二茂铁四氟硼酸盐的阳离子光引发性能的研究

制备并研究了[CpFeCp]BF4作为阳离子光引发剂在高压汞灯下引发环氧类预聚物的光引发活性。发现其在紫外及可见光区均有较强吸收（λm=355nm、620nm)；对环氧类预聚物，具有优良的光引发活性，感度值可达41.8mJ/cm^2，优于其它的阳离子光引发剂；[CpFeCp]BF4的最佳使用浓度为3％（质量分数）左右，由于光照后仍有强后聚合活性，发现其在较低浓度（质量分数1％）引发后放置，仍可使聚合完全；同其它的阳离子光引发剂相比，[CpFeCp]BF4制备简单，非常有应用价值。     

光催化芳茂铁盐作为热引发剂引发环氧化合物固化

[Cyclopentadien-Fe-naphthalene]BF4(CFN) and [cyclopentadien-Fe-anisole]BF4(CFA) thermal cationic initiators for the curing of epoxide E44 and GGE were investigated. CFN brought out the curing of E44 at 89.1℃ and that of GGE at 148.7℃. However, CFA had much less thermal initiating activity under 300℃.Under UV radiation for short time, the thermal initiating activities of CFN and CFA were enhanced obviously. It was observed that the initiating onset temperature decreased and the evolved heat of the curing increased. Both CFN and CFA can carrv out the polvmerization of E44 and GGE near 85℃ and 112℃ by UV radiation.     

阳离子光引发剂[CpFe（η^6—tol）]BF4光聚合活性及增感的研究

研究了阳离子光引发剂[CpFe(η^6-tol)]BF4引发环族环氧树脂ERL 4221阳离子光聚合的活性，其响应峰在374nm和450nm处，大于二甲苯基碘Weng盐的240nm，具有更高的感度，同时，研究了一些不同种类的过氧化物对[CpFe(η^6-tol)]BF4的增感作用，敏化效果与其氧化性一致：过氧化羟基异丙苯（CHP）≈过氧化苯甲酰（BPO）＞过氧化二异丙苯（DCP），研究了光敏体系的紫外吸收光谱和荧光发射光谱，对增感机理作出初步解释。     

载5-氟尿嘧啶的pH敏感自组装纳米粒制备及体外释放

In order to improve the cancer-targeting and selective activity of antineoplastic agent [5-fluorouracil （5-FU）], a novel pH-responsive drug delivery system [pullulan acetate/sulfonamide （PA/SDM） conjugate] was synthesized by a diafiltration method. Sulfonamide was grafted to the hydrophobicaUy modified pullulan acetate to enhance the pH sensitivity for better cancer-targeting delivery. 5-FU was loaded into the self-assembled nanoparticles by the same method. The drug-loaded self-assembled nanoparticles were successfully obtained and characterized in terms of particle size, morphology and drug loading and release profile at various pHs. The results showed that the mean diameter of the self-assembled particles was approximately 100nm, with uniform size and good spherical morphology. The nanoparticles showed good stability at pH 7.4, which is equal to that of the normal body fluid, but shrank and aggregated below pH 6.8, which is close to the pH with tumors. The loading efficiency and concentration of released 5-FU was monitored at 269 nm on the UVNis spectrophotometer. The release profile was heavily pH-dependent around phvsiological pH, and the release rate was significantly enhanced under pH of 6.8.     

琥珀酸酯为内给电子体的新型MgCl2载体催化剂用于丙烯聚合

A novel MgCl2-supported Ziegler-Natta catalyst containing diethyl diisopropylsuccinate donor was prepared and propylene polymerizations with the combination of such catalyst and four external donors were investigated in detail. The catalyst was compared with a commercial one with phthalate as internal donor in terms of catalytic activity, hydrogen sensitivity and stereospecificity in propylene polymerization. The molecular weight, molecular weight distribution and microstructure of the produced polypropylenes were compared also. It was found that the novel catalyst containing succinate internal donor showed higher activity and higher stereospecificity than those with phthalate as internal donor. Consequently, polypropylenes obtained by the succinate-based catalyst showed high molecular weight, high melting temperature, high isotactic index and broad molecular weight distribution than those obtained with the commercial catalyst.     

