Quality Aspects on the Power Cable Core Insulation Extrusion and Thermal Curing Process

2003 ◽  
Vol 18 (3) ◽  
pp. 291-297
Author(s):  
A. Harlin ◽  
P. Huotari
Keyword(s):  
Power Cable ◽  
Curing Process ◽  
Thermal Curing ◽  
Quality Aspects

Cure Studies of Fluorinated Polyamic Acids by Thermal-IR

1992 ◽  
Vol 264 ◽  
Author(s):  
Robert T. Roginski ◽  
Douglas E. Fjare
Keyword(s):  
Ir Spectroscopy ◽  
Phthalic Anhydride ◽  
Amic Acid ◽  
Back Reaction ◽  
Curing Process ◽  
Thermal Curing ◽  
Additional Mechanism ◽  
Polyamic Acid

AbstractThe thermal curing chemistry of a fluorinated polyamic acid based on 6FDA (hexafluoroisopropylidene bis(phthalic anhydride)) and APBP (4,4′-bis(4-aminophenoxy)biphenyl) was studied by thermal-IR spectroscopy. Anhydride formation was observed at intermediate cure temperatures and maximized at approximately 220°C. The degree of anhydride formation was affected by the solvent, being least in 2-methoxyethyl ether and increasing in the solvent order: 2-methoxyethyl ether < NMP < 2-(2-ethoxy)ethoxyethanol. In addition to the back reaction of amic acid to anhydride and amine, at least one additional mechanism of anhydride formation is observed. The onset of the second mechanism of anhydride formation is coincident with the onset of imidization, which leads us to propose that water generated by imidization can react with anhydride during the curing process, before escaping from the film, to form diacid. Cyclization of diacid to anhydride is proposed as the second mechanism of anhydride formation.

Preparation and properties of graphene oxide/polyimide composites by in situ polymerization and thermal imidization process

2016 ◽  
Vol 29 (2) ◽  
pp. 187-196 ◽  
Author(s):  
Lang Ma ◽  
Guojian Wang ◽  
Jinfeng Dai
Keyword(s):  
Graphene Oxide ◽  
In Situ Polymerization ◽  
Curing Process ◽  
Thermal Curing ◽  
Solution Blending ◽  
Blending Method ◽  
Thermal Imidization ◽  
Polyimide Composites ◽  
Properties Of Composites

Graphene oxide/polyimide (GO/PI) composites with different loadings of GO were prepared by in situ polymerization and solution blending method. By adding GO, the mechanical, electrical, and thermal properties of composites could be improved. The tensile strength of GO/PI composite with 3.0 wt% GO loading was up to 137.8 MPa, 75.5% higher than that of a pure PI. Besides, the electrical and the thermal conductivities increased with the increase of GO contents. An electrical conductivity value of 5.38 × 10−5 S m−1 and a thermal conductivity value of 0.10 W m−1 K−1 for GO/PI composites prepared via in situ polymerization at GO content of 3.0 wt% were achieved. The results indicated that in situ polymerization was able to make GO a better dispersion in the polymer matrix. Furthermore, the behavior of GO under the thermal imidization temperature was also discussed. The experimental results showed that GO could be partially reduced to graphene during the thermal curing process. Above works are conducive to the understanding of the effect and transformation of GO in the preparation process of graphene-based composites.

scholarly journals Optimized Synthesis of Biodegradable Elastomer PEGylated Poly(glycerol sebacate) and Their Biomedical Application

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 965 ◽  
Author(s):  
Yanxiang Wang ◽  
Haiwa Wu ◽  
Zihao Wang ◽  
Jingjing Zhang ◽  
Jing Zhu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Biomedical Applications ◽  
Bone Repair ◽  
Biomedical Application ◽  
Vascular Reconstruction ◽  
Curing Process ◽  
Thermal Curing ◽  
Potential Applications ◽  
Degradation Behaviors

Poly(glycerol sebacate) (PGS), a biodegradable elastomer, has been extensively explored in biomedical applications for its favorable mechanical properties and biocompatibility. Efforts have been made to fabricate multifunctional PGS copolymer in recent years, in particular PGS-co-PEG (poly(glycerol sebacate)-co-polyethylene glycol) polymers. However, rare research has been systematically conducted on the effect of reactant ratios on physicochemical properties and biocompatibility of PGS copolymer till now. In this study, a serial of PEGylated PGS (PEGS) with PEG content from 20% to 40% and carboxyl to hydroxyl from 0.67 to 2 were synthesized by thermal curing process. The effects of various PEGS on the mechanical strength and biological activity were further compared and optimized. The results showed that the PEGS elastomers around 20PEGS-1.0C/H and 40PEGS-1.5C/H exhibited the desirable hydrophilicity, degradation behaviors, mechanical properties and cell viability. Subsequently, the potential applications of the 20PEGS-1.0C/H and 40PEGS-1.5C/H in bone repair scaffold and vascular reconstruction were investigated and the results showed that 20PEGS-1.0C/H and 40PEGS-1.5C/H could significantly improve the mechanical strength for the calcium phosphate scaffolds and exhibited preferable molding capability for fabrication of the vascular substitute. These results confirmed that the optimized PEGS elastomers should be promising multifunctional substrates in biomedical applications.

