【作者】 苏桂仙；

【导师】 蹇锡高； 王锦艳；

【作者基本信息】 大连理工大学 ， 高分子材料， 2010， 博士

【摘要】 芳香型聚酰亚胺具有优异的耐热性能、优良的机械性能、高阻燃性以及良好的电学性能,因此已广泛应用于微电子领域。其中,以聚酰亚胺为绝缘膜的无粘结剂型柔性覆铜板(FCCL)具有优良的综合性能和超薄、可挠曲性,作为柔性印制电路板基材已广泛应用于小型电子信息产品。但是传统的聚酰亚胺绝缘膜存在固化温度高、加工难度大、与铜箔粘结性能差等缺陷,因此研制综合性能优异的聚酰亚胺对FCCL的发展具有非常重要的意义。本文从分子结构设计出发,将扭曲、非共平面结构的杂萘联苯结构引入到聚酰亚胺分子主链中,通过溶液缩聚法合成了系列可溶性聚酰亚胺共聚物,并且系统研究了聚酰亚胺共聚物的不同分子链结构对其耐热性能、溶解性能、介电性能、尺寸稳定性、力学性能等的影响规律。首先以含杂萘联苯结构的二胺(DHPZDA)和双酚A型二醚二酐(BPADA)通过一步溶液缩聚法合成了杂萘联苯结构可溶性聚酰亚胺。研究了反应溶剂、温度、时间、单体摩尔比以及固含量等反应条件对聚合物分子量的影响。得到最优反应条件是：以环丁砜为溶剂,反应体系的固含量为20%,BPADA与DHPZDA的摩尔比为1.01：1,在室温反应2h后升温至210℃反应时间为16h止。在25℃下,以NMP为溶剂采用乌氏特性粘度计法测得的聚合物特性粘度达到1.12 dL／g。其玻璃化转变温度为262℃,氮气氛围下5%的热失重温度为486℃,可溶解于NMP、DMAc等有机极性非质子溶剂中。其薄膜拉伸强度为67.8 MPa,弹性模量为1.3 GPa,断裂伸长率为18%。为了研究聚合物分子链刚性和柔性对聚酰亚胺综合性能的影响,设计合成了两个体系的可溶性聚酰亚胺,即采用以DHPZDA、二氨基二苯醚(ODA)与二苯酮四酸二酐(BTDA)、BPADA四元共聚合成的PIA系列,和以DHPZDA、ODA与二苯醚四酸二酐(ODPA)、BPADA共聚合成的PIB系列。所合成的两个系列聚合物均可在室温下溶解于NMP、DMAc等有机极性非质子溶剂中,且均有良好的耐热性(PIA系列Tgs：252～272℃,T5%：489～510℃；PIB系列Tgs：248～267℃,T5％:485～516℃),PIA系列中随着酮基的含量增大,其玻璃化转变温度略高于含醚键多的PIB系列。PIA系列共聚物的吸水率在0.90%～0.99%；PIB系列共聚物的吸水率在0.81%～0.88%。PIA薄膜的力学性能略低于PIB系列,例如,PIA11的拉伸强度为79.6 MPa,弹性模量为1.5 GPa,断裂伸长率为26%；PIB11的拉伸强度为82.8 MPa,弹性模量为1.7GPa,断裂伸长率为28%。在100kHz下测得PIA系列的介电常数(2.6～3.3)略高于PIB系列的介电常数(2.5～3.1)。为了得到具有较低介电常数的聚酰亚胺,设计以BTDA和六氟二酐(6FDA)与DHPZDA和ODA为共聚单体,合成了新型含氟的聚酰亚胺共聚物PIC系列,以及以ODPA和6FDA与DHPZDA和ODA为共聚单体合成的PID系列。所合成的聚合物可溶解于NMP、DMAc等有机极性非质子溶剂中,且具有良好的耐热性(PIC系列Tgs：248～262℃,T5%：504～513℃；PID系列Tgs：243～257℃,T5%：496～505℃)。该类聚合物薄膜具有优异的力学性能(PIC系列聚合物的力拉伸强度在77.2～83.2 MPa,弹性模量在1.5～1.7 GPa,断裂伸长率在25～28%,PID系列聚合物的力拉伸强度在81.0～85.9 MPa,弹性模量在1.7～1.8 GPa,断裂伸长率在28～34%)、低的介电常数(PIC系列2.2～3.1；PID系列2.1～2.9)、较低的吸水率(PIC系列0.62%～0.88%；PID系列0.59%～0.84%)。PIC和PID两个系列共聚酰亚胺的介电常数均低于不含氟的PIA和PIB系列的介电常数,且分子链中含柔性醚键多的PID系列表现出最低的介电常数。以咔唑为原料,经偶联反应、亲核取代反应和还原反应得到含咔唑结构的新型二胺单体(BCZDA),并通过1H-NMR、FT-IR、MS等分析手段对其结构进行了表征和确认。研究了BCZDA的合成工艺。采用Pd／C作催化剂,反应温度在90℃左右、反应时间6h、钯／炭用量为10g／mol时目标产物收率最高。用DHPZDA、BTDA与BCZDA及BPADA进行共聚,采用溶液缩聚法合成了一系列聚酰亚胺。对其结构进行了表征,测试了其分子量及其分子量分布,其数均分子量在10,500～27,600,分子量分布在2.29～5.18。与上述四种系列共聚酰亚胺相比,由于刚性咔唑结构的引入,使所合成的聚合物表现出优异的耐热性(Tgs：295～305℃,T5%：505～526℃),且可溶解于间甲酚、NMP、DMAc等有机极性非质子溶剂中。但是其薄膜的介电常数(3.1～3.3)和吸水率(0.92%～1.06%)略高于上述四个系列聚合物,其拉伸强度在69.5～79.3 MPa,弹性模量在1.2～1.5 GPa,断裂伸长率在16%～22%。选用5种上述有代表性的含杂萘联苯结构的聚酰亚胺探讨其在FCCL领域的应用潜力。采用涂布法直接将聚酰亚胺溶液涂覆于铜箔上制备无粘结剂型的柔性覆铜板,测试了聚酰亚胺薄膜的随着温度变化的尺寸稳定性及柔性覆铜板的耐锡焊性、与铜箔的粘附性等。结果表明,上述系列的共聚酰亚胺具有优异的综合性能,其热膨胀系数(25×10-6～34×10-6／℃)、剥离强度(1.66～3.08kN／m)均优于聚酰亚胺柔性覆铜板国家标准(GB13555-92),满足柔性覆铜板上耐锡焊性能要求,是一类很有发展潜力的FCCL用绝缘膜。更多还原

【Abstract】 It is well known that conventional polyimides are useful high performancematerials for their excellent comprehensive properties such as outstanding thermal stability, high flame retardance good mechanical properties and electronic properties. As a result, they have been widely used in the microelectronics as films, especially in flexible copper clad laminates (FCCLs) for flexible printed circuit board. However, the widespread applications of polyimides are generally limited by processing difficulties because of their poor solubility and high processing temperature, which are caused by their strong interchain forces, inherent macromolecular rigidity, or semicrystallinity. As a result, the development of soluble polyimides in imidized form without influence of their own excellent properties has