scholarly journals Colorless Polyimides Derived from an Alicyclic Tetracarboxylic Dianhydride, CpODA

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2824
Author(s):  
Hiroki Ozawa ◽  
Eriko Ishiguro ◽  
Yuri Kyoya ◽  
Yasuaki Kikuchi ◽  
Toshihiko Matsumoto
Keyword(s):  
Dipole Interaction ◽  
Amic Acid ◽  
Polymer Chains ◽  
Thermal Method ◽  
Polyimide Films ◽  
Molecular Weights ◽  
Flexible Films ◽  
Thermal Imidization ◽  
Tetracarboxylic Dianhydride ◽  
Low Temperature Cure

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.

Processable poly(ether ether ketone imide)s

2021 ◽  
pp. 095400832110550
Author(s):  
Aslam B Tamboli ◽  
Shivaji D Ghodke ◽  
Arati V Diwate ◽  
Makrand D Joshi ◽  
Vijay P Ubale ◽  
...  
Keyword(s):  
Weight Loss ◽  
Organic Solvents ◽  
Amic Acid ◽  
Good Thermal Stability ◽  
Molecular Weights ◽  
Good Solubility ◽  
Ether Ether Ketone ◽  
Poly Ether Ether Ketone ◽  
Ether Ketone ◽  
Tetracarboxylic Dianhydride

New aromatic poly(ether ether ketone imide)s, [PEEKimide]s, were synthesized successfully from 1,3-bis-4′-(4″-aminophenoxy benzoyl) benzene and various commercially available aromatic dianhydrides, such as pyromellitic dianhydride (PMDA), 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA), 3,3′,4,4′-biphenyl tetracarboxylic dianhydride (BPDA), 4,4′-oxydiphthalic anhydride (OPDA) and 4,4′-(hexafluro isoproylidene) diphthalic anhydride (HFDA), by two step polycondensation method. These PEEKimides were characterized by FT-IR, solubility in organic solvents, inherent viscosity, DSC, TGA and WXRD. Inherent viscosities of the precursor poly(ether ether ketone amic acid)s were in the range of 0.23–0.40 dl/g in DMF, indicating formation of moderate to high molecular weights. These poly(ether ether ketone imide)s showed good solubility in polar aprotic solvents such as N,N-dimethylacetamide (DMAc), N-methyl 2-pyrrolidone (NMP), N,N-dimethylformamide (DMF) and dimethyl sulphoxide (DMSO) and had glass transition temperatures in the range 245–279°C. Poly(ether ether ketone imide)s showed no weight loss below 280°C; temperatures for 10% weight loss (T10) were in the range of 406–483°C and char yields at 800°C were 17–34%, indicating their good thermal stability. All these poly(ether ether ketone imide)s were amorphous in nature, as per patterns of WXRD which exhibited diffuse broad halos at (2θ = 10–30°) and amorphous nature was reflected in polymer’s good solubility in common organic solvents.

scholarly journals Enhancement of the Mechanical Properties of Polyimide Film by Microwave Irradiation

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 477 ◽  
Author(s):  
Ju-Young Choi ◽  
Seung-Won Jin ◽  
Dong-Min Kim ◽  
In-Ho Song ◽  
Kyeong-Nam Nam ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Irradiation Time ◽  
Polyimide Film ◽  
Amic Acid ◽  
Polyimide Films ◽  
Inorganic Substance ◽  
Short Irradiation Time ◽  
Green Approach ◽  
Thermal Imidization ◽  
Mw Irradiation

Polyimide films have conventionally been prepared by thermal imidization of poly(amic acid)s (PAAs). Here we report that the improvement of tensile strength while increasing (or maintaining) film flexibility of polyimide films was accomplished by simple microwave (MW) irradiation of the PAAs. This improvement in mechanical properties can be attributed to the increase in molecular weight of the polyimides by MW irradiation. Our results show that the mechanical properties of polyimide films can be improved by MW irradiation, which is a green approach that requires relatively low MW power, very short irradiation time, and no incorporation of any additional inorganic substance.

