双硫腙改性的聚(二甲基丙烯酸乙二醇酯-甲基丙烯酸羟乙酯)微球的制备及其对铜离子的吸附研究

用悬浮聚合法由二甲基丙烯酸乙二醇酯(EGDMA)和甲基丙烯酸羟乙酯(HEMA)共聚制备得到聚(二甲基丙烯酸乙二醇酯-甲基丙烯酸羟乙酯)(PHEMA)微球,考察了NaOH浓度、反应时间等对用双硫腙进行PHEMA改性反应的影响以及铜离子水溶液浓度(5～500mg/L)、pH(2.0～6.5)、吸附时间等对改性后的微球对铜离子吸附性能影响的因素.改性的PHEMA微球对铜离子的最大吸附量为65.6mg铜离子/g双硫腙;而且,吸附有铜离子的改性PHEMA微球用0.1mol/L的硝酸的解吸率可达到90%以上,经过3次吸附-解吸循环后,解吸率仍基本不变,这表明双硫腙改性的PHEMA微球可以多次反复使用,具有良好的应用前景.     

丙烯酸共聚物囊壁的正十八烷微胶囊的制备和性能表征

以二丙烯酸1,4-丁二醇酯为交联剂, 成功制备了甲基丙烯酸甲酯-甲基丙烯酸共聚物为壁材, 正十八烷为囊芯的相变材料微胶囊. 采用扫描电子显微镜(SEM)、差示扫描量热仪(DSC)和热重分析仪(TG)分别考察了单体与芯材投料比、单体浓度和交联剂的含量对微胶囊形貌、相变热性能、热稳定性能的影响. 实验结果表明: 随着单体与芯材投料比或单体浓度的增加, 微胶囊表面均变得致密, 壁厚增加; 随着交联剂含量的增加, 微胶囊的表面变得更加致密光滑, 热稳定性显著增强; 随着单体与芯材投料比的增大, 微胶囊热焓值减小, 被包裹的囊芯含量减少.     

聚去氢枞酸丙烯酸乙二醇酯的合成与表征

从歧化松香中提取的去氢枞酸(DHA)出发,经酰氯化后与丙烯酸(2-羟基)乙酯反应,合成了去氢枞酸丙烯酸乙二醇酯(DHAAGE);并以此为单体,偶氮二异丁腈(AIBN)为引发剂,四氢呋喃为溶剂,在60℃下,利用常规自由基聚合(CPR)法制备了聚去氢枞酸丙烯酸乙二醇酯(PDHAAGE)。考察了单体转化率随聚合时间的变化,并利用FT-IR1、H-NMR、GPC、TG和DSC等对PDHAAGE进行了分析和表征。同时考察了PDHAAGE在不同溶剂中的溶解性。结果表明,得到的PDHAAGE的数均分子量(Mn)约为5400,分子量分布小于1.40;Tg为95.8℃,Tm为375.8℃,热分解温度Td为396.4℃,说明PDHAAGE具有很好的热稳定性;PDHAAGE易溶于中等极性的有机溶剂中。     

包覆紫外线吸收剂奥克立林的纳米胶囊的制备及其性能

以二甲基丙烯酸乙二醇酯(EGDMA)为壁材单体、2-氰基-3,3-二苯基丙烯酸异辛酯(奥克立林,OCT)和辛酸/葵酸三甘油酯(GTCC)为芯材、过硫酸铵(APS)为引发剂,采用自由基界面聚合法制备防晒纳米胶囊。利用扫描电镜(SEM)、透射电子显微镜(TEM)、纳米粒度与电位分析仪(Nano-ZS)、红外光谱仪(FT-IR)、紫外线透过率分析仪等对防晒纳米胶囊的形貌、核-壳结构、粒径分布、化学组成和防晒性能进行表征。利用CCK-8法探究防晒纳米胶囊的生物相容性。结果表明:制得的防晒纳米胶囊为规整的球形,具有明显的核-壳结构,平均粒径为318nm,多分散系数为0.293;与未包覆OCT/GTCC的相比,防晒纳米胶囊具有更好的防晒性能,且降低了OCT对皮肤的刺激性,具有良好的生物相容性。     

UV界面聚合法制备含磷环氧微胶囊及其性能研究

通过双酚A环氧与DOPO反应,合成含磷环氧树脂,并以此为囊芯,环氧丙烯酸酯和可聚合乳化剂共聚物为囊壁,通过UV界面自由基聚合制备兼具阻燃性和自修复性能的含磷环氧微胶囊,并对产物微胶囊的性质进行了进一步研究。用红外光谱(FT-IR)和扫描电镜(SEM)表征了含磷环氧微胶囊的核―壳化学结构和表面形态。采用差热扫描(DSC)分析了囊芯环氧树脂与固化剂的反应活性。通过热重分析法(TG)和极限氧指数法(LOI)研究了含磷环氧微胶囊的热稳定性及其在环氧复合材料中的阻燃性。结果表明:通过UV界面自由基聚合,在相分离作用下,能方便地实现微胶囊化,且所制含磷环氧微胶囊囊芯具明显的反应活性,其热稳定性和阻燃性能满足自修复复合材料性能要求。     

