Synthesis and characterization of low-CTE polyimide films containing trifluoromethyl groups with water-repellant characteristics

2016 ◽  
Vol 29 (5) ◽  
pp. 501-512 ◽  
Author(s):  
Wei Chen ◽  
Fulin Liu ◽  
Mian Ji ◽  
Shiyong Yang

A novel fluorinated ester-bridged aromatic diamine, bis(2-trifluoromethyl-4-aminophenyl)terephthalate (CF3-BPTP) was synthesized, which was employed to prepare a series of fluorinated ester-bridged polyimide (PFEI) films with controlled ester-bridged segments and fluorine contents in the polymer backbone. The PFEI films were prepared by copolymerization of biphenyl tetracarboxylic dianhydride as aromatic dianhydride monomer and the aromatic diamine monomer mixture consisting of p-phenylenediamine and different amounts of CF3-BPTP. Experimental results indicated that the films’ water uptakes (Wus) reduced with increasing of the CF3 groups loadings in the ester-bridged polyimide backbones while keeping the films with low enough coefficient of thermal expansion (CTE). By controlling CF3 group loadings, polyimide films with desirable combination of thermal, mechanical, and dielectric properties for application in high density and thinner flexible printed circuits (FPCs) have been obtained. Thus, polyimide films with CTE of ≤20 × 10−6 1/K (ppm/K) at 50–200°C, glass transition temperature of ≥310°C, Young’s modulus of ≥6.0 GPa, Wu of as low as 0.7 wt%, dielectric constant ( ε) of 3.3 have been obtained. The two-layer flexible copper clad laminate prepared by coating the polyimide precursor resin poly(amid acid) solution on the surface of copper foil followed by thermal imidization at elevated temperature did not show apparent curling due to its closed CTE value.

2018 ◽  
Vol 31 (5) ◽  
pp. 485-496 ◽  
Author(s):  
Xiao-Lan Zhang ◽  
Xiao-Ling Liu ◽  
Qiu-Ying Wang ◽  
Zhen-Zhong Huang ◽  
Shou-Ri Sheng

4-(4-Trifluoromethylphenyl)-2,6-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]pyridine (9FPBAPP), as a new aromatic diamine, was prepared by a modified Chichibabin reaction of 4-(4-nitro-2-trifluoromethylphenoxy)acetophenone with 4-triflouromethylbenzaldehyde, followed by a catalytic reduction. A series of fluorinated poly(ether imide)s containing pyridine and/or phenylphosphine oxide moieties were prepared from bis(3-aminophenyl)phenylphosphine oxide (BAPPO), 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), and 9FPBAPP via a conventional two-step thermal imidization procedure with various mole ratios of BAPPO and 9FPBAPP. All the polymers were amorphous and soluble in common organic solvents such as N, N-dimethylacetamide and N-methyl-2-pyrrolidone and had Tg’s of 277–285°C, 5% weight loss temperature of 521–550°C in nitrogen. Furthermore, high char yields and good limited oxygen index values indicated that these polymers exhibited good thermal stability and flame-retardant property. Tough and flexible polymer films also had good mechanical properties with tensile strengths of 75–99 MPa, tensile moduli of 1.1–1.6 GPa, and elongations at break of 12%–24% and low dielectric constants of 2.81–3.53 (1 MHz), as well as high optical transparency with the ultraviolet cutoff wavelength in the range of 350–384 nm.


1997 ◽  
Vol 476 ◽  
Author(s):  
Y.L. Zou ◽  
T.L. Alford ◽  
J.W. Mayer

AbstractPolyimides prepared from oxydiphthalic anhydride and diamine precursors can be photosensitive. The thermal, mechanical, and dielectric properties of the polyimide films have been characterized with various techniques. The thermal decomposition temperature of the cured film is 520 °C, and the coefficient of thermal expansion is 20 × 10−6/°C. The polymer chemistry and processing conditions result in a low stress (<26 MPa) in the polyimide film as measured in situ during the curing and cooling cycles. Pads of 6 μm were patterned through the photosensitive polyimide at a sensitivity of 110 mJ/cm2 to i-line wavelength. The polyimide films exhibit anisotropy with an in-plane refractive index of 1.74 and an oul-of-plane index of 1.62 measured at 632.8 nm wavelength. This indicates a preferred orientation of polymer chains in the film plane. The estimated dielectric anisotropy should be considered a major factor for device design and optimization.