attracted major interest.In this work, our efforts had been focused on synthesis of polyimides by introduction of twisted, noncoplanar phthalazinone moieties into the polymer backbone via one-pot imidization technique in the solution. The effect of molecular chain structure of polyimides on the properties of the polymers, such as thermal properties, solubility and dielectric constant was investigated systematically.In this thesis, the polyimides containing phthalazinone moieties were prepared from 1,2-Dihydro-2-(4-aminophenyl)-4-[4-(4-(aminophenoxyl)phenyl)](2H)phthalazin-1-one (DHPZDA) and 2,2-bis [4-(3,4dicarboxyphenoxy) phenyl] propane dianhydride (BPADA) by one-pot imidization technique in the solution firstly. The synthesis process was optimized with respect to reaction solvents, solid content, time, temperature, and molar ratio of the monomers. The best process was as follows:the polymerization was conducted at room time for 2 h and at 210℃for another 16 h in sulfolane, and the content was 20% and molar ratio of the monomers was 1.01. The inherent viscosity of this polymer could reach 1.12 dL/g in NMP at 25℃. The polyimide showed amorphous nature as determined by wide angle X-ray diffraction (WAXD) and was soluble in a variety of aprotic polar solvents, such as N-methyl-2-pyrrolidinone (NMP), N,N-dimethylacetamide (DMAc), chloroform etc. The polyimide exhibited good thermal properties with glass transition temperature (Tg) of 262℃and 5% loss temperature (T5%) of 486℃in nitrogen atmosphere. The polyimide film was subjected to tensile tests. And the tensile strength, elongation to break, and tensile modulus was 76.8 MPa,18%and 1.3 GPa, respectively. In order to analysis the effect of polymer chain flexibilty on the comprehensive performance of polyimides, two series of copolyimides were designed and synthesized by two diamines, DHPZDA and 4,4’-diaminodiphenyl ether (ODA), with two dianhydrides 3,3’,4,4’-benzophenonetetracarboxylic dianhydride (BTDA) and BPADA, or by DHPZDA ODA, and 4,4’-oxydiphthalic anhydride (ODPA) and BPADA, respectively. The copolyimides were named as series of PIA and series of PIB, respectively. The obtained polymers exhibited excellent thermal stabilities (series of PIA:Tgs:252～272℃, T5%:489～510℃；series of PIB:Tgs:248～267℃, T5%:485～516℃), good solubility in polar organic solvents. The Tg values of the series PIA were higher than the series PIB with the same ratio. The copolyimides exhibited good electrical properties with surface and volume resistances on the order of magnitude of 1015Ωand 1015Ω·m, respectively. The polymer thin films exhibited good mechanical properties (PIA11:the tensile strength:79.6 MPa, tensile modulus:1.5 GPa, elongation to break:26%; PIB11:the tensile strength:82.8 MPa, the tensile strength:1.7 GPa, the tensile strength:28%), low dielectric constant (series of PIA:2.6～3.3; series of PIB: 2.5～3.1), and low water absorption (series of PIA:0.90%～0.99%; series of PIB:0.81%～0.88%), indicating that the copolyimides series of PIB exhibited better performance in mechanical properties, dielectric constant and water absorption than series of PIA.In order to further reduced the dielectric constant, two series of novel fluorinated copolyimides