软膜型纤维素抑尘剂的制备及应用研究

发布时间：2018-03-29 14:19

本文选题：抑尘剂　切入点：水溶液聚合法　出处：《陕西科技大学》2015年硕士论文

【摘要】：近年来,我国大部分地区都发生了严重的雾霾现象,给交通运输及人们的生活和健康带来了非常恶劣的影响。雾霾形成的主要原因是空气中细颗粒物的含量超标,这些细颗粒物的形成存在多样化因素,如城镇拆建、散料运输、土地沙化等一系列与社会发展和人类生活息息相关的活动。随着科学发展,传统的抑尘方法(如篷布遮盖、洒水等)由于使用不便、抑尘时间短等缺点逐渐被市场淘汰,近年来各种化学抑尘剂应运而生,并且发展迅速。目前广泛使用的高分子抑尘剂多为硬壳型,产品喷洒后形成的固化层较脆,受到风吹和运输中震荡后容易碎裂,失去抑尘效果,且其成本较高。所以,制备价格低廉、成膜柔韧、抑尘性能优良的抑尘剂很有必要。本论文以来源广泛、价格低廉的天然小麦秸秆和羧甲基纤维素为原料,采用水溶液聚合法制备了软膜型秸秆纤维素抑尘剂和聚乙烯醇(PVA)/羧甲基纤维素(CMC)接枝丙烯酰胺(AM)抑尘剂。实验主要研究了秸秆纤维素的提取工艺、秸秆纤维素抑尘剂的制备工艺及PVA/CMC-g-AM抑尘剂的制备方法,并利用傅里叶红外光谱仪(FT-IR)、X-射线衍射仪(XRD)、热重分析仪(TG)、扫描电子显微镜(SEM)等对原料和抑尘剂产物进行了结构表征和形貌观察;利用柔软度仪考察了秸秆纤维素抑尘剂的成膜柔软度;利用静态接触角测量仪考察了去离子水对秸秆纤维素的润湿性和PVA/CMC-g-AM抑尘剂的润湿能力。以煤粉为试验对象,考察了两种抑尘剂的抗震荡性能、抗风蚀性能、保湿性能、渗透性能;通过煤堆模型浸泡实验考察了秸秆纤维素抑尘剂的耐水性能。主要结论如下:(1)秸秆纤维素的较佳提取工艺条件为:用质量分数为10%的Na OH溶液以12:1的液固质量比在100℃下蒸煮粉状秸秆90min。FT-IR分析结果表明天然秸秆中存在醚键、酯键等多种特征官能团,而秸秆纤维素结构简单,以羟基为主;XRD分析结果表明天然秸秆结晶度低,只有7.59%;经过提取处理,纤维素结构中的大量OH暴露出来,形成氢键,结晶度升高为27.04%。天然秸秆与去离子水的接触角为69.0°,而秸秆纤维素与去离子水的接触角为15.9°,进一步说明秸秆纤维素表面变粗糙,与试剂的接触面积大幅度增加。(2)秸秆纤维素抑尘剂的较佳合成工艺条件为:m(纤维素):m(丙烯酸):m(二甲基二烯丙基氯化铵)=6:5:1,引发剂过硫酸钾(KSP)用量为总单体质量的1.0%,交联剂N,N’-亚甲基双丙烯酰胺(MBA)用量为总单体质量的0.5%,65℃下反应5h后,其接枝率达到了83.2%。当丙三醇的添加量占总质量的20%时,得到的抑尘剂胶膜结晶度只有3.80%,此时抑尘剂成膜柔软。TG分析结果表明接枝共聚物的热分解温度在230℃以上。使用质量分数为8%的抑尘剂(固含量为32.3%)溶液喷洒煤粉后,10h的抗风蚀试验结果显示煤粉的损失率为5.2%,9h的连续震荡试验结果显示煤粉的损失率为5.4%,分别较单纯用水喷洒时的损失率降低了17.6%和46.6%。(3)当m(CMC):m(PVA):m(AM)=3:1:4,KSP为单体质量的1.2%,MBA为单体质量的0.5%,在65℃下反应5.5h后,制备出粘度合适的PVA/CMC-g-AM抑尘剂。PVA/CMC-g-AM共聚物的热稳定性良好,热分解温度在250℃以上,SEM观察到共聚物胶膜具有鲜明的多孔结构。正向渗透试验和接触角测量结果表明,在抑尘剂中加入0.2%的十二烷基本磺酸钠(SDBS)就可以提高其对煤粉的渗透性和润湿性;将质量分数1.0%的SDBS加入到6%的抑尘剂(固含量26.7%)溶液中,其与煤粉的接触角为18.9°,渗透厚度达到3.4cm。应用实验结果表明,此抑尘剂具有较好的保湿性和抗风蚀性,在煤粉表面喷洒抑尘剂溶液后,50℃下10h其水分的蒸发量为0.2g/cm2;风蚀实验12h,其煤粉损失率只有1.8%。
[Abstract]:In recent years, most areas of our country have undergone severe haze phenomenon, caused a very bad influence to the transportation and people's life and health. The main reason for the formation of haze is exceed the standard content of fine particles in the air, the formation of these fine particles of varied factors, such as urban construction and demolition, bulk transportation the land desertification, and a series of social development and human life activities. With the development of science, the traditional methods (such as dust suppression sprinkler tarpaulin cover, etc.) due to the use of inconvenience, short time dust suppression shortcomings gradually eliminated by the market, in recent years a variety of chemical dust suppressant came into being, and the rapid development of polymer widely. The use of dust suppressant for shell type, spray formed after the curing layer is brittle, by the wind and transport of shocks to fragmentation, loss of dust suppression effect, and the cost is high. Therefore, the preparation of price Low price, flexible film, dust suppression performance excellent dust suppressant is necessary. In this paper, a wide range of sources, low price of natural wheat straw and carboxymethyl cellulose as raw material, soft straw cellulose dust suppressant and polyvinyl alcohol prepared by aqueous solution polymerization (PVA) / carboxymethyl cellulose (CMC) acrylamide (AM) dust suppressant. The experiment mainly studied the extraction technology of straw cellulose, preparation method and preparation process of straw cellulose and PVA/CMC-g-AM dust suppressant dust agent, and by Fourier transform infrared spectrometer (FT-IR), X- ray diffraction (XRD), thermogravimetric analyzer (TG), scanning electron microscope (SEM) of raw materials and dust suppressant products were characterized and the morphology of