导电填料对炭系电热涂料电热性能的影响

研究了石墨含量对炭系电热涂料电热性能的影响,并对以石墨为主要导电填料,配入一定质量的炭黑和碳化硅原料制备的炭系电热涂料电热性能进行了分析讨论。电热性能测试和SEM分析表明:石墨是炭系电热涂料优良的导电填料,当石墨含量为50%(粘结剂为50%)时,在220 V的电压下通电10 min,其涂层的发热功率为18.6 W,发热温度为43℃;配入炭黑和碳化硅原料时,在同等测试条件下,配比为m(粘结剂)∶m(石墨)∶m(炭黑)=5∶3∶2的涂层电热性能最好,发热温度稳定在53℃,可用于民用采暖;配比为m(粘结剂)∶m(石墨)∶m(碳化硅)=5∶4∶1的涂层发热温度可稳定在37℃。实验表明:炭黑比碳化硅对炭系电热涂料的电热性能影响大,能较好地提高炭系电热涂料的电热性能。     

复合炭系电热涂料的制备及电热性能研究

为开发出电热性能优良、适用范围较宽、性能稳定的电热涂料，以炭黑、碳纤维、石墨烯为导电填料，丙烯酸乳胶为粘结剂，制备了水性炭系电热涂料。分析了 3种导电填料对涂层电热性能的影响，并对涂层的表面温度、体积电阻率、升温速率、附着力、耐热性以及表面形貌进行了测试。结果表明：在 24 V电压下，涂层尺寸为 60 cm×30 cm，厚度约为 0. 2 mm，炭黑添加量为 1. 5%，碳纤维添加量为 0. 6%，石墨烯添加量为 2. 5%时，涂层具有优良的电热性能，表面温度为 108. 1 ℃，体积电阻率为 2. 2 Ω·cm，附着力达到 0级，贮存稳定性和耐热性能均较好，初步具有工业应用价值。     

水性炭系电热涂料的制备及性能研究

以水性丙烯酸树脂为粘结剂,石墨为主要导电填料,配入其他导电填料制备了水性炭系电热涂料。研究了水性丙烯酸树脂添加量、溶剂水的用量、固化温度和导电填料种类对涂层电热性能的影响,并测试了最佳条件所得涂层的使用性能。结果显示,水性丙烯酸树脂与石墨的质量比为5∶5时,涂层在80 V的电压下通电5 min,表面温度可达95°C。溶剂水的添加量宜23%~27%,涂层固化温度宜50°C左右。在所选炭黑、煅后焦、无烟煤、三氧化二铝、二氧化硅和碳化硅这6种填料中,石墨与炭黑复合后所得涂层电热性能最好。当m(水性丙烯酸树脂)∶m(石墨)∶m(炭黑)=5∶4∶1时,40 V电压时涂层表面温度可迅速达到100°C以上,且耐水性、耐热性、硬度和附着力均满足使用要求。     

电热涂料的研制与应用

研制了性能稳定的电热涂料，并列举了该涂料的性能指标。讨论了基料树脂、导电材料、固化温度、固化时间和涂层厚度对涂料性能的影响c以电暖器为例，介绍厂电热涂料作为发热元件的应用实例。     

国内消息

新型无机耐热涂料合肥工业大学研制成功一种新型无机耐热涂料,它可在常温固化或300℃以下烘烤固化而形成耐热涂层。该涂层具有耐高温(500～600℃)、耐水、耐药品、硬度大等优良性能。外观近似陶瓷,硬度超过搪瓷。该涂料主要由聚烃硅氧胶粘剂、颜料、填料和辅助剂等组成。     

柔性石墨用耐高温涂料的研制

阐述了柔性石墨的表面特性及其对涂料的要求。以改性无机粘结剂为成膜物质，制备耐高温涂料，该涂料长期耐热温度250℃，短期耐热温度高于300℃。     

耐高温防粘柔性石墨涂料的研究

叙述了柔性石墨的特点及其对涂料的要求。以改性无机粘结剂作成膜物质，以无机非金属材料；滑石粉、SiO2、Cr2O3、TiO2作填料，制成耐高温防粘柔性石墨涂料。该涂料具有优良的耐热性和机械性能，长期耐热温度250℃，短期耐热温度高于300℃。     