containing phthalazinone moieties were prepared with BTDA, 4,4’-(hexafluoroisopropylidene) diphthalic anhydride (6FDA), DHPZDA and ODA, or ODPA, 6FDA, DHPZDA and ODA as reactive monomers, respectively. The copolyimides were named as series of PIA and series of PIB, respectively. The obtained polymers exhibited excellent thermal stabilities (series of PIC:Tgs:248～262℃,T5%:504～513℃; series of PID:Tgs:243～257℃, T5%:496～505℃) and good solubility in polar organic solvents. The copolyimides exhibited good electrical properties with surface and volume resistances on the order of magnitude of 1015Ωand 1015Ω·m, respectively. The obtained polyimides films exhibited good mechanical properties (series of PIC:tensile strength:69.5～79.3 MPa, elongation to break:16%～23%, tensile modulus:1.5～1.7 GPa; series of PIC:tensile strength:81.0～85.9 MPa, elongation to break:28～34%, tensile modulus:1.7～1.8 GPa GPa), low dielectric constant (series of PIC:2.2～3.1; series of PID:2.1～2.9) and low water absorption (series of PIC:0.62%～0.88%; series of PID:0.59%～0.84%).From the molecular design, a novel kind of diamine containing bicarbazole structure was synthesized and then reacted with some dianhydrides to prepare a series of soluble polyimides. Herein, the synthesis methods of diamine monomer containing carbazole moieties were studied, and the reduction process was optimized. The carbazole-based dinitro compound has been synthesized in high yield (>92%). Catalytic reduction was used to reduce the dinitro compound, which employed the Pd/C and as catalyst, with the hydrazine hydrate (80%) as reductant. The effect of reaction temperature, the amount of catalyst and solvent of the reaction were investigated in order to increase the production yield. The results showed that the Pd/C was a reasonable catalyst for the synthesis of diamine containing carbazole moieties, when the reduction was conduct after 6 hours at 90℃with Pd/C of lOg/mol, the yield of bis(N-4-amine-phenyl)-3,3’-bicarbazole (BCZDA) could reach more than 71%. The results of IR, NMR, MS showed it had the same structure as designed. A series of copolyimides were synthesized from BCZDA, BPADA, DHPZDA and BTDA. The structures of the polyimides were confirmed by IR and’H-NMR. The molecular weight and distributing of the copolymers obtained were tested by GPC. The thermal behavior data were obtained by DSC and TGA. The results showed all of the polyimides have excellent thermal stability (Tgs: 295～305℃，T5%:505～526℃) and could be soluble in some polar organic solvents such as NMP and DMAc etc. The obtained polyimides films had tensile strength, elongation to break, and tensile modulus in the ranges of 69.5-79.3 MPa,16%～23% and 1.2～1.5 GPa, respectively. Dielectric constant values of the polyimide films were in the range of 3.1～3.3.The flexible copper clad laminates were prepared by coating method with the polyimide solutions cast on the copper foil laminate directly. The obtained FCCL with good appearance surface and uniform dimension exhibited better comprehensive properties (dielectric constant: 2.3～3.1, water absorption:0.76%～0.94%, coefficient of thermal expansion:25×10-6～34×10-6/℃, peel strength:1.66～3.08 kN/m) than national standard GB13555-92.更多还原