Relationship between viscoelastic properties and gelation in the epoxy/phenol‐novolac blend system with N‐benzylpyrazinium salt as a latent thermal catalyst

A study of viscoelastic properties and gelation in epoxy/phenol‐novolac blend system initiated with 1 wt % of N‐benzylpyrazinium hexafluoroantimonate (BPH) as a latent cationic thermal initiator was performed by analysis of rheological properties using a rheometer. Latent behavior was investigated by measuring the conversion as a function of curing temperature using traditional curing agents, such as ethylene diamine (EDA) and nadic methyl anhydride (NMA) in comparison to BPH. In the relationship between viscoelastic properties and gelation of epoxy/phenol‐novolac blend system, the time of modulus crossover was dependent on high frequency and cure temperature. The activation energy (E_c) for crosslinking from rheometric analysis increased within the composition range of 20–40 wt % phenol‐novolac resin. The 40 wt % phenol‐novolac (N40) to epoxy resin showed the highest value in the blend system, due to the three‐dimensional crosslinking that can take place between hydroxyl groups within the phenol resin or epoxides within the epoxy resin involving polyaddition of the initiator with BPH. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2299–2308, 2001     

偶联阳离子表面活性剂和常用阴离子表面活性剂混合溶液的相分离和微观结构

The properties of aqueous two-phase system (ATPS) of mixed solution containing gemini cationic surfactant trimethylene-l,3-bis(dodecyldimethyl ammonium) bromide (12-3-12, 2Br-) and traditional anionic surfactant sodium dodecyl sulfate (SDS) with or without added salt have been studied. An ATPS is formed in a narrow region of the ternary phase diagram different from that of traditional aqueous cationic-anionic surfactant systems. In ATPS region, the lowest total concentration of surfactants varies with the mixing ratio of geminis to SDS. Photographs obtained from freeze-etching, negative-staining and transmission electron microscopy show that the microstructures of two phases are different from each other. Micelles and vesicles can coexist in a single phase. The addition of salts can change the phase diagram of ATPS. Furthermore, the added salts promote the aggregation of rod-like micelles to form coarse network structure that increase the viscosity of solutions. The negative ions of the added salts are the determining factor.     

Influence of Catalyst Content on the Thermal and Mechanical Properties of Epoxy Resins Initiated by a Cationic Latent Thermal Catalyst at Elevated Temperatures

The effect of catalyst content on the thermal and mechanical properties of diglycidyl ethers of bisphenol A (DGEBA)/BPH system was investigated at elevated temperatures. The contents of the catalyst, N‐benzylpyrazinium hexafluoroantimonate (BPH), examined were 0.5, 1, and 3 wt.‐% and the elapsed heating time was varied from 0 to 1 024 h. As a result, the thermal‐oxidative resistance and mechanical properties, including flexural strength, elastic modulus in flexure, and impact strength showed a maximum value at 1 wt.‐% BPH. By increasing the elapsed time to 4 h, the thermal and mechanical properties of the specimens were also improved. These results showed that the internal structure of the epoxy system was stabilized and post‐cured as the elapsed time increased, resulting in an improvement of the thermal and mechanical properties of the specimens.

Impact strength of the DGEBA/BPH system as a function of BPH content and elapsed heating time.     

