【作者】 李鹏辉；

【导师】 李光；

【作者基本信息】 东华大学 ， 材料物理与化学， 2010， 硕士

【摘要】 聚芳酰胺是一类重要的高性能聚合物,具有优异热稳定性、低介电性以及良好的阻燃性等特点。该类芳香族聚合物在航空航天、石油化工、机械、电子和核能等高科技领域得到了成功的应用,并使许多传统产品实现了更新换代。但这类耐高温聚合物通常难熔难溶,加工性能差。改善聚芳酰胺的溶解性,赋予其功能化是一项充满挑战又有应用价值的工作。本论文正从芳香二胺单体的设计与合成出发,利用Yamazaki磷酰化法一步缩聚制备了五个系列新型可溶性聚芳酰胺功能聚合物。成功的将三氟甲基、二甲基、环己烷以及不对称结构等分别引入到聚合物的分子主链中。该类聚芳酰胺不仅在某些常规溶剂中具有优良的溶解性和成膜性,还表现出优良的光学性能、介电性能和低的吸水率。主要研究内容和结果如下:1.由自制芳香二胺单体3,5-二甲基-4-(4-胺基-2-三氟甲基苯氧基)-4′-胺基苯甲酮和四种商品化芳香四酸,经一步Yamazaki磷酰化缩聚,制备了一系列分子主链含三氟甲基和二甲基、具不对称和非共平面结构的新型聚芳酰胺(PEKA3a-d)。FT-IR和~1H-NMR分析证实所合成的聚芳酰胺与所设计的聚合物结构完全一致。该系列聚芳酰胺的特性粘度在0.43～0.65 dL/g,具有相对较高的分子量。它们在室温下不仅可溶于N-甲基-2-吡咯烷酮、N,N-二甲基乙酰胺、N,N-二甲基甲酰胺等强极性溶剂中,还能溶于低沸点的氯仿、四氢呋喃、二氯甲烷等溶剂中,在这些溶剂中具有良好的成膜性能。DSC和TG分析表明该类聚合物的玻璃化转变温度在288～323℃,10%热失重温度在431～447℃。此外,该类聚芳酰胺所制薄膜还具有良好的介电性能和力学性能:它们在1 MHz下的介电常数小于3;其拉伸强度和断裂伸长率分别为78～98 MPa和1.6～1.9%。2.分别由两个含对位和邻位双醚结构的自制芳香二胺单体,制备了一系列分子主链含三氟甲基和双醚结构新型聚芳酰胺(PA1-PA3和PA4-PA7)。其特性粘度在0.55～0.78 dL/g。该系列聚芳酰胺表现出优良的溶解性能:室温下不仅可以溶于强极性溶剂中,而且还可以溶于低沸点溶剂中,溶解度可达10wt%。由该聚合物所制得的薄膜无色透明,截断波长在331～364 nm,400 nm后具有高度透明性。此外该系列聚芳醚酰胺还表现出良好的介电性能,它们在1MHz的介电常数在2.43～2.93之间。相比较而言,基于邻位双醚结构的含氟聚芳酰胺表现出更好的溶解性和光学性能。3.利用Willianmson反应然后再经还原,设计合成了两种含环己烷结构的新型芳香二胺,并由该二胺单体与三种商品化二酸单体经缩聚反应制得了系列新型含氟和含环己烷结构的聚芳醚酰胺(2a-2d和4b-4d)。用FT-IR、~1H-NMR及元素分析证实了所合成二胺单体及所得聚合物的结构。DSC和TG对聚合物热性能分析结果表明:玻璃化温度T_g在202～246℃之间,氮气中10%热失重温度在330℃以上;溶解性实验显示该类聚合物溶解性能优良,室温下能溶解在N-甲基吡咯烷酮、二甲基乙酰胺、氯仿等有机溶剂中,其中2a-2d系列具有更优异的溶解性能,溶解度大于10wt%,而且溶解速度快;对聚合物薄膜紫外-可见吸收光谱测试表明:该类聚芳酰胺的截断波长在335～357nm,500nm处的透过率大都超过85%。更多还原

