种子法制备聚合物乳液技术的进展

从建筑乳液的生产现状、自生种子法与外加种子法的区别、种子乳液的特点及外加种子法生产的乳液特性等方面介绍了种子法制备乳液技术的进展。     

聚偏氟乙烯/聚丙烯酸酯复合乳液的合成与性能

在含氟表面活性剂存在下，将聚偏氟乙烯超声分散于甲基丙烯酸甲酯和丙烯酸丁酯的混合单体中进行乳液聚合，制备了聚偏氟乙烯／聚丙烯酸酯复合乳液。采用动态光散射DLS、透射电镜TEM和红外光谱FT—IR对乳液组成及乳胶粒子的形态进行了表征，并对聚合物胶膜的性能进行了测试分析。结果表明：聚偏氟乙烯的加入，使复合乳液膜的拉伸强度显著增大，吸水率减小。     

聚甲基丙烯酸甲酯／纳米SiO2复合粒子的制备与表征

采用甲基丙烯酸-3-甲氧基硅丙酯（MPs）对分散于甲基丙烯酸甲酯（MMA）中的纳米SiO2粒子进行偶联改性，得到了表面改性的纳米SiO2单体分散液，用原位悬浮聚合方法制备了不同SiO2含量的PMMA／纳米SiO2复合粒子。通过红外光谱、透射电镜、差示扫描量热分析和热重分析等方法对制备的纳米复合粒子进行了表征，结果表明，纳米SiO2粒子在PMMA中分散良好；MMA可通过与MPS的共聚而有效地接枝到SiO2粒子表面，当SiO2含量为6．6％（质量分数，下同）、MPS用量为0．06g／gSiO2时，其接枝率可达73．8％；同时，纳米SiO2的引入可提高PMMA的耐热性能，当Si02含量为14.7％时，其玻璃化转变温度和最大热分解速率时的温度分别提高了11．8℃和18．8℃。     

Preparation and electrical conductivity of polyethers/WS2 layered nanocomposites

Utilizing the solvothermal synthesis technique, lithium intercalated tungsten disulfide Li_xWS₂ with x > 1 was obtained, which was allowed to react with water to the formation of single-molecule-layer suspension of tungsten disulfide. The layered nanocomposites PEG, PEO/WS₂, intercalating poly(ethylene glycol) (PEG, MW ≈ 1 × 10³, 6 × 10³, 1 × 10⁴) and poly(ethylene oxide) (PEO, MW ≈ 3 × 10⁵) into the tungsten disulfide host galleries, were prepared using the improved exfoliation-adsorption technique. It was revealed that the intercalated polymers within the host galleries are in a double-layer arrangement with an interlayer expansion of about 9 Å. Despite high conductivity of the host material, those of the PEG, PEO/WS₂ nanocomposites were found to be high in the order of 1 × 10⁻² to 10⁻³ S cm⁻¹ at ambient temperature, resulted from the guest-host charge transfers.     

角蛋白基药物载体的发展及应用探讨

从毛发中提取角蛋白，开发具有独特功能的角蛋白基药物载体材料，提高药物的活性和生物利用率，既能够增加毛发的利用价值，又能够实现节能减排，符合可持续发展战略要求。对毛发中提取角蛋白进行二硫键重建、自由基聚合、多糖改性和烷基化等改性处理，赋予角蛋白基药物载体优异地功能特性，进一步拓宽其作为角蛋白基药物载体的应用范围。角蛋白基药物载体可被加工成纳米粒子、纤维支架、水凝胶等各种形式用于药物的递送。作为一种高硫含量且具有良好细胞相容性的结构蛋白，角蛋白基药物载体在组织工程、再生医学等领域扮演着重要的角色。     

The beneficial effect of small amount of water in the ambient temperature atom transfer radical homo and block co-polymerization of methacrylates