耐保温层下腐蚀涂料的制备及性能研究

以环氧有机硅树脂改性酚醛环氧制备了一种耐保温层下腐蚀涂料,以 TGA（热重分析）、 DMA（动态力学分析）、 DSA（表面接触角分析）等对涂层性能进行评估,考察了树脂比例、固化剂种类、颜填料种类对涂层耐热性能、机械性能和防腐性能的影响。结果表明：环氧有机硅树脂与改性酚醛环氧的质量比为 4∶6 时可有效提高涂膜耐热性能;采用该树脂,以改性脂环胺为固化剂,片状云母氧化铁红为主颜料制备耐温涂料时,涂层具有良好的机械性能、耐热性能、耐腐蚀性能,并通过 250 ℃条件下耐保温层下循环腐蚀性能要求。     

低压高效石墨烯复合涂料的电热性能研究

分别在环氧、环氧改性有机硅、乙烯基树脂3种体系中,以石墨烯为导电填料,研究不同含量的石墨烯对涂料电热性能的影响。结果表明:石墨烯填充在乙烯基树脂中时,发热效率最高,石墨烯复合环氧树脂的涂层附着力最好;石墨烯与环氧改性有机硅复合综合性能最佳。当温度为25℃时,石墨烯含量为3%的环氧改性有机硅涂层在20 V低电压下通电2 min,涂层维持温度为61℃,涂层功率为12.5 W/dm~2,而且涂层物理性能最佳。石墨烯复合环氧改性有机硅树脂的电热涂料能满足安全、便捷、高效的要求。     

导电涂料的应用探索

采用了不同类型的基料树脂及不同的导电材料制得不同的导电涂料，对涂料的电热性能进行测试，探索导电涂料在电热方面的应用。     

Production of polystyrene microcellular foam plastics and a comparison of late‐ and quick‐heating

A batchwise process for the production of microcellular plastics was studied in the polystyrene–nitrogen system. The effects of saturation temperature, saturation pressure, and late‐ and quick‐heating on the microcellular structure were investigated by considering the solubility of the gas in the polymer. It was found that the mean cell diameter was reduced and the cell number density increased with increase in the gas solubility. Variation in the saturation temperature showed that the cell number density had a minimum and the mean cell diameter had a maximum at about 350 K, which was related to the minimum solubility of nitrogen in polystyrene. The long heating time at 393 K of a solution saturated under 25 MPa increased the cell diameter, reduced the cell number density, and gave a maximum volume expansion ratio at about 300 s. Further heating caused the cell size and volume expansion ratio to be decreased, which might be caused by diffusion of the gas out of the polymer sample. The effect of the saturation temperature under high saturation pressure on the cell number density was qualitatively well predicted by the nucleation theory. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2383–2395, 2000     

涂料用合成树脂生产加热方式的选择与节能

本文简述了涂料用合成树脂的生产工艺流程,着重论述了合成树脂系统加热方式的方案对比,并对导热油供热系统节能和环保方面作出较为详细的论述。     

Co-firing of coal and cattle feedlot biomass (FB) fuels. Part I. Feedlot biomass (cattle manure) fuel quality and characteristics

The use of cattle manure (referred to as feedlot biomass, FB) as a fuel source has the potential to solve both waste disposal problems and reduce fossil fuel based CO₂ emissions. Previous attempts to utilize animal waste as a sole fuel source have met with only limited success due to the higher ash, higher moisture, and inconsistent properties of FB. Thus, a co-firing technology is proposed where FB is ground, mixed with coal, and then fired in existing pulverized coal fired boiler burner facilities. A research program was undertaken in order to determine: (1) FB fuel characteristics, (2) combustion characteristics when fired along with coal in a small scale 30 kW_t (100,000 BTU/h) boiler burner facility, and (3) combustion and fouling characteristics when fired along with coal in a large pilot scale 150 kW_t (500,000 BTU/h DOE-NETL boiler burner facility). These results are reported in three parts. Part I will present a methodology of fuel collection, fuel characteristics of the FB, its relation to ration fed, and change in fuel characteristics due to composting. It was found that FB has approximately half the heating value of coal, twice the volatile matter of coal, four times the N content of coal on heat basis, and due to soil contamination during collection, the ash content is almost 9-10 times that of low ash (5%) coal. The addition of <5% crop residues had little apparent effect on heating value. The main value of composting for combustion fuel would be to improve physical properties and to provide homogeneity. The energy potential of FB diminished with composting time and storage; however, the DAF HHV is almost constant for ration, FB-raw, partially composted and finished composted. The fuel N per GJ is considerably high compared to coal, which may result in increased NO_x emissions. The N and S contents per GJ increase with composting of FB while the volatile ash oxide% decreases with composting. Based on heating values and alkaline oxides, partial composting seems preferable to a full composting cycle. Even though the percentage of alkaline oxides is reduced in the ash, the increased total ash percentage results in an increase of total alkaline oxides per unit mass of fuel. The adiabatic flame temperature for most of the biomass fuels can be empirically correlated with ash and moisture percentage.     

