Physical Characterization of Photosensitive Polyimide

1997 ◽  
Vol 476 ◽  
Author(s):  
Y.L. Zou ◽  
T.L. Alford ◽  
J.W. Mayer
Keyword(s):  
Coefficient Of Thermal Expansion ◽  
Polyimide Film ◽  
Decomposition Temperature ◽  
Film Plane ◽  
Polymer Chains ◽  
Dielectric Anisotropy ◽  
Polyimide Films ◽  
Design And Optimization

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.

Properties of Porous Polyimide Films Based on Melamine Template

2019 ◽  
Vol 821 ◽  
pp. 160-166
Author(s):  
Qing Jun Ding ◽  
Hua Feng Li
Keyword(s):  
Dielectric Constant ◽  
In Situ Polymerization ◽  
Polyimide Film ◽  
Decomposition Temperature ◽  
Porous Films ◽  
Wear Properties ◽  
Polyimide Films ◽  
Oil Storage ◽  
Friction And Wear Properties

In this paper, melamine was used as porogen to prepare porous polyimide film by in-situ polymerization. The mechanical properties, thermal properties, dielectric properties, oil content and friction and wear properties of polyimide films with different porosity were investigated. The tensile strength of porous films decreases obviously with increase of melamine content. It shows the lower thermal decomposition temperature and the faster decomposition speed compared with the non-porous film, indicating higher heat exchange rate due to holes in porous films. As the porogen content increases, the dielectric constant decreases significantly, and the film with melamine content of 20 wt.% has the lowest dielectric constant of 2.43. The holes lead to good oil storage performance and the wear rate and the friction coefficient decrease with the increase of porosity. Keywords: polyimide; porous; melamine; dielectric; friction

scholarly journals In-Situ X-Ray Characterization of Fiber Structure during Melt Spinning

2008 ◽  
Vol 3 (3) ◽  
pp. 155892500800300 ◽  
Author(s):  
Michael S. Ellison ◽  
Paulo E. Lopes ◽  
William T. Pennington
Keyword(s):  
Melt Spinning ◽  
Simultaneous Detection ◽  
Polymer Melt ◽  
Polymer Chains ◽  
Degree Of Crystallinity ◽  
Structure Evolution ◽  
X Ray ◽  
Spinning Process

The properties of a polymer are strongly influenced by its morphology. In the case of fibers from semi-crystalline polymers this consists of the degree of crystallinity, the spacing and alignment of the crystalline regions, and molecular orientation of the polymer chains in the amorphous regions. Information on crystallinity and orientation can be obtained from X-ray analysis. In-situ X-ray characterization of a polymer during the melt spinning process is a major source of information about the effects of material characteristics and processing conditions upon structure evolution along the spinline, and the final structure and properties of the end product. We have recently designed and installed an X-ray system capable of in-situ analysis during polymer melt spinning. To the best of our knowledge this system is unique in its capabilities for the simultaneous detection of wide angle and small angle X-ray scattering (WAXS and SAXS, respectively), its use of a conventional laboratory radiation source, its vertical mobility along the spinline, and its ability to simulate a semi-industrial environment. Setup, operation and demonstration of the capabilities of this system is presented herein as applied to the characterization of the melt spinning of isotactic poly(propylene). Crystallinity and crystalline orientation calculated from WAXS patterns, and lamellar long period calculated from SAXS patterns, were obtained during melt spinning of the polymer along the spinline.

Thermal characterization of coal using piezoelectric photoacoustic microscopy

1986 ◽  
Vol 64 (9) ◽  
pp. 1184-1189 ◽  
Author(s):  
A. Biswas ◽  
T. Ahmed ◽  
K. W. Johnson ◽  
K. L. Telschow ◽  
J. C. Crelling ◽  
...  
Keyword(s):  
Elastic Properties ◽  
Coefficient Of Thermal Expansion ◽  
Thermal Characterization ◽  
Photoacoustic Signal ◽  
Photoacoustic Microscopy ◽  
Piezoelectric Detection ◽  
Theoretical Predictions ◽  
Coal Macerals