α-蒎烯阳离子聚合工艺的改进

以A lC l3/SbC l3为催化剂,用SbC l3逐步滴加方式,通过两步聚合工艺制备了α-蒎烯树脂。通过正交实验,对α-蒎烯调控聚合的各影响因素进行了研究。结果表明,与传统的一步聚合工艺相比,该工艺在保持单体高转化率的同时,使聚合反应变缓,避免了由于反应过快而引起的聚合产物中低聚体含量高,Mn下降的现象;有效提高了聚合物的软化点;降低了聚合物的色值。在优化工艺条件下,催化剂用量比传统工艺减少30%以上,制得的α-蒎烯树脂软化点为138℃(环球法),色泽3(铁钴色),得率达81.0%,软化点提高8℃以上,色泽降低2级以上。产品各项指标均超过了我国行业标准LY/T1453—1999特级水平。     

C9石油树脂的合成研究

以三氯化铝、二氯乙烷和甲苯制备液体三氯化铝。介绍了液体三氯化铝作催化剂合成 C9石油树脂的新方法。实验结果表明 :该催化剂合成的 C9石油树脂收率高、色泽浅。     

高聚合度阳离子型聚丙烯酰胺的合成研究

采用丙烯酰胺(AM)与阳离子单体二甲基二烯丙基氯化铵(DMDAAC)共聚制备高分子量的CPAM。研究了影响AM与DMDAAC共聚物的平均分子量的因素,得到了优化条件为:单体浓度为30%,DMDAAC与AM摩尔比为5∶95,聚合温度为30℃,低温段引发剂用量为0.05‰(占单体质量分数,下同),K2S2O8与NaHSO3质量比为1∶1,偶氮二异丁基脒盐酸盐(V-50)用量为0.025‰,尿素用量为40‰,乙二胺四乙酸二钠(EDTA-2Na)用量为0.05‰,在此优化条件下聚合反应16 h后得到分子量为1.217×107的阳离子型聚丙烯酰胺(CPAM)。CPAM被广泛应用在各种水处理和固液分离过程中。     

空间质量作用模型预测小分子离子交换平衡

The steric mass-action (SMA) model has been widely reported in the literature for ion-exchange and metal-affinity interaction adsorption equilibrium of biomacromolecules. In this paper, the usefulness of SMA model is analyzed for describing micromolecule ion-exchange equilibrium onto cation exchangers, CM Sephadex C-25 and Streamline SP. Batch adsorption experiments with ephedrine hydrochloride as a model adsorbate are carried out to determine the model parameters, that is, steric factor, characteristic charge and equilibrium constant. The result shows that the SMA model parameters of micromolecule cannot be obtained using the nonlinear least-square fitting method as protein‘s due to the remarkable difference between the molecular mass and dimension of micromolecule and protein. It is considered that the small size of the adsorbates dealt with in this study justifies the neglect of steric hindrances arising from adsorbate bulkiness. Thus, the three-parameter SMA model is reduced to two-parameter one (i.e., steric factor is equal to zero) for describing micromolecule ion-exchange equilibrium. It is found that the equilibrium constant for CM Sephadex C-25 increases with increasing ionic strength, while the equilibrium constant for Streamline SP shows an opposite trend. This is probably due to the remarkable difference between the physicalpro perties of the two adsorbents. Then, the relationship between the equilibrium constant and ionic strength is described by an expression. The computer simulations show that, the theoretical model with the correlation is promising in the prediction of micromolecule adsorption decrease with increasing ionic strength in a wide range of salt concentration.     

新型有机盐光引发剂的双光子聚合特性研究

本文运用激光微细加工技术，通过对不同浓度引发剂的甲基丙烯酸类树脂的聚合行为进行评价，研究了1-甲基-2-[2-（9-戊基-咔唑-3-基）-乙烯基]-3，3-二甲基吲哚碘盐（Ⅰ）作为双光子光引发剂的聚合特性，结果表明该化合物在扫描速度为44μm／s时，双光子聚合阈值为139kJ／cm%2；当激光能量密度为286kJ／cm^2时，引发聚合的曝光时间阈值为0．7ms．实验结果为进一步作为双光子聚合三维结构的微细加工提供了可靠依据．