film was investigated; straw dust suppressant with softness tester flexibility; the use of static contact angle measuring instrument of deionized water of lignocellulose Wetting and wetting ability of PVA/CMC-g-AM anti dust agent. Using coal as the research object, the effects of two kinds of dust suppressant anti shock performance, anti erosion properties, moisture retention, permeability; water resistance effects of straw cellulose dust suppressant by coal pile model immersion test. The main conclusions are as follows: (1) conditions the better extraction process of straw cellulose is: the mass fraction of Na 10% OH solution with a 12:1 ratio of liquid to solid powdered straw cooking 90min.FT-IR results at 100 DEG C indicates the existence of ether bond natural straw, ester bond and other characteristics of functional groups, and the cellulose structure is simple, with hydroxyl; XRD analysis showed that natural straw low crystallinity, only 7.59%; after extraction processing, a large number of OH structure in the cellulose exposed, the formation of hydrogen bonds, increases the crystallinity of 27.04%. natural straw and deionized water contact angle is 69 degrees, and the straw fiber Cellulose and deionized water contact angle is 15.9 degrees, further shows the cellulose surface becomes rough, increasing the contact area with the reagent greatly. (2) straw dust suppressant optimum synthesis process conditions: m (cellulose): m (acrylic acid): m (two dimethyl diallyl ammonium chloride) =6:5:1, potassium persulfate (KSP) dosage is 1% of the total monomer mass, crosslinking agent N, N '- methylene bis acrylamide (MBA) amount for 0.5% of the total mass of monomer, reaction temperature 65 5h, the grafting rate of 83.2%. when adding glycerol accounted for 20% of the total mass when the dust suppressant film crystallinity of only 3.80%, the dust suppressant film is soft.TG analysis results show that the decomposition temperature at 230 DEG C of graft copolymer of heat. With the mass fraction of dust suppressant 8% (solid content 32.3%) solution spraying pulverized coal, anti erosion test results show 10h pulverized coal the loss The rate is 5.2%, the continuous vibration test results of 9h display coal loss rate is 5.4%, compared with the pure water spraying respectively when the loss rate decreased by 17.6% and 46.6%. (3) when m (CMC): m (PVA): m (AM) =3:1:4, KSP as the monomer mass of 1.2% MBA as monomer the quality of the 0.5%, 5.5h reaction under the temperature of 65 DEG C, prepared by the thermal stability of PVA/CMC-g-AM dust suppressant suitable viscosity.PVA/CMC-g-AM copolymer, temperature at 250 DEG to thermal decomposition, SEM observed copolymer adhesive film with porous structure. The distinctive forward osmosis test and contact angle measurement results show that the dust suppression agent adding 0.2% basic twelve alkyl sulfonic acid sodium (SDBS) can improve the coal permeability and wettability; the mass fraction of 1% SDBS was added to the dust suppressant 6% (solid content 26.7%) solution, the coal and the contact angle is 18.9 degree, penetration thickness of 3.4cm. application. The experimental results show that the this dust The agent has good moisture retention and wind erosion resistance. After spraying the dust suppressant solution on the surface of the coal powder, the evaporation amount of 10h is 0.2g/cm2 at 50 C, and the pulverized coal loss rate of the wind erosion test 12h is only 1.8%..

【学位授予单位】：陕西科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ352.79;X513

【参考文献】