The organic constituents that make up the heterogeneous coal mass are called macerals. Vitrinite and pseudovitrinite are two of the most abundantly occurring macerals in North American coals. Photoacoustic microscopy using piezoelectric detection offers a useful technique for probing the thermal-elastic properties of these coal macerals. The experimental and theoretical conditions under which photoacoustic microscopy can be used to characterize the in situ thermal-elastic properties of macerals, as a function of the percentage of carbon or "rank" of coal, are investigated in this paper. Existing piezoelectric photoacoustic theory has been applied to our sample–transducer configuration to arrive at an expression for the voltage measured from the piezoelectric transducer. The theory indicates that the photoacoustic signal is related to the following sample properties: coefficient of thermal expansion a, bulk modulus B, density ρ, and specific heat c. These properties are coupled together into a dimensionless parameter given by aB/ρc, to which the measured voltage is proportional. Some experimental results used to test the validity of the theoretical predictions are presented. Photoacoustic data gathered on 10 Appalachian Basin coals are plotted as a function of the coal rank. These results are shown to compare favourably with a calculated curve, constructed using independently measured values of a, B, ρ, and c.

scholarly journals Preparation and Characterization of Liquid Crystalline Polyurethane/Al2O3/Epoxy Resin Composites for Electronic Packaging

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Shaorong Lu ◽  
Jianfeng Ban ◽  
Kuo Liu
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Liquid Crystalline ◽  
Coefficient Of Thermal Expansion ◽  
Decomposition Temperature ◽  
Resin Composites ◽  
Thermal Decomposition Temperature ◽  
Epoxy Resin Composites ◽  
Oxidation Analysis

Liquid crystalline polyurethane (LCPU)/Al2O3/epoxy resin composites were prepared by using LCPU as modifier. The mechanical properties, thermal stability, and electrical properties of the LCPU/Al2O3/epoxy resin composites were investigated systematically. The thermal oxidation analysis indicated that LCPU/Al2O3/epoxy resin composites can sustain higher thermal decomposition temperature. Meanwhile, coefficient of thermal expansion (CTE) was also found to decrease with addition of LCPU and nano-Al2O3.

Synthesis and Characterization of Ni/Al2O3 Nanocomposite for Selective Reduction of Aliphatic Double Bond(s)

2014 ◽  
Vol 875-877 ◽  
pp. 346-350
Author(s):  
Hameed Ullah
Keyword(s):  
Double Bond ◽  
Hydrogen Pressure ◽  
Selective Reduction ◽  
Decomposition Temperature ◽  
Ni Nanoparticles ◽  
Ir And Nmr Spectroscopy ◽  
Particle Size Determination ◽  
By Products

Ni nanoparticles dispersed in Al2O3 are prepared in-situ by the reduction of Ni(acac)2 under steady stream of [H2Al(OtBu)]2 in a cold walled CVD reactor. The decomposition temperature is moderate (~500°C) and the by-products are removed as soon as produced. The resulting powder of Ni/Al2O3 nanocomposite is characterized by powder XRD giving diffraction pattern for metallic Ni only. Elemental composition of the powder is confirmed by EDX analysis. SEM and TEM are used for the study of morphology and particle size determination. The aliphatic double bond in 1,2-trans-diphenylethene is reduced under hydrogen environment using the as prepared Ni/Al2O3 nanocomposite as catalyst. The reduction of 1,2-trans-diphenylethene is carried out at low temperature (~80°C) and atmospheric hydrogen pressure. The hydrogenation of aliphatic double bond is followed by IR and NMR spectroscopy.

A Parametric Study and Characterization of Porous, Non-Permeable, and Conductive PEGDA-HEMA Hydrogels

2010 ◽  
Author(s):  
Christine Chan ◽  
Shannon Chang ◽  
Hani E. Naguib
Keyword(s):  
Electrical Properties ◽  
Water Content ◽  
Parametric Study ◽  
In Situ Polymerization ◽  
Decomposition Temperature ◽  
Mechanical And Electrical Properties ◽  
Conductive Hydrogels ◽  
Further Development

This study involved the development and characterization of novel porous, non-permeable, and conductive hydrogels. The hydrogels were fabricated with HEMA and crosslinked with PEGDA through a complete parametric study of the synthesis parameters which included water content and crosslinking content. The hydrogels were fabricated using UV photopolymerization and in situ polymerization of PPy, and characterization was conducted with respect to their physical, thermal, mechanical, and electrical properties. The physical properties were analyzed with respect to their swelling ratio and equilibrium water content. The thermal properties were analyzed based on the decomposition temperature and residue weight. The mechanical properties examined the elastic modulus of the hydrogels, and the electrical properties investigated the conductivity of the hydrogels. The relationships observed between the processing, structure, and resulting properties provide the basis for further development and application of these porous, non-permeable, and conductive hydrogels.

