聚苯乙烯-三乙醇胺树脂催化合成苄叉丙酮

以苯甲醛和丙酮为原料,在水-氢氧化钠体系中以聚苯乙烯-三乙醇胺树脂为相转移催化剂合成了苄叉丙酮,收率达92.5%,并讨论了其反应机理.     

抗高温蠕变高粘红性共聚酰亚胺应变胶研究

采用两苯酐间连接不同桥基的几种二元酐，与二元胺经溶液共聚合成共聚酰胺酸，两种不同结构的共聚酰胺酸共混再配加适量酚醛树脂，制成棕黄色透明粘稠应变胶。用其胶膜在不同温度下进行热亚胺（固）化反应，测试了形成的半互穿聚合物网络的粘接、蠕变等性能，其中粘结力和抗蠕变性突出。制成的箔式电阻应变计，经老化和蠕变测试达到并超过国空标准高等级指标。     

Reaction Mechanism,Synthesis and Characterization of Urea-glyoxal （UG） Resin

The reaction mechanism of glyoxal （G） with urea （U） under weak acid condition was theoretically investigated at PW91/DNP/COSMO of quantum chemistry using density functional theory （DFT） method. The results show that the addition reaction of G with U under the conditions mainly involves the reactions of U with protonated glyoxal （p-G）, protonated 2,2-dihy- droxyacetaldehyde （p-G 1） and protonated bis-hemdiol （p-G2） to form two important carbocation reactive intermediates of C-p-UG and C-p-UG1, and two important hydroxyl compounds of UG and UG1. These compounds play important roles in the formation of UG resin. According to the result of quantum chemical calculation, UG resin was synthesized successfully under weak acid conditions. The UG resin was characterized by matrix assisted laser desorption ionization time of flight mass spectrometry （MALDI-TOF-MS）, ultraviolet and visible spectroscopy （UV-vis）, Fourier transform infrared spectroscopy （FT1R） and nuclear magnetic resonance spectroscopy （13CNMR and 1HNMR）. These instrumental analytical results agree with each other and further confirm the addition reaction pathway of glyoxal with urea proposed by quantum chemical calculation.     

含介晶单元的反应性增韧剂改性环氧树脂研究──Ⅰ.柔性链分子量对动态力学与冲击性能的影响

本文合成了既含聚醚柔性链、又含刚性介晶结构单元的活性增韧剂（LCEU(PEG)），用其改性E－51／dicy固化体系。系统研究了增韧剂中柔性链分子量与改性体系动态力学性能、冲击性能之间的关系。动态力学分析表明：改性体系的100℃以下的模量没有降低，并且随LCEU(PEG)中柔性链分子量的降低而略有升高；Tg随LCEU(PEG)的加入而略微降低，随改性剂中柔性链分子量的降低而略微增大。冲击实验结果表明：当LCEU(PEG)柔性链分子链为1000、600时，改性体系的冲击强度可以提高6~7倍；而当LCEU(PEG)柔性链分子链为400、200时冲击强度最大只能提高4倍。     

镧离子掺杂的聚苯乙烯阳离子交换树脂碳化产物的组成、结构和电化学性能

制备了La3 掺杂的聚苯乙烯阳离子交换树脂 ,对其进行碳化处理 ,分析了树脂碳化产物的组成和结构 ,并进一步考察了树脂碳化产物作为二次锂离子电池碳电极材料的电化学行为。La3 掺杂的聚苯乙烯阳离子交换树脂碳化产物与相同处理条件下的未掺杂离子的树脂碳化样品相比 ,3种非C元素H ,O ,S的含量都发生了明显的变化 ,其中H ,O含量有所提高 ,而S含量则有所降低。La3 掺杂的聚苯乙烯阳离子交换树脂在碳化过程中更易形成直径较大的层片石墨微晶结构。电化学实验测试结果进一步证明 :La3 掺杂有效地提高了树脂碳化产物作为锂离子电池碳负极材料的电化学性能。掺杂La3 的树脂碳化样品制备的锂离子电池碳电极材料与未掺杂La3 的树脂碳化样品制备的碳电极材料相比 ,充放电容量平均提高了约 30mAh·g- 1。     

Novel routes to epoxy functionalization of PHA‐based electrospun scaffolds as ways to improve cell adhesion

Straightforward and versatile routes to functionalize the surface of poly(3‐hydroxyalkanoate) (PHA) electrospun fibers for improving cell compatibility are reported under relatively mild conditions. The modification of nanofibrous PHAs is implemented through two different methodologies to introduce epoxy groups on the fiber surface: (1) preliminary chemical conversion of double bonds of unsaturated PHAs into epoxy groups, followed by electrospinning of epoxy‐functionalized PHAs blended with nonfunctionalized PHAs, (2) electrospinning of nonfunctionalized PHAs, followed by glycidyl methacrylate grafting polymerization under UV irradiation. The latter approach offers the advantage to generate a higher density of epoxy groups on the fiber surface. The successful modification is confirmed by ATR‐FTIR, Raman spectroscopy, and TGA measurements. Further, epoxy groups are chemically modified via the attachment of a peptide sequence such as Arg‐Gly‐Asp (RGD), to obtain biomimetic scaffolds. Human mesenchymal stromal cells exhibit a better adhesion on the latter scaffolds than that on nonfunctionalized PHA mats. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 816–824     

