【摘要】：本文實(shí)驗(yàn)以三氟氯乙烯（CTFE）、乙烯（Ethylene）、乙酸乙烯酯（VAc）作為聚合反應(yīng)單體，以偶氮二異丁腈（AIBN）為引發(fā)劑，在1,2-二氯-1,1,3,3-五氟丙烷（F-225）溶劑中，用溶液聚合法制備了三氟氯乙烯/乙烯/乙酸乙烯酯三元含氟聚合物。通過傅立葉紅外光譜（FT-IR）和核磁氫譜（1HNMR）等方法對(duì)它的結(jié)構(gòu)進(jìn)行了表征。研究了加入單體比例對(duì)聚合物產(chǎn)率的影響，結(jié)果表明：保持三氟氯乙烯和乙烯的比例不變，隨著乙酸乙烯酯加入量的增加，聚合物產(chǎn)率升高，到達(dá)一定比例后，產(chǎn)率基本保持不變。然后研究了含氟聚合物的熱穩(wěn)定性能，結(jié)果表明：聚合物單體比例CTFE/E/VAc=50/50/0時(shí)，聚合物分解溫度高達(dá)370℃；聚合物單體比例CTFE/E/VAc=45/45/10時(shí)，聚合物分解溫度達(dá)到327℃；聚合物單體比例CTFE/E/VAc=35/35/30時(shí)，聚合物分解溫度達(dá)到260℃。我們還對(duì)聚合物進(jìn)行了結(jié)晶度的測試和比較。實(shí)驗(yàn)結(jié)果證明：制備出的三元共聚物結(jié)晶度非常低，它的低結(jié)晶度為下面制備薄膜階段起到了很積極的作用，使得聚合物隔膜有更高的性能。 我們通過相轉(zhuǎn)移方法制備出了三氟氯乙烯/乙烯/乙酸乙烯酯共聚物多孔隔膜。與乙烯-三氟氯乙烯共聚物（ECTFE）相比，新制備的聚合物在室溫下容易溶解于大部分溶劑，制作工藝簡單，得到的隔膜產(chǎn)物微孔分布均勻，適用于實(shí)驗(yàn)室制備和工業(yè)生產(chǎn)化。我們對(duì)自制的聚合物隔膜進(jìn)行了一系列的性能表征，并與Celgard公司工業(yè)生產(chǎn)的PP隔膜性能進(jìn)行對(duì)比。結(jié)果表明：聚合物隔膜和Celgard-PP隔膜對(duì)甘油的接觸角分別為72.4°和99.7°，證明自制隔膜有良好的親油性。自制的隔膜對(duì)電解液的吸液率達(dá)到329%，比Celgard-PP隔膜的吸液率（230%）高出將近100個(gè)百分點(diǎn)，隔膜吸液率越高，其電池內(nèi)阻就越小，電池隔膜的電化學(xué)性能越好。聚合物隔膜的拉伸強(qiáng)度為6MPa，斷裂伸長率為110%，與Celgard-PP隔膜相比性能較差，分析原因，可能是因?yàn)閷?shí)驗(yàn)室制備隔膜的方法不如工業(yè)化生產(chǎn)的工藝成熟。將制好的聚合物隔膜和工業(yè)PP隔膜作為電池元件的一部分進(jìn)行電池組裝，組成電池后，在0.2C倍率的條件下循環(huán)50次來測試電池充放電循環(huán)效率。結(jié)果發(fā)現(xiàn)，用自制隔膜和工業(yè)化PP膜組裝完成的電池在50次循環(huán)測試后，電池的充放電效率都可以保持90%以上且效率相差不大。證明我們制備的隔膜完全滿足電池性能的要求，可以作為鋰離子電池隔膜使用。 我們利用靜電紡絲技術(shù)對(duì)制備的三氟氯乙烯/乙烯/乙酸乙烯酯共聚物進(jìn)行了靜電紡絲，并成功的得到了聚合物纖維膜。在10KV高壓電壓，流速0.2mL/h，接受距離為10cm，，聚合物溶液濃度為15%的條件下，制備出了聚合物纖維膜。通過電鏡掃描可以觀察到纖維膜紡出的絲分布均勻，沒有明顯的珠絲，斷絲，結(jié)塊，粘連，聚合物堆積等缺點(diǎn)，纖維直徑分布均勻，主要集中在100-300nm左右，微孔和微孔孔徑分布均勻，孔徑基本集中保持在納米級(jí)，最大孔僅在1μm左右。將制備的纖維膜進(jìn)行電池組裝，測試其充放電循環(huán)效率。實(shí)驗(yàn)結(jié)果發(fā)現(xiàn)，電池經(jīng)過50次循環(huán)后，其效率也可以保持在90%以上。證明通過靜電紡絲制備的纖維膜可以作為鋰離子電池隔膜使用。
[Abstract]:Trifluorochloroethylene/ethylene/vinyl acetate terpolymer was prepared by solution polymerization in 1,2-dichloro-1,1,3,3-pentafluoropropane (F-225) solvent with CTFE, Ethylene and VAc as monomers and AIBN as initiators. The structure of the polymer was characterized by FT-IR and 1HNMR. The effect of monomer ratio on the yield of the polymer was studied. The results showed that the yield of the polymer increased with the addition of vinyl acetate, and remained unchanged after reaching a certain proportion. The thermal stability of fluorinated polymers was studied. The results showed that the decomposition temperature of the polymers reached 370 C when the ratio of CTFE/E/VAc=50/50/0, 327 C when the ratio of CTFE/E/VAc=45/45/10, and 260 C when the ratio of CTFE/E/VAc=35/35/30. The results show that the crystallinity of the copolymers is very low. The low crystallinity of the copolymers plays an active role in the next stage of film preparation, making the polymer diaphragms have higher performance.
