含杂芘结构的高耐热黑色聚酰亚胺合成及性能

Preparation and properties of black polyimide film containing heteropyrene structure with high thermal resistant

摘要:

以2,2’-联苯二甲酸为原料制备四硝基中间体,经铁粉还原得到含杂芘结构的二胺化合物,进而采用“两步法”合成黑色聚酰亚胺(PI)薄膜。GPC结果表明聚酰胺酸数均相对分子量在9.9×10₄^至12.9×10₄^之间,满足成膜要求。FTIR-ATR图谱中1784 cm_-1^、1722 cm_-1^{处特征峰证实}PI薄膜制备成功。CIE lab结果表明该系列PI薄膜400 nm~750 nm透过率为1.10%~3.17%,L*值在9.79~21.08之间,属于黑色薄膜。该系列PI薄膜的玻璃化转变温度(T_g)高于413 _°^C,其中PI-3(与BPDA聚合)的T_g高达482 _°^C；5%热失重温度超557 _°^C；50 _°^C~350_°^C之间CTE值为9.92 ppm/K~0.47 ppm/K,热性能优异。同时,PI薄膜表现出良好的力学性能,其拉伸强度在132.1 MPa~156.5 MPa之间,拉伸模量为4.4 GPa~5.3 GPa,断裂伸长率在3.33%~5.14%之间。

Abstract:

Tetranitro intermediates were synthesized from 2,2"-biphenyldicarboxylic acid and reduced with iron powder to obtain diamine compounds with a heteropyrene structure. The corresponding black polyimide (PI) films were then synthesized via the “two-step” method. GPC results showed that the number average molecular weights of the polyamic acids ranged from 9.9×10₄ ^{to 12.9×10}₄^{, sufficient for the formation} of self-standing film. FTIR-ATR spectra revealed characteristic peaks of the imide ring at 1784 cm_-1 ^{and 1722 cm}_-1^, confirming successful preparation of the PI films. CIE Lab analysis demonstrated that the transmittance of these PI films ranged from 1.10% to 3.17% between 400 nm and 750 nm, with L* values between 9.79 and 21.08, classifying the films as black. The glass transition temperature (T_g) of the PI films exceeded 413 °C, with PI-3 (polymerized with BPDA) reaching 482 °C. The 5% decomposition temperature was above 557 °C, while the CTE values ranged from 9.92 ppm/K to 0.47 ppm/K between 50 °C and 350 °C , indicating excellent thermal properties. The PI films also exhibited good mechanical properties, with tensile strength ranging from of 132.1 Mpa to 156.5 MPa, tensile modulus of 4.4 Gpa to 5.3 GPa, and elongation at break values between 3.33% and 5.14%.