高抗冲聚苯乙烯预聚体转化率的快速测定

本文介绍了折光指数法、密度法和粘度法等三种快速测定HIPS预聚体转化率的方法。应用Loreng-Lorentz方法检验折光指数法和密度法,表明此两种方法是可靠的,可用于控制预聚合的生产过程。     

近红外光谱检测技术在碳纤维生产中的应用

为了找到碳纤维工业化生产过程中对批量聚合液与原丝品质便捷、准确、快速检测评价的方法，将傅里叶近红外光谱检测技术应用于干喷湿纺聚丙烯腈聚合液的固含量和原丝含油率、含水率的检测中，并与干燥失重法和索氏萃取法进行了对比，试验结果表明，傅里叶近红外光谱检测方法可以成功配套高效、大规模的高性能碳纤维生产工艺，满足高频次样品快速检测需求。     

高固体分涂料用含羟基星形丙烯酸酯树脂的制备及性能

以占单体物质的量0.01%的低铜盐用量催化剂体系进行电子转移活化再生催化剂原子转移自由基聚合(ARGET ATRP), 制备了丙烯酸丁酯、甲基丙烯酸甲酯和丙烯酸羟丙酯为单体的线形和六臂星形共聚物。采用折光指数-激光-黏度三检测联用GPC, ¹H NMR和DSC对聚合物的分子结构、共聚组成和玻璃化转变行为进行了研究。将聚合物配制成涂料用树脂溶液, 流变行为研究表明星形聚合物溶液黏度最低。在高固含量时, 星形聚合物降低黏度的优势更明显。在适合喷涂施工的黏度下, 六臂星形共聚物比普通自由基聚合得到的商品化丙烯酸酯树脂的固含量可提高10%。采用异氰酸酯固化剂固化得到的漆膜性能测试表明, 星形聚合物对应清漆的表干时间很短, 同时力学性能达到良好水平。     

磁固相萃取-气相色谱联用法测定火锅底料中的罂粟碱

合成磁性聚合离子液体材料作为磁固相萃取吸附剂,通过优化样品吸附和解吸条件,确定了最佳实验条件:样品溶液p H值=6、磁性纳米材料用量8 mg、解析剂比例(甲醇:氯仿=6:4)、解析剂体积1 m L、萃取时间12 min、解析时间6 min,并结合气相色谱进行定量分析,建立了火锅底料中罂粟碱的检测方法。结果表明,所建立的方法能直接对食品中罂粟碱成分进行快速精确测定,灵敏度高、回收率高、成本低。     

超高分子量聚丙烯腈溶液的流变性

本文研究了超高分子量聚丙烯腈—二甲基亚砜溶液的流变性能,探讨超高分子量聚丙烯腈(UHMW—PAN)的分子量、总固浓度及不同的毛细管长径比对纺丝原液的粘度、非牛顿流动指数、结构粘度指数、最大松弛时间的影响,并探讨了与原液可纺性的关系,为纺制高强高模聚丙烯腈纤维和能耐反冲洗的聚丙烯腈中空纤维膜提供了依据。     

车前子中熊果酸的提取及工艺研究

以常见的中草药车前子为原料,通过三因素三水平的正交试验方法确定样品最佳提取条件,实验结果显示以95%的乙醇为提取剂,液固比为8∶1,提取时间为3小时的提取工艺为最佳。采用紫外分光光度法~([1]),以熊果酸标准品作为对照品测定样品,用5%香草醛-冰乙酸溶液、高氯酸进行显色,以冰醋酸作为溶剂,在最大吸收波长548 nm下测定吸光度,熊果酸含量在3~15μg/mL的浓度范围内呈良好线性关系,相关系数r=0.9988,然后使用此方法测定并计算样品中含量,测得提取出的有效成分熊果酸含量为1.05%。此测定方法操作简便、检验快速、稳定性高、重复性好,干扰小,结果准确可靠。     

聚丙烯腈—DMSO浓溶液的粘弹性及可纺性的探讨

制备具有添加剂(Ca)的聚丙烯腈(PAN)-二甲基亚矾(DMSO)的浓溶液,测定其流变性能并探讨其可纺性。研究结果指出:溶液中PAN浓度、添加剂含量和温度对原液的非牛顿流动指数、最大松弛时间、剪切弹性模量、结构粘度指数、零切粘度有较大影响。当PAN的分子量为4.5万时,添加剂含量为5％,PAN浓度为15％,原液温度40～45℃,原液的结构和可纺性较好,可用干—湿法顺利纺制聚丙烯腈中空纤维分离用膜。     