ATRP法合成聚去氢枞酸丙烯酸乙二醇酯的研究

本研究从歧化松香中提取的去氢枞酸(DHA)出发,经酰氯化后与丙烯酸(2-羟基)乙酯反应,合成了去氢枞酸丙烯酸乙二醇酯(DHAAGE);并以此为单体,2-溴-异丁酸乙酯(EBr-iB)为引发剂,CuBr/2,2'-联吡啶(2,2'-bipyridine)为催化体系,在90 oC下,利用原子转移聚合(ATRP)法制备了聚去氢枞酸丙烯酸乙二醇酯(PDHAAGE).利用FT-IR、1H-NMR和GPC对所制备的单体和聚合物进行了表征,同时考察了单体转化率随聚合反应时间的变化.结果表明,聚合反应动力学曲线呈良好线性关系,表观聚合速率常数kp′为3.6 ×10-7 s-1;所得聚合物的分子量分布很窄.     

细粒径石蜡微胶囊相变材料的制备与性能

采用阳离子和非离子复配乳化剂,通过原位聚合制备以丙烯酸酯为壁材,石蜡为芯材的细粒径微胶囊相变材料.采用傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)、差示扫描量热(DSC)、热重(TG)及激光粒度仪分析表征了微胶囊相变材料的化学结构、表面形貌和热性能.结果表明,乳化剂的种类和壁材单体的配比对微胶囊性能有重要的影响.当采用阳离子和非离子复配乳化剂,壁材中单体甲基丙烯酸甲酯(MMA)与丙烯酸(AA)的质量比为9∶1时,微胶囊相变材料呈球形且表面光滑紧凑,尺寸仅为0.2~0.35μm,具有良好的储热能力,相变潜热高达169 J/g;微胶囊中壁材对石蜡芯材的分解具有明显热阻滞作用,分解温度比纯石蜡提高了150℃.     

以聚脲为囊壁薄荷素油微胶囊的制备及表征

采用界面聚合法,以薄荷素油为芯材,以异佛尔酮二异氰酸酯为壁材单体,在催化剂四甲基乙二胺作用下和水反应形成聚脲外壳,制备出了薄荷素油微胶囊.通过扫描电镜、激光粒度分析仪、傅里叶红外光谱仪及热重分析仪分别对香精微胶囊的表面形貌、粒径分布、单体反应情况和热稳定性进行了分析表征.通过紫外可见分光光度计对香精微胶囊包覆率进行了测定.并分析了均质化速率和微胶囊平均粒径的关系以及不同乳化剂种类和芯壁比条件下微胶囊的形貌特征.结果表明,微胶囊平均粒径随均质化速率的增大而减小,下降到1μm左右时趋于平稳,当乳化剂采用聚乙烯醇且芯壁比为4∶1时,微胶囊形貌最佳,为规整球形.最终测得微胶囊芯材包覆率为84.09 wt%,粉末状微胶囊样品含油率为72.64 wt%,并且微胶囊芯材具有良好的热稳定性.     

石蜡/P(MMA-co-AA)核壳结构相变蓄能微胶囊的制备

以熔点在58~60℃的半精炼石蜡作为相变芯材,与单体、分散剂水溶液形成核壳结构分散液,室温下自由基聚合制备甲基丙烯酸甲酯-丙烯酸的共聚物(P(MMA-co-AA))为壳材的微胶囊.分别用相差显微镜、扫描电镜、差示扫描量热分析仪和傅里叶变换红外光谱仪测定了微胶囊的形貌、热性能和壳材化学结构.微胶囊的直径范围为1~5μm,其中相变芯材的含量可达70%左右,具有较高的相变潜热(99 J/g),有望应用于空调、供暖等领域.     

光致变色微胶囊的制备与性能

以蜜胺树脂为壁材、光致变色材料为芯材,采用原位聚合法制备了具有光致变色性能的微胶囊.研究了三聚氰胺/甲醛摩尔比、壁材与芯材的用量比、乳化剂浓度等因素对微胶囊形貌及性能的影响.在最佳工艺条件下制备的变色微胶囊,在日光和紫外光下具有快速、可逆的光致变色性能.     

