共查询到20条相似文献,搜索用时 46 毫秒
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采用改进的Hummers法制备氧化石墨(GO),超声剥离得到氧化石墨烯(GOs),借助TEM、AFM、FT-IR和XRD对样品的形貌结构进行了表证,结果表明制得了富有含氧基团(C=O、—OH、—COOH、C—O—C等)的具有较好稳定性的GOs。通过湿法成膜制备了GOs改性的聚氨酯微孔膜,探讨了加入的GOs含量对复合聚氨酯PU微孔膜相关性能的影响,结果表明:当加入质量分数0.1%的GOs时,PU微孔膜的力学性能提高最明显;随着GOs含量的增加,复合膜体积电阻系数较空白样先增大后减小,在加入1.0%的GOs时,体积电阻系数开始低于空白样的即导电性有所提高;复合膜的吸湿率、孔隙率和透湿量,随着GOs添加量的增加均呈现增大的趋势,说明GOs的加入对PU微孔膜通透性能的改善亦有显著影响。 相似文献
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本文主要探讨了聚氨酯亲水膜(PU)透湿量与涂层厚度之间的关系,提出了使用聚氨酯亲水膜(PU)模拟人体与环境之间热湿交换的仪器设备,期待在降低成本的同时提高该产品材质物理化学性能。 相似文献
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聚氨酯微孔涂层在保持一定孔径分布率的同时,具有良好的弹性、硬度和极好的抛光研磨性,可作为抛光材料。以炭黑为增强填料与聚氨酯共混制备复合浆料,采用PU/DMF/H2O湿法交换技术,在超细纤维合成革基布上构筑炭黑/聚氨酯微孔涂层。研究炭黑用量、有机硅泡孔调节剂用量、基布含水率对聚氨酯涂层微孔结构、耐磨性和力学性能的影响。试验结果表明:以HDW-0070 HPM为基体树脂,控制炭黑用量为13.0%,有机硅助剂用量为1.5%(以聚氨酯有效质量计),基布含水率为20%,凝固浴DMF浓度为20%,温度25℃,凝固时间为20 min可获得孔隙率高、孔径分布均匀的耐磨聚氨酯微孔涂层。 相似文献
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在用湿法生产高档防水透湿织物时 ,为了改善成品的性能 ,降低成本 ,经常要在涂覆液中添加一定量的木粉、纸浆、纤维等产品。为了提高该产品透湿防水性能 ,利用改性羧甲基纤维素 (MCMC)作为添加剂 ,制成PU膜 ,并利用PMI孔径仪、透湿仪等仪器对PU膜进行性能测试 ,探讨了MCMC对PU膜防水透湿性能的影响。 相似文献
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根据在实践中的经验.分析、讨论了聚氨酯摩擦盘对成品丝质量的影响,尤其是在生产多孔数品种时,使用聚氨酯摩擦盘可以有效地减少毛丝,提高成品丝的染色性能,从而提高产品质量。 相似文献
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介绍掺有3%Bi2O3的SnO2超微粒膜的感湿特性。这种薄膜材料的阻湿特性曲线具有较好的线性,湿滞回差小,并有较好的重复性和长期稳定性. 相似文献
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P. A. Brookes 《Journal of the Institute of Brewing》1982,88(4):256-260
The mechanisms of formation of NDMA in malting are briefly discussed to allow grouping of methods for NOMA control. The techniques to control NDMA are considered in relation to their effect on other malt properties and the difficulties of balancing all aspects to achieve a malt specification is highlighted. The use of low NOx conditions, the lowering of hordenine production, the prevention of hordenine nitrosation, the reduction of nitroso-hordenine breakdown and the removal of DMA and NDMA in kiln exhaust are all considered with the aim of producing malt of brewing quality with NDMA less than 5ppb. The outlook for the future is briefly examined when it seems likely that indirect firing of malt may have to be employed. 相似文献
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The effectiveness of modified atmosphere packaging and barrier properties of films upon the product attributes of frozen (IQF) ham strips, that are normally found at salad bars, was studied every 28 days over a period of 196 days. Three gases/mixture were used (CO2, N2 and ambient air) for flushing two pouches, one made from normal barrier film (861) and the other from a high barrier film (863). A triangle test and sensory evaluations were performed by a semi-trained panel (six members) for the following traits: freshness, structure, mouth feel, overall evaluation, aroma, appearance and off-flavors. Overall evaluation scores were acceptable up to 140 days of storage, regardless of the pouch used, but from 140 to 196 days, the product would be only marginally acceptable. Ham strips stored in N2 or CO2 atmospheres had a higher acceptance level than those stored frozen in ambient air. Panelists distinquished between fresh and stored product more frequently (75%) when the product was stored in ambient air pouches rather than CO2 or N2 atmospheres. Pouches made from the higher barrier film had lower (398/g) total aerobic plate counts than pouches (736/g) made from normal barrier film, but these counts are low and would be acceptable in industry. 相似文献
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采用化学共沉淀法和浸渍法制备了不同金属或氧化物掺杂的TiO2气敏材料,通过透射电镜、电子衍射和x射线衍射对材料的结晶形态和物相进行了分析,用静态配气法测试了气敏材料的敏感特性.结果表明:这些材料的颗粒尺寸小于0.1μm,800℃处理样品为金红石型TiO2与锐钛矿型TiO2的混合物.通过选择合适的添加剂和工作温度可分别获得选择性酒敏元件、CO气敏元件和可燃气体普敏元件 相似文献
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