新型含硫聚苯并咪唑質(zhì)子交換膜的制備與性能研究
發(fā)布時間：2018-08-08 12:00
【摘要】：質(zhì)子交換膜作為質(zhì)子交換膜燃料電池的核心部件,其抗氧化穩(wěn)定性一直是制約其使用壽命的關(guān)鍵因素之一,尤其是聚苯并咪唑類的質(zhì)子交換膜材料,由于其具有活性反應(yīng)位點,較易受到來自燃料電池工作過程中所產(chǎn)生氧化自由基的進攻而降解。另一方面,硫醚結(jié)構(gòu)在抗氧化方面有著潛在的廣闊應(yīng)用,一直以來,在藥學、生物學、有機化學等領(lǐng)域的研究有很多報道,但是在聚合物材料方面,尤其是聚苯并咪唑結(jié)構(gòu)中的抗氧化應(yīng)用罕見報道。因此,研究硫醚添加劑作為聚苯并咪唑系列聚合物中的有效抗氧化措施,具有重要的意義。本文合成了三種具有不同結(jié)構(gòu)特點的硫醚添加劑,以一定的比例將其引入了己二酸／吡啶二酸與聯(lián)苯四胺的共聚體系,得到了不同比例的各具結(jié)構(gòu)特征的含硫聚苯并咪唑聚合物,并進行了成膜和后續(xù)性能研究,包括基本結(jié)構(gòu)表征、機械性能測試、熱穩(wěn)定性測試、摻酸及溶脹測試、質(zhì)子傳導率測試,以及高濃度的Fenton測試等。具體研究成果如下：(1)合成了結(jié)構(gòu)中具有剛性芳香硫醚結(jié)構(gòu)的新型單體3,3'-[(硫代二(4,1-亞苯基))二硫]二丙酸二甲酯(DTMA),將其引入己二酸／吡啶二酸與聯(lián)苯四胺的共聚體系,并制備得到一系列共聚膜。測試結(jié)果表明芳香硫醚結(jié)構(gòu)的引入使膜的抗氧化性有了顯著提高,其中含硫比例最高的PBI-DTMA-5%在高濃度Fenton試劑浸泡24 h后失重不到3%,遠優(yōu)于文獻值。本研究由此提出了可能的硫醚抗氧化過程猜想,并通過紅外分析、拉伸測試、熱重測試進行了討論。進一步的研究表明,在高濃度的Fenton試劑處理后,含硫膜保持了相當程度的力學與熱穩(wěn)定性。(2)為進一步研究引入硫醚結(jié)構(gòu)對聚苯并咪唑的綜合影響,本文特定地合成了與己二酸結(jié)構(gòu)相似的3-[(2-甲氧基-2-氧代乙基)硫代]丙酸甲酯(MTMA),按一定比例替換己二酸進行與吡啶二酸、聯(lián)苯四胺的共聚反應(yīng),得到系列聚合物并制備成膜。在160℃時,PBI-MTMA-7%膜的質(zhì)子傳導率已經(jīng)達到29.25 mS·cm-1。此外,聚合物溶解性測試結(jié)果還表明,脂肪硫醚結(jié)構(gòu)的存在極大促進了聚苯并咪唑結(jié)構(gòu)的溶解,對于加工性能一直存在缺陷的聚苯并咪唑類材料而言是一個非常明顯的性能改善。(3)在之前的硫醚研究工作基礎(chǔ)上,本文合成了具有立體結(jié)構(gòu)的硫醚單體10-乙基-10H-吩噻嗪-3,7-二醛(PTZA),將其引入聚苯并咪唑主鏈并制備成膜。測試表明含立體硫醚結(jié)構(gòu)的聚苯并咪唑不只溶解性能更佳,相應(yīng)的膜在熱穩(wěn)定性、摻酸量及質(zhì)子傳導率等方面均比無硫醚添加的膜有明顯優(yōu)勢。在160℃時,PBI-PTZA-5%膜的質(zhì)子傳導率已經(jīng)達到38.63 mS·cm-1,骨架分解溫度大于450℃,綜合性能優(yōu)異。本文提出的以硫醚添加劑作為聚苯并咪唑抗氧化措施的方法簡便易行,原料廉價易得,測試性能優(yōu)異。通過共聚的途徑引入,不容易出現(xiàn)相分離等現(xiàn)象,具有普適性。本文的研究工作為聚苯并咪唑系列聚合物的抗氧化提供了新的思路。
[Abstract]:As the core component of proton exchange membrane fuel cell, the antioxidant stability of proton exchange membrane is one of the key factors that restrict its service life, especially the proton exchange membrane material of polybenzimidazole, because of its active reaction site. It is easy to be degraded by the attack of oxidized free radicals produced during the operation of the fuel cell. On the other hand, the structure of thioether has a potential wide application in antioxidation. It has been reported in many fields such as pharmacy, biology, organic chemistry and so on, but in the field of polymer materials, Especially in the structure of polybenzimidazole, the application of antioxidation is rare. Therefore, it is of great significance to study sulfide additive as an effective antioxidation measure in polybenzimidazole series polymers. In this paper, three kinds of thioether additives with different structure were synthesized and introduced into the copolymerization system of adipic acid / pyridylic acid and biphenyl tetraamine at a certain proportion. Different proportions of sulfur containing polybenzimidazole polymers were obtained, and film formation and subsequent properties were studied, including basic structure characterization, mechanical properties test, thermal stability test, acid doping and swelling test. Proton conductivity test and high concentration Fenton test. The specific research results are as follows: (1) A new monomer 3C3O- [(thiobis (4- (4- (4-) -phenylene)] dithio-dimethyl propionate (DTMA),) with rigid aromatic sulfide structure has been synthesized and introduced into the copolymerization system of adipic acid / pyridinic acid and biphenyl tetraamine. A series of copolymer membranes were prepared. The results showed that the antioxidation of the membrane was improved by the introduction of aromatic thioether structure. The PBI-DTMA-5%, which had the highest sulfur content, lost less than 3% weight after immersion in high concentration Fenton reagent for 24 h, which was much better than the reference value. In this study, the possible antioxidation process of sulfide was suggested and