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.

Characterization of Fluorinated Polyimide Films

1992 ◽  
Vol 264 ◽  
Author(s):  
Pradnya V. Nagarkar ◽  
Jiong Ping Lu ◽  
David Volfson ◽  
Klavs F. Jensen ◽  
Stephen D. Senturia
Keyword(s):  
Photoelectron Spectroscopy ◽  
Polyimide Film ◽  
Binding Energies ◽  
Polyimide Films ◽  
Chemical Modifications ◽  
X Ray ◽  
Fluorinated Polyimide ◽  
Peak Assignment ◽  
Good Agreement

Abstract:X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) have been used to characterize the polyimide film based on 4,4′ hexafluoro-isopropylidene -bis pthalic anhydride (HFDA) and 4,4′ -bis (4-aminophenoxy) biphenyl (APBP). Films of varying thicknesses made from diluted precursors were studied by IR and XPS. An elemental analysis and a tentative peak assignment for C 1s in XPS is presented. The HFDA-APBP thick films are stoichiometric in composition and binding energies are in good agreement with data on hexafluorodianhydride-oxydianiline (HFDA-ODA). For thinner films, certain chemical modifications were observed at high cure temperatures.

scholarly journals Copolymer chain formation of 2-oxazolines by in situ1H-NMR spectroscopy: dependence of sequential composition on substituent structure and monomer ratios

RSC Advances ◽  
2021 ◽  
Vol 11 (18) ◽  
pp. 10468-10478
Author(s):  
Sabina Abbrent ◽  
Andrii Mahun ◽  
Miroslava Dušková Smrčková ◽  
Libor Kobera ◽  
Rafał Konefał ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Polymer Chains ◽  
Chain Formation ◽  
Molar Ratios ◽  
H Nmr ◽  
Copolymer Chain ◽  
Nmr Characterization ◽  
Insight Into

In situ1H NMR characterization of copolymerization reactions of various 2-oxazoline monomers at different molar ratios offers detailed insight into the build-up and composition of the polymer chains.

Properties Of A Photoimageable Thin Polyimide Film II.

1991 ◽  
Vol 227 ◽  
Author(s):  
Taishih Maw ◽  
Richard E. Hopla
Keyword(s):  
Thin Film ◽  
Weight Loss ◽  
Electrical Properties ◽  
Dissipation Factor ◽  
Polyimide Film ◽  
Decomposition Temperature ◽  
Polyimide Films ◽  
Mechanical And Electrical Properties ◽  
Thermal And Electrical Properties ◽  
Cure Temperature

ABSTRACTThe polylmide synthesized from benzophenonetetracarboxylic dianhydride and alkyl-substituted diamines is inherently photosensitive at ≤365 nm, and a solvent soluble, negative-acting system can be formulated from the fully-imidized resin. The lithographic, thermal, mechanical, and electrical properties of the polyimide films have been characterized. This polyimide film shows good thermal, mechanical, and electrical properties, and a 1:1 aspect ratio is consistently achieved on 10 μm thick films. The thermal properties of the films were determined using TGA and TMA methods. The decomposition temperature was 527°C, the weight loss of the cured film at 350°C in nitrogen was 0.04 %/hour and the thermal expansion coefficient was 37 ppm/°C. The dielectric constant and dissipation factor of the film were 3.0 and 0.003 respectively at 4% humidity. The effects of hard-bake time, hard-bake temperature, nitrogen purge rate during heat treatment, and humidity on the thermal and electrical properties of the thin film were also examined, and are presented here. The rate of weight loss of the cured film increases when the rate of nitrogen purge decreases or when the cure temperature increases. Longer heat treatments resulted in a slight decrease in the CTE and an Increase in the Tg. The electrical properties of the films are dependent both on the humidity during measurement and on the hard-bake temperature.

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