改性双氰胺衍生物固化环氧树脂的研究

针对双氰胺固化环氧树脂时固化温度过高的缺点,从自行设计并合成的一系列改性双氰胺中筛选出一种,将其与环氧树脂复配制成单组分潜伏性环氧树脂胶粘剂,利用差示扫描量热法(DSC)和红外光谱法(FT-IR) 对单组分环氧树脂固化体系的固化反应进行了分析和研究。结果表明,改性双氰胺与双氰胺相比,具有较高的活性,显著降低了固化反应的反应温度;所配制的单组分环氧树脂胶粘剂具有较长的贮存期和良好的固化性能。     

多壁碳纳米管修饰电极测定诺氟沙星

运用循环伏安法、线性扫描伏安法及示差脉冲伏安法等测试技术研究了诺氟沙星在多壁碳纳米管修饰玻碳电极上的电化学行为,建立了一种直接测定诺氟沙星的电化学分析方法.结果表明,与裸玻碳电极相比,多壁碳纳米管修饰电极能显著提高诺氟沙星的氧化峰电流.在优化的实验条件下,氧化峰电流与诺氟沙星浓度在1.0×10-7～1.0×10-6mol/L和1.0×10-6～2.5×10-5 moL/L范围呈现良好的线性关系,检出限为3.0×10-8mol/L对1.0×10-5mol/L诺氟沙星溶液平行测定10次的RSD为4.1%.测定了诺氟沙星胶囊中诺氟沙星的含量,结果满意.     

环氧接枝改性水性丙烯酸树脂的合成研究

通过丙烯酸酯类单体与环氧树脂接枝共聚反应,对水性丙烯酸树脂进行改性。研究了环氧树脂种类、用量、加料方式、反应温度及中和度等因素对其性能的影响。研究结果表明,当环氧树脂E-44在反应前期加入,用量为6%~9%(占总单体质量分数),反应温度为110℃,中和度为110%时,改性树脂具有较好的成膜性能和优异的物理机械性能。红外光谱分析证实接枝产物的存在;用扫描电镜观察了接枝共聚物的水分散体的粒子形态及大小。     

多壁碳纳米管修饰电极测定水样中痕量镉

通过多壁碳纳米管修饰玻碳电极,建立了水样中痕量镉的线性扫描阳极溶出伏安分析法。优化了支持电解质及pH、修饰剂用量、富集电位及时间等测定条件,在pH 4.0的NaAc-HAc缓冲液中,-1.10 V富集5 min后,溶出峰电流与Cd2 浓度在2.0×10-8~5.0×10-5mol/L的范围内呈良好的线性关系,检测限为8.0×10-9mol/L。该法用于实际水样中痕量镉的测定,平均回收率在98.7%~105.0%之间,结果满意。     

水性碳纳米管接枝改性环氧树脂的合成

用酸氧化法对多壁碳纳米管(MWNTs)进行羧化处理后引入酰氯基团,利用酰氯基团与环氧酯聚合物中的羟基进行缩聚反应将MWNTs接枝到环氧树脂结构中,合成得到碳纳米管接枝改性的环氧酯聚合物。该聚合物与丙烯酸单体进行自由基聚合,在聚合物中引入羧基,利用羧基与有机胺中和成盐,制得水性碳纳米管接枝改性环氧酯聚合物。对聚合物进行红外光谱和透射电镜分析表明,碳纳米管与环氧酯聚合物进行了接枝反应。     

环氧树脂增韧改性的研究进展

环氧树脂(EP)具有优异的综合性能,在许多领域中都得到广泛应用。综述了EP的增韧改性研究(包括橡胶、热塑性树脂、热致液晶、互穿聚合物网络以及纳米粒子等增韧改性方法),并指出了EP增韧的主要发展趋势。     

环氧基POSS改性环氧树脂的研制与性能研究

以苯基三乙氧基硅烷(PTES)和β-3,4-环氧环己基乙基三甲氧基硅烷(A186)为原料,甲醇、乙醇混合溶液为溶剂,酸性条件下水解制得含有Si—H键的环氧基低聚倍半硅氧烷(EP-POSS),通过傅里叶红外光谱(FT-IR)、核磁共振氢谱(¹H NMR)、核磁共振硅谱(²⁹Si NMR)等手段对其结构进行表征。用制备的EP-POSS对环氧树脂进行改性,分析了EP-POSS用量对树脂涂层附着力、耐冲击性、疏水性、耐热稳定性的影响。结果表明:当EP-POSS加入量为5%时,环氧树脂涂层附着力达到1级,耐冲击性达到50 cm,对水的接触角为90°,热稳定性大幅提升。     

环氧树脂改性水性聚氨酯胶粘剂的合成研究

使用环氧树脂E44和内交联剂三羟甲基丙烷(TMP)共同交联改性水性PU,采用小分子扩链剂 BDO,亲水扩链剂二羟甲基丙酸(DMPA),制得聚醚型的改性水性PU乳液,当环氧E44含量为4％,DMPA含量为9％-10％,TMP含量为2％-3％时乳液性能最佳。     