New oxidized sterols from Aspergillus awamori and the endo‐boat conformation adopted by the cyclohexene oxide system

Two new oxidized sterols 1 and 2 were obtained from the active fraction of a mangrove fungus Aspergillus awamori isolated from the soils around the mangrove plant Acrostichum speciosum. Their structures were elucidated using spectroscopic methods as 22E‐7α‐methoxy‐5α,6α‐epoxyergosta‐8(14),22‐dien‐3β‐ol (1) and 22E‐3β‐hydroxy‐5α,6α,8α,14α‐diepoxyergosta‐22‐en‐7‐one (2). The NMR data and complete assignments for both DMSO‐d₆ and CDCl₃ were given. Their cytotoxic activity against A549 cell line was evaluated. Furthermore, the detailed conformation analysis for ring B (cyclohexene oxide system) of sterol 1 was given on the basis of NOEs. The endo‐boat conformation was considered as the preferred conformation for ring B rather than half‐chair conformation. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis of Siloxanes Containing Vinyl and Epoxy Group and its Enhancement for Adhesion of Addition-Cure Silicone Encapsulant

Three types of siloxanes containing vinyl and epoxy group, (3-glycidoxypropyl) allyloxydimethoxysilane (GAMS), [2, 2-bis (allyloxymethyl) butoxy] (3-glycidoxypropyl) dimethoxysilane (AGMS) and [3-allyloxy-2, 2-bis (allyloxymethyl) propoxy] (3-glycidoxypropyl) dimethoxysilane (AAGMS) were prepared by the transetherification of 3-glycidoxypropyltrimethoxysilane with allyl alcohol, trimethylolpropane diallyl ether and pentaerythritol allyl ether, respectively. The chemical structures were characterized by Fourier transform infrared (FTIR) spectroscopy and ¹H nuclear magnetic resonance (¹H-NMR) spectroscopy. GAMS, AGMS and AAGMS were used as adhesion promoter for addition-cure silicone encapsulant (ASE) with a large amount of alumina (Al₂O₃) as thermally conductive fillers. It was found that the adhesion promoters not only greatly improved the adhesion strength of ASE but also significantly enhanced the mechanical strength of ASE. Among them, AAGMS gave the best adhesion strength and mechanical strength of ASE. The shear strength and tensile strength of ASE were increased from 0.34 and 2.23 MPa to 1.14 and 3.27 MPa with addition of 1.5 phr AAGMS, which was about 335% and 147% higher than that of ASE without adhesion promoter, respectively. The scanning electron microscopy (SEM) results showed that the adhesion promoters could improve the compatibility between Al₂O₃ particles and ASE matrix. Additionally, the viscosity of ASE with less than 3.5 phr AAGMS did not exceed 5000 mPa?s, which could meet the requirements of electronic encapsulation.     

Water-Mediated Epoxy/Surface Adhesion: Understanding the Interphase Region

Epoxy resins coatings are commonly found in corrosion protection coatings but the presence of water can affect their adhesion to the substrate, often weakening the adhesion of the coating to the solid, reducing its efficiency. Nevertheless, small amounts of water can enhance the epoxy/substrate interactions. In this work, the interphase region of an epoxy precursor and metal oxide substrates is investigated using molecular simulations and it is found that water accumulates between the epoxy layer and the solid substrate. At high water concentrations (9 wt %) the interaction between the epoxy precursor and the solid surface is weakened regardless of the nature of the solid, but at low water concentrations the nature of the solid surface becomes important. For hematite, the presence of water decreases the strength of adhesion but for goethite the presence of a small amount of water (3 wt %) enhances the adhesion to the surface resulting in a densification at the interface.     

环氧树脂掺量对发光树脂透水混凝土性能的影响

选择环氧树脂E51作为改性填料,制备出一系列不同树脂质量分数（0%、2%、4%和6%）的发光树脂透水混凝土。环氧树脂的引入使发光树脂透水混凝土的抗压强度和抗折强度均得到了提高,且随着树脂掺量的增加呈现出先升高后降低的趋势,在树脂质量分数为4%时,抗压强度和抗折强度均达到最大值21.7和6.11 MPa,发光树脂透水混凝土的透水系数随着环氧树脂质量分数的增加呈现出先降低后升高的趋势,在4%时透水系数最低为5.1 mm/s。微观形貌分析发现未经改性的环氧树脂透水混凝土的断面处有明显的裂痕和气孔,整体结构较为疏松,在引入环氧树脂后,裂痕和气孔的数量明显减少,整体结合较为紧密,发光树脂透水混凝土的发光时间与树脂质量分数关系不大,且发光透水混凝土在光照1 h下可以保持超过5 h的较为高效的发光时间。