, TG, DTA and SEM studies. The heat resistance property and corrosion behaviour of the IPNs were also determined. It was different from those of the individual resins. Silicone microdomains could be seen uniformly distributed in epoxy regions. Corrosion resistance property of the IPNs was evaluated by salt spray and impedance measurements. The IPNs withstood longer durations in the salt spray chamber.     

Radiochemische untersuchung der austauschgeschwindigkeit von harzaustauschern

The determination of half life times for the exchange on resins using labelled strontium ions and two different methods shows the influence of cross-linking, grain size and porosity. The big pores of the macroporous resins effect the exchange in the inner parts of the grains to be approximately as fast as in the outer parts.     

Bond quality of soy-based phenolic adhesives in southern pine plywood

Increased demand for wood adhesives, environmental concerns, and the uncertainty of continuing availability of petrochemicals have led to recent attention on protein-based adhesives. This study was conducted to investigate the glue bond qualities of soy-based phenolic adhesive resins for southern pine plywood. Two types of soy-based resins were formulated and tested. The first was made by cross-linking soy flour with phenol-formaldehyde (pf) resins at neutral pH. The second type was obtained by cross-linking soy flour hydrolyzates with pf resin under alkaline conditions. Plywood bonded with the neutral phenolic soy resins containing 70% soy flour and 30% 1.6 g/cm² pf without the use of extenders and fillers compared favorably with the traditional southern pine pf glue mixes. Plywood bonded with alkaline phenolic soy resins, containing 40 or 50% 0.5 g/cm² PF with the addition of extender (19% corn-cob powder), provided better adhesive glue bond properties than traditional southern pine pf glue mixes. These results suggest that soy-based phenolic adhesive resins have potential for the production of exterior southern pine plywood.     

Preparation of Poly(N-butyl methacrylate-co-glycidyl methacrylate) and Toughness Improvement for Powder Epoxy Resin E663

Copolymers of poly(n-butyl methacrylate-co-glycidyl methacrylate) were prepared by a free radical polymerization. The structures of the copolymers were characterized. The copolymers could be added to a powder epoxy resin (E663) to form modified epoxy resins. It was found that toughness of the cured modified epoxy resins were greatly improved, impact strength increased 3 times and fracture elongation increased 20% compared to the cured unmodified E663 resin. This is because that the copolymers had epoxy groups and flexible butyl groups, the former were involved in cross-linking reaction of the E663, and the latter made contribution to the toughness improvement.     

氯乙酰化聚苯乙烯树脂的胺基化反应

以氯乙酰化聚苯乙烯(PS-Acyl-Cl)代替氯甲基化聚苯乙烯作为载体,引入乙二胺(EDA)和己二胺(HMD)得到2种胺基树脂。考察了反应时间、油浴温度、物料比、溶剂体系等对胺化反应的影响,在最佳反应条件下,乙二胺和己二胺树脂的担载量分别达到1.60 mmol/g和2.6 mmol/g。将2种胺基树脂进行比较:在相同条件下,制备的己二胺树脂的担载量明显高于乙二胺树脂。该方法避免了氯甲基化法存在的弊端,并消除了烷基化引起的二次交联及多取代等副反应。制备的胺基树脂可以作为一个活性中间体,进一步衍生化制备多种功能介质。     

Diacetylene-containing polymers. XI. Synthesis and characterization of poly(hexa-2,4-diynylene-1,6-dioxydibenzoate) and poly(octa-3,5-diynylene-1,8-dicarboxylate) containing p-nitroaniline groups

Summary Two novel polymers containing p-nitroaniline group in the side chain and diacetylene groups in the main chain, were synthesized, and characterized. The polymers gave films of excellent optical quality by spin coating from DMF or chloroform. The one containing benzoate had a T_g of 103°C and its thermal cross-linking through the diacetylene group started at around 160°C. The one containing pentynoate had a T_g of 35°C and its cross-linking started at around 120°C. It was shown that thermosetting resins with functional groups could be obtained by using diacetylene-containing polymers. Although these two polymers have a same polar dye molecule, the second order nonlinear optical property was so different, showing that the main chains are very important for nonlinear optical property. Irradiation of UV light converted the polymer films to completely insoluble thermoset resins. Received: 13 February 2001/Revised version: 25 July 2001/Accepted: 30 July 2001