【Abstract】 Polymaides have achieved a remarkable position among other polymers because of their unique combination of thermooxidative stability, electrical performance, flame retardancy and retention of physical properties at high temperatures. So they have been successfully applied in many fields such as aviation, spaceflight, nuclear energy, communication, telecom, petroleum etc. At the same time, this kind of polymer, usually processed at high temperature was considered as a disadvantage for processing. So a great deal of research has been made on improving the solubility of these polamides by introduction of pendent fluorine substitution and bulky side groups onto aromatic polyamides. The aim of this dissertation was concentrated on synthesis of new polyamides containing trifluoromethyl, methyl and cyclohexane by Yamazaki Phosphorylation to improve the solubility of resultant polyamides. In addition, other functions such as optical behavior, dielectric performance, and thermal stability were supplied to these polyamides.1. Novel fluorinated poly(ether ketone amide)s (PEKAs) were prepared from an unsymmetrical aromatic diamine, (4’-(4"-amino-2"-trifluoromethylphenoxy)-3’,5’-dimethylphenyl)(4-aminophenyl)-met hanone synthesized in our lab, with various aromatic dicarboxylic acids by means of the phosphorylation polycondensation technique. The PEKAs displayed inherent viscosities ranging from 0.43 to 0.65 dl/g. All the fluorinated PEKAs could be soluble in many polar organic solvents such as N-methyl-2-pyrrolidinone (NMP), N,N’-dimethylacetamide (DMAc), N,N’-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and tetrahydrofuran (THF). Flexible and tough polyamide films were prepared by casting from DMAc solvent. The PEKA films exhibited good mechanical properties with tensile strengths of 78-98 MPa and elongations at break of 11.5-18.5%. The obatanined PEKAs showed glass-transition temperatures in the range of 288-323℃and the 10% decomposition temperatures in the range of 431-447℃in nitrogen atmosphere. Meanwhile, the PEKA films possessed low dielectric constants less than 3 at 1 MHz.2. A series of novel fluorinated poly(aryl ether amide)s were prepared from an aromatic diamine made in our laboratory, with various aromatic dicarboxylic acids through the phosphorylation polycondensation. The fluorinated polymaides (PA1-PA7) were obtained in almost quantitative yields with inherent viscosities ranging from 0.55 to 0.78 dl/g. All the polyamides revealed good solubility in many polar organic solvents such as N-methyl-2-pyrrolidinone (NMP), dimethyl sulfoxide (DMSO) and tetrahydrofuran (THF) and so on. Flexible and tough polymer films could be easily prepared by casting from DMAc solvent. The PA1-PA7 films exhibited high optical transparency with a cutoff wavelength of 331-364 nm and good mechanical properties with tensile strengths of 78.4-104.8 MPa and elongations at break of 5.4-10.3%. They showed high glass transition temperatures in the range of 227-244℃. They also exhibited good thermal stability, the 10% weight loss temperatures ranged from 453 to 464℃in nitrogen atmosphere. Meanwhile, the obtained poyamide films possessed low dielectric constants of 2.43-2.98 at 1 MHz. These polyamides based on ortho diamine exhibited better solubility and optical properties.3. New aromatic diamines with trifluoromethyl pendent groups, 1,4-Bis((4-amino-2-(trifluoromethyl)phenoxy)methyl)cyclohexane and 4,4’-(cyclohexane-1,4-diylbis(oxy))bis(3-(trifluoromethyl)aniline), were successfully synthesized in two steps from 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol and 2-chloro-5-nitrobenzotrifluoride as starting materials. And the newly obtained diamines with various aromatic dicarboxylic acids, including isophthalic acid(IPA), 2,2-bis(4-carboxy-phenyl)hexafluoropropane(6FA) and 4,4’-oxydibenzoic acid(OBA), were polymerized respectively via the usual Yamazaki reaction to prepare series of fluorinated polyamides (2a-2d and 4b-4d). The resulting polymers were characterized by FT-IR, DSC, TGA and WAXD. The prepared polymaides showed inherent viscosities ranging from 1.85 to 2.36 dL/g. All the polymers presented excellent solubility and could be easily dissolved in amide-type polar aprotic solvents (e.g., N-methyl-2-pyrrolidone (NMP), DMAc, and DMF) and even dissolved in less polar solvents (e.g., pyridine, and tetrahydrofuran). These polymers could also be easily cast into transparent, tough and flexible films. In addition, these polyamide films exhibited low dielectric constants of 2.15-2.88 at 1MHz, high transparency with an ultraviolet-visible absorption cut-off wavelength in the 332-357 nm range, and the transmittance more than 85% at 500 nm. Furthermore these polyamides still retained good thermal stability.更多还原