Imidization of polyamide acid by laser radiation

Il'yasov, S. G.; Kal'vina, I N; Kyulyan, G A; Moskalenko, V. F.; Ostapchenko, E. P.

doi:10.1070/qe1975v004n10abeh011756

Cited by 13 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The continuous structure of all the deposits (Fig. 1) and their absorption at 2100cm-' are in line with the assumption of the repolymerization of 'living' particies according to the process in Eqn [2]. We note that highermolecular biradical species travelling from the laser-irradiated spot to the nearby cold surface can possess an increased stability due to their bulkiness and an easier stabilization of both radical centres inside long (coiled) entities.…”

Section: Resultsmentioning

confidence: 59%

“…The other alternatives can be (a) cleavages of two remote Si-Si bonds to yield biradicals (' SiMe,+Me,Si -) or (b) reorganization of polysilane to polycarbosilane skeleton (Eqn [2]) and -(Me,Si)n-+ 5 + -(HSiMeCH,),- [2] subsequegt cleavage of Si-C bonds to form radical centres at silicon and carbon atoms. The second process has been previously postulated''. ''…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Laser evaporation of some solid organosilicon polymers

Pola

Vítek

Polyakov

et al. 1991

Applied Organom Chemis

View full text Add to dashboard Cite

Continuous wave (cw) C 0 2 laser irradiation of some organosilicon polymers composed of -Me,Si-, -Me2SiMe,SiCH,-, RMeSi-and RMeSiMe,SiCH,CH,-units (where R =methyl, adamantyl, phenyl and hydrogen) leads to the evaporation of the polymer and is dominated by the formation of a solid deposit that has a continuous structure. It is assumed that chemical changes occur prior to the transfer of ejected material to the gas phase and that these consist mainly of the formation of high molecular biradicals or 1,t-disilacyclobutane monomer that both re-polymerize spontaneously upon their deposition onto a nearby cold surface. The mechanism of these specific decompositions of the polymers is assessed on the basis of the IR spectra of the deposits and, for the minor gaseous products, identification by GC MS techniques.

show abstract

Section: Resultsmentioning

confidence: 59%

Section: Resultsmentioning

confidence: 99%

Laser evaporation of some solid organosilicon polymers

Pola

Vítek

Polyakov

et al. 1991

Applied Organom Chemis

View full text Add to dashboard Cite

show abstract

“…2. After being scanned by CO 2 laser beam, the poly(amic acid) in the area exposed was transformed into polyimide through thermal imidization (Il'yasov et al 1975;Karlov et al 1982), simultaneously the thickness of irradiated areas was reduced and grooves were formed. Since the polyimide has higher solvent resistance than its corresponding poly(amic acid) (Ding and He 1998), the unexposed poly(amic acid) is more soluble in suitable solvents than the irradiated.…”

Section: Materials and Waveguide Fabricationmentioning

confidence: 99%

Mechanism and process of fabricating fluorinated polyimide optical waveguide by CO2 laser direct-writing

Zhu

Liu

et al. 2011

Opt Quant Electron

View full text Add to dashboard Cite

Fluorinated polyimide waveguides were fabricated by CO 2 laser direct-writing. The poly(amic acid) micro-region irradiated by CO 2 laser beam was studied with FT-IR micro-spectroscopy. The FT-IR spectra implied that the laser induced thermal-imidized polyimide was of optical anisotropy, and the imidization degree of exposed micro-region increased with the rising of output laser power. The increased aspect ratio of waveguide and smoothness of surface can be achieved by increasing the pre-cured temperature (below 120 • C) and writing speed, and optimizing laser power and the distance between the lens and the annular aperture. The guided light was clearly confined to the core of the fabricated waveguide, which means this technique can be used for fluorinated polyimide waveguide fabrication.

show abstract

“…Within the context of laser beam interactions with inorganic=organic compounds, particularly in the solid phase [12][13][14], the studies of laser interactions with pharmaceutical compounds are scarce in the literature.…”

Section: Introductionmentioning

confidence: 99%

IR Laser‐Induced Changes to L‐adrenaline‐D‐hydrogentartrate Incorporated in KBr Matrices

et al. 2002

View full text Add to dashboard Cite

Changes in the pharmaceutical L-adrenaline-D-hydrogentartrate, incorporated in KBr matrices, induced by a pulsed carbon-dioxide Transversely Excited Atmospheric (TEA) laser, were observed. Modifications of the sample were monitored via infrared spectra. Special attention was devoted to the dependence of the sample changes on the laser energy density used. The irradiation of the pharmaceutical has been performed with two laser lines at wavelengths of about 10.6 µm. The laser lines coincide well with the absorption band of the pharmaceutical, which is assigned to the ring vibrations/out-of-plane OH deformation vibrations, within the carboxyl (COOH) group of L-adrenaline-D-hydrogentartrate. Laser energy densities of 1.20 and 1.70 J/cm2 modified the pharmaceutical/compound. It was found that this modification is in essence a thermal effect. The level of change showed a dependence on the laser energy density, number of accumulated laser pulses and temporal shape of the pulse.

show abstract

Imidization of polyamide acid by laser radiation

Cited by 13 publications

References 0 publications

Laser evaporation of some solid organosilicon polymers

Laser evaporation of some solid organosilicon polymers

Mechanism and process of fabricating fluorinated polyimide optical waveguide by CO2 laser direct-writing

IR Laser‐Induced Changes to L‐adrenaline‐D‐hydrogentartrate Incorporated in KBr Matrices

Contact Info

Product

Resources

About