Compared with the ethylene-trichloroethylene copolymer (ECTFE), the newly prepared polymer is easy to dissolve in most solvents at room temperature. The preparation process is simple and the pore distribution of the diaphragm product is uniform, which is suitable for laboratory preparation and application. The results show that the contact angles between the polymer diaphragm and the Celgard-PP diaphragm on glycerol are 72.4 degrees and 99.7 degrees respectively, which proves that the self-made diaphragm has good lipophilicity. The electrolyte absorption rate reached 329%, which was nearly 100 percentage points higher than that of Celgard-PP diaphragm (230%). The higher the liquid absorption rate, the smaller the internal resistance and the better the electrochemical performance of the cell diaphragm. Because the method of preparing diaphragm in laboratory is not as mature as that in industrial production, the polymer diaphragm and industrial PP diaphragm are assembled as part of the battery element, and the battery is composed of the polymer diaphragm and the industrial PP diaphragm. After 50 cycles at 0.2C rate, the cycling efficiency of the battery is tested. The results show that the self-made diaphragm and the industrial PP diaphragm are used to test the Cycli After 50 cycles of test, the charge and discharge efficiency of the battery assembled by P-film can be maintained above 90% and the efficiency difference is not significant.
Polymer fiber membranes were prepared by electrospinning of trifluorovinyl chloride/ethylene/vinyl acetate copolymers. The polymer fiber membranes were prepared at 10 KV high voltage, flow rate of 0.2 mL/h, acceptance distance of 10 cm and polymer solution concentration of 15%. It was observed that the fibers were uniformly distributed, without obvious defects such as beads, broken fibers, agglomeration, adhesion and polymer accumulation. The diameter of the fibers was uniformly distributed, mainly concentrated in the range of 100-300 nm. The micropore and micropore size were uniformly distributed. The pore size was basically concentrated in nanometer scale, and the maximum pore size was only about 1 micron. The results show that after 50 cycles, the cell efficiency can be maintained above 90%. It is proved that the fiber membrane prepared by electrospinning can be used as a separator for lithium ion batteries.
【學(xué)位授予單位】：濟(jì)南大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TM912;TQ317

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