以碳酸钙为模板中空羟基磷灰石微球的合成

水浴条件下,中空球形碳酸钙(HSCCs)与磷酸氢二钠溶液反应成功合成了中空羟基磷灰石微球(HHMs).利用X射线衍射(XRD)、扫描电子显微镜(SEM)、傅里叶红外光谱(FTIR)对合成的中空羟基磷灰石微球的组成、结构、形貌进行了表征.结果表明,羟基磷灰石(HA)由模板碳酸钙直接转化而成,羟基磷灰石微球由杂乱分布的层片状晶粒聚集而成中空结构,直径约为4 μm,并对转化反应机理进行了初步探讨.     

微波加热制备水玻璃发泡保温材料及其结构表征

以钠水玻璃为实验原料,采用微波加热方式制备一种新型无机轻质发泡材料.与传统马弗炉加热方式对比,该材料具有更加良好的保温性能和更低的密度.为寻求最佳制备工艺,分别研究了发泡温度、加热功率以及加热时间对材料结构与性能的影响.同时采用扫描电镜、红外光谱等手段表征样品的结构性能及发泡机理.实验结果表明:微波加热功率为680 W,加热时间为9 min制备出的保温材料具有最优的性能,该材料密度仅为0.097 g/cm3,室温(25℃)下导热系数为0.0527 W/(m·K).     

石油焦制备活性炭工艺条件的优化及其孔结构表征

以独山子石油焦为原料,以氯化锌为活化剂,采用微波加热方式制备活性炭,通过碘吸附、苯吸附等考察所制活性炭的吸附性能,并对活性炭的制备工艺条件进行筛选和优化。结果表明：微波加热法制备活性炭时,最佳工艺条件是：氯化锌、石油焦、煤沥青的质量比为1．5：7．5：1,微波功率1300W,辐照时间6min。所得样品比表面积1095．7m^2／g,碘吸附值673．7mg／g,苯吸附值781．1mg／g,强度20．3N。通过与电炉法对比发现,微波加热和电加热制备的活性炭孔结构不同,微波法制备的活性炭在比表面积、孔径分布等方面优于电炉法制备的活性炭。     

双模版剂法制备SAPO-5和SAPO-34分子筛

以二乙胺和四乙基氢氧化铵为混合模版剂,采用水热法合成了SAPO6和SAPO-34分子筛,并用XRD,SEM,XRF,NH3-TPD等手段对其表征,以氧化苯乙烯重排反应为探针反应评价其活性.分别讨论了加料顺序和晶化升温模式对合成SAPO-5和SAPO-34的影响.结果表明,改变加料顺序和晶化升温模式时,在原料和合成物料配比不变的条件下可以分别合成出纯相的SAPO6和SAPO-34分子筛.在氧化苯乙烯重排反应中,由于SAPO-34含有强酸位,会产生大量聚合物,使得苯乙醛的选择性较低,而只含有弱酸位的SAPO-5表现出较好的活性和选择性.     

多孔混凝土应用于地暖填充层的试验探讨

试验研究了多孔混凝土应用于地面辐射供暖系统填充层对结构使用功能的影响.结果表明:多孔混凝土28 d抗压强度值达到23.9 MPa,完全满足地暖填充层材料强度要求;相同供热量、相同环境条件下,有效孔隙率14.6％的多孔混凝土地暖填充层比豆石混凝土地暖填充层热传递速率更快,热平均作用更明显.     

多孔硅颗粒在微波加热诱导下荧光增强效果研究

本文主要研究了在丙醇体系中,不同微波加热条件(反应时间和温度)对于多孔硅颗粒的荧光强度的调控和其相应的机理.结果显示,随着微波时间和温度增加,多孔硅颗粒的荧光强度也得到相应的增加.为了进一步研究其荧光增强机理,我们利用红外光谱和扫描电子显微镜,研究了微波前后的多孔硅颗粒的化学组分和形貌,其结果表明,在微波辐照下,多孔硅颗粒粒径变小,同时其表面氧化也增加,这些因素协同作用导致了多孔硅颗粒的荧光强度有效增加.     

A110-1型氨合成催化剂升温还原总结

叙述了A110－1型氨合成催化剂的装填、升温还原的原则及过程,并与其它类型催化剂升湿还情况进行比较,总结了使用效果。