Laser evaporation of some solid organosilicon polymers

Abstract

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.

UV‐laser‐induced photolysis of trimethyl(vinyloxy)silane for chemical vapour deposition of polysiloxane films

“…A similar reactivity of deposited solid particles was observed in laser evaporation of some solid organosilicon polymers. 31 These results thus stress that the morphology and composition, but not the UV and IR spectra of the deposited polysiloxane films, are strongly affected by substrate and laser-beam configuration.…”

IR laser ablative desulfurization of poly(1,4-phenylene sulfide)

“…A completely different mode of thermal decomposition of polymers is pulsed infrared laser-induced ablation (PLAD) that can take place by exposing a polymer with pulsed IR laser radiation [10][11][12][13][14][15][16][17][18]. This specific thermal process occurs within a T-jump and is controlled by kinetic rather than thermodynamic polymer degradation.…”

“…IR laser ablative deposition of almost structurally identical films was demonstrated with irradiation of poly(ethylene glycol) [16,17], polysilanes and polycarbosilanes composed of -(CH 3 ) 2 Si-, -(CH 3 ) 2 Si(CH 3 ) 2 SiCH 2 -, -R(CH 3 )Si-and -R(CH 3 )Si(CH 3 ) 2 SiCH 2 CH 2 -units (R = methyl, adamanthyl, phenyl and H [14]) and poly(ethylene-alt-maleic anhydride) [18], whereas significant structural modifications (cross-linking) of the polymer was reported with irradiation of poly[oxy(tetramethyldisilane-1,2-diyl)] [15].…”

Laser Ablative Structural Modification of Poly(ethylene-alt-maleic anhydride)

“…Laser ablative deposition of structurally identical films is very uncommon and was demonstrated only with UV irradiation of poly(tetrafluoroethylene), 6,7 IR irradiation of poly(ethylene glycol), 27,28 and IR irradiation of polysilanes and polycarbosilanes composed of -(CH 3 ) 2 Si-, -(CH 3 ) 2 Si(CH 3 ) 2 SiCH 2 -, -R(CH 3 )Si-, and -R(CH 3 )Si(CH 3 ) 2 SiCH 2 CH 2 -units (R ) methyl, adamanthyl, phenyl and H, ref. 25). Negligibly modified films were obtained from poly(p-phenylenevinylene), 18 poly(3-octylthiophene), 16 and polycarbonate 4 using UV (VIS) radiation.…”

“…The pulsed laser ablation − for deposition (PLAD) of thin polymeric films using ultraviolet − and infrared − radiation has been continuously attracting much attention. The UV PLAD involves both photochemical and thermal features, ,, whereas the IR PLAD is a specific thermal process controlled by kinetic rather than thermodynamic polymer degradation.…”