Synthesis, pyrolysis of a novel carborane ceramic precursor, and coating on carbon fiber

2019 ◽  
Vol 31 (9-10) ◽  
pp. 1085-1100 ◽  
Author(s):  
Yakun Zong ◽  
Dejin Tong ◽  
Zhanxiong Li
Keyword(s):  
Carbon Fiber ◽  
Chemical Structure ◽  
Temperature Stability ◽  
Gas Chromatography Mass Spectrometry ◽  
Curing Process ◽  
Thermal Curing ◽  
High Temperature Stability ◽  
Ceramic Yield ◽  
Pyrolysis Gas ◽  
Pyrolysis Method

A novel carborane–carbosilane–(cyclo-silazane) polymer has been synthesized as precursor of ceramic and applied to the surface treatment of carbon fiber (Cf) by precursor infiltration and pyrolysis method. The preparation of carborane precursor was carried out by hydrosilylation of trivinyltrimethylcyclosilazane with dimethylchlorosilane firstly, and then by polycondensation reaction with hydroxylated 1,1′-hydroxysilylene-2,2′-bis(hydroxydimethylsilyl)biscarborane whose −OH was formed by transferring the newly introduced C–H bond via hydroxylation. Chemical structure of the polymer was studied by liquid-nuclear magnetic resonance while evolution of various ceramic phases was studied by Fourier transform infrared spectroscopy and the thermal curing process was studied by thermogravimetric/differential thermal analysis and pyrolysis-gas chromatography/mass spectrometry. The cross-linked polyborosilazane precursor exhibited higher ceramic yield of 65.6% at 1000°C. The coating on the Cf was identified to be uniform, relatively smooth, and continuous with a thickness ranged from 0.1 to 0.5 μm through scanning electron microscope and energy dispersive spectroscopy. Thermogravimetric analysis revealed high temperature stability of the coated Cf in flowing air up to 600°C.

Structural Transformation in PECVD Ultralow-k Material during Porogen Removal by UV Assisted Thermal Curing

2007 ◽  
Vol 990 ◽  
Author(s):  
Aziz Zenasni ◽  
Vincent Jousseaume ◽  
Olivier Gourhant ◽  
Laurent Favennec ◽  
Patrick Maury ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Uv Curing ◽  
Structural Transformations ◽  
Curing Process ◽  
Thermal Curing ◽  
Signal Delay ◽  
Mechanical And Electrical Properties ◽  
Fundamental Understanding ◽  
Parasitic Signal ◽  
Peak Increase

ABSTRACTNext-generation microelectronic interconnects require the use of dielectrics with continuously lower permittivity (k) to overcome limitations induced by crosstalk parasitic signal delay. Using PECVD, Ultralow-k film (ULK, k ≤ 2.5) can be developed by creating pore inclusions within an organosilicate matrix through porogen approach. Both ULK deposition and subsequent curing process has to be adjusted in order to achieve optimized mechanical and electrical properties and maintain stability during integration. For this concern, the attention was recently focused on ultraviolet (UV) radiation to sustain the thermal curing. In the present work, a fundamental understanding of structural transformations occurring during porogen extraction from as-deposited ULK materials when exposed to thermal-assisted UV radiation is proposed. This thermal-assisted UV cure technique is very efficient in porogen removal since in a few minutes the desired porosity is reached. During the first stage of curing, the film shrinks strongly whereas the porosity is created. After porogen removal step, the porous film continues shrinking under UV radiation leading to an increase of SiOSi bonds concentration (film densification). The normalized FTIR SiOSi peak increase during UV curing (related in literature to an improvement of mechanical properties) is mainly due to the film densification, in addition to the SiOSi bridging bond creation. In this case, correlation is found between shrinkage and elastic modulus.

Effective formation of hierarchical wavy shapes using weak photopolymerization and gradual thermal curing process

2015 ◽  
Vol 141 ◽  
pp. 47-54 ◽  
Author(s):  
Hee-Jin Park ◽  
Changmin Son ◽  
Man-Yeong Ha ◽  
Sang-Hu Park
Keyword(s):  
Curing Process ◽  
Thermal Curing
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