Naphthalene Containing Polyimide Nanocomposites Hybrid with Organo-Modified Montmorillonite

2006 ◽  
Vol 111 ◽  
pp. 43-46
Author(s):  
B.K. Chen ◽  
S.Y. Tsay ◽  
C.P. Chen
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Dielectric Constant ◽  
Amic Acid ◽  
Aggregate Formation ◽  
Thermal And Mechanical Properties ◽  
Modified Montmorillonite ◽  
Thermal Imidization ◽  
Tetracarboxylic Dianhydride ◽  
Acid Precursor

To improve the thermal and mechanical properties of polyimides, a nanocomposite of naphthalene containing polyimide (PI) was hybridized with Montmorillonite (MMT). The PI was synthesized from a diamine, 2,7-bis (4-aminophenoxy) naphthalene and polymerized with a 3,3’,4,4’-benzophenone tetracarboxylic dianhydride via thermal imidization. PI-MMT nanocomposites were then prepared from a DMAc solution of poly(amic acid) precursor and a DMAc dispersion of MMT which were organo-modified with various amount of n-dodecylamine. Characterization results demonstrated that the introduction of a small amount of MMT (up to 5%) led to enhanced thermal stability and mechanical properties of PI. The 5% weight loss temperature in N2 was increased by 46oC in comparison to pristine PI with an organoclay content of 5%. The CTE and dielectric constant were decreased. However, at organoclay contents higher than 5% these properties were reduced because the organoclay was poorly dispersed and resulted in aggregate formation.

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
Keyword(s):  
Coefficient Of Thermal Expansion ◽  
Aromatic Diamine ◽  
Polyimide Films ◽  
Polymer Backbone ◽  
Printed Circuits ◽  
Thermal Imidization ◽  
Trifluoromethyl Groups ◽  
Tetracarboxylic Dianhydride ◽  
Polyimide Precursor

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.

Mechanisms Of Liquid Crystal Alignment On Buffed Polyimide Surfaces

1994 ◽  
Vol 345 ◽  
Author(s):  
Hirotsugu Kikuchi ◽  
J. A. Logan ◽  
Do Y. Yoon
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Amic Acid ◽  
Polymer Chains ◽  
Polymer Surfaces ◽  
Polyimide Films ◽  
Force Microscopy ◽  
Liquid Crystal Alignment ◽  
Smectic C ◽  
Crystal Alignment

AbstractThe surfaces of poly(amic acid) and cured polyimide films, subjected to different buffing and cure profiles, have been examined by atomic force microscopy (AFM). The ability of these buffed polymer surfaces to align nematic and chiral smectic C liquid crystals were also investigated. These studies show that the presence of microgrooves on buffed polymer surfaces are not necessary for alignment of liquid crystals. Rather, it is concluded that the liquid crystal alignment is mainly caused by the anisotropic intermolecular interactions between liquid crystal molecules and the polymer chains oriented by buffing. For the alignment of smectics, both the degree of order and mechanical properties of polyimide films are found to be important factors.

Synthesis and Characterization of Polyimides Derived from 5-Amino-2(p-aminophenyl) Benzoxazole Monomer

2011 ◽  
Vol 415-417 ◽  
pp. 1789-1793
Author(s):  
Xiang Li Meng ◽  
Peng Wang ◽  
Ling Jiang
Keyword(s):  
Amic Acid ◽  
Synthesis And Characterization ◽  
Polyimide Films ◽  
Glass Transition Temperatures ◽  
Good Thermal Stability ◽  
Light Yellow ◽  
Structures And Properties ◽  
Ft Ir ◽  
Tetracarboxylic Dianhydride

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.

Soluble poly(imide)s based on the phenylindane structure element

1994 ◽  
Vol 6 (4) ◽  
pp. 335-346 ◽  
Author(s):  
Gerhard Maier ◽  
Dazhong Yang ◽  
Martin Wolf ◽  
Oskar Nuyken
Keyword(s):  
Room Temperature ◽  
Amic Acid ◽  
Polymer Chains ◽  
Structural Elements ◽  
Aromatic Polyimides ◽  
Flexible Films ◽  
Polymer Properties ◽  
Poly Imide ◽  
Acid Precursor

This paper describes the synthesis and characterization of several poly(imide)s containing different phenylindane structural elements. A comparison with known polymers of similar structure but no indane rings reveals the influence of the presence of the indane system on polymer properties. In general, solubility is improved and the glass transition temperature is increased by the introduction of the bulky indane groups. Crystallization of the polymer chains is prevented by the presence of 1,1,3-trimethylindane units. Variation of the indane structure itself allows some adjustment of the solubility behaviour. 1,3-Dicyclohexyl-l-methyl units in place of the trimethylindane groups decrease the range of possible solvents, but still allow solubility at room temperature in DMAc. All polymers in this study can be cast into tough. clear, flexible films, either directly as poly(imide) solution or via the poly(amic acid) precursor. The thermal stability is decreased compared with fully aromatic polyimides. Decomposition temperatures (5% weight loss) are between 450 and 480C in air.

