微胶囊型单组分室温固化压敏胶的制备及性能表征

采用原位聚合法，以三聚氰胺-甲醛（MF）为壁材分别制备了包覆环氧树脂与硫醇的微胶囊，并将两种微胶囊混合制备成单组分环氧压敏胶。当外力使微胶囊囊壁破裂后，由于两种芯材具有良好的互溶性，有利于其释放后的相互扩散和均质化，实现快速均匀固化。对微胶囊的微观形貌、尺寸分布、化学结构、热稳定性进行了表征，并研究了单组分压敏胶的固化放热过程与粘接性能。研究结果表明：所制备的微胶囊都呈规则球形，表面光滑，平均粒径在8～10μm左右，包封率都在70%以上；所制备的微胶囊具备良好的储存稳定性，室温下可长期储存而不发生质变，升温到150℃时皆能高效适用；将活性组分进行微胶囊化包覆不会破坏芯材的反应活性，且该胶粘剂在室温甚至低温下都有较好的固化效果；将两种微胶囊混合制备成单组分胶粘剂，并对其进行粘接强度测试，结果表明该微胶囊型单组分室温固化压敏胶十分具有发展潜力。     

聚酯材料微胶囊的制备及其对降解的影响

以PBS为壳材,通过对己二酸和十八醇2种芯材的微胶囊化,得到2种不同芯材的微胶囊.用扫描电子显微镜观测了微胶囊的表面形貌.偏光显微镜观测r在芯材参与下PBS的结晶状态.红外光谱表征了微胶囊芯材与壳材的化学组成,并采用X射线衍射对微胶囊壳材的结晶度进行了分析.将2种微胶囊添加到基材PBS当中,考察了其对基材降解的影响.     

原位聚合法制备脲醛树脂微胶囊过程中稳定剂及芯壁比的作用

采用原位聚合法制备了以异丙苯过氧化氢为芯材、脲醛树脂为壁材的微胶囊。研究了稳定剂类别和芯壁比对微胶囊化过程的影响。结果表明,稳定油滴的形成是能得到微胶囊产品的前提条件,而稳定剂对油滴的稳定效果越好,壁材越倾向于形成囊壁;芯壁比的增加会使微胶囊产率下降,芯含量增加;改变芯材或壁材用量调节芯壁比会影响壁材利用率。     

辐射余热回收用相变微胶囊的制备与表征

用原位聚合法制备了以58号石蜡为芯材、脲醛树脂为壁材的微胶囊。基于正交实验法得到了九组样品,并且对微胶囊产物的化学组成、相变特性、微观形貌和粒径分布进行了测试分析,考察了芯壁比、聚合反应温度、乳化搅拌转速和乳化剂添加量等因素对微胶囊制备过程及产物性能的影响。得到较佳的微胶囊产物为白色粉末,平均粒径81. 3μm,部分颗粒为球形,相变潜热约90 J/g。为得到适用于辐射余热回收的相变微胶囊,还需进一步优化制备工艺。     

EP-UF微胶囊的制备及改性环氧树脂

制备了EP-UF微胶囊,探讨了芯材/壁材配比对微胶囊性能的影响,并选择组分配比最优的微胶囊改性EP。结果表明:当芯材乳液用量为壁材预聚体质量的80%时,所制得的EP-UF微胶囊质量较好;当EP-UF微胶囊用量为5%~7%时,EP复合材料的力学性能较好;当EP-UF微胶囊含量为5%左右时,经加热处理后的EP复合材料的力学性能最好,相比未经加热处理的EP复合材料,拉伸强度提高了38.3%,断裂伸长率提高了32.7%。     

相变微胶囊芯材结晶性能研究

利用差示扫描量热仪(DSC)和原子力显微镜(AFM)研究了不同芯材(石蜡)与壁材(聚脲)比例的相变微胶囊的结晶性能以及结晶机理。结果表明:石蜡分子以片晶结构进行结晶相变,通过其焓值可计算芯材包裹率。随着芯材加入量的增加,包裹率先上升后下降;微胶囊中的芯材晶体熔限均大于纯样,且随着芯壁材投料比的升高,微胶囊熔点先上升后下降,其中当芯壁材投料比为1.8:1时,得到了最大的微胶囊相变潜热以及最高的包裹率。     

