【作者】 梁亮；

【导师】 徐文彬；

【作者基本信息】 广东工业大学 ， 环境科学与工程， 2021， 硕士

【摘要】 硝基漆稀释剂是一种无色透明且带有强烈气味的易燃易挥发混合型有机溶液,广泛应用于家具、装修和汽车等行业的涂漆、除漆和清洗等工艺中。由硝基漆稀释剂所引发的安全事故已屡见不鲜,除此以外,这类型有机溶剂在运输过程中由于发生事故而导致大量泄漏从而影响环境的事故也时有发生。硝基漆稀释剂主要由真溶剂、助溶剂和非溶剂的三种类型溶剂构成。其中,真溶剂是指能够直接溶解硝基纤维素的溶剂;助溶剂是指本身不能直接溶解硝基纤维素,但是与真溶剂共同使用能够促进硝基纤维素溶解的溶剂;非溶剂是指为了溶解树脂等其他成分而添加的溶剂。本文的研究对象为硝基漆稀释剂的主要成分:6种真溶剂(乙酸甲酯、乙酸乙酯、乙酸正丙酯、乙酸丁酯、丙酸乙酯和丁酸乙酯),3种助溶剂(乙醇、异丙醇和异丁醇)和3种非溶剂(正己烷、正庚烷和石油醚)。从硝基漆稀释剂主要成分及其混合物的溶漆效率、爆炸危险性和环境影响性的角度出发,通过固化漆膜溶解实验、爆炸下限测试实验和藻类生长抑制实验,对硝基漆稀释剂的三种主要类型的溶剂(真溶剂、助溶剂和非溶剂)进行研究,并从中筛选出溶漆效率较高、爆炸危险性相对小和环境影响相对小的溶剂及其组合。本文得到的主要结论如下:(1)从溶漆效率的角度上看,在真溶剂的对比实验中,乙酸甲酯是较好的真溶剂(39.64mg/min);在助溶剂的对比实验中,乙醇相对其他两种溶剂对真溶剂的促进作用更加明显,在助溶剂浓度较低时(含量为20%),助溶剂的效果更好;在非溶剂的对比实验中,三种非溶剂所组成的混合溶液对固化硝基漆膜的溶解效率都比较接近,但总体而言,正己烷的效果较好。(2)从爆炸危险性的角度上看,在真溶剂的对比实验中,乙酸甲酯有较高的爆炸下限(3.17%),因此乙酸甲酯是较安全的真溶剂;在助溶剂对比实验中,乙醇的含量增加有助于提升混合溶剂的爆炸下限,因此乙醇是较安全的助溶剂;在非溶剂对比实验中,当非溶剂浓度较低时(如真溶剂-助溶剂-非溶剂体积比例为4:1:1时),含有正己烷或者石油醚的混合溶剂爆炸下限较高,因此正己烷和石油醚在低浓度时是较安全的非溶剂。(3)从环境毒性的角度上看,在真溶剂的实验中,乙酸甲酯有较高的半数致死量(20.47g/L),因此乙酸甲酯是毒性较小的真溶剂;在助溶剂的对比实验中,含有乙醇或异丙醇的混合溶剂对藻类的半数致死量较大,因此乙醇和异丙醇是毒性相对较小的助溶剂;在非溶剂对比实验中,含有正庚烷的混合溶剂对藻类的半数致死量比含有正己烷或者石油醚的混合溶剂更高,但几种非溶剂之间的差距不大。综上所述,本文认为对于硝基漆稀释剂的主要成分,可按照乙酸甲酯(真溶剂),乙醇(助溶剂)和正己烷(非溶剂)约4:1:1的体积比例混合,这种组合溶漆效率较高,爆炸危险性较小;虽然这种组合并不是环境毒性较小的组合,但是该组合的环境毒性与其他组合差异不大,是相对较为理想的组合。更多还原

【Abstract】 Nitrocellulose lacquer thinner,a colorless,transparent,flammable and volatile mixed organic solution with strong odor,is widely used in the painting,paint removal and cleaning processes of furniture,decoration and automobile industries.Safety accidents caused by nitrocellulose lacquer thinners are pretty common.In addition,accidents of this type of organic solvents that cause a large number of leaks during transportation,which affect the environment,also occur from time to time.Nitrocellulose lacquer thinner is mainly composed of three types of solvents: true solvent,co-solvent and non-solvent.Among them,the true solvent refers to a solvent that can directly dissolve nitrocellulose,mainly esters and ketones.Cosolvent cannot directly dissolve nitrocellulose by itself,but can promote the dissolution of nitrocellulose when used together with a true solvent.The non-solvent refers to the solvent added to dissolve other components such as resin.The research objects of this article are 6 kinds of true solvents(methyl acetate,ethyl acetate,n-propyl acetate,butyl acetate,ethyl propionate and ethyl butyrate),3 kinds of cosolvents(ethyl alcohol,isopropanol and isobutyl Alcohol)and 3 kinds of non-solvents(nhexane,n-heptane and petroleum ether).We investigated the paint removal efficiency,explosion hazard and environmental impact of nitrocellulose lacquer thinner,through the curing paint film dissolution experiment,the lower explosion limit test and the algae growth inhibition experiment.And solvents with higher paint removal efficiency,relatively small explosion risk and relatively small environmental impact are selected from them.The conclusions of this article are as follows:(1)From the perspective of the efficiency of dissolving paint,methyl acetate is a better true solvent(39.64mg/min)in the comparison experiment of true solvents.In the comparison experiment of cosolvent,ethyl alcohol is better than the other two co-solvents,because the promotion effect is more obvious.When the concentration of the co-solvent is lower(the content is 20%),the effect of the co-solvent is better.In the non-solvent comparison experiment,the dissolving efficiency of the mixed solution composed of the three non-solvents on the cured nitro paint film is relatively close,but in general,the effect of n-hexane is better.(2)From the perspective of explosion hazard,in the comparison experiment of true solvents,methyl acetate has a higher lower explosion limit(3.17%),so methyl acetate is a safer true solvent.In the co-solvent comparison experiment,the increase in the content of ethanol helps to increase the lower explosive limit of the mixed solvent,so ethyl alcohol is a safer co-solvent.In the non-solvent comparison experiment,when the non-solvent concentration is low(for example,when the volume ratio of true solvent-cosolvent-nonsolvent is 4:1:1),the lower explosive limit of the mixed solvent containing n-hexane or petroleum ether is higher.n-heptane and petroleum ether are safer non-solvents at low concentrations.(3)From the perspective of environmental toxicity,in the comparison experiment of true solvent,methyl acetate has a higher IC50 value(20.47g/L),so methyl acetate is a less toxic true solvent.In the comparison experiment of cosolvents,mixed solvents containing ethyl alcohol or isopropyl alcohol have a higher IC50 value to algae,so ethyl alcohol and isopropyl alcohol are relatively less toxic cosolvents.In the comparison experiment of non-solvent,the mixed solvent containing n-heptane has a higher IC50 value to algae than the mixed solvent containing n-hexane or petroleum ether,but the discrepancy among several non-solvents is limited.In summary,we believed that for the main components of nitrocellulose lacquer thinner,methyl acetate(true solvent),ethanol(cosolvent)and n-hexane(non-solvent)can be mixed in a 4:1:1 volume ratio.This kind of combination has higher dissolving efficiency and lower explosion risk.Although it is not a combination with less environmental toxicity,the environmental toxicity of this combination is not much different from other combinations,and it is a relatively ideal combination.更多还原