农贸市场水发产品中甲醛含量的测定

采用乙酰丙酮分光光度法测定水发产品中的甲醛含量,并对样品的前处理过程进行了系统的探讨,确定了比色测定参数,并对其用于快速测定水发产品中甲醛含量的可行性进行了讨论。实验结果表明,用水浴浸泡法前处理样品时,最佳浸泡时间为10min,样液pH值用100g/L氢氧化钾溶液调至6;沸水浴中最佳显色时间为3min,比色波长为412nm;当甲醛含量在0~2.5ug/mL内时,该方法具有很好的线性关系和精密度。     

聚偏氟乙烯中空纤维膜纺丝凝固浴中有机物含量测定方法的研究

通过紫外光谱扫描分析PVDF中空纤维膜纺丝凝固浴的主要成分,用折光指数法测定了聚偏氟乙稀(PVDF)中空纤维膜纺丝过程中凝固液主要成分N,N-二甲基乙酰胺(DMAc)随时间的变化及其与COD的关系。结果表明,紫外光度法、折光指数法、COD法都可以用于DMAc的测定,其中折光指数法对0~70%体积分数的DMAc溶液有很好的线性相关性;在纺丝过程中,凝固浴的COD与其折射率具有很好的相关性。随着凝固浴中DMAc含量升高,膜孔径和断裂强度变化不大,膜通量降低。可利用折光指数法分析监控纺丝过程中凝固浴组成。     

四丁基溴化铵水合物浆液浓度电导率法在线测定

四丁基溴化铵(TBAB)水合物浆液浓度快速测定对TBAB水合物形成分解动力学研究和水合物浆液生产过程控制具有重要作用。通过在线电导率测定,本文研究了温度、TBAB浓度、TBAB水合物固含量对TBAB水合物浆液电导率的影响,建立了电导率法快速测定TBAB水合物浆液中溶液浓度及TBAB水合物固含量的方法,并提出了一种工业TBAB水合物浆液制备过程中溶液浓度和水合物固含量在线取样定量测量方案。研究结果表明:TBAB溶液电导率随溶液温度升高线性增大,随TBAB水合物固含量的增大而减小;TBAB解离度随浓度增大而减小,低浓度时(摩尔分数0.54%),溶液电导率随浓度增大线性增加,高浓度时,因TBAB解离度显著减小,溶液电导率增长缓慢,出现一个最高值;实验所得的TBAB水合物浆液固含量和TBAB溶液浓度计算经验公式,与实际浓度之间最大相对误差约9.0%,结果较可靠。     

鱼鳔及其鱼鳔胶粘剂(二)鱼鳔胶粘剂

实验选择三种不同的鱼鳔 ,分别考查了胶液固体含量与粘度的关系 ,粘温特性和固体含量与折射率的关系     

Preparation and characterization of novel ZnS/sulfur-containing polymer nanocomposite optical materials with high refractive index and high nanophase contents

A series of novel transparent bulk ZnS-polymer nanocomposites with high refractive index were successfully prepared via in-situ bulk polymerization in the presence of 2-mercaptoethanol (ME)-capped ZnS NPs. The polymerization mechanism combined the step-growth and free radical polymerization of different monomers of episulfide, m-xylylene diisocyanante (XDI), 2-hydroxyethyl methacrylate (HEMA) and N,N-dimethylacrylamide (DMAA). The high refractive index of episulfide compounds, including ESGMES, ESDGEBA and MPS, were synthesized and used as monomers in polymerization systems. The cured nanocomposites with 30 wt% nanoparticles show high refractive index and good transparency. The refractive index of the nanocomposites could be continuously regulated in the range from 1.59 to 1.65 by the content of ZnS NPs and the pencil hardness is round about 5H. The content of ME-ZnS NPs can affect the thermal stability, mechanical and optical properties of the resulting nanocomposites, and the relationship between them were studied by TGA, DMA, pencil hardness test, Charpy impact test.     

Relation Between Refractive Index and Elastic Moduli of a Borosilicate Glass After Heat-Treatment

Several specimens of a borosilicate glass were subjected to a series of different annealing schedules and the refractive indices and elastic moduli were measured and compared after each heat-treatment. The elastic moduli were determined by a dynamic resonance method at frequencies both within and slightly above the sonic range. The refractive indices were measured on the Grauer refractometer. A linear relation was found to exist between these two properties for specimens with different heat-treatments. A linear relation has already been established between refractive index and density by several investigators. This indicates that a single fictive temperature (τ) scale can be used to characterize the condition of a glass with respect to three properties: index of refraction, density, and elastic moduli.     

