DSC study of transitions involved in thermal treatment of foamable mixtures of PE and EVA copolymer with azodicarbonamide

The transitions and reactions involved in the thermal processing of binary mixtures of polyethylene and poly(ethylene‐co‐vinyl acetate) copolymers with different concentrations of a foaming agent (azodicarbonamide) were studied using differential scanning calorimetry (DSC). The effect of ZnO as a kicker also was discussed. The temperature at the maximum rate and the heat evolved were measured for all the processes—melting, transitions, and reactions—all the mixtures prepared were measured and compared. Azodicarbonamide decomposed differently depending on the polymeric matrix. These data can be very useful for the plastic processing industry. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2015–2025, 2006     

Nickel foam and carbon felt applications for sodium polysulfide/bromine redox flow battery electrodes

The first use of nickel foam (NF) as electrocatalytic negative electrode in a polysulfide/bromine battery (PSB) is described. The performance of a PSB employing NF and polyacrylonitrile (PAN)-based carbon felt (CF) as negative and positive electrode materials, respectively, was evaluated by constant current charge-discharge tests in a single cell. Charge/discharge curves of the cell, positive and negative electrodes show that the rapid fall in cell voltage is due to the drop of positive potential caused by depletion of Br₂ dissolved in the catholyte at the end of discharge. Cell voltage efficiency was limited by the relatively high internal ohmic resistance drop (iR drop). Polarization curves indicated that both NF and CF have excellent catalytic activity for the positive and negative redox reactions of PSB. The average energy efficiency of the single cell designed in this work could be as high as 77.2% at 40 mA cm⁻² during 48 charge-discharge cycles.     

天然茶皂素的提取及泡沫性能

茶皂素是一种天然的表面活性剂 ,通过几种浸取剂的研究 ,表明 60 %甲醇溶液为最好浸取剂。浸取温度 40℃～ 50℃ ,浸取时间 4 5h左右。浸取的茶皂素与多种表面活性剂比较 ,说明它是一种发泡性好、泡沫稳定性优良的发泡剂     

可发泡性酚醛树脂的合成研究

考查了可发泡性酚醛树脂的合成条件,如反应时间、温度和催化剂用量等对树脂活性、物理以及酚醛泡沫塑料容重和表观品质的影响,结果表明:催化剂用量越大,树脂粘度越大,泡沫固化时间越长;反应时间介于65～95min,泡沫塑料容重和表观品质较好;用加热板测定了合成的可发泡性树脂的固化速度,并求出固化反应活化能。     

混杂增强聚氨酯复合硬质泡沫塑料的研制

系统介绍混杂增强聚氨酯复合硬质泡沫塑料的制备情况，详细分析聚氨酯硬质泡沫塑料制备过程中的工艺问题，表征与分析其结构与性能，着重分析偶联剂对填充物增强性能的影响以及填充物含量对聚氨酯硬质泡沫塑料吸水性能的影响，介绍聚氨酯硬质泡沫塑料的应用，最后指出其发展前景。     

聚氨酯软泡压陷性能的测试

介绍了软质聚氨酯泡沫塑料压陷性能的测试标准，不同厚度样品的压陷硬度测试值的差异，采用50%压缩负荷估计压陷硬度的简易测试方法，以及压陷性能测试的影响因素，并对测试聚氨酯软泡压陷性能的国家标准与国外标准的差别进行了比较。     

泡沫微晶玻璃的研究进展

概述了泡沫微晶玻璃的性能及应用,综述了泡沫微晶玻璃的研究进展,并对泡沫微晶玻璃的发展方向进行了展望。     

由沥青制备多孔炭的工艺研究

采用沥青加发泡剂加炭黑制备了孔结构较好的多孔炭材料，分析和讨论了该工艺中沥青、发泡剂及炭黑的作用和影响，对多孔炭材料进行了力学性能测试和微观电镜观察分析，探讨了其可能的应用前景。     

不同粒径可膨胀石墨无卤阻燃高密度硬质聚氨酯泡沫塑料研究

采用高速混合破碎机对可膨胀石墨（EG）进行处理，制得不同粒径的EG。考察了不同粒径EG填充的硬质聚氨酯泡沫塑料（RPUF）的微观形态，研究了EG对于RPUF燃烧行为的影响。结果表明：EG的粒径越小，其在聚氨酯体系中的分散就越困难；20％未经处理的EG粒子（EG0）填充的RPUF氧指数为39．5％，比未填充的RPUF氧指数提高了近一倍，而经过13min破碎的EG粒子（EG13）其氧指数仅为23．5％，与纯RPUF的氧指数在同一水平；水平垂直燃烧结果可进一步验证氧指数结果，当EGO填充量超过10％时，RPUF燃烧已经达到了V-0级，而RPUF／EG13因其阻燃性能较差只能用水平燃烧分级。由此可见，EGO可有效提高RPUF的阻燃性能，而EG13对RPUF的燃烧性能几乎没有影响；研究同时提出了不同粒径EG无卤阻燃高密度硬质聚氨酯泡沫塑料的阻燃机理。     

制浆造纸工业用消泡剂的开发及应用进展

制浆造纸工业生产过程中不可避免会产生泡沫,泡沫控制不当会严重影响制浆造纸工艺条件的执行以及设备的正常运转,导致产品产量和质量降低,而控制泡沫最直接有效的措施是添加合适的消泡剂.该文介绍了制浆造纸工业生产中泡沫的产生和稳定机理,泡沫对制浆造纸工业生产过程和产品质量的影响,并针对制浆造纸生产中制浆、抄纸、涂布和脱墨等工段泡沫特性和消泡要求,综述了制浆造纸用消泡剂的发展历程、各工段消泡剂种类和性质,介绍了消泡剂的研制开发和实际应用成本及使用效果等,并对制浆造纸用消泡剂的发展进行了展望.