discussed by infrared analysis, tensile test and thermogravimetric test. Further studies showed that the sulfur-containing membrane maintained a considerable degree of mechanical and thermal stability after treatment with high concentration of Fenton reagent. (2) for further study, the influence of the structure of sulfide on polybenzimidazole was studied. In this paper, 3- [(2-methoxy-2-oxyethyl) thiothioyl] propionate (MTMA), which is similar to adipic acid in structure, was specially synthesized by replacing adipic acid with pyridinedioic acid and biphenytetracylamine in a certain proportion, and a series of polymers were obtained and the films were prepared. The proton conductivity of PBI-MTMA-7% membrane has reached 29.25 mScm-1 at 160 鈩，
本文編號：2171725
[Abstract]:As the core component of proton exchange membrane fuel cell, the antioxidant stability of proton exchange membrane is one of the key factors that restrict its service life, especially the proton exchange membrane material of polybenzimidazole, because of its active reaction site. It is easy to be degraded by the attack of oxidized free radicals produced during the operation of the fuel cell. On the other hand, the structure of thioether has a potential wide application in antioxidation. It has been reported in many fields such as pharmacy, biology, organic chemistry and so on, but in the field of polymer materials, Especially in the structure of polybenzimidazole, the application of antioxidation is rare. Therefore, it is of great significance to study sulfide additive as an effective antioxidation measure in polybenzimidazole series polymers. In this paper, three kinds of thioether additives with different structure were synthesized and introduced into the copolymerization system of adipic acid / pyridylic acid and biphenyl tetraamine at a certain proportion. Different proportions of sulfur containing polybenzimidazole polymers were obtained, and film formation and subsequent properties were studied, including basic structure characterization, mechanical properties test, thermal stability test, acid doping and swelling test. Proton conductivity test and high concentration Fenton test. The specific research results are as follows: (1) A new monomer 3C3O- [(thiobis (4- (4- (4-) -phenylene)] dithio-dimethyl propionate (DTMA),) with rigid aromatic sulfide structure has been synthesized and introduced into the copolymerization system of adipic acid / pyridinic acid and biphenyl tetraamine. A series of copolymer membranes were prepared. The results showed that the antioxidation of the membrane was improved by the introduction of aromatic thioether structure. The PBI-DTMA-5%, which had the highest sulfur content, lost less than 3% weight after immersion in high concentration Fenton reagent for 24 h, which was much better than the reference value. In this study, the possible antioxidation process of sulfide was suggested and discussed by infrared analysis, tensile test and thermogravimetric test. Further studies showed that the sulfur-containing membrane maintained a considerable degree of mechanical and thermal stability after treatment with high concentration of Fenton reagent. (2) for further study, the influence of the structure of sulfide on polybenzimidazole was studied. In this paper, 3- [(2-methoxy-2-oxyethyl) thiothioyl] propionate (MTMA), which is similar to adipic acid in structure, was specially synthesized by replacing adipic acid with pyridinedioic acid and biphenytetracylamine in a certain proportion, and a series of polymers were obtained and the films were prepared. The proton conductivity of PBI-MTMA-7% membrane has reached 29.25 mScm-1 at 160 鈩，
本文編號：2171725
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