Polystyrene resins cross-linked with di- or tri(ethylene glycol) dimethacrylates as supports for solid-phase peptide synthesis

Polystyrene resins cross-linked with di(ethylene glycol) dimethacrylate (DEGDMA) and tri(ethylene glycol) dimethacrylate (TEGDMA), DEGDMA-PS and TEGDMA-PS, were synthesized by suspension copolymerization. Four functionalized resins, chloromethyl resin, 4-hydroxymethylphenoxymethyl resin (Wang resin), 4-methylbenzhydrylamine resin (MBHA resin) and 2-chlorotrityl chloride resin, were prepared from DEGDMA-PS and TEGDMA-PS. DEGDMA-PS and TEGDMA-PS showed high reactivity in the functionalization reactions in comparison with Merrifield resin (polystyrene cross-linked with divinylbenzene, DVB-PS). DEGDMA-PS-Wang resin and TEGDMA-PS-Wang resin were used as the solid-phase support for the synthesis of a difficult sequence, the fragment of acyl carrier protein 65-74. The yields of the crude peptide synthesized using DEGDMA-PS-Wang resin, TEGDMA-PS-Wang resin and DVB-PS-Wang resin were 92.3%, 91.6% and 78.8%, respectively. The purities of the crude peptides were 85.7%, 88.1% and 73.3%, respectively.     

高效液相色谱用标样——多缩乙二醇二甲基丙烯酸酯的研制

本工作对多缩乙二醇二甲基丙烯酸酯标样的制备条件进行了研究。结果表明,应用经典柱色谱及制各级高效液相色谱两步分离,能方便地从合成反应所得粗试样制取纯样品,但是合成反应所用阻聚剂(包括贮存时所用阻聚剂)需要选择易分离的化合物,例如对苯二酚。结果还表明,对于已经过经典色谱柱预分离的二缩三乙二醇二甲基丙烯酸酯试样,硅胶/含0.25%(体积比)甲醇的二氯甲烷二元溶剂,是制备级HPLC比较理想的分离体系,可高效率地制备标样。     

沉淀聚合法Poly(DVB-co-EGDMA-co-MAA)功能聚合物微球的制备及表征

采用二乙烯基苯-55(DVB-55)和乙二醇二甲基丙烯酸酯(EGDMA)作为混合交联剂,乙腈为溶剂,偶氮二异丁腈(AIBN)为引发剂,以甲基丙烯酸为功能单体采用沉淀聚合法合成了单分散或窄分散的、表面具有羧基的交联聚合物微球,所得微球的粒径变化范围为0.6～3.8μm.通过调节交联剂DVB-55和EGDMA的投料比,可以对微球的粒径、粒径分布、产率、热稳定性以及表面官能团含量进行有效控制.文中对混合交联剂DVB-55与EGDMA比例的改变对微球的粒径、粒径分布以及产率的影响机理给出了理论解释;对DVB和EGDMA的兼容性研究表明,制备的三元聚合物微球的核拥有比投料比稍多的DVB单元,而微球的外层则以在预聚混合物中占更大比例的交联剂为主.     

Microgel formation in the free radical crosslinking polymerization of ethylene glycol dimethacrylate (EGDMA). I. Experimental

An important feature of free radical crosslinking polymerization of ethylene glycol dimethacrylate (EGDMA) resin is the formation of heterogeneous structure through intramolecular reaction. Such structure formation affects not only the cure behavior and rheological changes of the resin but also the physical properties of the formed polymers. In this study, the reaction kinetics, morphological changes, and characteristics of formed polymers were examined by a differential scanning calorimeter, a Rheometrics Dynamic Analyzer, a dynamic light scattering goniometer, and a Fourier transfer infrared spectrometer. Experimental data showed the formation of bimodal polymers before gelation. These polymers are partially crosslinked and can be considered as microgel particles. © 1995 John Wiley & Sons, Inc.     

Synthesis of highly cross-linked poly(diethylene glycol dimethacrylate) microparticles in supercritical carbon dioxide

Herein we report the synthesis of poly(diethylene glycol dimethacrylate), poly(DEGDMA), by free-radical heterogeneous polymerization in supercritical carbon dioxide (scCO₂), using a commercially available carboxylic acid end-capped perfluoropolyether oil (Krytox 157FSL) as stabiliser. The effect of initial concentration of stabiliser, monomer and initiator on the yield and morphology of the resulting polymer has been investigated. Krytox worked effectively as a stabiliser and discrete poly(DEGDMA) particles with diameters ranging from 1.28 to 2.08 μm and narrow particle size distribution were produced in supercritical carbon dioxide, in high yield and in short reaction times, without making use of harmful organic solvents.     

