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1、 讲解导体及半导体转变的共轭结构聚苯胺的化学合成是在酸性介质中用氧化剂使苯胺单体氧化聚合。化学法能够制备大批量的聚苯胺样品，也是最常用的一种制备聚苯胺的方法。用 hci 作介质，用(nh4)2s208 作氧化剂，一次性可用 22500g 苯胺合成聚苯胺。化学法合成聚苯胺主要受反应介质酸的种类、浓度。氧化剂的种类及浓度，单体浓度和反应温度、反应时间等因素的影响。Chemical synthesis of polyaniline is in acidic medium with antioxidant oxidation polymerization of aniline monomer. Che
2、mical method to the preparation of large quantities of polyaniline samples, which is the most commonly used a method of preparation of polyaniline. Using hci as medium, using (nh4) 2 s208 as oxidant, one-time use 22500 g aniline synthesis of polyaniline. Chemical synthesis of polyaniline is mainly a
3、ffected by reaction medium type, concentration of acid. The kinds and concentrations of oxidizing agent, monomer concentration and reaction temperature, reaction time and so on factors. http:/ http:/ http:/ http:/ 1 酸的种类及其浓度对合成聚苯胺性能的影响。 1 acid type and concentration of effect the performance of the
4、synthesis of polyaniline. 苯胺在 hci,hbr,h2so4,hcio4,hno3,ch3cooh,hbf4 及对甲苯磺酸等介质中聚合都能得到聚苯胺，而在 h2so4,hci,hcio4 体系中可得到高电导率的聚苯胺，在 hno3,ch3cooh 体系中所得到的聚苯胺为绝缘体。非挥发性的质子酸 h2so4,hcio4 最终会残留在聚苯胺的表面，影响产品质量，最常用的介质酸是hci。质子酸在苯胺聚合过程中的主要作用是提供质子，并保证聚合体系有足够酸度的作用，使反应按 1，4-偶联方式发生。只有在适当的酸度条件下，苯胺的聚合才按 1，4-偶联方式发生。酸度过低，聚合按头一
5、尾和头一头两种方式相连，得到大量偶氮副产物。当酸度过高时，又会发生芳环上的取代反应使电导率下降。当单体浓度为 0.5mol.l-1 时，最佳酸浓度范围为 1.02.0mpl.l-i。Hcio4 aniline in hci, six HBR, - h2so4, hno3, ch3cooh, hbf4 and p-toluene sulfonic acid medium, such as polymerization can be http:/ http:/ http:/ http:/ polyaniline, and in - h2so4, hci, hcio4 system in the h
6、igh conductivity of polyaniline can be obtained, in hno3, ch3cooh system of polyaniline as insulators. Non-volatile proton acid - h2so4 hcio4, eventually will remain on the surface of polyaniline, affect the product quality, the most commonly used medium acid is hci. Proton acid in aniline polymeriz
7、ation process, the main function is to provide the proton, and ensure the polymerization system have enough acidity, the reaction occurred in 1, 4 - coupling way. Only under the condition of proper acidity, the polymerization of aniline was happened in 1, 4 - coupling way. Too low acidity, aggregate
8、 according to the first end and a head of one of two ways is linked together, get a lot of azo by-products. Will happen when the acidity is too high, and the substitution reaction of aromatic ring made conductivity decreased. When the concentration of monomer is 0.5 mol. L - 1, the best acid concent
9、ration in the range of 1.0 1.0 MPL. L - I. 2 氧化剂种类及其浓度对合成聚苯胺性能的影响http:/ http:/ http:/ http:/ 2 oxidant species and concentration on the influence of the synthesis of polyaniline 苯胺聚合常用的氧化剂有：(nh4)2s2o8,k2cr2o7,kio3,h22,fecl3 等。也有用(nh4)2s2o8 和碳酸酯类过氧化物组成复合氧化剂制备聚苯胺。以 fe2+为催化剂和 h2o2 为氧化剂可合成高溶解性的聚苯胺。(nh4)
10、2s2o8 不含金属离子，后处理简便，氧化能力强，是最常用的氧化剂。在一定范围内，随着氧化剂用量的增加，聚合物的产率和电导率也增加。当氧化剂用量过多时，体系活性中心相对较多，不利于生成高分子量的聚苯胺，且聚苯胺的过氧化程度增加，聚合物的电导率下降。当用(nh4)2s2o8 合成聚苯胺时，过硫酸铵与苯胺的摩尔比为 1.0 时，聚合物的电导率最高，过硫酸铵与苯胺的摩尔比为 1.5 时，产率最大。Aniline polymerization of oxidant with (nh4) 2 s2o8 and k2cr2o7, kio3, h22, fecl3, etc. Also useful (nh
11、4) 2 s2o8 and http:/ http:/ http:/ http:/ carbonic acid ester peroxide compound preparation of polyaniline. With fe2 + as catalyst and h2o2 as oxidant can synthesize the high solubility of pani. (nh4) 2 s2o8 do not contain metal ions, post processing is simple, strong oxidation ability, is the most
12、commonly used oxidant. Within a certain range, with the increase of dosage of oxidant, the yield of the polymer and the conductivity increases. When excessive dosage of oxidant, the system of active center is relatively more, unfavorable to generate high molecular weight of polyaniline, and polyanil
13、ine peroxide level increases, the conductivity of polymers. When using (nh4) 2 s2o8 synthetic polyaniline, ammonium persulfate and the molar ratio of aniline to 1.0, the electrical conductivity of polymer is highest, the molar ratio of ammonium persulfate and aniline was 1.5, the yield is the larges
14、t. 3 反应温度及单体浓度对合成聚苯胺性能的影响http:/ http:/ http:/ http:/ 3, reaction temperature and monomer concentration on the influence of the synthesis of polyaniline 反应温度对聚苯胺的电导率影响不大，在低温下(0左右)聚合有利于提高聚苯胺的分子量并获得分子量分布较窄的聚合物。在过硫酸铵体系中，在一定温度范围内。随着反应体系温度升高，聚合物的产率增加，羟丙基甲基纤维素当温度为 30时，产率最大。苯胺聚合是放热反应，且聚合过程有一个自加速过程。如果单体浓度过高会
15、发生暴聚，一般单体浓度取 0.250.5moll-l 为宜。Reaction temperature on the conductivity of polyaniline, at low temperature (0 or so) polymerization to improve the polyaniline polymer molecular weight and narrow molecular weight distribution. In the ammonium persulfate system, to a certain temperature range. With increasing temperature of reaction system, the yield of the polymer increases, when the temperature is 30 , the yield is the largest. Anili