Effect of modified carbon nanotube on the properties of aromatic polyester nanocomposites

Aromatic polyester nanocomposites based on poly(ethylene 2,6-naphthalate) (PEN) and carbon nanotube (CNT) were prepared by melt blending using a twin-screw extruder. Modification of CNT to introduce carboxylic acid groups on the surface was performed to enhance intermolecular interactions between CNT and the PEN matrix through hydrogen bonding formation. Morphological observations revealed that the modified CNT was uniformly dispersed in the PEN matrix and increased interfacial adhesion between the nanotubes and the PEN, as compared to the untreated CNT. Furthermore, a very small quantity of the modified CNT substantially improved thermal stability and tensile strength/modulus of the PEN nanocomposites. This study demonstrates that the thermal, mechanical, and rheological properties of the PEN nanocomposites are strongly dependent on the uniform dispersion of CNT and the interactions between CNT and PEN, which can be enhanced by slight chemical modification of CNT, providing a design guide of CNT-reinforced PEN nanocomposites with a great potential for industrial uses.     

有机硅硼改性环氧树脂胶粘剂的研制

以环氧树脂(EP)和有机硅硼改性EP预聚物为主体材料,研制出一种可室温固化、高温使用且固化压力仅为接触压力的胶粘剂。并通过SEM、热重分析法和力学性能测试等手段对该胶粘剂的性能进行了研究。实验结果表明,有机硅硼改性EP预聚物与纯EP相容性很好,有机硅硼的加入明显提高了EP的韧性、耐热性和力学性能(尤其是高温时的剪切强度);当m(EP)∶m(有机硅硼改性EP预聚物)=100∶40时,剪切强度为14.84 MPa(20℃)和4.88 MPa(100℃),与未改性前相比,高温时的强度损失率由改性前的81.0%降低至67.1%;该胶粘剂可在100℃时长期使用,短期可耐150℃的高温。     

Aminofunctionalization effect on the microtribological behavior of carbon nanotube/bismaleimide nanocomposites

Original multiwalled carbon nanotubes (O‐MWCNTs) and aminofunctionalized ethylenediamine‐treated multiwalled carbon nanotubes (MWCNTs‐EDA) were mixed with bismaleimide (BMI) resin to prepare O‐MWCNT/BMI and MWCNT‐EDA/BMI composites, respectively. Raman spectroscopy, thermogravimetric analysis, and infrared spectroscopy were used to investigate the influence of aminofunctionalization on the multiwalled carbon nanotube (MWCNT) framework. Dynamic mechanical analysis, scanning electron microscopy images of the fractured surface, and field emission scanning electron microscopy of the worn surface were used to determine the possible friction and wear mechanisms of the system. The MWCNT‐EDA/BMI composite exhibited a higher friction coefficient value and a lower wear loss rate value than the O‐MWCNT/BMI composite, which was attributed to the larger number of defects caused by the aminofunctionalization of the MWCNTs, the stronger interfacial adhesion formed between the MWCNTs‐EDA and the BMI resin, and the better dispersive state of the MWCNTs‐EDA in the BMI matrix. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

碳纳米管修饰电极的研究进展

化学修饰电极如今在电化学和电分析化学中应用极为广泛。综述了碳纳米管的结构和性能,介绍了碳纳米管修饰电极的制备及应用。     

环氧树脂改性氰酸酯树脂的研究进展

综述了采用环氧树脂(EP)增韧改性氰酸酯(CE)树脂的共聚反应机理、固化产物的性能和复合材料的性能。CE在水分或残留的酚及金属离子等作用下自聚生成三嗪环,接着与EP反应生成口恶唑烷酮。CE改性后树脂的韧性和弯曲强度提高,而玻璃化温度和耐热性下降很少,且固化产物耐湿热性能和介电性能基本维持不变。     

改性环氧树脂制备的热固性环氧沥青材料性能

采用改性环氧树脂和脂肪族多元羧酸固化剂（由C22：三元酸和二聚脂肪酸固化剂复配而成）及石油沥青制备了热固性环氧沥青材料。通过力学性能测试、DSC及扫描电镜研究了沥青含量对环氧沥青固化物拉伸性能、玻璃化温度、固化反应活性及相结构的影响。结果表明,沥青质量分数为44％的环氧沥青固化物的拉伸强度达8．37MPa,断裂伸长率达223．50％,玻璃化温度22．25℃,吸水率为0．2％。随着沥青含量的增加,沥青作为分散相的粒径越来越大,因而环氧沥青材料的拉伸强度降低。沥青含量的增加对固化物的玻璃化温度没有显著的影响。有沥青的环氧固化体系的反应活化能要小于无沥青的环氧固化体系。     

室温固化耐高温环氧树脂胶粘剂的研究

介绍了一种具有一定韧性的耐高温胶粘剂。室温固化 1d基本达到最高强度 ;长期使用温度为2 0 0℃ ,短期使用温度达 2 5 0℃ ;对多种材料具有良好的粘接性能。     