GRAFTING OF ETHYLENE GLYCOL DIMETHACRYLATE ONTO SILK IN AQUEOUS ALCOHOLIC SOLUTION

The grafting of ethylene glycol dimethacrylate (EGDMA) onto silk in aqueous alcohol systems using potassiumpersulfate (KPS) in the presence of air was investigated. Effects of grafting conditions, such as concentrations of monomer,initiator and formic acid, temperature and time, on the graft yield were determined. The optimum graft conditions were foundto be: T = 80℃, t = 30 min, [KPS] = 1.85% [on the weight ofmonomer (owm)]; [formic acid] = 0.2% (V/V); [EGDMA] =80% [on the weight of fiber (owf)]. The activation energy of grafting at 50-80℃ was found to be 71.31 kJ/mol for EGDMA.Grafting equations were also evaluated. The graft yield value can be regulated by the concentration of monomer. The graftcopolymerization of EGDMA onto silk is effective in improving the crease-proofing of silk fabrics.     

Poly(PEGDMA‐MAA) copolymeric micro and nanoparticles for oral insulin delivery

Poly(ethylene glycol) dimethacrylate (PEGDMA) and methacrylic acid (MAA) based micro and nanoparticles were prepared and evaluated as a carrier for oral delivery of insulin. PEGDMA was synthesized by esterification reaction of the PEG4000 with MAA in the presence of an acid catalyst. Particles of different size were prepared by emulsion polymerization reaction using different concentration of sodium lauryl sulphate (SLS) as an emulsifying agent. Synthesized copolymeric particle were characterized by attenuated total reflectance‐Fourier transform infrared spectroscopy (ATR‐FTIR), scanning electron microscopy, and acid value. The mean particle diameter of the polymeric micro and nanoparticles at various physiologically relevant pH values was measured using dynamic light scattering. Insulin loading efficiency of the particles was found to be directly proportional to the particle size and inversely proportional to the acid value of the particles. In vitro insulin release studies from various insulin loaded particles were performed by simulating the gastrointestinal tract conditions using HPLC. At pH 2.5, the release of insulin from polymeric particles was observed in the range of 5–8% while a significant higher release (20–35%) was observed at pH 7.4 during first 15 min of in vitro release. Largest size copolymeric particles of 8.3 µm also showed the highest efficiency to reduce the blood glucose level in diabetic rabbits. Copyright © 2010 John Wiley & Sons, Ltd.     

Quantification and identification of components released from dental composites using different chromatographic techniques

This study aimed to review recent chromatographic methods for quantifying and identifying components released from dental composites. Resin-based dental restorative materials are extensively used in dentistry today. Although composite materials are known to be highly stable structures, they are susceptible to degradation because of the incomplete polymerization. Several components may be released from resin composite restorations into the oral environment. The elution of components from composite resins may affect the biocompatibility of the restorations. Therefore, it is essential to understand the nature and quantity of substances that are segregated into the oral cavity.     

2种氧杂类大环化合物的光合成

在乙腈溶液中,6,6′-二甲基-4,4′-(三亚甲二氧基)-二-2-吡喃酮与乙二醇二甲基丙烯酸酯类化合物（n=1~3）在二苯酮的光敏化作用下,经由光二重[2+2]环加成反应,同时合成了2种氧杂类的大环化合物,收率为14%和7%、20%和11%及31%和14%。 产物的结构经FTIR、1H NMR和MS表征。 该法具有反应条件温和、操作简单和对环境友好的优点。     

一缩二乙二醇二甲基丙烯酸酯接枝真丝的结构

通过电子扫描电镜 (SEM)、红外光谱 (IR)、双折射、X 射线衍射及氨基酸分析等手段 ,研究了真丝用一缩二乙二醇二甲基丙烯酸酯 (P 2 )接枝后其结构与接枝率之间的关系 .氨基酸分析结果表明P 2接枝主要在真丝大分子中酪氨酸、丝氨酸、组氨酸和精氨酸的NH2 、OH和—NH—活性基团上 .通过X 射线衍射分析 ,P 2接枝并不直接影响结晶区 ,但引起分子取向的下降 ,接枝后真丝双折射下降说明接枝后因大分子取向度下降 ,接枝真丝的红外光谱显示出真丝具有 β折迭结构和P 2高聚物的结构特征峰 ,从而说明P 2接枝在纤维的无定型区内部进行 .当接枝率大于 35 %时 ,纤维的表面覆盖了一层高聚物 (P 2 ) ,并且纤维的横截面表现出明显的分纤现象 ,接枝真丝的红外光谱表明了纤维与P 2重叠吸收峰 ,说明了P 2在丝纤维内部接枝聚合 .