2011 ◽  
Vol 415-417 ◽  
pp. 1789-1793
Author(s):  
Xiang Li Meng ◽  
Peng Wang ◽  
Ling Jiang

Polyimides prepared from 5-amino-2(p-aminophenyl) benzoxazole (AAPB) with pyromellitic dianhydride(PMDA), 2,2’3,3’-biphenyl tetracarboxylic dianhydride(i-BPDA), 4,4’-oxdiphthalic anhydride(ODPA), 1,4-bis(3,4-dicarbosyphenoxy) benzene dianhydride(HQDPA) and 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) were synthesized successfully via a conventional two-stage method. Their structures and properties were characterized by FT-IR, DSC, TG and XRD. The intermediate poly(amic acid)s had inherent viscosity range of 0.86~2.18 dL/g and could be thermally converted into light yellow polyimide films. The polyimides showed excellent solvent resistance and good thermal stability. The glass transition temperatures (Tg) were found to be 336oC~369 oC .The decomposition started at a temperature above 530oC in N2 atmosphere.


2011 ◽  
Vol 287-290 ◽  
pp. 1388-1396 ◽  
Author(s):  
Juo Chen Chen ◽  
Wen Yen Tseng ◽  
I Hsiang Tseng ◽  
Mei Hui Tsai

Colorless alicyclic polyimides (ALPIs) were synthesized from an alicyclic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BCDA) and an aromatic diamine, 3,4'-oxydianiline (3,4'-ODA). For comparison, a series of crosslinkable ALPI membranes with different content of crosslinkable reagents were prepared. The crosslinkable PI reacts with the crosslinkers and forms covalent bond to create the crosslink structure between PI backbones by free radical reaction. Almost of the crosslinkable PIs exhibit excellent dimensional stability and higher transparency because of the crosslink structure and non-conjugate alicyclic chain. All of the crosslink ALPIs could be coated into flexible and tough films. They had a UV-Vis cut-off at 297 nm and a transmittance of higher than 80% in near ultraviolet region. These PIs show low coefficient of thermal expansion ranging from 57.36 to 47.53 ppm/°C, the glass transition temperature in the range of 336.2-333.0 °C, the decomposition temperature in the range of 433.7-440.0 °C. The crosslinkable ALPIs show excellent optical properties with the excited wavelength ranging from 340 to 328 nm and stronger emission intensity than linear PI, the haze lower than 0.7, the refractive index about 1.6 and the abbe numbers over 165.


2019 ◽  
Vol 57 (2) ◽  
pp. 94-103
Author(s):  
Iuliana Stoica ◽  
Ion Sava ◽  
Georgiana Bulai ◽  
George Stoian ◽  
Mitachi Strat ◽  
...  

Two different polyimide structures were synthesized by two-step polycondensation reaction in solution, in the first step using equimolar amounts of one of two aromatic diamine (DDM or MMDA) and one dianhydride (6HDA) in N,N-dimethylacetamide (DMAc) to obtain the poly(amic acids), followed in the second step by thermal imidization. In order to obtain novel polyimide/metal nano hybrid materials, conductive Ni/Cu nanoparticles were embedded on polyimide substrates, using laser ablation technique. The morphology of the resulted thin metal layers was investigated using atomic force microscopy (AFM), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The results highlighted different surface characteristics of the auto-organized metallic/polymer nanoparticles, depending on the chemical structure of the polyimide substrate, the parameters of the laser ablation setup, the deposition time, the type of the metallic target. The obtained features of these polyimide/metal nano hybrid materials can be employed as an indicator of the possibility of using them for potential applications as conductive circuits or substrates for adhesion control.


Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2824
Author(s):  
Hiroki Ozawa ◽  
Eriko Ishiguro ◽  
Yuri Kyoya ◽  
Yasuaki Kikuchi ◽  
Toshihiko Matsumoto

An alicyclic tetracarboxylic dianhydride having cyclopentanone bis-spironorbornane structure (CpODA) was polycondensated with aromatic dianhydrides to form the corresponding poly(amic acid)s which possessed logarithmic viscosities in the range 1.47–0.54 dL/g. The poly(amic acid) was imidized by three methods: a chemical, a thermal, and a combined chemical and thermal process. In a thermal method, imidization temperature markedly influenced the film quality and molecular weight of the polyimide. When the poly(amic acid) was cured over the Tg of the corresponding polyimide, the flexible polyimide films were obtained and the molecular weights increased several times, which means that the post-polymerization took place. In spite of low-temperature cure below Tg flexible films with the imidization ratio of 100% were fabricated by a combined chemical and thermal imidization technique. The films possessed the decomposition temperatures in a range of 475–501 °C and Tgs over 330 °C. The high Tg results from a dipole–dipole interaction between the keto groups of the polymer chains as well as development of the rigid polyalicyclic unit. The polyimide films exhibited CTE between 17 and 57 ppm/K. All the films fabricated were entirely colorless and possessed the λcut-offs shorter than 337 nm. Notably, the films prepared by a chemical method exhibited outstanding optical properties.


2014 ◽  
Vol 34 (9) ◽  
pp. 867-873 ◽  
Author(s):  
Revathi Purushothaman ◽  
I. Mohammed Bilal

Abstract Polyimides are a sophisticated family of materials, which cover an exhaustive range of high performance polymers and find applications from aerospace to microelectronics. Microelectronic applications demand low dielectric constant and high performance. Aromatic terpolyimides were synthesized by reacting 3,3′,4,4′-biphenyl tetracarboxylic dianhydride (BPDA), 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA) and 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) with 4,4′-oxydianiline (ODA) by thermal imidization with the view to decrease their dielectric constant without compromising thermal properties and mechanical properties compared to their homo and copolyimides. They were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Their FTIR spectra established formation of polyimide by the characteristic vibrations at 1375 cm-1 (C-N stretch) and 1113 cm-1 (imide ring deformation). The TGA results showed decomposition of imides at about 515°C. The glass transition temperature (Tg) of the polymers varied from 261°C to 281°C. The XRD spectrum of BPDA/BTDA/6FDA-ODA, which contained 50% of 6FDA, showed a broadened envelope with a peak at 16.8° (2θ), illustrating a semicrystalline nature. Incorporation of 6FDA, with a bulky bridging group into the backbone of BPDA/6FDA-ODA and BPDA/BTDA/6FDA-ODA (0.25:0.25:0.5::1) caused a decrease in the dielectric constant (2.13 and 2.38, respectively). Such polyimides can find application in microelectronics such as flexible printed circuits and tape automated bonding applications.


Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1056 ◽  
Author(s):  
Ibon Aranberri ◽  
Sarah Montes ◽  
Itxaso Azcune ◽  
Alaitz Rekondo ◽  
Hans-Jürgen Grande

Feathers are made of keratin, a fibrous protein with high content of disulfide-crosslinks and hydrogen-bonds. Feathers have been mainly used as reinforcing fiber in the preparation of biocomposites with a wide variety of polymers, also poly(urea-urethane)s. Surface compatibility between the keratin fiber and the matrix is crucial for having homogenous, high quality composites with superior mechanical properties. Poly(urea-urethane) type polymers are convenient for this purpose due to the presence of polar functionalities capable of forming hydrogen-bonds with keratin. Here, we demonstrate that the interfacial compatibility can be further enhanced by incorporating sulfur moieties in the polymer backbone that lead to new fiber-matrix interactions. We comparatively studied two analogous thermoplastic poly(urea-urethane) elastomers prepared starting from the same isocyanate-functionalized polyurethane prepolymer and two aromatic diamine chain extenders, bis(4-aminophenyl) disulfide (TPUU-SS) and the sulfur-free counterpart bis(4-aminophenyl) methane (TPUU). Then, biocomposites with high feather loadings (40, 50, 60 and 75 wt %) were prepared in a torque rheometer and hot-compressed into flexible sheets. Mechanical characterization showed that TPUU-SS based materials underwent higher improvement in mechanical properties than biocomposites made of the reference TPUU (up to 7.5-fold higher tensile strength compared to neat polymer versus 2.3-fold). Field Emission Scanning Electron Microscope (FESEM) images also provided evidence that fibers were completely embedded in the TPUU-SS matrix. Additionally, density, thermal stability, and water absorption of the biocomposites were thoroughly characterized.


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