建筑用微胶囊型相变储热材料的制备及性能分析

为解决常规保温复合材料物理、化学性能不稳定的问题,提出了一种微胶囊包覆技术,将聚乙二醇复合芯材包覆于微胶囊中。以PEG 800和PEG 1000为主要材料,通过水浴加热法制备聚乙二醇复合芯材,在此基础上结合IPDI、DETA、SDBS等壁材制备微胶囊型相变储热材料。扫描电镜测试发现,微胶囊型相变储热材料对聚乙二醇复合芯材起到了良好的保护作用,且仍然保持了较为理想的储热性能,在建筑保温材料领域具有一定的应用价值。     

己二酸微胶囊的制备及其在降解塑料中的应用

以可生物降解聚丁二酸丁二醇酯(PBS)为壳材,通过溶剂挥发法制备包覆己二酸微胶囊,采用扫描电子显微镜观测微胶囊的表面形貌,用FT-IR表征微胶囊芯材与壳材的化学组成,用TGA分析微胶囊的热稳定性;并将微胶囊添加到基材PBS中,测试其对基材PBS降解的影响.研究结果表明:投料比为1:3时,微胶囊有较高的包覆率和较好的表面形貌;己二酸微胶囊的热力学稳定性稍有下降,这有利于芯材的释放,其对基材PBS的降解有一定的促进作用.     

二甲酸钾微胶囊的构建与缓释抑菌性

以自制沸石分子筛为载体,通过水热法将二甲酸钾负载形成芯材,海藻酸钠、壳聚糖为壳材,以复凝聚法制备出缓释微胶囊。通过FTIR、XPS对微胶囊进行了结构表征,通过缓释及抑菌率测试对其性能进行表征。结果表明:沸石分子筛与二甲酸钾之间可形成复配效应,构成微胶囊的芯材;壳聚糖和海藻酸钠发生静电作用,形成聚电解质膜,构成微胶囊的壳材;制备的微胶囊在pH=2.0的模拟胃环境中稳定,在pH=7.2的模拟肠道环境中二甲酸钾得到了释放,并在3 h内可释放完全;微胶囊包封率为68.33%,二甲酸钾的释放量为137.50 mg/g。微胶囊对大肠杆菌的生长具有一定的抑制作用,并随着微胶囊浓度的增大对大肠杆菌的抑制率呈现增长的趋势,最高抑菌率可以达到85%。     

界面聚合法制备聚脲微胶囊

采用界面聚合法制备了聚合物微胶囊,以十六烷为芯材,PVA为乳化剂,异佛尔酮二异氰酸酯和水直接反应生成聚脲作为壳材。得到的微胶囊形貌规整、表面光滑、粒径分布较窄。采用DSC表征微胶囊的热性能,结果证明:聚脲包覆对微胶囊的相变行为影响较小,且微胶囊具有良好的热稳定性,焓值计算显示微胶囊芯材质量分数可以达到70%。通过控制异佛尔酮二异氰酸酯的加入量,研究了微胶囊形成过程中的形貌变化。     

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。     

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     

气化给煤系统故障分析

气化给煤装置自投运以来,出现了气化煤仓堵煤、称重给煤机输送皮带因跑偏而损伤以及清扫装置故障频繁等问题,多次造成气化系统减负荷运行。通过对出现的各种问题进行分析,找到了产生这些问题的原因,并有针对性地采用配煤和改进清扫链等措施,使出现的问题得到了极大的改善。     

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     

醋酸纤维素取代基分布与性质的关系

分析了以吡啶为溶剂的醋酸纤维素的13C-NMR核磁共振谱,得出了三种不同位置羟基的取代度。结合X—射线和DSC分析,初步说明具有相同取代度但未经水解和经过水解的醋酸纤维素(CA) 性质上的差异是由于三个羟基上的取代度分布不同及消晶程度差异所致。     

Generalization of vdW type of equations of state

1 INTRODUCTIONBecause of importance of equations of state (EOS)in science and industry,hundreds forms of EOS havebeen presented since latter 19th century.It seems impossible to develop a general equation covering vari-ous kinds of EOS.But for cubic EOS,several generalequations have been reported already. Martin presented the first general equation whichis following p=RT/V-α(T)/(υ β)(υ γ) δ(T)/υ(υ β)(υ γ) (1) Kumar et a1.presented an equation called the most general form of a density-cubic or, alterna tively,volume-cubic mathematical equation,the form of which is as follows     

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。