Synthesis and Properties of Polyimides Containing Tert-Buty Group

2013 ◽  
Vol 275-277 ◽  
pp. 1636-1639
Author(s):  
Yun Hua Lu ◽  
Peng Pan ◽  
Bing Wang ◽  
Hong Bin Zhao ◽  
Zhi Zhi Hu
Keyword(s):  
Optical Properties ◽  
Fourier Transform ◽  
Amic Acid ◽  
Structure And Properties ◽  
Visible Spectroscopy ◽  
Polyimide Films ◽  
Solubility Test ◽  
Tert Butyl ◽  
Thermal Imidization ◽  
Ft Ir

Two diamine monomers 2-tert-butyl-1,4-bis(4-nitro-2-trifluoromethylphenoxy)benzene and 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene were reacted with the alicyclic dianhydride monomers 1,2,3,4-cyclobutanetetracarboxylic dianhydride to synthesize the poly(amic acid)s, and then obtain the corresponding polyimide films through thermal imidization. The structure and properties were characterized by fourier transform infrared spectroscopy (FT-IR), ultraviolet visible spectroscopy (UV-vis), thermogravimetic analysis (TGA), solubility test and so on. The effect of introduction of bulky tert-butyl and trifluoromethyl to the polyimide backbone on the properties of polyimide films was investigated. The experimental results showed that polyimides with tert-buty group exhibit excellent solubility, but their thermal and optical properties decreased slightly.

Transparent Polyimides and their ITO Flexible Conductive Film

2011 ◽  
Vol 239-242 ◽  
pp. 1211-1214 ◽  
Author(s):  
Yun Hua Lu ◽  
Zhi Zhi Hu ◽  
Ji Ming Bian ◽  
Yong Fei Wang
Keyword(s):  
Indium Tin Oxide ◽  
Room Temperature ◽  
Visible Spectrum ◽  
Amic Acid ◽  
Polyimide Films ◽  
Transparent Conducting ◽  
Conductive Film ◽  
Thermal Imidization ◽  
Average Transmittance ◽  
Ito Films

The preparation and properties of indium tin oxide (ITO) coated transparent polyimide substrates were reported in the paper. The transparent polyimide films were prepared through thermal imidization of poly(amic acid) films. Transparent conducting ITO films were prepared on polyimide substrates by magnetron-sputtering technique at room temperature. The optical and electrical properties of the obtained films have been investigated. Polycrystalline ITO films were deposited with resistivity as low as 10-4Ω.cm on polyimide substrates. The average transmittance exceeded 78% in the visible spectrum for 200nm thick films deposited on polyimide.

scholarly journals Water vapor induced self-assembly of islands/honeycomb structure by secondary phase separation in polystyrene solution with bimodal molecular weight distribution

2021 ◽  
Author(s):  
Maciej Łojkowski ◽  
Adrian Chlanda ◽  
Emilia Choińska ◽  
Wojciech Swieszkowski
Keyword(s):  
Molecular Weight ◽  
Phase Separation ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Self Assembly ◽  
Secondary Phase ◽  
Honeycomb Structure ◽  
Polymer Chains ◽  
Molecular Weights ◽  
Secondary Phase Separation

<p>The formation of complex structures in thin films is of interest in many fields. Segregation of polymer chains of different molecular weights is a well-known process. However, here, polystyrene with bimodal molecular weight distribution, but no additional chemical modification was used. It was proven that at certain conditions, the phase separation occurred between two fractions of bimodal polystyrene/methyl ethyl ketone solution. The films were prepared by spin-coating, and the segregation between polystyrene phases was investigated by force spectroscopy. Next, water vapour induced secondary phase separation was investigated. The introduction of moist airflow induced the self-assembly of the lower molecular weight into islands and the heavier fraction into a honeycomb. As a result, an easy, fast, and effective method of obtaining island/honeycomb morphologies was demonstrated. The possible mechanisms of the formation of such structures were discussed.</p>

Sign in / Sign up

Export Citation Format

Share Document