ATRP of several methacrylates viz. methyl methacrylate (MMA), ethyl methacrylate (EMA), n-butyl methacrylate (nBMA), t-butyl methacrylate (tBMA), benzyl methacrylate (BzMA) and (N,N-dimethylamino)ethyl methacrylate (DMAEMA) has been studied in neat as well as aqueous (up to 12 vol% water) acetone at 35 °C using CuCl/bipyridine (bpy) catalyst and ethyl 2-bromoisobutyrate as the initiator. Addition of water significantly enhances the rate of polymerization without losing control. Unlike CuCl/bpy the CuBr/bpy catalyst gives poor control which is attributed to the lower solubility and consequent heterogeneity in the latter case. Of the other ligands used with the CuCl catalyst viz. o-phenanthroline (o-phen), 1,1,4,7,7-pentamethyldiethylenetriamine (PMDETA), 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA), Me₆TREN only o-phen offers reasonably good control. The CuCl/bpy catalyst system has been used also in preparing some di- and tri-block copolymers with reasonably low polydispersity index (PDI) at ambient temperature (35 °C) using aqueous acetone as the solvent. The following block copolymers have been prepared PMMA-tBMA, PMMA-b-tBMA-b-MMA, PMMA-DMAEMA, by this method.     

Synthesis and characterization of poly(vinyl chloride‐co‐vinyl acetate)‐graft‐poly[(meth)acrylates] by atom transfer radical polymerization

The graft polymerization of methyl methacrylate and butyl acrylate onto poly(vinyl chloride‐co‐vinyl acetate) with atom transfer radical polymerization (ATRP) was successfully carried out with copper(I) thiocyanate/N,N,N′,N′,N″‐pentamethyldiethylenetriamine and copper(I) chloride/2,2′‐bipyridine as catalysts in the solvent N,N‐dimethylformamide. For methyl methacrylate, a kinetic plot of ln([M]₀/[M]) (where [M]₀ is the initial monomer concentration and [M] is the monomer concentration) versus time for the graft polymerization was almost linear, and the molecular weight of the graft copolymer increased with increasing conversion, this being typical for ATRP. The formation of the graft polymer was confirmed with gel permeation chromatography, ¹H‐NMR, and Fourier transform infrared spectroscopy. The glass‐transition temperature of the copolymer increased with the concentration of methyl methacrylate. The graft copolymer was hydrolyzed, and its swelling capacity was measured. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 183–189, 2005     

Characterization of end‐functionalized styrene–butadiene–styrene copolymers and their application in modified asphalt

End amino, carboxylic acid, and hydroxyl functionalized styrene–butadiene–styrene (SBS) triblock copolymers were prepared with 1,5‐diazabicyclo[3.1.0]hexane, carbon dioxide, and epoxy ethane as capping agents, respectively. The effects of the end polar groups on the morphology and dynamic mechanical properties were investigated. Transmission electron microscopy images suggested that the group at the end of the polystyrene (PS) segment made the morphology of the PS domains disordered and incompact. Dynamic mechanical results showed that the storage and loss modulus increased after SBS was end‐functionalized. End amino and carboxylic acid groups improved the compatibility and storage stability of SBS‐modified asphalt. However, the effect of the end‐hydroxyl group on the improvement of the storage stability of SBS‐modified asphalt was not obvious. The differential scanning calorimetry analysis of SBS‐modified asphalt further showed that the compatibility and storage stability of SBS‐modified asphalt were improved by the attachment of amino or carboxylic acid groups through the anionic polymerization method. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 8–16, 2007     

聚醋酸乙烯酯树脂聚合度的快捷检测方法

通过实验得出不同聚合度、不同质量分数下的黏度数据，并作出平均聚合度-质量分数-黏度三者的关系曲线。在此基础上，提出通过检测聚醋酸乙烯酯树脂的质量分数和黏度，直接查出对应的聚合度的快速检测方法。     

醋酸乙烯-丙烯酸无皂乳液共聚的研究

以醋酸乙烯(VAc)为主单体,丙烯酸(AA)为改性功能单体,以半连续加料方式进行无皂乳液共聚过程,得到了稳定且固含量为30%左右的乳液。探讨了功能单体AA含量、反应温度等对共聚的影响。采用FT-IR、粒径分析等方法对共聚物的组成、乳胶粒子的尺寸及分布进行了分析表征。结果表明:在(65±2)℃下聚合,所得乳液稳定性好、转化率高、反应完全,且随着功能单体AA含量的增加,乳液黏度上升、单体转化率下降、乳胶粒粒径变小且粒径呈单分散性。