Self-extinguishing and transparent epoxy resin modified by a phosphine oxide-containing bio-based derivative

A phosphine oxide-containing bio-based curing agent was synthesized by addition reaction between furan derivatives and diphenylphosphine oxide. The molecular structure of the as-prepared bio-based curing agent was confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. Dynamic mechanical analysis results indicated that with the increase of bio-based curing agent content, the glass transition temperature of epoxy/bio-based curing agent composites decreased, which was related to the steric effect of diphenylphosphine oxide species that possibly hinder the curing reaction as well as the reduction in the cross-linking density by mono-functional N-H. By the addition of 7.5 wt-% bio-based curing agent, the resulting epoxy composite achieved UL-94 V-0 rating, in addition to limiting oxygen index of 32.0 vol-%. With the increase of content for the bio-based curing agent, the peak of heat release rate and total heat release of the composites gradually decreased. The bio-based curing agent promoted the carbonization of the epoxy matrix, leading to higher char yield with good thermal resistance. The high-quality char layer served as an effective barrier to retard the diffusion of decomposition volatiles and oxygen between molten polymers and the flame. This study provides a renewable strategy for fabricating flame retardant and transparent epoxy thermoset.     

聚氨酯改性环氧树脂耐磨涂料的研制

以2,4-甲苯二异氰酸酯和蓖麻油为原料,合成了聚氨酯预聚体。使用该聚氨酯预聚体对环氧树脂进行了改性。对各种固化剂进行了筛选。最后研制了一种双组分常温固化耐磨涂料。通过正交实验和单因素实验确定了涂料的最佳配方:聚氨酯5 g,环氧树脂10 g,填料3 g,固化剂2．3 g。由此获得的耐磨性优良的涂膜性能为:表干时间10 h,实干时间不到40 h;耐磨性实验中,磨痕弦长5．4 mm;附着力0级,硬度5 H。     

环氧树脂改性氰酸酯树脂固化体系研究

采用差示扫描量热(DSC)法对脂环族环氧树脂(L2)改性双酚A型氰酸酯树脂(CE)的固化反应历程进行了研究,并探讨了L2用量对CE耐热性能和粘接强度等影响。结果表明:L2对CE的固化反应具有催化作用,但当w(L2)≥30%时,其催化效果因稀释作用而降低;纯CE和CE/L2体系在等温(210℃)固化反应过程中,其转化率在起始反应10 min内分别达到80%和91%左右;当w(L2)=10%时,CE/L2改性体系的拉伸剪切强度(22.80 MPa)和压缩剪切强度(44.40 MPa)较高,同时其耐热性能较好。     

改性纳米碳酸钙对环氧树脂胶粘剂性能的影响

采用剪切强度测定、热重分析(TGA)、扫描电子显微镜(SEM)、交流阻抗(EIS)及其他测试方法研究了DL-α-丙氨酸改性纳米碳酸钙(CaCO3)对环氧树脂(EP)胶粘剂性能的影响。研究结果表明:对含改性纳米CaCO3的EP胶粘剂而言,其剪切强度比含未改性纳米CaCO3的EP胶粘剂提高了2MPa,其热分解温度比未加纳米CaCO3的EP胶粘剂提高了10℃,并且其耐蚀性能也得到显著提高;填料分散性良好且无明显的团聚现象。     

Simultaneous voltammetric determination of ascorbic acid, acetaminophen and isoniazid using thionine immobilized multi-walled carbon nanotube modified carbon paste electrode

A carbon paste electrode (CPE) modified with thionine immobilized on multi-walled carbon nanotube (MWCNT), was prepared for simultaneous determination of ascorbic acid (AA) and acetaminophen (AC) in the presence of isoniazid (INZ). The electrochemical response characteristics of the modified electrode toward AA, AC and INZ were investigated by cyclic and differential pulse voltammetry (CV and DPV). The results showed an efficient catalytic role for the electro-oxidation of AA and AC, leading to a remarkable peak resolution (∼303 mV) for two compounds. On the other hand, the presence of INZ, which is considered as important drug interference for AC, does not affect the voltammetric responses of these pharmaceuticals. The mechanism of the modified electrode was analyzed by monitoring the CVs at various potential sweep rates and pHs of the buffer solutions. Under the optimum conditions, the calibration curves for AA, AC and INZ were obtained in the range of 1 × 10⁻⁶ to 1 × 10⁻⁴ M, 1 × 10⁻⁷ to 1 × 10⁻⁴ M and 1 × 10⁻⁶ to 1 × 10⁻⁴ M, respectively. The prepared modified electrode shows several advantages such as simple preparation method, high sensitivity, long-time stability, ease of preparation and regeneration of the electrode surface by simple polishing and excellent reproducibility. The proposed method was applied to determination of AA, AC and INZ in commercial drugs and in plasma samples and the obtained results were satisfactory.