La-Si-O-N glasses: Part II: Vickers hardness and refractive index

Vickers hardness and refractive index have been determined for a series of La-Si-O-N oxy-nitride glasses containing 30–62 e/o of La and 9–68 e/o of N. The hardness varies between 7.7 and 11.5 GPa at a load of 1 kg and is dependent of the N content, while the La content does not influence it significantly. The increase of the hardness with N content is, contrary to reported findings for other oxy-nitride glasses, found not to be linear over the whole compositional range. The refractive index varies between 1.8 and 2.3 and increases non-linearly with increasing N content. The compositional variations of hardness and refractive index are compared with previously published results.     

Vibrating Orifice Droplet Generator for Studying Fast Processes Associated with Microdroplets

ABSTRACT

A light scattering technique, based on resonances, has been applied to a linear stream of highly monodisperse droplets generated by a modified vibrating orifice aerosol generator to study evaporation of ethanol droplets. The residence time of droplets was varied by altering the distance between the orifice and a laser beam. Frequencies at which intensity peaks (i.e., resonances) appear in elastic and Raman scattered light were determined by varying the frequency of droplet generation. The absolute droplet size and refractive index were determined by matching the observed resonances with theoretical resonances that minimize the difference between the observed and calculated resonance frequencies. The size and refractive index changes between two successive residence time observations were determined from the frequency shifts of the resonances. These procedures permit determination of size and refractive index with a precision of 2 parts in 10⁴, and their changes within 1 part in 10⁴ of the absolute values. For the examined residence time of 650 μs the evaporation process was unsteady. The evaporation rate as well as droplet temperature estimated from the refractive index was found to decrease with time. The experimental technique can be applied to study any fast process associated with microdroplets where observable changes occur over microsecond level time scales.     

利用测定磷矿浆相对密度快速确定磷矿浆含固量的方法

由于目前生产中测定磷矿浆含固量的方法需要3h,影响生产控制,为此,对磷矿浆相对密度、含固量的实验数据进行统计分析,找出两者相关关系,列出回归方程。生产中可方便测定矿浆相对密度,通过回归方程快速计算出磷矿浆含固量,用于指导生产,其误差为生产所允许。     

基于黏度的润滑油特性通用关联(英文)

Lubricating mineral base oils are normally extracted from lube-oil cuts with furfural solvent.Aromatic content in the raffinate phase from extraction process is an essential parameter that affects the quality of the lubricating base-oils.For determination of aromatic content by the usual ASTM D3238 method,density,refractive index and molecular weight of the raffinate are required.In this work,a new generalized correlation is developed for de-termination the aromatic content by using only the measured viscosity of lubricating oil.With a mole fraction of aromatic compounds,the kinematic viscosity may be obtained at any temperature between 60-100°C along with their molecular weight and refractive index.     

Plasma polymerized ferrocene films

This communication describes the formation of high index of refraction polymer thin films using a novel plasma polymerization deposition process. A flowing afterglow plasma reactor was modified to enable sublimation of solid samples into the gas phase for subsequent plasma polymerization. Thin films of plasma polymerized ferrocene were deposited on substrates and subsequently characterized. The refractive index as a function of processing conditions was obtained. Relatively high values of n (∼1.73 at 589 nm) were obtained. The chemical nature of the polymer thin films was characterized using FTIR and XPS spectroscopy. This work demonstrates that plasma polymerization is an enabling technology for the fabrication of photonic thin films that utilize solid state precursors.     

固体石蜡/丙烯酸改性乳液相行为的研究

初步研究固体石蜡及固体石蜡丙烯酸改性乳液的相行为,讨论固体石蜡乳液及改性乳液的温度对折射率的影响、乳化剂用量对乳液粘度的影响、温度对乳液粘度的影响及乳化时间对乳液粘度的影响。结果表明,两种乳液的折射率随温度变化不大,粘度随着乳化剂用量的增大而增大,且随着乳化时间的增加而逐渐增大。     

利用离子色谱快速测定磷酸二铵的水溶磷以及水溶性聚磷酸铵的聚合率

水溶磷含量是磷酸二铵的重要产品指标。介绍了一种利用离子色谱快速测定磷酸二铵产品中的水溶磷含量的方法。通过与重量法比较,二者的偏差小于2%,证明其精度较高。聚合率是衡量聚磷酸铵产品品质的重要指标,介绍了一种利用离子色谱快速测定水溶性聚磷酸铵的聚合率的方法。