PVA/明胶/淀粉水凝胶的制备及性能

采用反复冷冻一解冻法制备了不同配比的聚乙烯醇／明胶／淀粉水凝胶膜。测试了共混膜的力学性能、脱水率和溶胀度，用扫描电镜观察了共混膜的断面形貌。结果表明：除1：1配比的水凝胶膜成膜性差，其他配比的水凝胶成膜性较好，膜表面比较光滑。m（PVA）：m（明胶）为6：1时力学性能较好。脱水率和溶胀度均随PVA和明胶比例增大而减小。扫描电镜显示，水凝胶膜内部具有多孑L结构，可以用作组织工程支架材料。     

明胶对明胶/壳聚糖共混膜性能影响的研究

采用溶液共混法制备出了一系列明胶／壳聚糖共混膜,并考察了制备条件对膜性能的影响。结果表明：明胶的溶解方式对吸水率和溶胀比影响很小;随明胶分子量增加,共混膜的吸水率和孔洞体积增大;而随共混体系中明胶质量分数的增加,吸水率和孔洞体积亦增加,但溶胀比下降。     

光交联明胶-壳聚糖共混膜制备及性能研究

本实验用以聚乙烯醇-苯乙烯基吡啶盐的缩合物(PVA-SbQ)为光敏剂,运用紫外光辐照法以制备交联明胶-壳聚糖共混膜。用傅立叶红外、X-射线衍射方法对膜的结构进行表征,并对膜的力学性能、吸湿率、透光率性能进行研究。研究表明:PVA-SbQ分子与明胶、壳聚糖分子间存在氢键作用,光交联后,共混膜形成网状结构,有效地改善了共混膜的力学性能、吸湿性和紫外屏蔽性能等。     

聚乙烯醇-羟乙基纤维素共混膜的制备及性能

以羟乙基纤维素(HEC)和聚乙烯醇(PVA)为原料,通过溶液浇铸共混制备不同含量的羟乙基纤维素/聚乙烯醇(HEC/PVA)共混膜,用傅立叶红外分析(FT-IR)、扫描电子显微镜(SEM)进行表征,并考察了HEC/PVA膜的力学性能.结果表明:当PVA质量含量为40％时,共混膜的力学性能较纯HEC有显著提高;温度越低膜的溶胀度越小,但当温度升到60℃以后,膜的溶胀度几乎不变化,说明膜在高温下尺寸的稳定性很好;随着温度的升高,膜的含水率不断增加,制备的共混膜的使用温度不要超过80℃.     

微波脱硫废胶粉/天然橡胶共混弹性体的制备与性能

采用微波脱硫法对废胶粉(WRP)进行表面活化改性,初步探索了WRP脱硫的最佳微波条件;将在最佳微波条件下脱硫的废胶粉(DRP)与天然橡胶(NR)制成共混弹性体,考察了共混弹性体的力学性能、压缩永久变形、溶胀率和交联密度。结果表明,WRP脱硫的最佳微波条件为功率750W、辐射时间60s;DRP/NR共混弹性体的力学性能比WRP/NR共混弹性体有所提高;而相同胶粉用量下,DRP/NR共混弹性体的溶胀率均比WRP/NR共混弹性体低,而交联密度大。     

静电纺PLA/丝素-明胶复合纤维膜的性能研究

通过静电纺丝先制备聚乳酸(PLA)纤维膜,在PLA纤维膜上分别喷射不同比例的丝素-明胶纺丝液制得PLA/丝素-明胶复合纤维膜,对复合纤维膜的溶解性能、尺寸稳定性、力学性能及生物性能进行表征。结果表明:与丝素-明胶纤维膜相比,PLA/丝素-明胶复合纤维膜的溶失率明显下降,尺寸稳定性及柔软性得到改善,且经甲醇处理后,复合纤维膜的力学性能提高。将制备的复合纤维膜进行小鼠胚胎细胞(3T3)培养实验,3T3在PLA/丝素-明胶复合纤维膜上能更好地粘附、伸展和繁殖。     

聚醚砜/磺化聚醚醚酮共混膜的制备和性能

采用流延法制备了聚醚砜(PES)含量不同的PES/磺化聚醚醚酮(SPEEK)共混膜。PES与SPEEK具有良好的相容性。所制备PES/SPEEK共混膜的含水率、溶胀度和甲醇透过系数均随PES含量的增加而降低。虽然共混膜的质子传导性能有所降低.但阻醇性能和溶胀性能提高,这说明PES/SPEEK共混膜是一种很好的直接甲醇燃料电池用固体高分子电解质膜材料。     

明胶-海藻酸钠复合纤维的研制及性能表征

明胶(Gel)与海藻酸钠(SA)溶液共混得到不同配比的纺丝原液,通过黏度法,从热动力学角度对两种高分子材料的相容性及分子间作用力进行表征,结果表明,当SA∶Gel比例为3∶1时最优,此时共混液中两种高分子间存在较为强烈的分子间作用力,并辅以红外光谱分析,再对各种比例条件下共混液的膜材料进行了力学性能的检测,结果显示在该比例时膜材料具有最强的抗张强度。采用正交试验方法对SA-Gel共混纤维的后处理条件进行优化,结果表明,对共混纤维的断裂强度和断裂伸长率影响最大的因素,分别是热处理温度和拉伸率,而共混纤维的线密度和吸湿性均受拉伸率的影响最大。     

快速溶胀pH敏感明胶水凝胶的研究

明胶具有生物降解性及良好的生物相容性,已被广泛用于照相、食品及医药工业。为开发明胶的新用途,用乙二胺四乙酸酐(EDTAD)成功地对明胶进行了乙酰化改性,研制出了酰化明胶水凝胶,用紫外-可见分光光度法确定了酰化反应的工艺条件为:调节w(明胶)=1%水溶液的pH到12,在室温下反应2~3 h。酰化后明胶溶液的等电点向低pH方向移动,改性明胶所生成的水凝胶达到溶胀平衡所需的时间大幅度减小,平衡溶胀率呈几十甚至几百倍提高,且当m(EDTAD)∶m(明胶)<1∶15时,随着酰化剂用量的增加,改性明胶水凝胶的平衡溶胀率最高可达110左右。且水凝胶具有pH敏感性和离子强度敏感性,pH敏感点为pH≈4。     

聚乙烯醇／羧甲基壳聚糖共混膜的结构性能研究

为了提高羧甲基壳聚糖(CMCT)的物理机械性能,采用溶液共混法以羧甲基壳聚糖和聚乙烯醇(PVA)为原料制备不同比例的PVA/CMCT共混膜.用扫描电镜(SEM)观察了共混膜的截面形貌;用DSC、FTIR表征了共混膜的结构;测试了共混膜的力学性能.结果表明:PVA与CMCT分子链间在共混膜中有一定的相互作用,PVA的加入有利于改善CMCT的综合力学性能;当CMCT与PVA质量比为40:60时,两组分相容性好,膜表面均匀光滑规整,共混膜的断裂强度可以达到49 MPa.     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

三种煤样燃烧热的测定

本文通过三个厂家提供的三种煤样燃烧热的测定,由测定结果综合得出3号煤样燃烧最完全、燃烧热也最大,是三个煤样中最好的一种。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

我国聚碳酸酯工业发展概况

介绍我国聚碳酸酯生产能力和消费需求,对聚碳酸酯在信息工业中的应用作了简短介绍     

小议汽车涂装工艺设计对涂装成本的影响

论述了涂装工艺设计对涂装设备投资、涂装生产成本的影响。     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003     

Measurement of the gradient of viscosity with composition of mixtures of non-ideal gases

A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%.